Knitting terms and definition

Fabric forming process

Weaving is the interlacement (Fig.a) of two sets of threads (i.e. warp and weft) at a right angle. Interlooping
(Fig.c) consists of forming yarn(s) into loops, each of which is only released after a succeeding loop has been
formed and intermeshed with it.

Includes a number of techniques, such as braiding and knotting, where threads are caused to intertwine (Fig.c)
with each other at right angles or some other angle.

Knitting :

Knitting is a process of fabric forming by the intermeshing the loops of yarns. When one loop is drawn through
another, loops are formed in horizontal or vertical direction.

Types of Knitting

There are two of knitting-

1. Weft knitting

2. Warp Knitting

Weft knitting :

Weft Knitting is a method of forming a fabric in which the loops are made in horizontal way from a single
yarn and intermeshing of loops take place in a circular or flat form on across wise basis.

Warp Knitting :

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Warp Knitting is a method of forming a fabric in which the loops are made in vertical way along the length of
the fabric from each warp yarns and intermeshing of loops take place in a flat form of length wise basis.

Classification of weft knitting machinery

Course & Wales

Course:

The series of loops those are connected horizontally, continuously are called as course. The horizontal row
of loops that are made by adjacent needles in the same knitting cycle.

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Wales:
The series of loops that intermeshes vertically are known as Wales. Vertical column of loops that are made
from same needle in successive knitting cycle

Features of wales

 When loop transfer occurs, it is possible to transfer a wale of loops from one needle A to another B.

 In warp knitting a wale can be produced from the same yarn if the same warp guide laps the same
needle at successive knitting cycles.

 Wales are connected together across the width of the fabric by sinker loops (weft knitting) or underlaps
(warp knitting).

 Wales show most clearly on the technical face and courses on the technical back of single needle bed
fabric.

Parts of a loop

Each knit stitch (knit loop) is a basic unit for the knitted goods.

H: Head or Crown or top arc

L: Side limbs or Legs

S: Bottom arc or Sinker loop

→Needle loop=H+2L

→A complete loop=Needle loop+Sinker loop

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Needle loop:

Needle loop is the upper part of the

loop produced by the needle drawing
the yarn.

Sinker loop:

The lower part of the knitted loop is

technically referred as sinker loop. It
is the connection of two legs
belonging to neighboring stitches
lying laterally.

Open loop:

The open loop is one in which the loop forming yarns do not cross at the bottom of the loop.

Closed loop:

In closed loop the legs cross at the bottom, so that the loop closing takes place.

Face loop and technical face

Face loop:

During loop formation,

when the new loop
emerges through the old
loop from back to the face
side then it is termed as
face loop or weft knitted
loop.

Technical face:

The side of the fabric

which contains all face
loops or weft knit loops is
known as technical face.

Back loop and Technical Back

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Back loop:

During loop formation, when the new loop passes from the face side to the back of the previous loop then it
is termed as back loop or purl loop.

Technical back:

The side of the fabric which contains all back loops or purl loops is known as technical back.

Knitted stitch

The knitted stitch is the basic unit of intermeshing. It usually consists of three or more
intermeshed needle loops. The centre loop has been drawn through the head of the
lower previously-formed loop and is, in turn, intermeshed through its head by the loop
above it.

Stitch length

 The length of yarn required to produce a complete knitted loop (i.e Needle loop and sinker loop) is
known as stitch length or loop length.

 Stitch length is a length of yarn which includes the needle loop and half the sinker loop on either side
of it.

 Generally, the larger the stitch length, the more extensible and lighter the fabric and the poorer the
cover and bursting strength.

A course length

In weft knitted fabrics, a course of loops is composed of a single length of yarn termed a course length.

Definition: The length of yarn required to produce a complete knitted course is known as course length.

Course length= No. of loops per course X Stitch length

Course length= No. of needles X Stitch length

Stitch density

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Stitch density refers to the total number of loops in a measured area of fabric. It is the total number of needle
loops in a given area (such as a square inch

Stitch density= Wales density x Courses density

=Wales per inch X Courses per inch

= WPI X CPI

Unit: number of loops per square inch

Or, SD= CPC x WPC (cm scale)

GSM

GSM means gram per square meter. It is a number which indicates the thickness of knit fabric. GSM is directly
proportional to the fabric thickness. GSM depends on yarn count, density of needle, wales per unit length and
course per unit length.

Actual width

The distance between the first and last needles in flat needle bed during knitting action is known as actual
width.

Working width

The distance among the first and last needles in a flat needle bed id termed as working width.

Working diameter

The diameter of knitting machine is measured at the bottom of two opposite needles grooves in a cylinder or
at the top of two opposite needles in a circular bar is termed as working diameter.

Technically upright

A knitted fabric is technically upright when its courses run horizontally and its wales run vertically, with the
heads of the needle loops facing towards the top of the fabric and the course knitted first situated at the bottom
of the fabric.

Fabric draw-off

The fabric loops are always drawn from the needles on the side remote from their hooks. When two sets of
needles are employed, the fabric will be produced and drawn away in the gap between the two sets.
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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Single jersey & Double jersey

Single jersey or plain fabric: The weft knitted fabric (Tubular/flat) which is produced by one set of needles.

Double jersey: The weft knitted fabric (Tubular/flat) which is produced by two sets of needles.

Needle bed or needle carrier

Needle bed or needle carrier is the place where the needles are located or mounted in a knitting machine.
Needle moves up and down in the trick of a needle carrier.

Two types of needle carrier:

1. Cylindrical or circular

2. Flat

Cylinder and Dial

Cylinder:

 Cylinder is a circular steel bed having grooves / tricks /cuts on it’s outer periphery into which the
needles are mounted.

 With reference to the tricks, the needles move vertically up and down by their butt being in contact
with the cam track.

 The diameter of the cylinder also varied based on the type and width of the fabric.

 Maximum diameter of the cylinder: 46 inches.

Dial:

 Dial is the upper steel bed used in double knit circular machines.

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
  Into the grooves of the dial, the needles are mounted horizontally and are allowed to move radically in
and out by their dial cams.

 The number of grooves per unit space conforms with the cylinder gauge in most of the cases.

Machine gauge or Needle gauge

The number of needles in one inch of a needle bed is called machine gauge. It is denoted by G, or E. 2.5E
means that there are 2.5 needles per inch on the needle bed of the knitting machine.

Needle pitch

The distance between two neighboring needles Space required for each needle.

Feeder

Feeders are the yarn guides placed close to the needles to the full circumference of the knitting zone. The
feeders feed the yarn into the needle hooks and control the needle latches in their open position while the
needle attain their clearing position.

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
VDQ Pulley

VDQ means Variable Dia for Quality. Because this kind of pulley controls the quality of knitted fabric by
adjusting GSM and stitch length during the knitting process, it is called VDQ pulley. To increase fabric GSM,
the pulley is moved in the positive direction, and to decrease fabric GSM, the pulley is moved in the reverse
direction. This pulley is also known as a quality adjustment pulley (QAP) or quality adjustment disk (QAD).

Yarn feeding process in knitting machine

In a knitting cycle, yarn feeding is commonly fed at the same time as the needle is raised for clearing and the
hook is open. For non-stop knitting, yarn is to be supplied or fed to the needles or to the knitting zone
continuously. In weft knitting, yarn is usually provided from cones or other appropriate yarn packages located
in a creel.

The principals involved in supplying yarn may be summed as follows:

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
  Negative feeding
 Positive Feeding

Negative feeding

Yarn is pulled through the needles directly from the package through
guides, tensions, etc. It does now not require any extra attachment as
yarn is drawn automatically due to the knitting process. This
approach does not maintain uniform yarn tension. But it can easily
alter and deal with the difference in stitch cam setting in different
feeds

Positive feeding

In the case of positive feeding, the yarn is first

measured as required and then supplied to the
needle or knitting zone. This technique allows
equal lengths of yarn to be supplied to all feeds
and maintains uniform tension of the input yarn.
The result is a uniform loop length and better
fabric quality.

Basic Knitting elements

There are 3 Basic Knitting elements. They are:

1. Needle

2. Sinker

3. Cam

Needle:
Function of Needle: Needle is raised to clear the old loop from the hook & to receive the new loop above it
on the needle stem.

Types of Needle: In general there are 3 types of needles. They are

1. Latch needle

2. Breaded needle

3. Compound needle
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Md. Yousuf Ali, Assistant Professor, TE, BUBT
According to the butt position latch needles are 4 types:

1. One butt latch needle

2. Two butt latch needle

3. Three butt latch needle

4. Four butt latch needle

CAM:
Cams are the device that convert the rotary drive into a suitable reciprocating action for the needles or other

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Md. Yousuf Ali, Assistant Professor, TE, BUBT
elements.
Types of cam: There are 2 types of cam. They are:

· Engineering cam

· Knitting cam

1. Knit cam

2. Tuck cam

3. Miss cam

Function of cam: The function of cam is given below

1. Produce motion of needles

2. Drive the needle

3. Formation of loop

Sinker:
This is the secondary knitting element. It is a thin metal plate with an individual and collective action
approximately at right angles from the hook side between adjoining needles.

Function of sinker: The functions of sinker are given below:

1. Loop formation

2. Holding down

3. Knocking over
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Md. Yousuf Ali, Assistant Professor, TE, BUBT
Model Questions

Q1. Define stitch, stitch density, wale, course and course length with figures.
Q2. Write the functions of needle, sinker and cam.
Q3. Draw the schematic diagram of various types of knitting cam.
Q4. Draw the schematic diagram of various types of needles. What are the methods of yarn feeding? Discuss
in brief.
Q5. Show the elements of knitted loop structure.
Q6. Draw and describe the different parts of a latch needle.
Q7. Give the functions of the following machine parts: Cam, Spreader, VDQ pulley, Dial.
Q8. State the classification of weft knitting machinery.
Q9. Define the following terms: Face loop, Working width, Needle gauge and Stitch length.
Q10. Draw the back side of a single jersey structure and mention the course and wales directions.
Q11. Classify weft knitting machines.
Q12. Describe different types of cam in a cam system with suitable sketch.
Q13. Differentiate between face loop and back loop with figure.
Q14. What is the principle knitting element?
Q15. Draw and describe the different parts of latch and bearded needles.
Q16. What is pitch and what do you mean by 2.5E?
Q17. Classify circular knitting machine.
Q18. What are the identification features of face loop and back loop? Explain with figure. What is the principal
knitting element? Draw and describe the different parts of latch and compound needles.
Q19. What is pitch and what do you mean by 3.5E?
Q20. Draw and describe different parts of a Latch needle.

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Md. Yousuf Ali, Assistant Professor, TE, BUBT