Knitting-1

1. What are the basic structures of weft knitting? State the features of a
circular knitting machine. (23)

Weft knitting is a type of knitting where the yarn runs horizontally, forming loops across
the fabric width. Each loop is drawn through the previous loop to create a knitted fabric.

There are four basic structures in weft knitting:

1. Plain Knit (Single Jersey)

• Structure: Made with one set of needles. All loops are knitted in the one direction.
Only knit stitches (face loops) on one side and purl stitches (back loops) on the other.
• Machine: Produced on single bed circular or flat knitting machines.
• Appearance:
o Front side: Vertical rows called wales (V-shaped loops).
o Back side: Horizontal rows called courses (wave-like loops).
• Characteristics:
o Lightweight and thin
o Good widthwise stretch, but limited lengthwise
o Tends to curl at the edges (face curls to back and vice versa)
• Applications: T-shirts, underwear, casual tops, lightweight fabrics.

2. Purl Knit

• Structure: Alternating rows of knit and purl stitches on the same side of the fabric.
Creating a bumpy texture .
• Machine: Requires special purl machines (double-ended needle machines).
• Appearance: Both sides look like purl stitches (waves).
• Characteristics:
o Soft and thick
o Excellent lengthwise elasticity
 o Lies flat, does not curl
• Applications: Baby clothes, scarves, sweaters, and garments where softness is
important.

3. Rib Knit

• Structure: Rib also called double knit. Knit and purl stitches are placed alternately in a
single row (e.g., 1x1, 2x2 rib).
• Machine: Made on double bed knitting machines (cylinder and dial).
• Appearance: Vertical lines (ribs) on both sides of the fabric.
• Characteristics:
o Great widthwise stretch and recovery
o Lies flat (does not curl)
o More elastic than plain knit
• Applications: Cuffs, collars, waistbands, stretchable garments.

4. Interlock Knit

• Structure: A variation of rib knit where two rib structures are interlocked together.
Made with two sets of needles.
• Machine: Produced on special interlock circular machines.
• Appearance:
o Smooth surface on both sides
o Thicker and more stable than single jersey
• Characteristics:
o Very stable and firm
o Doesn’t curl
o Less stretch than rib but more dimensional stability
• Applications: Polo shirts, dresses, leggings, sportswear.

Features of a Circular Knitting Machine:

1. Circular Needle Arrangement

• The needles are arranged in a circular cylinder.

• The machine produces tube-shaped fabric (can be cut open later if needed).
2. High Production Speed

• Runs at high RPM (revolutions per minute).

• Can produce fabric at a faster rate than flat knitting machines.

3. Multiple Feeders

• Equipped with multiple yarn feeders, often between 30–100 depending on machine
size.
• Allows for continuous knitting from several yarn cones simultaneously.

4. Knitting Elements

• Consists of needles, sinkers, cams, and cylinder.

• May use latch needles (commonly) for weft knitting.

5. Types of Fabric

• Can produce single jersey, rib, interlock depending on the machine type.
• Machine type varies: Single Jersey, Double Jersey, or Jacquard.

6. Diameter and Gauge

• Available in various diameters (e.g., 14" to 60") and gauge (needles per inch).
• Higher gauge means finer fabric; lower gauge gives thicker fabric.

7. Automation and Controls

• Modern circular machines have computerized control systems (for speed, pattern,
tension).
• Some include auto yarn stop, fabric take-down rollers, and lubrication systems.

8. Fabric Take-Down Mechanism

• Pulls the knitted fabric downward.

• Helps maintain tension and shape of the fabric tube.

9. Less Wastage
 • Since the fabric is continuous, it produces minimal yarn wastage.

10. Compact Design

• Takes up less space compared to flat knitting machines for the same production
output.

2. Compare and contrast single jersey, rib knit, interlock and purl fabrics in
terms of structure, appearance, and applications. 23

Feature Single Jersey Rib Knit Interlock Purl

Structure - Single set of - Alternating knit - Double-knit - Alternating knit

needles (one and purl stitches in structure (two and purl stitches in
needle bed) columns. layers interlocked) rows (rather than
- All knit stitches - Uses two needle - Requires two columns like rib)
on the face, all purl beds (cylinder + needle beds with - Made on a
on the back dial) alternating knit purl/links-links
stitches machine
Appearance - Smooth face with - Vertical ridges on - Smooth on both - Bumpy texture
V-shaped stitches both sides sides (like two (similar to the back
- Curled edges - Highly elastic single jerseys back- of single jersey)
- Thin and stretchy widthwise to-back) - Stretches
- Lies flat (no - Thicker, more lengthwise
curling) stable - Reversible
- Less stretchy than
rib
Applications - Bumpy texture - Cuffs, collars, - Durable - Sweaters, scarves,
(similar to the back waistbands, sportswear, baby clothes,
of single jersey) sweaters dresses, baby reversible
- Stretches clothes garments
lengthwise
- Reversible
3. What are the Primary advantages of knitted fabrics over woven fabrics?
(23)

Primary advantages of knitted fabrics over woven fabrics

1. More stretchable

Knitted fabrics can stretch in both directions due to their loop structure, making them ideal
for body-fitting garments.

2. Better Comfort

They are soft, flexible, and smooth on the skin, providing greater comfort than woven fabrics.

3. Good Wrinkle Resistance

Knitted fabrics do not wrinkle easily and maintain their shape after folding or stretching.

4. Better Air Permeability

The loop structure allows better airflow, keeping the body cool and comfortable.

5. Lightweight

Knitted fabrics are generally lighter in weight, making them easy to wear and handle.

6. Good Drapability

They drape well and adjust easily to body shape, enhancing appearance and fit.

7. Easy Care

These fabrics are easy to wash, quick to dry, and often don’t require ironing.

8. Fast Production

Knitting machines operate at high speed, producing fabric faster than weaving machines.
9. Cost-Effective

Due to quicker production and less labor, knitted fabrics are often cheaper to manufacture.

10. Ideal for Stretchable Garments

Perfect for items like T-shirts, underwear, activewear, and baby clothing that need flexibility.

4. What is knitting notation? Write the types of notation. (23)

Knitting notation is a symbolic or graphical method used to represent the structure,

pattern, and loop formation in a knitted fabric. It helps knitters, designers, and engineers
understand how stitches are made, arranged, and repeated.

Why is it important?

• To design and communicate knitting patterns clearly

• To create or analyze complex structures
• Useful in both hand and machine knitting

Notations are used to express the knitted fabric structure and design.

Notations are of four types:

1. Verbal notation.

2. Line diagram/ Looping diagram

3.Diagrammatic notation/ Chain notation

4.Symbolic notation

5. Show five basic overlap and underlap variations. (23,20) [ B Part]

In warp knitting, overlap and underlap refer to the movement of the guide bars and yarn
over the needles. These movements determine the fabric structure. Here are five basic
variations of overlap and underlap:
1. An overlap followed by an underlap in the opposite direction (closed lap)

• Overlap: Full loop formation around the needle

• Underlap: Yarn moves behind to the next needle
• Effect: Strong and stable fabric (e.g., Tricot)

2. An over lap followed by an underlap in the same direction (open lap)

• Overlap: Yarn partially overlaps the needle

• Underlap: None or very short
• Effect: More open and stretchable fabric

3. Only overlaps and no underlaps (open laps).

• Overlap : All loops are overlaps

• Underlap : no underlap
• Effect: More open and less stable

4. Only underlaps and no overlaps (Laying-in).

• Overlap: None
• Underlap: All loops are underlaps.
5. Neither overlaps nor underlaps (Miss-lapping).

• Overlap: None
• Underlap: None

6. How will you identify single jersey fabric? (23)

1. Different Face and Back

o Face (front): Shows vertical rows of V-shaped stitches (called wales).
o Back: Shows horizontal rows of semi-circular loops (called courses).
o ✅ This is the most common and clear sign.

2. Curling Edges
o When cut, the fabric curls:
▪ Face curls to the front (lengthwise edges).
▪ Bottom curls upward.
o ✅ Common in T-shirts and stretchy garments.

3. More Stretch Widthwise

o The fabric stretches more sideways (width-wise) than lengthwise.
o ✅ Good elasticity, but not as much as rib fabrics.

4. Lightweight and Thin

o Lighter and thinner compared to double jersey or interlock fabrics.
o ✅ Feels soft and breathable.

5. Made with One Set of Needles

o Usually produced on circular knitting machines or flat knitting machines with
a single needle bed.
 6. Used in Common Garments
o Commonly used in T-shirts, leggings, casual wear, etc.

7. Give the functions of the following machine parts: Fabric spreader, air
nozzle, Sinker and cam. (23)

1. Fabric Spreader

• Function:
Spreads the fabric evenly and flat on the cutting table before cutting.
• Purpose:
Avoids wrinkles, tension, or misalignment to ensure accurate cutting.
• Spreads fabric layers evenly on the cutting table before cutting.
• Prevents wrinkles, tension, or distortion in fabric layers.
• Ensures accurate and uniform cutting for mass production.

2. Air Nozzle

• Function:
Blows air at high pressure to move yarn or fabric.
• Purpose:
In air-jet weaving machines, it pushes the weft yarn across the shed.
• Found in air-jet looms (weaving) or pneumatic yarn feeders.
• Uses compressed air to propel the weft yarn across the warp shed (in weaving).
• Ensures fast and smooth yarn insertion without contact.
• Also used to clean or move fibers/yarn in some machines.

3. Sinker

• Function:
Helps in holding down the fabric loop, forming loops, and knocking off the old loop.
• Works with:
The needle during knitting (especially in weft knitting machines).
• Hold the fabric down during knitting.
 • Form loops and knock-off old loops.
• Maintain proper fabric tension.
• Essential for loop formation and fabric control.

4. Cam

• Function:
Controls the movement of the needle up and down.
• How it works:
• Converts rotary motion into up-and-down (or sliding) motion.
• Helps perform actions like knit, tuck, or miss in knitting.
• In weaving, cams control heald frames or shedding motions.

8. What are the characteristics of knitting yarn? (22)

Characteristics of knitting yarn

1. Good Flexibility
The yarn should bend easily to form loops without breaking.
2. Even Thickness
The yarn must have a uniform thickness to ensure smooth and even loops during knitting.
3. Smooth Surface
A smooth yarn surface helps it move easily through needles without breaking or snagging.
4. Good Tensile Strength
The yarn should be strong enough to withstand the stress during the knitting process.
5. Softness
Soft yarn provides comfort in the final fabric, especially for garments worn close to the skin.
6. Low Hairiness
Less hairy yarn reduces problems like lint, fly, and needle blockage.
7. Good Elasticity
Knitting yarn should stretch and recover easily to help the fabric return to its shape.
8. Even Twist
Uniform twist in the yarn ensures consistent loop formation and prevents breakage.
9. Low Friction
Yarn with low surface friction passes smoothly through the knitting elements.
10. Good Dye Affinity
Yarn should accept dye uniformly for a consistent fabric color.

9. Mention the effects of tuck stitch on knitted fabric. (23)

Effects of Tuck Stitch

1. Thicker Fabric
– The fabric feels thicker because more yarn is used in each stitch.
2. Heavier Fabric
– It becomes heavier than normal knit fabric.
3. Narrower Width
– The fabric becomes a little narrower (smaller side to side).
4. More Stretch (Sideways)
– The fabric can stretch more sideways (horizontally).
5. Open and Textured Look
– The surface looks patterned or has small holes. It’s good for design.
6. Warmer Fabric
– Keeps more air inside, so the fabric feels warmer.
7. Nice for Patterns
– Good for making fancy or decorative designs.
8. Less Stretch (Lengthwise)
– The fabric doesn’t stretch as much from top to bottom.

