Differences between some testing methods of national standards and American standards

The difference between some testing methods of national standards and American standards

The testing methods and assessment methods for various physical indicators of textiles vary from country to country. Generally, buyers will specify testing method standards, which mainly include: GB, which is a Chinese standard; ISO, which is applicable to European countries; AATCC and ASTM, which are applicable to American countries; BS, applies to the United Kingdom; AS, applies to Australia and New Zealand; DIN, applies to Germany; JIS, applies to Japan; WS, applies to most countries in the world, mainly referring to wool products; CAN, applies to Canada. At present, our company often encounters many customers who require the use of American standard testing methods.

Below is a comparison of several main detection methods:

1. Washing fastness

As far as the American standard method A2 and the national standard method 2 are currently selected, the temperature of the American standard is 1℃ lower than the national standard, the water volume is 3 times of the national standard, the steel cup required is 1200ml, while the national standard is 550ml; the lining used They are also different. The American standard uses 10# multi-fiber cloth, while the national standard uses DW multi-fiber cloth. The sample sizes are different. The American standard is 5×15cm, while the national standard is only 4×10cm. The detergent and dosage used are different. The US standard uses 10# multi-fiber cloth. The American standard uses phosphorus-free detergent, while the national standard uses phosphorus-containing detergent. In the American standard test, 50 steel balls were added for kneading, but the national standard did not. That is to say: It means that the same piece of cloth will produce different results if tested by two standard methods, and the American standard will be different. Therefore, when testing is required, you must choose a good testing standard, or confirm the testing standards clearly with the customer.

2. Rubbing fastness

In terms of equipment, the national standard is motor-automatic, and the American standard is manual shaking. The results of the two methods of dry friction will not be much different. The national standard of wet friction requires 100% water content, and the American standard requires 65%, so the results will be different.

3. Perspiration fastness

The national standard and the American standard are basically the same in operation, but the formula of the perspiration solution is different. The American standard adds an extra lactic acid ingredient than the national standard, and only detects sweat acid; while the national standard contains perspiration alkali, and the time is also different. The American standard It takes 6 hours to press, and the national standard only needs 4 hours to press. The test results of the American standard will be worse than the national standard.

4. Formaldehyde content

The national standard commonly uses water extraction method, which takes 1 hour; while the American standard uses vapor phase extraction for 20 hours, and the result will be much higher than the national standard. For example, the result measured by the national standard is 60ppm, and the American standard may measure 200ppm.

5. PH value

The national standard is to extract 2g of cloth with 100ml of water at 40°C for 1 hour and measure the pH value of the water; while the American standard is to boil 250ml of water and 10g of cloth for 10 minutes and measure the pH of the water. It is difficult to achieve consistency between the two methods. Not comparable.

6. Shrinkage

The national standard uses a horizontal washing machine, while the American standard uses a vertical washing machine. The results of the two washing machines with different movement modes cannot be compared. Different drying methods can also be a factor that makes a big difference. Therefore, be sure to confirm with the customer the washing method and drying method.