Ⅰ . The fastness of the fabric

In the process of using the fabric, the most basic forms of stress damage are tensile fracture, tear, crack and wear

1.Tensile tester
(1)Test methods

Side - drawn strip yarn method
The method is a test method of pulling a cloth with a width of 6cm and a length of 30 ~ 33cm away from the edge yarn to make a cloth with a width of 5cm, and clamping it all into the upper and lower clamps of the strength machine

Cut-Strip method
The Cut-Strip method is used for some knitted fabrics, staple fabrics, nonwovens, coated fabrics and fabrics that are not easy to detangle

Grasp sample method
A method of testing a fabric specimen of a specified size held in a chuck of only a portion of its width

Trapezoidal and annular spline method
When rectangular strips are used to stretch knitted fabrics, obvious stress concentration and transverse contraction will occur near the collet, which will cause the samples to break near the collet and affect the correctness of test data. Trapezoidal or annular samples can avoid such situation.

(2)Common indicators
A.Tensile strength B. breaking elongation C. breaking work

(3)Factors affecting strength
A.Properties of fiber raw materials: Strength, elongation, modulus, elasticity, crimp and clasp of fiber
B. Yarn structure and properties: thickness, twist, etc
C. Fabric density
D. Fabric texture
E. After finishing
F. Test conditions: width, length, tensile speed, environment, etc

2.Tearing tester
The phenomenon that the edge of the fabric is subjected to a concentrated load, which causes the fabric teared is called tearing

(1)Tear method
A. single slit method
The single seam method is also known as the tongue method, as shown on the right

B.the trapezoidal method
The specimen is clamped in a trapezoidal manner. One side of the specimen with a notch is the tight side, and the other side is the loose side, and the specimen is in a relaxed and wrinkled state

C.Drop hammer method (impact type)
The falling hammer method is actually a kind of single seam method, but its force mode is the impact of the free falling body, so it is also called impact tearing

(2)Tear index
A.Maximum tearing force
The maximum peak on the tear curve.

B.Five-peak mean tearing force
The average value of the four peaks on the tear curve from the maximum peak and the four peaks that decrease in turn.

C.12 peak mean tearing force

D. Full-peak mean tearing force

3.Bursting tester
The rupture of the fabric caused by the force of the vertical surface is called jacking.
In practical tests, a steel ball is used to apply a force on the fabric until it breaks.

The main indicators are:
(1) Bursting strength
(2)Bursting height

4.Abrasion tester
The surface damage caused by repeated tangential friction is called abrasion.This is the most common form of fabric damage in daily life.Due to the different abrasion modes, there will be different damage effects, so there are many types of equipment in the laboratory to test the abrasion performance.

(1) flat abrasion
A. Repeat flat abrasion
B. Rotary flat abrasion

(2)curved abrasion
(3)Flanged abrasion
(4)dynamic abrasion
(5)turning abrasion
(6) Abrasion index

There are many specific indexes to express the wear resistance of the fabric, which are difficult to describe one by one. They can be roughly classified as follows:

A. After a certain number of friction, the physical and mechanical properties of the fabric, such as the change of shape, rate of change, change grade, etc. Such as strength loss rate, increase rate of light transmittance, permeability, thickness reduction rate, surface color, gloss, pilling change grade, etc.

B. The number of wears required to break a fabric.

C. The number or time of wear when a physical property has reached a specified change. If 2 yarns are broken or holes appear, the number of times the fabric is subjected to friction. Such indicators are often used in wear tests.

D. The comprehensive wear-resisting value is obtained by averaging the single index of flat abrasion, curved abrasion and flanged abrasion.