Determination of fabric stiffness by stiffness tester

Introduction: Stiffness is a special property of fabric. It is the tendency of fabric to keep standing without any support. It is the key factor in the study of handle and drop of fabric.

GSM means gm/m² of a textile mtl

The ratio of small change in bending movement per length width of mlt to the corresponding small change in curvature is called Flexural Rigidity (G). It is express in mg/cm.

stiffness tester

The weft way remains straight when the fabric is bent warp way of when the flexural rigidity by the bending length is called warp bending length.

Flexural Rigidity G= 0.1 HC₃ mgl cm

where, H=GSM of the fabric

       C= Bending length in cm

The length of the fabric that with bend order its own wt to a define extent is called bending length (e).

Objects:

• To measure the stiffness at the fabric
• To control the fabric quality
• To make fabric comfortable

Calculation:

Warp direction:

Average bending =(5.6+5.8+5.6+5.3+5.4)/5=5.48

Average stiffness= (2.8+2.9+2.8+2.5+2.7)/5=2.74

Weft direction:

Average bending =(7.2+7+6.8+7.4+7.6)/5=7.2

Average stiffness= (3.5+3.6+3.4+3.7+3.8)/5=3.6

Table:

Table 1. For weft direction:-

Obs no	Sample size	Bending Angle	Bending length	Average Bending Length	Stiffness	Average stiffness
1	20×2.5	41.5	7	7.2	3.5	3.6
2			7.2		3.6
3			6.8		3.4
4			7.4		3.7
5			7.6		3.8

Table 2. For averagestiffness warp direction

Obs no	Sample size	Bending Angle	Bending length	Average Bending Length	Stiffness	Average stiffness
1	20×2.5	41.5	2.8×2=5.6	5.48	2.8	2.74
2			2.9×2=5.8		2.9
3			2.8×2=5.6		2.8
4			2.5×2=2.		2.5
5			2.7×2=5.4		2.7