Calendering object
To upgrade the fabric handle and co
impart silky touch to the fabric.
To compress the fabric and reduce its thickness.
To improve the Opacity of the fabric.
To reduce the Air Permeability of the fabric by changing its porosity.
To impart different degree of Luster to the fabric.
To reduce the Yarn Slippage.
7 Bowl calender or ordinary calendar
It is one type of calendering
machine
In a typical 7 bowl calendar, the arrangement of the bowl is shown below
The calendering effect produced depends on the
1) The moisture content of the fabric
2) The number of bowls used in the calender.
3) The composition of the bowls.
4) The arrangement of bowls
5) Temperature.
6) Pressure.
7) Speed of the machine.
Generally the compressed material bowls are made from either Cotton or
Wool paper, Linen pager or Flax paper.
The hard bowl is made up of either Chilled Iron or Close Crained Cast
Iron or Steel.
Iron bowls are made with highly polished
surface and by steam or gas.
The fabric is passed through the
machine in between are the bowls and as the result Gloss is developed in the
calendered fabric.
They run at a speed of 8 mats/min.
In this machine, there are 5 iron bowls
and 4 cotton. In between two metallic bowls, one cotton bowl is arranged
Care should be taken in such a way
that no two iron bowl together to avoid damage to the fabric.
Sufficient pressure is employed by either weighting the rollers with heavy
weights or by spring weighing or by Hydraulic pressure weighing.
Normal speed is 60 to 80
yards/min.
The normal pressure is 40 to 60 tons.
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