GB/T 7742.1-2005Textiles -- Bursting properties of fabrics -- Part 1: Hydraulic method for determination of bursting strength and bursting distension (English PDF)

5.2.3 "Articles may be set only when there are two or above articles in the same

level".

This Part replaces GB/T 7742-1987 "Textiles - Determination of Bursting Strength and

Bursting Distension - Diaphragm Method".

This Part has made the following technical modifications to GB/T 7742-1987.

— The standard name is changed to "Textiles - Bursting Properties of Fabrics -

Part 1. Hydraulic Method for Determination of Bursting Strength and Bursting

Distension"; a comparison description of using two kinds of apparatus is added

in the Scope.

— 5 terms. test area, bursting pressure, diaphragm pressure, bursting height and

bursting volume and their definitions are added; the definition of bursting

distention is modified.

— Requirements for apparatus accuracy are added and modified. The bursting

pressure is adjusted to ±2% of full scale from ±1%; the bursting height is

adjusted to ±1mm from ±0.25mm. Bursting volume accuracy does not exceed

±2% is added; the volume increase rate accuracy is ±10%.

Textiles - Bursting Properties of Fabrics - Part 1.

Hydraulic Method for Determination of Bursting

Strength and Bursting Distension

6.1 Apparatus shall be possessed of constant volume increase rate in the range of

100cm3/min~500cm3/min; the accuracy is ±10%. If the apparatus is not equipped with

a device adjusting liquid volume, time to burst 20s±5s may be adopted; such situation

shall be indicated in the test report.

6.2 When the bursting pressure is larger than 20% of the full scale, its accuracy is

±2% of the full scale.

6.3 When the bursting height is less than 70mm, its accuracy is ±1mm. At the

beginning of the test, the zero point of measurement separation shall be capable of

being adjusted in order to adapt to test specimen thickness.

6.4 If the bursting volume may be displayed, its accuracy shall not exceed ±2% of

the indicating value.

Note 1. For most textiles, especially knitted fabrics, test area 50cm2 is applicable. For fabrics possessed of low

extensibility (according to experience or trial test), such as industry use textiles, the recommended test area is at least

100cm2. When conditions are not met or unsuitable, if both sides agree, test area in 6.5 may be used.

Note 2. Comparison test shall be performed with the same test areas and the same rate of volume increase.

8.3 Set a constant rate of increase in volume of between 100cm3/min and

500cm3/min. Or adjust a time to distend a test specimen to burst of (20±5)s using

preliminary trials.

8.4 Place the test specimen over the diaphragm so that it lies in a flat tensionless

condition, avoiding distortion in its own plane. Clamp it securely in the clamping ring,

avoiding damage, to prevent slippage during the test. Place the distension recording

device into the measuring position and adjust it to the zero position. Fasten the safety

cover in position according to machine requirements. Apply pressure to the test

specimen until the fabric bursts.

Immediately after burst, reverse the apparatus to starting position. Note bursting

pressure and height at burst and/or bursting volume. If the test specimen bursts close

to the edge of the clamping device, report this fact.

Repeat the test at least four more times at different places on the fabric. The number

of test specimens may be increased if agreed mutually.

8.5 Determination of diaphragm pressure

With the same test area and rate of increase in volume or time to burst as that

employed in the above tests, distend the diaphragm without the presence of a test

specimen by an amount equal to the mean height at burst or the mean volume at

burst of the test specimen. Note the pressure at this distension of the diaphragm as

the "diaphragm pressure".

8.6 Wet test

For tests in the wet condition, immerse the test specimen for a period of 1h in Grade 3

water in accordance with GB/T 6682 at a temperature of (20±2)°C. For tropical

regions, temperature according to GB 6529 may be used. An aqueous solution

containing not more than 1g of a nonionic wetting agent per litre may be used instead

of Grade 3 water.

Immediately after removal of a test specimen from the liquid and briefly placing it on

blotting paper to remove excess water, perform the test according to 8.2 to 8.5.