10. Differentiate between fabric length and garment length machine.

(23,20)

Fabric length Machine Garment Length Machine

1. Used before garment production. 1. Used after garment Stitched.

2. Measure and cuts fabric rolls. 2. Measure and cuts finished garment.
 3. Raw or processed fabric 3. Finished garments

4. Control fabric roll length. 4. Ensure correct garment length.

5. Circular knitting machines. 5. Flatbed (V-bed) machines.

6. High speed or mass production. 6. Slower speed.

7. Waste is Higher 7. Waste is minimum.

8, Fabric can used for multiple garment 8. Limited to pre-design garment shapes

design.

9. T-shirts, leggings 9. Sweaters, socks, seamless garment

10. More seams 10. Fewer seams.

11. Define Sinker Timing, Synchronize and Delay timing. (23,22,21,20,19)

Sinker Timing:

The most forward position of the sinker during the knitting cycle is known as the push point
and its relationship to the needles is known as the sinker timing.

Or, Sinker timing means the right time when the sinker moves in a knitting machine to help
the needle make loops properly.

Synchronize:

Synchronized timing means that different parts of a machine (like needles and sinkers) move
at the right time together, so the machine works smoothly and correctly.

If the needle goes up to make a loop, and the Sinker moves in at the correct time to hold the
fabric that is synchronized timing.
Delay timing:

Delay timing means when a part (needles, Sinkers, or cams) of a machine moves later than
expected during it's cycle. It is intentional pause or lag of machine components to control
loop formation, Stitch shape, or fabric properties.

If the sinker comes in too late after the needle Starts moving, it is called delay timing. This can
cause problems in loop formation and affect fabric quality.

12. Mention five major faults in weft knitted fabrics. (23,20)

1. Dropped Stitch

• Cause:
o Broken or Faulty needle
o Yarn not laid properly
o Insufficient yarn tension
o Improper cam setting
• Remedy:
o Check and replace broken needles
o Adjust yarn tension
o Set cam correctly
o Ensure proper yarn feeding

2. Hole or Press-Off

• Cause:
o Yarn breakage during knitting
o Needle not picking yarn
o Sudden machine stop/start
o Incorrect take-down tension

• Remedy:
o Use stronger yarn
o Check yarn path regularly
 o Maintain smooth machine operation
o Adjust take-down and cam settings

3. Barre (Stripes or Shading)

• Cause:
o Yarn count variation
o Tension difference between feeders
o Dye variation
• Remedy:
o Use yarns of uniform count and quality
o Set even tension across feeders
o Control dyeing process properly

4. Horizontal Lines (Fabric Row Marking)

• Cause:
o Machine stoppage
o Faulty yarn feeder or tensioner
• Remedy:
o Avoid frequent stops
o Keep yarn tension uniform
o Maintain consistent yarn feed

5. Vertical Lines (Needle Line)

• Cause:
o Damaged or faulty needle
o Needle wear
o Yarn tension variation
• Remedy:
o Replace faulty needles
o Check needle bed alignment
6. Oil Stains

• Cause:
o Excess or leaking machine oil
o Dust or dirty machine parts
• Remedy:
o Regular machine cleaning
o Use controlled oiling system

7. Thick and Thin Places

• Cause:
o Uneven yarn tension
o Irregular yarn quality
• Remedy:
o Use good quality yarn
o Adjust and monitor yarn tension

8. Holes in Fabric

Cause:

• Drop stitches or yarn breakage

• Damaged latch needles

Remedy:

• Replace broken needles

• Use stronger or better-quality yarn
13. Differentiate between woven fabric and knit fabric. (21)

Sl. Woven Fabric Knit Fabric

No

1 Made by interlacing two sets of yarns (warp Made by interlooping a single yarn
& weft)

2 Yarns run in two directions Yarn runs in one direction (usually

horizontal)

3 Less stretchable without elastane Naturally stretchable

4 Poor elasticity Good elasticity

5 Wrinkles easily Wrinkle-resistant

6 Edges may fray after cutting Edges may curl but don’t fray

7 Slower production process Faster production process

8 Less breathable More breathable

9 Used in shirts, pants, and formalwear Used in T-shirts, underwear,

sportswear
10 Has a stiffer drape, less flexible Softer drape, more body-conforming

14. Write short note on stich density, stich length, technical back, sinker
loop, working width and the overlap. (21)

Stich density: Stitch density refers to the number of stitches (loops) per unit area in a knitted
fabric, typically measured in stitches per square inch.

Stich length: Stitch length is the length of yarn in one stitch, usually measured in mm. It
controls the tightness or looseness of the fabric – longer stitches make the fabric looser and
softer.

Technical back: The technical back is the reverse side of a knitted fabric, where the back
loops are more visible , usually the side with purl bumps .
Sinker loop: The sinker loop is the horizontal part of the loop between two adjacent needle
loops. It is formed by the action of the sinker and helps connect the vertical wales in the
fabric.

Working width: Working width is the total width of the fabric being knitted at a time. It
depends on the number of needles used and is important for determining production
capacity.

Overlap: Overlap is the sideways (lateral) movement of the warp yarn in front of the
needle during the stitch formation process in warp knitting.

15. Define stitch density, loop length, technical face and machine gauge.
(22)

Stitch density: Stitch density refers to the number of stitches (loops) per unit area in a
knitted fabric, typically measured in stitches per square inch.

Loop length: Loop length is the total length of yarn used to make one complete loop in a
knitted fabric.

Technical face: The technical face is the front side of knitted fabric where the face loops are
most visible, usually the side that shows ‘V’ shaped loop.

Machine gauge: Machine gauge refers to the number of needles per inch (or per 1.5 inches)
in a knitting machine, determining the fineness of the fabric in produces.

16. Sketch primary knitting elements/What are the main knitting elements?
(22,21,20)

Main Knitting Elements (Primary Knitting Elements)

1. Needle

• Function: Forms loops by catching and pulling yarn.

• Types:
o Latch needle (most common)
o Spring-beard needle
 o Compound needle

2. Sinkers

• Function:
o Holds down the fabric during loop formation
o Helps to knock off old loops from the needles

3. Cam:

Cams are the devices which convert the rotary machine drive into a suitable reciprocating
action for the needles and other elements.

• Function:
o Guides needle movement up and down
o Controls actions like knit, tuck, or miss

4. Yarn Feeder

• Function:
o Delivers yarn to the needles during knitting
o Controls the amount and tension of yarn

5. Take-Down Mechanism

• Function:
o Pulls the knitted fabric downward
o Maintains proper tension during knitting

17. What are the function of sinker knitting? (22)

The Sinker is a thin metal plate of which is placed between each needle. In weft knitting machines
(especially in circular and flatbed machines), the sinker plays an important role during the loop
formation process.

The main function of sinker is to hold down, knock over and supporting the fabric loops.
Functions of Sinker
• Holds the fabric down
– Keeps the fabric in place while the needle works.
• Helps make sinker loop
– Shapes the bottom part of the loop (between two side-by-side loops).
• Controls loop size
– Helps decide how big or small the loop will be.
• Helps drop old loop
– Pushes the old loop off the needle when the new one is made.
• Keeps tension steady
– Keeps the fabric tight enough for smooth knitting.
18. State the main features of knitting machine. (21)

Main Features of Knitting Machine:

1. Frame: --The frame, normally free - standing and either circular or rectilinear according
to needle bed shape, provides the support for the majority of the machines
mechanisms.
2. Power supply: The machine control and drive system co - ordinates the power for the
drive of the devices and mechanisms.
3. Needles
– Used to form loops from the yarn. (Types: latch, spring beard, compound)
4. Cams
– Control the up-and-down movement of the needles.
5. Sinkers
– Hold the fabric down and help with loop formation
6. Yarn Feeders
– Feed yarn to the needles in the right amount.
7. Take-Down System
– Pulls the knitted fabric down smoothly after it's made.
8. Knitting Elements Arrangement
– Can be circular (round) or flat depending on machine type.
 9. Speed Control
– Controls how fast the machine runs (RPM – revolutions per minute).
10. Gauge (GG)
– Number of needles per inch; decides fabric fineness.
11. Quality control: The quality control system includes stop motions, fault detectors,
automatic oilers and lint removal systems.
12. Fabric Collection System
– Rolls or collects the knitted fabric after production.
13. Lubrication System
– Keeps moving parts smooth and reduces friction.

19. Explain needle timing and sinker timing. (21)

Needle Timing
Definition:
Needle timing means the correct time when the needle should move up or down during
the knitting cycle. Needle timing occurs in rib and interlock knitting machines. Needle timing
influence the appearance, the quality and properties of the fabric produced on a rib circular
knitting machine.
Why it’s important:

• Ensures proper loop formation

• Helps avoid yarn breakage or fabric faults
• Works in sync with the cam system.
There are 3 types of needle timing:
i. Synchronized timing
ii. Delayed timing
iii. Advanced timing
Sinker Timing

Definition:
The most forward position of the sinker during the knitting cycle is known as

the push point and its relationship to the needles is known as the sinker timing.
Or, Sinker timing means the right time when the sinker moves in a knitting machine to help
the needle make loops properly. Sinker timing occurs in single jersey knitting machines.

Why it’s important:

• Makes sure the sinker holds the fabric at the right moment
• Helps form the sinker loop properly
• Prevents the fabric from rising with the needle

20. What are the features of tuck loop and miss loop? (21)

The features of tuck loop and miss loop in knitting:

Tuck Loop – Features:

1. Formed when a needle holds the old loop and also receives a new loop without
knocking off the old one.
2. Two or more loops are held on the same needle at once.
3. Creates a thicker, wider fabric because of extra yarn.
4. Fabric has less stretch and more dimensional stability.
5. Produces a textured or patterned effect on the fabric surface.
6. Often used in rib, pique, or decorative knit fabrics.

Miss Loop (or Float Stitch) – Features:

1. Formed when the needle does not receive any yarn but the yarn passes behind the
needle.
2. No new loop is made; instead, yarn floats behind the fabric.
3. Makes fabric lighter and thinner in that area.
4. Fabric has more stretch and can have a loose or open structure.
5. Often used to create designs or color patterns.
6. Common in jacquard or striped knit fabrics.
21. In which machine double bearded latch needle & slider are used and
why? (21,22) [ B Part]

Double bearded latch needle & slider are used in: Warp Knitting Machines (Raschel or
Tricot machines)

Why are they used?

1. Double-bearded needle :
o Forming small and precise loops.
o The double beard allows the needle to form loops in both directions (forward
and backward), enabling more complex patterning and efficient knitting.
o Unlike single bearded needles, double bearded needles can hold two loops at
once, making them suitable for intricate designs.

o Suitable for fine gauge warp knitting.

o Provide high-speed knitting with better fabric quality.
2. Slider:
o Works together with the needle.
o The slider closes the needle during loop formation.
o Unlike single bearded needles, double bearded needles can hold two loops at
once, making them suitable for intricate designs.
o Unlike single bearded needles, double bearded needles can hold two loops at
once, making them suitable for intricate designs.

o Helps form and transfer loops correctly.

Reason for Use:

• In warp knitting, many yarns are fed at the same time to many needles.
• The double-bearded needle + slider system gives:
o Smooth loop formation
o High speed operation
o Durability for continuous work
o Best suited for producing fine, lightweight, and delicate warp knitted fabrics.
22. What are the features of V-bed knitting machine? (22)

A v-bed flat knitting machine is a flat knitting machine with two needle beds arranged in a V-
shape.

