Test method for gray cloth pulp-free dry weight - Clothing Manufacturer

Textile business negotiations and contract signings often have weight requirements for gray fabrics. The weight of gray fabrics refers to the slurry-free dry weight of gray fabrics per square meter, which is referred to as the slurry-free dry weight of gray fabrics. It is an important technical indicator of gray fabrics and the main indicator for economic accounting of fabrics.

According to the size and specific conditions of the gray fabric sample, it can be divided into two test methods: weighing method and calculation method. The calculation method requires knowing the weaving shrinkage of warp and weft yarns, and sometimes the estimated warp and weft yarn shrinkage deviations are large, resulting in The calculation results have a large error. Generally, enterprise laboratories and testing centers use more accurate weighing methods to test the pulp-free dry weight of gray fabrics.

Instruments and tools required to test the slurry-free dry weight of gray cloth by weighing method: balance (pallet balance or electronic balance ), induction cooker (usually 1500W), copper pot (or beaker), measuring cup, glass rod, concentrated sulfuric acid, iodine solution (protected from light), oven, etc.

1. Preparation of dilute sulfuric acid solution:

Configure more than 95% concentrated sulfuric acid into a certain concentration of dilute sulfuric acid: (add 100ml of concentrated sulfuric acid to 500ml of water) first pour a certain amount of water into the beaker, and use a measuring cup to measure an appropriate amount of concentrated sulfuric acid. Hold the measuring cup in your left hand and the glass rod in your right hand. While stirring, slowly pour the concentrated sulfuric acid into the water in the beaker. After cooling, pour the prepared dilute sulfuric acid into a small glass container and seal it.

Note: Concentrated sulfuric acid will evaporate and splash during dilution and stirring. When exiting, operators must wear plastic gloves and masks

2. The test steps are as follows:

1. Sampling cloth: Use a disc sampler to take a gray cloth sample (area 100 square centimeters) for testing or use scissors to cut the sample cloth into a rectangle or square, and use a ruler to measure the length and width of the sample cloth. , calculate the area of the sample cloth (square centimeters) 2. (According to the ratio of 10 grams of gray cloth to 700ml less water) measure the amount of water required for the test sample cloth in the measuring cupAdd water to a copper pot (or beaker), then heat it on an induction cooker. After the water boils, put in the sample cloth and cook for 10 minutes. Use a glass helper to take out the sample cloth and wash it with clean water.

3. (According to the ratio of 10 grams of gray cloth to 700ml less water) Then use a measuring cup to measure the water required for the test sample cloth, add it to a copper pot (or beaker), put it on the induction cooker and heat it until it boils, (press The ratio of 700ml water to 14ml dilute sulfuric acidExample) Use a measuring cup to add an appropriate amount of dilute sulfuric acid, put the sample cloth into the boiling water, cover it, and cook for 40 minutes. