Fabric thickness :
Thickness is a parameter of a fabric which controls handle, creasing, thermal resistance, heaviness or stiffness in use and many other properties of fabric.
Fabric thickness test principle :
The Principle of the measurement of fabric thickness is expressed in B.S. Hand book as follows.
“Essentially, the determination of the thickness of a compressible material such as a textile fabric consists of the precise measurement of the distance between two plane parallel plates when they are separated by the cloth, a known arbitrary pressure between the plates are applied and maintained. It is convenient to regard one of the plates as the pressure foot and the other as the anvil.”
Points to be considered in measuring thickness:
The shape and size of pressure foot:A circular foot of diameter inch is usually used. The ratio of foot diameter and cloth thickness should not be less than 5: 1.
Shape and size of Anvil:If a circular anvil is used it should be at least 2 inch greater in diameter than the pressure foot. Where the sample is larger than the anvil, the anvil should be surrounded with a suitable support .e.g. a smooth plane board.
Applied pressure: Recommended pressure is specified e.g. 0.1 lb/inch2 or 10.0 lb /inch2. Suitable weights may be added to pressure foot to obtain these pressures.
Velocity of pressure foot: The pressure foot should be lowered slowly on sample i.e. it needs slow and careful movement.
Time: The thickness is read from the dial of the instrument when the movement of pointer has stopped.
Indication of thickness: A clock type dial is usually built into a thickness tester.
Instruments for measuring fabric thickness :
Reynolds and Branson thickness tester.
Heal’s thickness gauge.
Shirley thickness gauge.
Mag Ana thickness tester
Shirley thickness gauge :
For testing the thickness of compressible materials like carpets, sponge rubber, foam, felts etc., Shirley thickness gauge is used.
Description of Shirley thickness gauge :
Range of measurement: 0-2’’
Least count of dial gauge: 0.001’’
Area of pressure foot: 10 inch2, 1inch2 4.
Load on the pressure foot.