Main Features

1. Two needle beds - arranged in an upside-down or inverted 'V' shape.

2. Latch needles commonly used for loop formation

3. Carriage system that moves back and front to form loops.

4. Cam system controls needle movements (knit, tuck, Miss) .

5. In modern machine computer control for patterns and shaping.

6. Can knit complex structures (rib, interlock)

7. Used for sweater bodies, ribbed collars, cuffs, shaped garments.

8. It's have multiple feeder system.

9. The machines are designed for high productivity.

Or,

Features of V-Bed Knitting Machine:

1. Two Needle Beds in V-Shape

– The machine has two flat needle beds placed in a V angle, facing each other.
2. Used for Rib and Interlock Fabrics
– Can knit rib, interlock, purl, and other double knit structures.
3. Latch Needles Are Used
– Both beds are equipped with latch-type needles for loop formation.
4. More Design Possibilities
– Can perform tuck, miss, and transfer stitches, allowing complex designs.
5. Carries Multiple Cams/Carriages
– One or more carriages move back and forth to control needle actions.
 6. Can Do Loop Transfer
– Transfers loops from one bed to the other to make fashion or shaped garments (like
collars or cables).
7. Produces High-Quality Flat Fabrics
– Commonly used for sweaters, scarves, collars, and fashionwear.
8. Manual, Semi-auto, or Computerized
– Available in different models: hand-flat, semi-automatic, and fully computerized
(like Shima Seiki or Stoll machines).

Function of different parts:

1. Needle Bed: Holds the needles and forms the fabric.

2. Latch Needles: Catch yarn and form loops,

3. Sinker: Holds fabric down during loop formation.

4. Cam box/ carriage: Operate needles via cam tracks.

5. Cams: It control needle movement.

6. Yarn Feeder: Supplies yarn to the needles during knitting.

7. Tension Device: Controls yarn tension for smooth feeding.

8. Take down system: Pulls the knitted fabric down and collects it.

23. What are the advantageous features of V-bed knitting machine? [21]

Advantages of V-Bed Knitting Machine:

1. Flat Fabric Production

– Produces flat, non-tubular fabric (unlike circular machines), suitable for panels.
2. Precise Loop Formation
– The V-shaped needle bed ensures accurate and smooth loop formation.
3. Capable of Complex Structures
– Can produce rib, purl, interlock, links-links, and many fancy designs.
4. Stitch Transfer Facility
– Allows stitch transfer between beds for shaped knitting (e.g., collars, armholes).
 5. Ease of Pattern Making
– Modern V-bed machines can be computer-controlled to knit varied patterns easily.
6. Good for Fully Fashioned Garments
– Ideal for sweaters, cardigans, and other shaped garments without cutting and
sewing.
7. Better Loop Control
– Enables tight or loose loop adjustments easily, giving better control over fabric
properties.
8. Capable of Knitting Narrow or Wide Panels
– Can knit anything from narrow bands to full-width garment parts.
9. Automatic Carriage Movement
– Carriage can be programmed for variable speed and direction, improving efficiency.
10. Low Yarn Waste
– Especially in fully-fashioned knitting, there is minimal yarn wastage.

Features of V bed knitting machine

Versatility: V-bed flat knitting machines can produce a wide range of fabrics.

V-Bed Design: The V-shaped needle bed allows for increased flexibility in creating various
stitch patterns and designs.

Multiple Feeder Systems: These machines often come equipped with multiple feeder
systems.

High Productivity: The machines are designed for high productivity, with the ability to
produce large quantities of knitted fabric in a relatively short time.

Automatic Yarn Control: Some machines have automatic yarn control systems, ensuring
consistent tension and minimizing yarn-related issues during the knitting process.

24. State the features of weft knitting machine? (22)

Features of weft knitting machine

1. Yarn is Fed Horizontally

– Yarn is fed from side to side (weft direction), forming loops across the fabric width.
 --A single yarn can create the entire fabric

2. Uses One Yarn at a Time (Per Feeder)

– Each feeder usually supplies one yarn to knit the fabric.

3. Types: Flat or Circular

– Can be flat-bed (for flat fabrics) or circular (for tubular fabrics like T-shirts).

4. Latch Needles Used

– Most weft machines use latch-type needles for making loops.

5. High Production Speed

– Especially circular machines can knit very fast.

--Widely used in mass production of garments due to speed and ease of operation.

6. Loop-by-Loop Formation
– Loops are formed row by row it’s called courses, making the fabric stretchy.

7. Can Make Single or Double Jersey

– Single bed makes single jersey, double bed makes rib, interlock, etc.

8. Good Stretch and Comfort

– Weft knits are soft, flexible, and stretchable, suitable for garments.

9. Easy Pattern and Design Options

– Capable of creating various stitches like knit, tuck, miss, and fancy designs.

10. Used in Garments and Fashionwear

– Common in T-shirts, sweaters, underwear, and sportswear.

Used widely in: T-shirts, Underwear, Sweaters, Sportswear, Socks, Casual and stretch
garments
25. Explain the functions of various knit cam in weft knitting/ Illustrate
different cam knitting state its functions. (22,21,20)

Cam Name Function

Knit Cam Lifts the needle up to clear the old loop and catch new yarn.
Stitch Cam (Knock-over Controls how deep the needle goes down, thus deciding the
Cam) loop length.
Keeps the needle in a fixed height when it should not knit
Guard Cam
(used in miss/tuck).
Makes the needle hold the old loop and receive a new one
Tuck Cam
without knocking off.
Makes the needle stay in rest position (no loop formed, yarn
Miss Cam (Idle Cam)
floats).

Main Functions of Knit Cams:

1. Control Needle Movement

– Raise and lower the needles to form loops.
2. Form Different Loop Types
– Knit, tuck, and miss loops can be formed by changing cam settings.
3. Adjust Stitch Length
– Stitch cam adjusts how deep needles go, which affects loop size and fabric density.
4. Decide Knitting Pattern
– By selecting which cams operate on which needles, designs and patterns can be
made.
5. Ensure Synchronization
– Works in sync with yarn feeders and sinkers for smooth loop formation.

26. Describe the construction of Bearded Needle with suitable sketch. (21)

A spring-bearded needle is a long, thin needle used in warp knitting machines. It has a
flexible, curved hook end that looks like a beard, which gives the needle its name.
Main Parts of a Bearded Needle:

1. Butt
– The thick part at the back, used for pushing the needle up and down using cams.
2. Shank (Stem)
– The long body of the needle that connects the butt and the hook.
3. Hook
– The curved end that catches the yarn to form loops.
4. Beard
– The flexible curved part of the hook that can be pressed down to close the hook
during loop formation.
5. Eye
– A small groove near the hook where the yarn is held before the loop is formed.

27. Define Knitting. Differentiate between warp knitting and weft knitting.
(23,22,21,19,20)

Knitting is a method of fabric formation where yarn is interlooped to form a fabric structure
using needles.
It produces stretchy and soft fabrics and is widely used in making garments like t-shirts,
sweaters, socks, etc.
Aspect Weft Knitting Warp Knitting

Yarn Direction Yarn runs horizontally (weft-wise) Yarn runs vertically (warp-wise)

Yarn Feed A single yarn can feed many needles Each needle gets a separate yarn

Loop Formation Loops made across the width Loops made along the length

Most of the weft knitting is of tubular

Warp knitted fabric are flat or open w
form.

Dimensional stability of the fabric are

Dimensional stability of the fabric are
lower.

Unraveling Easily unravels if a loop breaks Does not unravel easily

Machine Type Used in circular or flatbed machines Used in tricot or raschel machines

Fabric Type Stretchy, soft and elastic Stable, less stretch

Also fast, especially in circular

Speed Very high-speed production
machines

Common Products T-shirts, sweaters, socks, scarves Lingerie, nets, sportswear

28. State the properties of weft knitted fabric. (20)

Properties of Weft Knitted Fabric:

1. High Stretchability
– Weft knits can stretch in both directions, especially width-wise, making them very
comfortable.
2. Soft and Comfortable
– The fabric feels soft, light, and is ideal for next-to-skin wear like t-shirts and
underwear.
 3. Good Drape
– Weft knits fall nicely on the body and give a smooth, flexible shape.
4. Wrinkle Resistant
– Less prone to wrinkles compared to woven fabrics.
5. Easily Unravels
– If a loop breaks, the fabric can ladder or run, which is a disadvantage.
6. Good Air Permeability
– The loop structure allows air to pass, making the fabric breathable.
7. Fast Production
– Especially on circular machines, weft knitted fabrics are produced quickly.
8. More Elastic than Warp Knits
– Excellent for stretchy garments like sportswear and activewear.
9. Variety of Designs Possible
– Can produce different textures, patterns, and structures (rib, purl, tuck, etc.).
10. Low Dimensional Stability
– Fabric may shrink or distort if not properly finished or treated.

Common Uses:

• T-shirts
• Underwear
• Sportswear
• Socks
• Sweaters

Properties of Weft Knitting fabric are: • Very elastic • Warm to wear • Comfortable • Shrinks
easily • Different properties can be achieved depending on the yarns used • Can stretch out
of shape easily • Does not fray • Unravels when cut • Curls up at the edges • Various colors
/patterns can be achieved • Good Insulator

29. Draw and describe different parts of a latch needle. (20,22)

Part Name Description / Function

Butt The thick part at the back that interacts with the cam to move the needle.
Part Name Description / Function

Stem (Shank) The long body of the needle; it holds other parts together.

Hook The curved end that catches and holds the yarn during loop formation.

Latch A small flap that opens and closes the hook to form loops.

Latch Spoon The rounded end of the latch that sits inside the hook to close it.

Hinge A pivot point where the latch is attached and allowed to swing freely.

The tail, which is an extension below the butt, giving additional support to
Tail
the needle and keeping the needle in its trick.

Clearing Point The highest point the needle reaches to clear old loops.

Or,

Parts of a Latch Needle

Part Function / Description

1. Hook Catches and holds the new loop of yarn.
2. Slot / Saw Cut The groove where the latch blade fits in.
3. Cheeks / Slot
Holds the latch blade in place; acts as the hinge support.
Walls
 Part Function / Description
Fixes the latch blade; modern needles often replace this with pinched
4. Rivet
slot walls.
5. Latch Blade Attaches the latch to the needle and allows it to open and close.
The curved tip of the latch that covers the hook when closed to form
6. Latch Spoon
the loop.
7. Stem The main body of the needle, which carries loops during knitting.
A small projection that moves through cam tracks to raise/lower the
8. Butt
needle.
The lower extension of the needle that gives extra support and holds it
9. Tail
in position.

30. Describe the knitting action of single jersey fabric. (22)

Single jersey fabric is made on a circular knitting machine using latch needles. The fabric
consists of knit loops on the face side and purl loops on the back side.

Main Steps of Knitting Action (Loop Formation Cycle):

1. Clearing
o The needle moves upward.
o The old loop slides down the stem and clears the hook.
o The needle is now ready to receive a new yarn.
2. Yarn Feeding
o A new yarn is laid into the open hook of the raised needle by the yarn feeder.
3. Loop Formation
o The needle moves downward.
o The latch closes as the old loop slides up and pushes the latch shut, trapping the
new yarn inside the hook.
4. Knock-over
o The old loop is knocked off the needle and forms a new stitch below.
 o The new yarn becomes the new loop.
5. Sinker Action (if used)
o The sinker holds the fabric down to help form a clean loop and maintain fabric
tension.

Result:

• Each needle forms one loop per course.

• The structure forms V-shaped knit stitches on the face and horizontal purl bumps on
the back.

31. Illustrate the knitting action of single jersey circular knitting machine.
(20)

Same as 30.

