Calendaring Finish

Md. Sherazul Islam

Lecturer
Department of Textile Engineering
Green University of Bangladesh
Calendaring
Calendaring may be defined as the modification of the surface of the fabric by the action of time,

temperature, pressure and dampness. The finish is obtained by passing the fabric between heated

rotating rollers, where both speed of rotation and pressure applied are the variables. The rotating roller

surface can be either smooth or engraved to provide appropriate finish to fabric. These rotating rollers

may be made of various materials from hard steel to elastic thermoplastics.

Calendaring
Objectives of Calendaring

 To produce a smooth, glossy and highly lustrous appearance on the surface of the cloth.

 To reduce fabric thickness.

 To reduce air permeability and water permeability of fabric by changing its porosity.

 To reduce yarn slippage.

Process of Calendaring
Essential Elements of Calendaring

The following 3 elements should be controlled during calendaring namely:

 High pressure

 High temperature

 Suitable degree of dampness.

Damping
To prepare the cloth for finishing operations, conditioning machine is useful in restoring the

moisture content of the goods before making up and hence improving the handle and appearance.

Damping can be done in 3 ways: -

 By brush damping machine.

 By spray damping machine.

 By steam.
Brush Damping Machine
Working Principle & Construction

 There is a brush made of fibers, bristles and copper spikes in this machine.

 The brush rotates at high speed in contact with water in a trough.

 The cloth passes over usual tension rails, and guide rollers to the position above the water trough.

 The water in spray form falls on the passing due to centrifugal force produced by high speed of brush

roller.

 The fabric then passes round draw drawn over a pressing roller which forms a nip to the batching

apparatus or plating device.

Brush Damping Machine
Brush Damping Machine

Regulating points

 Adjusting the level of water in the through by a over flow pipe.

 Adjusting the opening of the top of the box by using lid. For heavy fabric the lid should more

open and for fine fabric less open.

 Adjusting the speed of brush roller.

 Adjusting the speed of fabric passing.

Spray Damping Machine
Working Principle with Construction

 The no of nozzles which are essential parts of this machine, varies according to the width of

machine.

 Nozzles are attached to a common feed pipe which supplies water under pressure.

 The feed pipe and nozzles are enclosed in a wooden box.

 An inclined disc is arranged in the front of the nozzle inside the box.

 Due to high pressure, water discharges through the nozzle on the disc and from there the fine

droplets of water deposits on the cloth which passes over the box at a suitable distance.
Spray Damping Machine
Spray Damping Machine

Regulating Points

 Adjustable lid is fixed inside the wooden box which permits the amount of damping.

 The automatic device is provided to stop spraying immediately when the m/c stops.

 Material speed is controlled.

Damping by Steam
This is not a separate damping m/c. In this method fabric passed between two perforated steam

pipes which are placed in the entry zone of the calendaring m/c.
Calendar

A calendar is a machine consisting of two or more massive rollers which are compressed by means of

hydraulic or pneumatic pressure and having high temperature.

Perhaps the most important factor in calendar design is the composition of the rollers and the surface

characteristics of the rotating rollers. One roller is considered as the pattern roller and is responsible

for the finished appearance of the fabric; while the other roller is called bowl and serves to

transport the fabric through the machine. Number of bowls is 2-7.

Calendar

Normally number of bowls is 3, 5 or 7, with the most common being the three-bowl calendar.

Number of bowls are more for heavy or jute fabric.

Two types of bowls are used-

1. Metallic (1/2-inch metal wire on bowl)

2. Compressed material (1/2-inch rubber or synthetic leather on bowl)

Types of Calendaring

Different types of calendaring machine are-

 Swizzing Calendaring

 Chasing Calendaring

 Friction Calendaring

 Embossing Calendaring

 Compaction Calendaring

 Schreiner/Silk Calendaring
Swizzing Calendaring
Features

 It is a British term.

 Denotes that fabric runs through all the nips and then either plaiting or batching.

 It usually consists of 7-10 bowls.

 All bowls rotate at the same speed.

 Softening and filling agents should be applied to produce luster.

 It gives smooth appearance and gloss without high glaze.

 Smoothness and luster are increased with the increase of bowl temperature.
Swizzing Calendaring
Swizzing Calendaring
Advantages

 Uniform calendaring is obtained.

 Removes wrinkles and creases.

 Smooth fabric surface can be obtained.

 Very high glossy fabric is obtained.

 No risk of displacing of fabric.

Chasing Calendaring
Features
 It is similar with swizzing calendar.

 5-7 rolls are needed & all of them rotate with same speed.

 The major difference is the cloth makes several passage through the nips before it exits to a
take-up roll.
 The cloth is compressed as 5-6 layers being superimposed & entering into the nip again.

 At this the weft of one layer will lie in between two adjacent wefts of the next layer & give
additional pressure.

 Roller pressure & this additional pressure soften the fabric & gives a linen appearance (soft
feel).
Chasing Calendaring
Chasing Calendaring

Advantages

 Gives very smooth linen appearance.

 Produce soft handle.

 More the fabric is passed, more the glazy appearance is achieved.

 Removes wrinkles & creases.

Friction Calendaring

Features

 Friction calendar apply friction force to the face of the fabric.

 Friction is done by driving the pattern roll faster (5-10%) than the support bowl.

 Here, strong fabric is needed to withstand the strain.

 Friction produces a high degree of luster at one side and gets similar effect to ironing with hot air.

 It is generally a 3 bowl machine.

 Middle bowl is made with polished iron, heated and speed is more than its bottom roller.

 Pressure between bottom two bowls are more.

Friction Calendaring
Friction Calendaring

Advantages

 Produces smooth, glossy and highly lustrous appearance.

 Fabric thickness is reduced.

 Remove crease and wrinkles.

 Suitable for finishing of highly glazed linings, prints, etc.

Embossing Calendaring

Features

 A special type of calendaring machine. Generally, 2-3 bowl machine.

 Middle one is engraved according to design.

 The other bowls are soft (e.g. cotton bowl) so that it can accept the embossing pattern.

 Diameter of compressed material bowl is about three times than that of metallic bowl.

 Small roll provide sharper and a deep embossing effect.

 Used for thermoplastic fiber.

 This finish may be temporary or permanent.

Embossing Calendaring
Embossing Calendaring
Embossing Calendaring
Advantages

 Crepe of pebble effect is produced.

 Temporary (cotton) or permanent effect may be produced .

 Due to smaller metallic bowl, it is cheap.