6 Types of Calendering Process in Textile !
Calendering, the temporary finish is given to the fabric in the presence of high temperature, heavy pressure and a suitable degree of dampness. No matter you want a smooth, glossy, silky touch and highly lustrous fabric, it is easy to achieve with calendaring process.
In this article, we cover different types of calendering process. It you are interested about it, just go through the content.
Different Types of Calendering Process
Different types of finishes are carried out in the factory to make the fabric marketable. But Calendering process, the temporary finish is the most common in textile industry. Find out 6 types of calendering process below!
- It is a British term
- Denote that fabric runs through all the nips and then either plaiting or batching
- Usually consists of 7-10 bowls
- All bowls rotate at same speed
- Softening and filling agents should be applied to produce lustre
- It gives close inter stiches, smooth appearance and gloss without high glaze (which we get from friction calender)
- Smoothness and lustre are increased with the increase of bowl temperature (150-180°C)
- Uniform calendaring is obtained
- Remove wrinkles and creases
- Smooth fabric surface can be obtained
- Very high glossy fabric is achieved
- No risk of displacing of fabric
- It is similar with swizzing calender
- 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 and entering into the nip again
- At this the weft of one layer will lie in between two adjacent wefts of the next layer and give additional pressure
- Roller pressure and this additional pressure soften the fabric and gives a linen appearance (soft feel)
- Gives very smooth linen appearance
- Produce soft handle
- More the fabric is passed, more the glazy appearance is achieved
- Removes wrinkles and creases
- Friction calender 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 lustre at one side and gets similar effect to ironing with hot air
- It is generally 3 bowl m/c
- Middle bowl is made with polished iron, heated and speed is more than its bottom roller
- Pressure between bottom two bowls are more depending on the amount of starch and moisture in the fabric, the starch deposited on the fabric varies
- If MC> 20%, starch sticks to bowl and if it is <15%, no lustre is produced
- Generally a friction calender runs at 31.5 m/min
- Highly lustrous, glossy surface, heavy closing up of threads, iron effect can be achieved
- It is mainly used for share, lungi, bed sheet etc
- Produce more smooth, glossy and higher lustrous appearance
- Fabric thickness reduced
- Heavy close up of threads
- Remove crease and wrinkles
- Suitable for finishing of highly glazed linings, prints etc
- A compaction calender has an adjustable gap between the pattern roll and bowl
- Nip point between two rollers is controlled according to design to control thickness
- Produce filter media of certain thickness
- A special type of calendaring machine
- Generally 2-3 bowls m/c
- Middle one is engraved according to design feature
- The other bowls are soft like cotton bowl so that it can accept the embossing pattern
- Diameter of metallic bowl is more than half (20 cm diameter) than the compressed bowl (60 cm diameter)
- Small roll provide sharper and a deep embossing effect
- Fabric is deformed according to definite design by pattern roller and both the rolls may be heated
- Used for thermoplastic fiber
- This finish may be temporary or permanent
- Raised design effect or pebble or crepe effect can be achieved
- Crepe or pebble effect is produced
- Temporary or permanent effect may produce.
- Mercerized cotton with starch (semi-permanent finish) or resin (melamine resin) for permanent embossing finish.
- For thermoplastic fiber, this effect can only be achieved by 190-220°C temperature
- For acetate, 190-210°C is required.
- Due to smaller metallic bowl, it is cheap
- Cotton fabric is given a silk like brilliance through this process. This is operated on sateen, cotton linings and printed fabric
- A fine linen engraved pattern roller is used
- A soft lustrous handle can be achieved by choosing correct cloth construction and the correct linen direction of the engraving
- Approximately 250 to 350 lines per inch can be seen on schreiner steel bowl
- The cut lines may be rounder or sharp
- The cross-section of engraving is either a v-shape (high lustrous) or u-shape (low lustrous)
- Angle of the line 200-300°C
- 15-19% moisture content, 120-160°C temperature, 3.5-5 bar pressure and 2-10 m/min will give silk finish to cotton goods
- Gives silk like appearance to cotton
To Wrap Up!
Calendering plays an important role in the appearance of the final fabric. It increases the marketability of the fabrics. You can check out: 10 Facts about calendering process in Textile!
We have gather a lot of information about Calendering. So, Let’s check out how it is carried out in Textile Industry:
Video Source: Easy Concept
I would like to more about Friction Calendering and Schriener Calendering. Can i have a discussion through email? Pls advise.