32. Differentiate between single jersey and interlock machine. (22)

Feature Single Jersey Machine Interlock Machine

1. Number of One set of needles (cylinder Two sets of needles (cylinder + dial)
Needle Sets only)

2. Type of Fabric Produces single jersey fabric Produces interlock fabric

3. Loop Structure Only knit loops (one side knit, Double-knit loops (identical face on
one side purl) both sides)

4. Fabric Face: knit; Back: purl Looks same on both sides (smooth
Appearance and thick)
5. Fabric Thickness Thin and light Thicker, heavier, and more stable
6. Curling Tends to curl at edges Does not curl easily

7. Stretchability More stretch in width Less stretch; more dimensional

direction stability
Thinner & lighter Thicker & more compact
Lightweight Heavier
8. Production Speed Higher speed Lower speed (needs two needle sets
working alternately)

9. Common T-shirts, underwear, vests Polo shirts, leggings, dresses

Products

33. How can you differentiate single jersey and double jersey machine and
fabric? (20)

A. Machine Comparison

Feature Single Jersey Machine Double Jersey Machine

One set of needles
1. Needle Arrangement Two sets of needles (cylinder and dial)
(cylinder only)
2. Type of Fabric Single jersey fabric (one Double jersey fabric (both sides
Produced face knit) interlocked)
Front and back look
3. Fabric Appearance Both sides look same
different
4. Number of Cam Two cam systems (one for each needle
One cam system
Systems set)
Produces thin, lightweight
5. Fabric Thickness Produces thicker, more stable fabric
fabric
Fabric tends to curl at
6. Curling Fabric is flat, no curling
edges
Makes loops on one side
Makes loops on both sides
only
7. Machine Complexity Simple structure More complex due to two needle sets
8. Common Products T-shirts, vests, underwear Polo shirts, jackets, leggings
Difference Between Single Jersey and Double Jersey Fabric

Feature Single Jersey Fabric Double Jersey Fabric

1. Number of Yarn
Made with one yarn set Made with two yarn sets
Sets
Formed by two sets of loops
2. Fabric Structure Formed by one set of loops
interlocked
Different on both sides (knit front, Same on both sides (smooth face on
3. Sides Appearance
purl back) both sides)
4. Thickness Thin and lightweight Thicker and heavier
Less stretch, more dimensional
5. Stretchability More stretch, especially in width
stability
Curls at edges (especially sides and
6. Edge Curling Does not curl at edges
bottom)
7. Durability Less durable, can deform easily More durable and stable
Smooth on one side, looped on the
Smooth on both sides (reversible)
back
More breathable Less breathable (denser structure)
Low Production Cost High Production Cost
Polo shirts, jackets, leggings, formal
8. Common Uses T-shirts, vests, underwear
knitwear

34. Show the chain notation and features of Rib and interlock structure. (20)

Features of Rib Fabric:

1. Made with two needle beds

– Uses needles in both front and back.
2. Knit and purl lines
– Has knit and purl stitches side by side (like 1×1 or 2×2).
3. Very stretchable
– Stretches a lot side to side, good for tight areas.
 4. Same look on both sides
– Front and back look the same.
5. Doesn’t curl at the edges
– Lies flat, no rolling like single jersey.
6. Used in cuffs and necks
– Great for collars, sleeves, and waistbands.
7. Good Recovery
– Can return to shape after stretching, offering a snug fit.

Features of Interlock Fabric:

1. Made with two needle beds

– Uses both front and back needle beds, like rib.
2. Looks same on both sides
– Front and back are identical, smooth and flat.
3. Soft and thick
– Feels soft, and thicker than single jersey.
4. Does not curl
– The edges stay flat, no rolling.
5. Stable and strong
– Holds shape well and is more durable than single jersey.
6. Less stretch than rib
– Has some stretch, but less than rib fabric.
 7. Used for quality garments
– Good for T-shirts, babywear, leggings, etc.

34/35. Show the looping diagram and notation diagram of plain, Rib and
Interlock structure along with 3 features of each structure. (22)

Features of Plain (Single Jersey) Fabric:

1. Made with one set of needles

– Uses only one needle bed (usually circular machine).
2. Different on both sides
– Front side: V-shaped knit stitches
– Back side: Horizontal purl loops
3. Thin and lightweight
– Fabric is soft, light, and breathable.
4. Good stretch (width-wise)
– Stretches well side-to-side, less in length.
5. Curls at edges
– Tends to curl at sides and top/bottom.
6. Fast production
– Easier and faster to produce than double knits.
7. Used for casual wear
– Common in T-shirts, underwear, sportswear, etc.
Notation diagram of plain fabric

36. What is face loop and back loop? Explain with figure. (19)

In weft knitting, loops are formed by intermeshing yarns. The loop can appear either on the
face (front) or back (reverse) side of the fabric, depending on the direction of knitting and
how the loop is formed.
1. Face Loop (Knit Loop)

• A face loop is formed when the yarn is drawn through the loop from back to front.
• The loop appears like the letter "V" on the surface.
• Found on the technical face of single jersey or on both sides of rib/interlock.

Characteristics:

• Vertical appearance (wale direction)

• Smooth and flat
• Provides strength and elasticity
2. Back Loop (Purl Loop)

• A back loop is formed when the yarn is drawn through the loop from front to back.
• The loop appears like a small “bump” or curve (~) on the fabric.
• Commonly found on the back side of single jersey.

Characteristics:

• Horizontal, bumpy appearance

• Softer and bulkier feel
• More absorbent and flexible

37. What are the knitting elements and which one is principal knitting
element? State the functions of different parts of a knit cam system. (19)

Same as 16.

38. What is gauge and what do you mean by 3.5 E? (19)

Gauge refers to the number of needles per inch (or per 2.54 cm) on a knitting machine.
It determines the fineness or coarseness of the fabric.
 • Higher gauge = more needles per inch = finer fabric
• Lower gauge = fewer needles per inch = coarser fabric

What do you mean by 3.5 E?

• "3.5 E" means the knitting machine has 3.5 needles per inch. 7 needles in 2 inch .
• The "E" stands for English gauge (a common unit for gauge).

🔸 So, 3.5 E indicates a coarse gauge, used for thick fabrics like heavy sweaters, scarves, or
blankets.

39. What is double jersey structure? How you will identify rib, interlock and
purl fabric? (19,19)

Double jersey is a weft knitted fabric structure that is produced using two sets of needles
operating in two needle beds (cylinder and dial in circular machines, or two flat beds in V-
bed machines).

It is also called double knit because it is made by interlocking two single jersey fabrics
together.

1. Rib Fabric

Identification Points:

• Vertical ribs (lines) are visible on both sides of the fabric.

• Looks the same on both sides.
• When stretched widthwise, the ribs separate clearly.
• Has excellent elasticity in the width direction.
• Made with alternating knit and purl wales (e.g., 1×1, 2×2 rib).

Simple Test:

Pull the fabric sideways – it will stretch a lot and show visible rib lines.
2. Interlock Fabric

Identification Points:

• Smooth surface on both sides (looks like single jersey on both faces).
• Thicker and firmer than single jersey.
• Less stretch than rib fabric.
• Loops are perfectly aligned between front and back beds.
• Doesn’t curl or roll at the edges.

Simple Test:

Try to pull the fabric layers apart – you can’t; it’s dense and feels like a double layer.

3. Purl Fabric

Identification Points:

• Looks like horizontal waves (~) or purl loops on both sides.

• Very soft and bulky.
• Has high lengthwise stretch.
• Loops appear reversed (bumpy) on both front and back.
• Fabric edges do not curl.

Simple Test:

Rub the fabric with fingers – it feels soft and bumpy on both sides.

40. State the features of single jersey machine. (19)

Features of Single Jersey Machine:

1. Circular Knitting Machine

– Typically uses a single set of needles arranged in a circular cylinder.
 2. Produces Single Jersey Fabric
– Makes light, stretchable fabric with knit stitches on the front and purl on the back.
3. One Set of Needle Bed
– Has only one needle bed (cylinder), no dial (unlike rib or interlock machines).
4. Latch Needles Used
– Commonly uses latch-type needles for loop formation.
5. High Production Speed
– Runs at high speed with multiple feeders, suitable for mass production.
6. Fabric Output is Tubular
– The fabric is produced in tube form, which can be slit open if needed.
7. Flexible and Lightweight Fabric
– The fabric is soft, breathable, and used widely in T-shirts, underwear, etc.
8. Curling Tendency
– The fabric edges curl (face to back and vice versa) due to unbalanced loop structure.
9. Less Complicated Mechanism
– Simple machine structure makes it easy to operate and maintain.
10. Available in Various Gauges
– Can produce both coarse and fine single jersey fabric by changing gauge.

41. What are the main features of flat knitting machine? State the function
of carriage and cam system of flat knitting machine. (19)

Main Features of Flat Knitting Machine:

1. Flat Needle Bed

– Needles are arranged in two flat beds (V-shaped), unlike circular machines.
2. Produces Flat Fabric
– Creates flat (open-width) fabric instead of tubular fabric.
3. Two Sets of Needles
– Front and back beds can form rib, purl, interlock, and other structures.
4. Reciprocating Carriage Movement
– The carriage moves back and forth across the needle beds.
 5. Stitch Transfer Capability
– Can transfer loops between beds, useful for fully fashioned and shaped garments.
6. Suitable for Complex Designs
– Good for making collars, panels, ribs, and jacquard or intarsia patterns.
7. Manual or Computer-Controlled
– Available in both hand-flat and computerized (CNC) versions.
8. Flexible Fabric Width
– Can produce fabrics of variable widths, depending on needle selection.
9. Used in Shaped Garment Knitting
– Commonly used in making sweaters, cardigans, cuffs, and panels.
10. Fine to Medium Gauges Available
– Machines are available in different gauges to produce both fine and heavy fabrics.

Functions of the carriage and cam system in a flat knitting machine:

1. Carriage
Function:
• The carriage moves back and forth (reciprocating) across the needle beds.
• It carries and positions the cams that control the movement of the needles.
• It also feeds yarn to the needles during knitting.
Main roles:
• Drives the cam system
• Controls needle movement (up and down)
• Ensures loop formation
• Supports automatic patterning (in computerized machines)
2. Cam System
Function:
• The cam system guides the needles through their knitting actions by pushing them up
and down in a controlled sequence.
Main roles:
• Controls knit, tuck, and miss functions of the needles
• Determines stitch length and loop size
• Converts carriage motion into needle movement
• Allows pattern selection and structural variation
42. How can you produce tuck stitch on latch and bearded needle? (19)

On Latch Needle

Process to form tuck stitch:

• The old loop is kept on the needle hook.

• A new yarn is laid over the needle hook, but the needle is not cleared.
• As the needle retracts, it holds both the old and new loops together.
• This forms a tuck stitch (two loops retained on the same needle).

Result:
A tuck loop is created which appears as a textured or mesh effect in the fabric.
On Bearded Needle

Process to form tuck stitch:

• The needle does not rise high enough to clear the previous loop.
• A new yarn is laid into the beard of the needle.
• The presser or slider closes the beard, holding both the old and new loops.
• The two loops are retained in the same hook — this forms a tuck stitch.

Result:
The tuck loop creates a more open, textured structure in the knitted fabric.

43. Explain the knitting action of tuck loop formation technique. (19)

The tuck loop formation is a special knitting action where the old loop on the needle is not
cast off during knitting. Instead, the needle holds the old loop while a new yarn is laid over
the needle hook. This happens when the needle rises only partially, not high enough to clear
the old loop, which allows the old loop to stay on the needle.

Next, the new yarn is fed into the needle hook along with the old loop. As the needle moves
downward, it pulls the new yarn through, but since the old loop is still held, the needle ends
up carrying two loops simultaneously — the old loop from the previous course and the
newly formed loop. This creates a tuck stitch.

The tuck stitch results in a loop being tucked on the fabric surface, creating a textured effect
and often a thicker, less stretchy area in the fabric. This technique is widely used to add
decorative patterns or structural variation to knitted fabrics.

44. Illustrate the cam system (needle cam and sinker cam) of single jersey
knitting machine. (19)

The cam system controls the movement of the needles and sinkers to form loops during
knitting.

1. Needle Cam

• The needle cam guides the needles in up and down movements.

• It controls the different needle actions:
o Rise (to clear the old loop)
o Fall (to form a new loop)
o Hold (to keep the needle in a fixed position)
• By pushing the needle's butt, the cam makes the needle move accordingly.

2. Sinker Cam

• The sinker cam controls the sinkers, which hold the fabric down and prevent loops
from being pulled out during knitting.
• It moves the sinkers in and out of the needle hooks at the right time.
• This action helps in forming proper loops and maintaining fabric tension.
 Part B

1. Define overlap, underlap, rack run-in and run-in ratio. 23

Overlap (in Warp Knitting):

Definition:
Overlap is the sideways (lateral) movement of the warp yarn in front of the needle during
the stitch formation process in warp knitting.

Explanation:

• The guide bar swings across the needle, laying the yarn over it.
• It forms the loop part of the stitch.
• It helps in building the wales (vertical columns) of the fabric

Underlap (in Warp Knitting):

Definition:
Underlap is the movement of the yarn behind the needles from one stitch to the next in the
wale direction.

Explanation:

• It connects stitches in adjacent wales, adding strength and elasticity.

• It is longer than the overlap.
• Influences fabric width, stretch, and cover.

Run-in (in Warp Knitting):

Rack: The unit of production in warp knitting is a ‘rack’. A rack is 480 courses of knitting.

Run-in: The length of yarn consumed in knitting one rack is called a run in.

Thus the main factor controlling fabric quality is the rate of ‘run in’ of each warp.
Run-in Ratio (in Warp Knitting):

Definition:
The proportional relationship between the run-ins of two or more guide bars.

Formula:

𝑅𝑢𝑛 𝑖𝑛 𝑜𝑓 𝐺𝑢𝑖𝑑𝑒 𝐵𝑎𝑟 𝐴

Run-in Ratio =
𝑅𝑢𝑛 𝑖𝑛 𝑜𝑓 𝐺𝑢𝑖𝑑𝑒 𝐵𝑎𝑟 𝐵

Use:

• Used to design fancy or functional fabrics.

• Affects texture, structure, and mechanical properties

Define needle, guide & sinker, needle bar, guide bar, sinker bar, Pattern
drum, Pattern disc, types of chain link in warp knitting.

Needle: A needle is a slender/fine metal tool used in knitting machines to form loops
from yarns and intermesh them to create fabric.

Functions of a Knitting Needle:

1. Catches the yarn to form a loop.

2. Holds the loop during fabric formation.
3. Releases old loops and forms new ones.
4. Works continuously to build rows (courses) of fabric.

Guide: A guide is a small metal element with a hole through which the yarn passes, and it
directs the yarn to the needle during knitting.

Functions of a Guide:

1. Feeds the yarn to the needle at the correct position.

2. Controls the movement of yarn across or behind the needles (for overlap or
underlap).
 3. Works with a guide bar to produce specific lappings and fabric designs.

Sinker: The Sinker is a thin metal plate of which is placed between each needle. Its help to
hold down the fabric and assist in loop formation .

Needle bar: A needle bar is a long metal bar or rod in a knitting machine that holds and
moves all the needles together during the knitting process.

Guide bar: A guide bar is a long, flat metal bar in a warp knitting machine that holds and
controls the movement of multiple yarn guides, directing yarns to the needles during loop
formation.

Functions of a Guide Bar:

• Holds yarn guides, each of which carries a yarn.

• Moves laterally (sideways) to form overlaps and underlaps.
• Controls yarn path/lapping movement, which determines the fabric structure.
• Helps create various designs and textures in warp knitted fabrics.

Sinker bar: A sinker bar is a long bar that holds multiple sinkers, which assist in loop
formation by helping to knock over old loops and hold the fabric down during knitting.

Or, A sinker bar is a long, horizontal bar that holds and controls the movement of sinkers in
a weft knitting machine.

Functions of a Sinker Bar in Warp Knitting:

• Holds and guides sinkers across the machine width.

• Moves in and out to assist in the knock-over of old loops from the needles.
• Supports and controls fabric tension during loop formation.
• Prevents fabric lifting when the needles rise.

Pattern disc: A pattern disc is a circular component in a warp knitting machine that controls
the lapping movement of the guide bars according to a pre-set pattern. Pattern disc has a
single chain links.
Pattern drum: A pattern drum is a cylindrical component / set of chain links in a warp
knitting machine that controls the lapping movement of the guide bars according to a pre-
set design.

Types of chain link in warp knitting: There are 4 types of chain link. 1.
Unground 2. Fork end ground 3. Tail end ground 4. Both end ground

2. Explain lapping mechanism with suitable sketch. (23)

Definition:

Lapping is the movement of the yarn around the needle in a horizontal and vertical direction
during loop formation in warp knitting.
It determines the design and structure of the fabric.
Mechanism:

• The lapping movement is created by the guide bars, which carry yarns back and forth
across the needles.
• Each guide bar performs a shogging motion (sideways) and swinging motion
(forward and backward):
o Shogging: Movement laterally across the needle bed.
o Swinging: Movement in and out towards the needle.
• The combination of these two movements causes the yarn to lap around the needles
and form loops.

Purpose of Lapping:

• To produce different warp knit structures such as tricot, atlas, or pillar stitches.
• The lapping movement pattern defines the fabric design, like plain, net, or fancy
patterns.

3. State the rules of plotting lapping diagram. (23)

Rules for Plotting a Lapping Diagram:

1. One yarn line for each guide bar

o If more than one guide bar is used, draw a separate line (thread path) for each
one.
2. Start from the same row (course)
o All guide bar movements must begin from the same horizontal line (course) so
they match correctly.
3. Needle numbers must match pattern drum
o The spaces between needles should be numbered the same way as in the
machine’s pattern mechanism.
4. Chain and movement must match
o When putting the chain on the pattern drum, make sure its position correctly
matches the movement of the guide bar and needle.
5. Draw from bottom to top
 o Always draw the diagram starting from the bottom (1st course) and go upward
(next courses).
6. Vertical line = no side movement
o Yarn goes to the same needle again.
7. Slanted line = side movement
o Yarn goes to the next or previous needle (shogging).

4. Draw the lapping diagram and chain notation of basic stitches of warp
knitting. (23)

Chain notation:

A chain notation is a list in correct sequence of chain link numbers spaced in to knitting cycles
for each guide bar necessary to produce a particular structure repeat.
Chain notation of basic stitches of warp knitting

1. An overlap followed by an underlap in the opposite direction (closed lap)

• Overlap: Full loop formation around the needle

• Underlap: Yarn moves behind to the next needle
• Effect: Strong and stable fabric (e.g., Tricot)

2. An over lap followed by an underlap in the same direction (open lap)

• Overlap: Yarn partially overlaps the needle

• Underlap: None or very short
• Effect: More open and stretchable fabric

3. Only overlaps and no underlaps (open laps).

• Overlap : All loops are overlaps

• Underlap : no underlap
• Effect: More open and less stable

4. Only underlaps and no overlaps (Laying-in).

• Overlap: None
• Underlap: All loops are underlaps.
5. Neither overlaps nor underlaps (Miss-lapping).

• Overlap: None
• Underlap: None

5. Why is chain link numbering needed for warp knitting? (23)

Chain link numbering is needed in warp knitting to control the movement of the guide bars
accurately during the knitting process. It determines how the yarns are laid over the needles
to form different stitches and fabric designs.

Reasons in short

1. It guides the yarn to move left or right.

2. It helps make the correct loop pattern (like tricot or atlas).
3. It allows the machine to make beautiful and repeated designs.
4. It makes the fabric strong and correct by avoiding wrong movements.
5. It works like a program that runs the warp knitting machine.

Or,

Main Reasons:

1. Controls Guide Bar Movement

o Each number on the chain link corresponds to a specific shogging movement
(sideways movement) of the guide bar.
2. Determines Lapping Movement
o Chain links create the pattern that determines how the yarn laps around the
needles (e.g., 1–0 / 1–2).
3. Ensures Accurate Stitch Formation
o The correct numbering ensures that loops are formed properly and the fabric is
not defective.
 4. Pattern Creation
o Different designs and textures (like tricot, atlas, or net) are made by using
different chain link numbers.
5. Machine Automation
o In modern warp knitting machines, chain links work like a programming system
that controls the guide bar's motion automatically.
6. Easy Repeatability
o The chain links allow the same pattern to be repeated consistently and precisely
over a long production run.

6. Give the classification of chain link used in tricot warp knitting machine.

(23) [ Not sure about this answer ]

Types of chain link in warp knitting: There are 4 types of chain link. 1.
Unground 2. Fork end ground 3. Tail end ground 4. Both end ground

7. Write the features of Raschel warp knitting machine. (23,22,21,20)

Features of Raschel Warp Knitting Machine

1. Latch Needles Used

– Raschel machines use latch needles, which are strong and suitable for heavy or
coarse fabrics.
2. High Number of Guide Bars
– Usually has 2 to 48 guide bars, allowing for complex patterns and designs (nets,
laces, etc.).
 3. Fabric Type
– Produces open, net, lace, mesh, and spacer fabrics—used in curtains, sportswear,
and technical textiles.
4. Yarn Feeding from Beam
– Yarn is fed from warp beams, and each guide bar controls one or more beams.
5. Heavier & Coarser Fabrics
– Suitable for thicker yarns and heavy fabric production.
6. Possibility of Patterning
– Can create raised effects, multi-thread designs, and jacquard patterns using
additional mechanisms.
7. Individual Needle Control
– Each needle is independently controlled, making the machine suitable for patterned
or shaped fabrics.
8. Pattern Controlled by Pattern Drum or Electronic System
• The lapping movement of yarns is controlled by chain links or electronic drives.

9. Slower Speed Than Tricot

– Generally slower than tricot machines, but more versatile.
10. Used for Both Flat & Spacer Fabrics
– Can be used to make flat, three-dimensional, or double-layered (spacer) fabrics.
11. Working Width
– Common machine widths range from 84 to 134 inches.

Raschel warp knitting machines are versatile machines used for producing coarse, open,
and fancy fabrics with latch needles and multiple guide bars, and are controlled by pattern
chains or electronics.

8. What are the function of sinker and latch guard in Raschel warp knitting
machine ? (22)

Sinker: The Sinker is a thin metal plate of which is placed between each needle. Its help to
hold down the fabric and assist in loop formation .
Functions of Sinker in Raschel Warp Knitting Machine:

1. Holds down the fabric:

Keeps the knitted loops in place during the formation of new loops.
2. Supports loop formation:
Provides a stable base for yarn to form proper stitches.
3. Controls fabric take-down:
Helps move the fabric downward after loop formation.
4. Maintains fabric tension:
Keeps the fabric tight and prevents looseness during knitting.
5. Prevents fabric ride-up:
Stops the fabric from lifting with the needles, ensuring smooth operation.

Functions of Latch Guard in Raschel Warp Knitting Machine:

1. Holds the latch in position:

Keeps the latch of the needle steady during knitting.
2. Prevents early latch closing:
Ensures the latch does not close before the yarn enters, avoiding missed stitches.
3. Supports correct loop formation:
Helps the needle form proper and complete loops.
4. Reduces faulty stitches:
Prevents errors like dropped or incomplete loops.
5. Guides needle movement:
Assists the needle in moving smoothly during its knitting cycle.
9. Describe the shogging and swinging mechanism with figure. (23)

Swinging Motion (Definition):

Swinging motion is the arc-like forward and backward movement of the guide bars. It
helps the yarn go around the needle to make loops.

Mechanism

• The guide bars move in front of and behind the needles like a swing.
• This movement helps form the loop on the needle.
• The swinging action is fixed and collectively applied to all guide bars.
• All guide bars swing together at the same time.
• The motion is derived from the main camshaft, just like the needle and sinker motions.
• The movement comes from the main camshaft using levers and rods.
• It creates the two side parts of the loop.

Shogging Motion (Definition):

Shogging motion is the side-to-side/sideways movement that occurs parallel to the needle
bar produces the underlaps and overlaps.
Mechanism :

• Each guide bar can move side to side in a different way.

• This side movement is called a shog.
• The time, direction, and distance of each shog is controlled separately for each guide
bar.
• This control comes from a pattern chain or pattern wheel.
• These parts are connected to a horizontal pattern shaft, which is driven by the main
camshaft of the machine.

Types of Shogging Motion

Positive Shogging:

• Here pattern wheel pushes the guide bar away from the pattern mechanism.
• Movement is active and forced outward.

Negative Shogging:

• The pattern wheel pulls the guide bar toward the pattern mechanism.
• Movement is inward, controlled by pulling action.

10. Define the terms: rack and quality. (23)

Rack: The unit of production in warp knitting is a ‘rack’. A rack is 480 courses of knitting.

Quality : The length of cloth knitted during one rack measuring in inches is called quality.

11. What are advantages of using pattern wheel instead of pattern disc?
(22,21)

Advantages of Using Pattern Wheel Instead of Pattern Disc (in Warp Knitting Machines):
1. Greater Pattern Length
• Pattern wheels can carry more links, allowing longer and more complex patterns
than pattern discs.
2. Smooth and Continuous Operation
 • Pattern wheels provide smoother rotation and less vibration during high-speed
operation.
3. Easier Handling of Complex Designs
• Suitable for fancy or decorative designs that require a larger number of lapping
movements.
4. Better for Modern Automation
• Pattern wheels are more adaptable to computerized or automatic control systems.
5. Increased Durability
• Pattern wheels are generally more robust and wear-resistant than pattern discs.
6. Larger Link Capacity
• A pattern wheel can hold more chain links, which is ideal for fabrics with long repeat
designs.
7. Supports Electronic Control
• Easily integrated with electronic drive systems, enabling automated pattern changes.
8. Reduced Noise and Friction
• Better mechanical balance reduces operating noise and friction compared to pattern
discs.
9. Best For Long runs of the same fabric.
10. Improved Machine Performance
• Reduces mechanical stress, leading to lower maintenance and longer machine life.

12. Explain the lapping movement of guide bar. (22,21,20)

Definition:

The lapping movement of a guide bar refers to the combined forward-backward and side-
to-side movement of the yarn carrier (guide bar) over the needles during warp knitting to
form loops.

Types of Movement Involved:

1. Swinging Movement (In and Out):

o The guide bar moves forward and backward across the needle bed.
 o Forward: To lay the yarn in front of the needle.
o Backward: To allow the needle to rise and form a loop.
2. Shogging Movement (Side to Side):
o The guide bar moves sideways (left or right) to lay yarn on a different needle.
o This creates the lapping path (e.g., 1–0 / 1–2).

The swinging and shogging movements together form the lapping path, which defines the
stitch type and design of the fabric. This movement is controlled by a pattern chain (or
electronically).

13. Describe the functions of the needle bar, guide bar and sinker bar in
warp knitting . (22,21)

Needle bar: A needle bar is a long metal bar or rod in a knitting machine that holds and
moves all the needles together during the knitting process.

Function:
• Holds and moves all the needles together in a straight line.
• Forms loops by raising and lowering the needles.
• Moves upward to allow yarn entry and downward to form the loop.
• Works synchronously with guide and sinker bars.
• Ensures uniform loop formation across the fabric width.

Guide bar: A guide bar is a long, flat metal bar in a warp knitting machine that holds and
controls the movement of multiple yarn guides, directing yarns to the needles during loop
formation.

Functions of a Guide Bar:

• Holds yarn guides, each of which carries a yarn.

• Moves laterally (sideways) to form overlaps and underlaps.
• Controls yarn path/lapping movement, which determines the fabric structure.
• Helps create various designs and textures in warp knitted fabrics.
Sinker bar: A sinker bar is a long bar that holds multiple sinkers, which assist in loop
formation by helping to knock over old loops and hold the fabric down during knitting.

Or, A sinker bar is a long, horizontal bar that holds and controls the movement of sinkers in
a weft knitting machine.

Functions of a Sinker Bar in Warp Knitting:

• Holds and guides sinkers across the machine width.

• Moves in and out to assist in the knock-over of old loops from the needles.
• Supports and controls fabric tension during loop formation.
• Prevents fabric lifting when the needles rise.

14. What are the prospects of warp knitting in Bangladesh? (22,21)

Warp knitting holds promising prospects in Bangladesh due to several key factors. Firstly, the
country's knitwear industry is rapidly growing, and warp knitted fabrics—like tricot, lace,
mesh, and nets—are becoming increasingly demanded for sportswear, innerwear, and
decorative purposes. Secondly, warp knitting allows for diversification of textile products.
Through this technology, Bangladesh can produce value-added items such as mosquito nets,
lace curtains, automotive fabrics, and even technical textiles, helping the country reduce
dependency on basic garments.

Additionally, warp knitting machines offer very high production speed, making them ideal for
meeting large export orders efficiently. This speed advantage can give Bangladesh a
competitive edge in the global market. Another important prospect is the opportunity for
import substitution. Currently, many warp knitted items like lace or mesh fabrics are
imported; local production would reduce this dependence and help retain foreign exchange.

Moreover, the expansion of warp knitting opens the door for entering the technical textile
sector. These include products like geotextiles, medical textiles, and industrial fabrics, which
are in high demand globally. Lastly, warp knitting can create new employment and training
opportunities in the textile sector, especially for skilled machine operators and engineers.
With proper investment, government support, and technical education, Bangladesh has
strong potential to emerge as a regional hub for warp knitted fabric production.
15. Describe the advantages & features of flat knitting machine. (22,21)

Features of Flat Knitting Machine

1. Has two flat needle beds placed in an inverted V shape.

2. Uses latch needles for loop formation.
3. Carriage moves left and right to operate needles.
4. Capable of knit, tuck, and miss stitches.
5. Offers independent needle selection.
6. Suitable for both rib and plain structures.
7. Can produce shaped garments (fully fashioned).
8. Computerized models support automatic patterning.
9. Stitch cam controls stitch length accurately.
10. Allows easy stitch transfer for cable designs.
11. Can knit both forward and backward directions.
12. Enables wide range of design and structure options.

Advantages of Flat Knitting Machine

1. Produces complex patterns like cable, jacquard, and intarsia.

2. Ideal for shaped garments like sweaters and collars.
3. Minimizes fabric wastage during garment making.
4. Suitable for short runs and sample production.
5. Allows easy change of yarns and colors.
6. Easy to control stitch density and fabric tension.
7. Lower maintenance cost than circular machines.
8. Supports seamless and 3D garment knitting.
9. Good for both coarse and fine gauge fabrics.
10. High flexibility in stitch and width control.
11. Useful for fashion, home textiles, and accessories.
16. Why stitch density is measured in warp knitting machine ? (22)

Stitch density in warp knitting is measured to ensure fabric quality, performance, and
consistency. Here are the main reasons:

1. Controls Fabric Weight and Thickness

• Stitch density affects how heavy or light the fabric is.

• Higher density means thicker and heavier fabric; lower means lighter and more open.

2. Ensures Fabric Strength

• Denser stitches provide more strength and durability, which is essential for technical
or functional fabrics.

3. Maintains Dimensional Stability

• Helps to prevent fabric distortion, shrinkage, or stretching during use or washing.

4. Affects Appearance and Texture

• Stitch density impacts how the fabric looks and feels (e.g., smooth, rough, fine, or
coarse).

5. Supports Quality Control

• Measuring stitch density allows manufacturers to maintain consistency from one

batch to another.

6. Influences Fabric Properties

• It affects air permeability, elasticity, and drapability—important for sportswear,

lingerie, etc.

7. Assists in Machine Settings

• Helps technicians to adjust machine speed, tension, and yarn feed to achieve desired
fabric.
In Short:

Stitch density is measured in warp knitting to control fabric quality, strength, appearance,
and performance, ensuring that the final product meets the required specifications.

17. How do you recognize the face and back side of the warp knitted fabric.
(21)

To recognize the face (front) and back side of a warp knitted fabric, we can look for these
key features:

Face Side (Front):

1. Clearer, smoother, and more uniform appearance — The loops and knitting structure
look neat and well-formed.
2. Visible guide bar movement — The guide bar thread usually shows as distinct, well-
aligned loops.
3. More defined stitch pattern — The pattern or design intended by the knitting is
usually clearer on the face side.
4. Shiny or polished look — Sometimes the face side has a slight sheen due to the
tension and thread positioning.

Back Side:

1. Less uniform, rougher texture — The loops may look looser or more irregular.
2. More visible floats or yarns — You might see longer yarn floats (loops that skip
needles) on the back side.
3. Less clear stitch pattern — The design or knitting pattern appears less distinct.
4. Dull appearance — The back side tends to be matte or less shiny.

18. Mention the end products of warp knitting. (22,21)

The common end products of warp knitting:

1. Lingerie and underwear — soft, stretchable fabrics for intimate wear

 2. Sportswear and activewear — breathable and elastic for comfort during physical
activities
3. Swimwear — durable and elastic fabrics resistant to water and chlorine
4. Automotive textiles — seat covers, upholstery with good strength and appearance
5. Home textiles — curtains, upholstery fabrics, and decorative fabrics
6. Industrial textiles — conveyor belts, filtration fabrics, and medical textiles (e.g.,
surgical meshes)
7. Netting and lace fabrics — for fashion, curtains, and decorative uses
8. Elastic fabrics and trimmings — elastic bands, waistbands, and tapes
9. Sports nets and safety nets — used in various sports and safety applications
10. Carpet backings — strong backing fabrics for carpets and rugs

19. Explain the useful elements of Tricot warp knitting machine. (21,19)

Useful elements of Tricot warp knitting machine

1. Compound Needle

• Used to form loops by catching the yarn.

• Helps in producing the knitted fabric.

2. Needle Bar

• Holds all the needles in one line.

• Moves up and down to help the needles form loops.

3. Guide Bar

• Guides the yarn to the needle through small holes.

• Moves sideways (shogging) to create the fabric structure and design.

4. Sinker & Sinker Bar

• Sinker holds down the loops and supports loop formation.

• Sinker bar keeps the sinkers in position and helps them move together.
5. Sliding Latch

• Closes the hook of the compound needle during knitting.

• Helps the needle catch and release the yarn properly.

6. Sliding Latch Bar

• Keeps all sliding latches aligned.

• Moves all latches together while knitting.

7. Cloth Roller

• Rolls the finished fabric smoothly.

• Helps in collecting the knitted fabric.

8. Let-off Mechanism

• Releases the warp yarn from the warp beam.

• Works according to machine speed and fabric take-up.

9. Take-up Mechanism

• Pulls the knitted fabric downward.

• Rolls the fabric on the cloth roller with proper tension.

10. Link

• Part of the pattern system.

• Different thickness of links helps to create different designs.

11. Pattern Chain

• A series of connected links.

• Guides the movement of the guide bar to form fabric patterns.

12. Pattern Drum

• Drives the pattern chain using grooves.
• Gets motion from the machine motor through gears.

13. Comb

• Separates warp yarns like a reed in weaving.

• Helps control the fabric width.

14. Warp Beam

• Supplies warp yarns to the machine.

• Usually, 8 beams are used—4 upper and 4 lower.

15. Machine A/C

• Keeps the motor and machine cool.

• Prevents overheating during long production.

16. Main Shaft

• Transfers motion from the motor to the machine parts.

• Drives the machine.

17. Lubrication System

• Automatically applies oil to moving parts.

• Reduces wear and increases machine life.

18. Controlling Unit

• A digital system to control machine operations.

• Makes handling and monitoring easier.

19. Toothed Belt

• Transfers motion without slipping.

• Keeps machine movements accurate and synchronized.
20. What are the features of Tricot Structures? (21)

Features of Tricot Structures:

1. Fine and Smooth Surface

o Tricot fabrics have a soft, smooth, and silky feel on the front side.
2. Lightweight Fabric
o Suitable for thin, breathable materials.
o Usually made with fine yarns and light construction, ideal for lightweight
garments.
3. Good Dimensional Stability
o Less tendency to stretch out of shape due to the tight and stable structure.
4. Little or No Curling
o Edges do not curl easily, unlike some weft-knit fabrics.
5. Good Drapability
o Tricot fabrics drape well, making them suitable for garments like lingerie,
linings, and sportswear.
6. Limited Stretch
o Has good lengthwise stability, but limited stretch across the width (unless
elastane is added).
7. Suitable for dyeing and printing:
o Smooth surface allows clean prints.
8. Formed by Two Guide Bars
o Typically made using two guide bars, allowing for basic lapping and limited
patterning.
9. Smooth Face, Ribbed Back
o The face side is smooth, and the back shows fine wales (vertical ribs).
10. Used with Filament Yarns

• Commonly uses nylon or polyester filament yarns for a shiny, durable finish.
21. Explain the knitting cycle of the Tricot warp knitting machine equipped
with compound needles. (21)

1. Start of the Knock-over (0°)

• This is the starting position.

• Old loops are about to be knocked over.
• The sinker moves forward to press the fabric down.
• The guide bar begins to shog (move sideways).

2. Swinging through of the guide bars (120°)

• The guide bar swings forward and lays yarn over the needle hook (overlap).
• The needle is open at this point to receive the yarn.
• Shogging movement is complete.

3. Overlapping of yarns (165°)

• The guide bar reaches the frontmost position.

• The yarn is fully wrapped around the open hook.
• This completes the overlap.

4. Swinging back of the guide bars (180°–195°)

• The guide bar swings back to its original position.

• The yarn stays in the hook.
• The needle starts to close by moving the slider forward.

5. Closure of the needle (235°)

• The slider moves inside the groove of the needle, closing the hook and securing the
new yarn.
• The needle begins to move upward.
6. Taking the threads through the old loops (285°)

• The needle rises, pulling the new loop through the old one.
• The old loop is knocked over the closed hook.
• The new stitch is formed.

7. End of swing and start of next knock-over (345°)

• The guide bar shogs to the next needle position.

• Sinkers press down the fabric to hold it in place.
• Machine is ready for the next knitting cycle.

22. Which one you choose between pattern disc and pattern drum as
pattern mechanism and why? (20)

The choice between a pattern disc (flat plate) and a pattern drum/wheel (cylindrical) depends
on production needs, fabric complexity, and machine speed. Here’s a breakdown to help
decide:

A. Choose a Pattern Drum/Wheel If You Need:

1. High Design Capacity – Can store long and complex lapping sequences.
2. Better for Multi-bar Control – Synchronizes multiple guide bars efficiently.
3. Stable at High Speed – Provides smooth, continuous motion in high-speed knitting.
4. Advanced Patterning – Capable of producing lace, net, jacquard, and textured fabrics.
5. Long-Term Efficiency – Better for large-scale production with fewer interruptions.
6. More Precision – Improved pattern accuracy and fabric consistency.
7. Supports Automation – Easily linked with electronic controls or jacquard systems.

Best For:
Factories producing high volumes of simple-to-medium complexity fabrics.
Machines like high-speed tricot or Raschel knitters.
B. Choose a Pattern Disc If You Need:

1. Low Cost – Cheaper to manufacture and replace.

2. Simple Construction – Fewer moving parts; easy to handle.
3. Easy Maintenance – Quick to clean, adjust, or replace.
4. Compact Design – Takes less space inside the machine.
5. Faster Setup for Small Orders – Good for short runs and fast design changes.
6. Suitable for Basic Fabrics – Ideal for plain tricot and simple mesh.
7. Less Training Needed – Easier for operators to understand.

Best For:
Sample development or niche fabrics (e.g., architectural textiles).
Older machines or budget-friendly setups.

23. Explain the features of tricot warp knitting machine. (22,20)

Features of Tricot Warp Knitting Machine:

1. Uses Compound Needles

• Tricot machines mainly use compound needles, which are suitable for high-speed
operations and fine fabrics.
2. High-Speed Operation
• Tricot machines run at very high speeds (up to 3000 rpm), making them suitable for
mass production.
3. Smooth and Fine Fabric
• Produces lightweight, fine, and smooth fabrics like tricot, satin, or mesh structures.
4. Multiple Guide Bars
• Usually contains 2 to 4 guide bars for creating different fabric patterns and
structures.
5. Lapping Movement
• Guide bars perform shogging (side-to-side movement) and forward/backward
lapping for yarn placement.
 6. Small Warp Beams
• Uses smaller warp beams than in weaving, usually arranged in upper and lower
rows.
7. High Production Rate
• Tricot machines are designed for continuous and efficient production with minimal
defects.
8. Digital Pattern Control
• Modern machines include electronic or digital pattern control systems for more
complex designs.
9. Fabric Take-up and Let-off Mechanisms
• Automatically controls fabric winding and yarn release, ensuring proper tension and
uniform quality.
10. Automatic Lubrication
• Has an auto-lubrication system to reduce friction and increase machine life.
11. Cooling System (A/C)
• Equipped with air-cooling units to prevent overheating during continuous operation.
12. Produces Warp Knitted Fabrics
• Commonly used for lingerie, sportswear, curtains, linings, and automotive fabrics.

24. Write short note on Full Tricot structure and Locknit fabric. (20)

Full Tricot Structure:

Full Tricot structure is a warp knitted fabric made using two fully threaded guide bars. Both
guide bars follow a 1-and-1 lapping movement in opposite directions. This produces a
lightweight fabric because the underlaps are very short.

Although the fabric looks attractive and smooth, it is rarely used commercially due to a
major disadvantage. Each wale is only connected to its neighboring wale, If a yarn breaks or a
stitch drops, the fabric splits very easily .
The technical face looks like weft knitted fabric and the technical back shows horizontal
underlaps. The fabric is smooth and soft, suitable for lingerie, linings, etc.

Locknit fabric:

Locknit is the most widely produced warp-knitted fabric, known for its pleasant touch,
elasticity, and lightweight nature. It features a two-guide-bar construction: the front bar
moves two needle spaces while the back bar follows a 1-and-1 lapping movement. The
fabric's free-floating underlaps on the technical back enhance its softness.

Key Characteristics:

• Shrinkage: Contracts to about 2/32/3 of the needle bar width after knitting, influenced
by yarn type and tension.
• Curl: Selvedges may curl toward the technical back but are stabilized during heat-
setting (common for thermoplastic yarns).
• Gauge Trends: Traditionally made on 28-gauge machines, now popular on 32–40
gauge machines for finer fabrics.
• Chain Notation:
 o Front bar: 2−3−2/1−0−12−3−2/1−0−1
o Back bar: 1−0−0/1−2−21−0−0/1−2−2

Locknit’s lightweight, non-splitting nature and versatility cement its status as a staple in
warp knitting.

25. What is pitch? (20)

In warp knitting, pitch refers to the distance between two adjacent needles on the needle
bar of a knitting machine. It is a critical parameter that determines the fineness (gauge) of
the fabric and influences stitch density, fabric weight, and overall structure.
26. Compare between tricot and raschel warp knitting machine. (20)

Point Tricot Machine Raschel Machine

In the past, bearded needle was

used but now a days compound Rachel machine used latch needle.
needle used.

Gauge expressed in needles per Gauge expressed in needles per 2

inch inches

Chain link numbering: even numbers

Chain link numbering: 0, 1, 2, 3...
(0, 2, 4...)

Warp sheets pass over the top

Warp sheets pass below the guide bar
of the guide bar rocker shaft

Guide bars numbered from Guide bars numbered from front to

back to front back

Makes heavy, openwork or coarse

1. Fabric type Makes lightweight, fine fabrics
fabrics

2. Needles used Uses latch needles

3. Guide bars Usually has 2 to 4 guide bars Can have 2 to 48 guide bars

4. Fabric
Smooth, fine surface Rougher, open or mesh-like surface
appearance

5. Patterning Limited patterning (simple Can produce complex patterns, lace,

ability designs) nets

6. Speed Runs at higher speeds Runs at lower speeds

High-speed production, due to Low-speed production, due to complex

simple design. design

Often used for narrow or shaped

7. Fabric width Mostly used for wider fabrics
fabrics
27. Define Knitting. Differentiate between warp knitting and weft knitting.
(23,22,21,19,20)

Knitting is a method of fabric formation where yarn is interlooped to form a fabric structure
using needles.
It produces stretchy and soft fabrics and is widely used in making garments like t-shirts,
sweaters, socks, etc.

Aspect Weft Knitting Warp Knitting

Yarn Direction Yarn runs horizontally (weft-wise) Yarn runs vertically (warp-wise)

Yarn Feed A single yarn can feed many needles Each needle gets a separate yarn

Loop Formation Loops made across the width Loops made along the length

Stretchable to the width wise. Stretchable to the length wise.

Higher shrinkage. Less shrinkage.

All types of design is complex. Any design is done easily.

Most of the weft knitting is of tubular

Warp knitted fabric are flat or open w
form.

Dimensional stability of the fabric are

Dimensional stability of the fabric are
lower.

Unraveling Easily unravels if a loop breaks Does not unravel easily

Machine Type Used in circular or flatbed machines Used in tricot or raschel machines

Fabric Type Stretchy, soft and elastic Stable, less stretch

Speed Also fast, especially in circular machines Very high-speed production

Common Products T-shirts, sweaters, socks, scarves Lingerie, nets, sportswear

28. Show the types of chain link. (20)

Types of chain link in warp knitting: There are 4 types of chain link.

1. Unground

2. Fork end ground

3. Tail end ground

4. Both end ground

29. Show the basic five types of overlap or underlap variations. (20)

In warp knitting, overlap and underlap refer to the movement of the guide bars and yarn
over the needles. These movements determine the fabric structure. Here are five basic
variations of overlap and underlap:

1. An overlap followed by an underlap in the opposite direction (closed lap)

• Overlap: Full loop formation around the needle

• Underlap: Yarn moves behind to the next needle
• Effect: Strong and stable fabric (e.g., Tricot)
2. An over lap followed by an underlap in the same direction (open lap)

• Overlap: Yarn partially overlaps the needle

• Underlap: None or very short
• Effect: More open and stretchable fabric

3. Only overlaps and no underlaps (open laps).

• Overlap : All loops are overlaps

• Underlap : no underlap
• Effect: More open and less stable

4. Only underlaps and no overlaps (Laying-in).

• Overlap: None
• Underlap: All loops are underlaps.

5. Neither overlaps nor underlaps (Miss-lapping).

• Overlap: None
• Underlap: None
30. Explain the swinging and shogging mechanism of the guide bar. (20)

Swinging Motion (Definition):

Swinging motion is the arc-like forward and backward movement of the guide bars. It
helps the yarn go around the needle to make loops.

Mechanism

• The guide bars move in front of and behind the needles like a swing.
• This movement helps form the loop on the needle.
• The swinging action is fixed and collectively applied to all guide bars.
• All guide bars swing together at the same time.
• The motion is derived from the main camshaft, just like the needle and sinker motions.
• The movement comes from the main camshaft using levers and rods.
• It creates the two side parts of the loop.

Shogging Motion (Definition):

Shogging motion is the side-to-side/sideways movement that occurs parallel to the needle
bar produces the underlaps and overlaps.
Mechanism :

• Each guide bar can move side to side in a different way.

• This side movement is called a shog.
• The time, direction, and distance of each shog is controlled separately for each guide
bar.
• This control comes from a pattern chain or pattern wheel.
• These parts are connected to a horizontal pattern shaft, which is driven by the main
camshaft of the machine.

Types of Shogging Motion

Positive Shogging:

• Here pattern wheel pushes the guide bar away from the pattern mechanism.
• Movement is active and forced outward.

Negative Shogging:

• The pattern wheel pulls the guide bar toward the pattern mechanism.
• Movement is inward, controlled by pulling action.

31. What are the basic elements of tricot warp knitting machine? Describe
the function of guide bar. (19)

A Tricot warp knitting machine consists of several key elements that work together to
produce warp-knitted fabrics. The basic elements include:

Useful Element and functions of different parts of a Tricot warp knitting machine

1. Compound Needle: In Tricot warp knitting machines, compound needles are used.
Their main function is to form loops by receiving yarns from the guide bar, which leads
to fabric production.
2. Needle Bar: The needle bar holds all the needles in alignment and helps them move
together in synchronization during loop formation.
3. Guide Bar: The guide bar directs the warp yarns properly to the needles. It feeds yarn
around the needle and performs lapping movements that control the fabric structure
and regulate the warp feed rate from the warp beam.
4. Sinker and Sinker Bar: The sinker holds down the loops formed by the needles and
helps in knocking over the old loops. The sinker bar ensures all sinkers move together
during knitting, providing proper support to the fabric.
5. Sliding Latch: Since compound needles are used, a sliding latch mechanism is applied
to close the hook of the needle during the loop formation process.
6. Sliding Latch Bar: The sliding latch bar holds all sliding latches together and enables
their synchronized movement during the knitting cycle.
7. Cloth Roller: This part winds the knitted fabric after it is formed, ensuring smooth and
continuous take-up of the produced fabric.
8. Let-off Mechanism: The let-off mechanism controls the release of warp yarns from the
warp beam based on the knitting speed and requirement of the machine.
9. Take-up Mechanism: It draws the knitted fabric downwards and rolls it onto the cloth
roller under proper tension. It also plays a role in maintaining warp sheet tension and
controlling warp beam speed.
10. Link: In the pattern mechanism, different links are used to form fabric designs. The
thickness of the links determines the extent of guide bar movement and thus helps to
produce various patterns.
11. Pattern Chain: The pattern chain is formed by connecting several links. It governs the
lateral (shogging) motion of the guide bars to create the desired design on the fabric.
12. Pattern Drum: This drum contains grooves to carry the pattern chain. It drives the
pattern chain and receives motion from the main motor via a gear system.
13. Comb: The comb separates individual warp yarns as they come from the beam. It acts
like the reed in a weaving machine and also helps control the width of the knitted
fabric.
 14. Warp Beam: The warp beam supplies the warp yarns in a parallel manner. Tricot
machines usually have 8 warp beams, 4 placed on the upper side and 4 on the lower
side, and they are smaller than typical weaver's beams.
15. Machine A/C: A cooling unit that prevents the machine and its motor from overheating
during long or continuous operation.
16. Main Shaft: The main shaft transmits driving motion from the motor to various moving
parts of the machine.
17. Lubrication System: The machine is equipped with an automatic lubrication system
that ensures smooth and wear-free operation of moving components.
18. Controlling Unit: A digital control unit that allows operators to easily manage machine
settings, monitor performance, and handle different fabric patterns.
19. Toothed Belt: Toothed belts are used to transfer motion precisely and without
slippage, ensuring synchronized operation of different machine parts.

Function of Guide Bar in Tricot Warp Knitting Machine:

The guide bar is one of the most critical elements in warp knitting.
Functions:
1. Yarn Feeding:
o Carries and guides the yarns to the needles through holes in each guide.
2. Lapping Movement:
o Moves side-to-side (shogging) and forwards/backwards to wrap yarn around the
needles, forming loops and overlap/underlap patterns.
3. Pattern Formation:
o Controls the design of the fabric (like tricot, atlas, or satin) through specific
lapping motions.
4. Stitch Construction:
o Helps in forming chain links, open loops, and other warp knit structures.
5. Yarn Control:
o Keeps the yarn at the proper tension and path during loop formation.
32. Illustrate the main features of different types of atlas stitches in warp
knitting with lapping diagram and chain notation. (19)

An atlas stitch is a loose, open structure formed by a combination of open and closed
laps. The guide bar laps in one direction for a few courses, then reverses and laps in the
opposite direction — giving the fabric a diagonal or zigzag effect.

The structure is formed by the combination of open and close laps.

a) Tricot atlas: Two course tricot atlas

• Three course tricot atlas

b) Cord type atlas: This type atlas is form on the basis of cord stitch.--5 wales and 4 course in
repeat .

C) Satin type atlas: On the basis of satin stitch principle

--7 wales and 4 course in each repeat

D) Velvet type atlas: On the basis of velvet stitch principle

--In each repeat at least 9 wales and 4 course

33. Which one you choose between pattern disc and pattern drum as
pattern mechanism and why?

In warp knitting machines, both pattern disc and pattern drum are used to control the
lateral movement (shogging) of the guide bars to produce different fabric designs. However,
their working principles, flexibility, and application areas differ significantly.

The pattern disc (also known as a pattern chain plate) is a simple mechanism made up of a
series of interconnected links or cams. Each link corresponds to a specific guide bar
movement. It is suitable for producing simple, repetitive patterns such as those used in
basic tricot fabrics. Although this mechanism is cost-effective and easy to operate for limited
designs, it has significant limitations. One major drawback is that it can store only short
pattern repeats, and changing the pattern requires manual replacement of the chain links,
which is time-consuming and labor-intensive.

On the other hand, the pattern drum (or pattern wheel) is a more advanced and flexible
mechanism. It can control longer and more complex lapping movements, making it ideal
for producing decorative, lace, or technical fabrics. Modern pattern drums often come with
electronic control systems, allowing for quick pattern changes without manual
adjustments. This makes the pattern drum especially suitable for high-speed production and
fabrics that require frequent design variation. It also reduces downtime and improves
productivity.
Considering these points, the pattern drum is generally the better choice in today’s warp
knitting industry. It supports automation, handles complex patterns efficiently, and offers
greater flexibility in production. Therefore, for most applications — especially where design
complexity and speed are essential — pattern drum is preferred over pattern disc.

34. What is chain link? State different chain link with sketch. (19)

Types of chain link in warp knitting: There are 4 types of chain link.

1. Unground

2. Fork end ground

3. Tail end ground

4. Both end ground

35. Draw and describe the stitch formation cycle of Raschel warp knitting
machine with compound needle. (19)

The knitting action of Rasche! machine equipped with compound needles is different from
that of a Tricot machine. In the following series of figures, the loop formation sequence of a
multibar Rasche! machine is described and it is important to note the following points:

• The sinker bar is stationary,

• The guide bars do not swing, and
• The swinging movement is made by the needle bar, closing element bar and trick
plate.
The sequence can be described as follows:

1. The needles are at knock-over position, after the completion of the previous
course.
2. The needles rise through the loops of the previous course. The closing elements
stay down so that the hooks are opened.
3. The needles are in the clearing position with the previous loops resting on the
stem. Underlap shagging movement is now completed.
4. The needle bar, closing element bar and trick plate swing to the front of the
machine.
5. The needle bar, closing elements bar and trick plate swing back, so that the guides
move between the needles to the back. The needles can start to descend when the
ground bars are at the back.
6. Both needles and closing elements descend simultaneously and maintain a closed
hook. The old loops slide outside the closing elements.
7. The needles draw the newly wrapped loops through the previous loops. The swing
movement is nearly finished and the guide bars continue to shog the underlap
lateral movement
36. Show the notation diagram and chain notation of tricot, locknit, shark
skin and queens cord fabric. (19)

Notation diagram and chain notation of tricot fabric:

The chain notations are: Front bar: 1- 0 / 1- 2

Back bar: 1- 2 / 1- 0

Notation diagram and chain notation of locknit fabric:

Front bar: 2 - 3 - 2 I 1- 0 - 1

Back bar: 1- 0 - 0 / 1- 2 - 2
Notation diagram and chain notation of sharkskin fabric:

Front bar: 1- 2 - 2 / 1- 0 - 0

Back bar: 1- 0 - 1 / 3 - 4 - 3

Notation diagram and chain notation of Queenscord fabric :

Front bar: 1-0/ 0-1

Back bar: 3-4/ 1-0

37. Describe swinging and slogging movement. (19)

Swinging Movement

Definition:

The swinging movement is the forward and backward motion of certain machine parts to
help position the yarn in front of or behind the needles.

In Raschel Machines:

• Performed by the needle bar, closing element bar, and trick plate (not the guide
bars).
• Allows the guide bars to reach between the needles and lay the yarn in position.

In Tricot Machines:

• The guide bars perform the swinging movement.

• They swing forward (to lay yarn in the needle hook) and backward (to clear the
needles).

Purpose:

• Helps in placing the yarn properly in relation to the needle.

• Supports loop formation and yarn wrapping.

Shogging Movement

Definition:

The shogging movement is the side-to-side (lateral) movement of the guide bars across
the needle bed.

What It Does:

• Controls how yarn moves across the wales (columns).

• Creates different stitch types: overlap, underlap, closed lap, open lap, etc.
Types:

• Overlap Shogging: Yarn laid in front of the needle (forms main stitch).
• Underlap Shogging: Yarn moves behind the needle (connects stitches between
courses).

Purpose:

• Builds the fabric structure by controlling the yarn path.

• Defines the design and openness of the knitted fabric.

38. Illustrate various types of atlas stitches with chain notation. (19)

Same as 32 .

39. State the basic rules for plotting a lapping diagram. (19)

Same as 3.

40. Explain the main features of reverse locknit, sharkshin and queen's cord
fabric with lapping diagram and chain notation. (19)

1. Reverse Locknit
Structure Type:

• Warp knitted fabric made using two guide bars (usually GB1 & GB2)
Main Features:
• Made by reversing the overlap movement of a normal locknit.
• Produces a vertical stripe effect on the face of the fabric.
• The back side looks like locknit (slightly rough or textured).
• Slightly more open structure than locknit.
Front bar: 1- 2 - 2 / 1- 0 - 0

Back bar: 1- 0 - 1/ 2 - 3- 2
2. Sharkskin (Sharkshin)

Structure Type:

• Created using two guide bars (commonly)

Main Features:

• Has a diagonal twill-like appearance on the face.

• The surface of the technical back is rough which is probably the reason for the name
sharkskin.
• Named "sharkskin" because the surface resembles a fine diagonal grain, like a
shark’s skin.
• More compact than reverse locknit.

Front bar : 1-2-2 / 1-0-0

Back bar : 1-0-1 / 3-4-3

3. Queen’s Cord

Structure Type:

• A more decorative warp knit structure, often using two or more guide bars
Main Features:

• Has a cord-like, raised effect running vertically.

• Looks like small ropes or cords on the fabric surface.
• Made by combining specific overlap and underlap movements to create texture.
• Heavier and thicker than locknit or sharkskin.

Front bar: 1-0/ 0-1

Back bar: 3-4/ 1-0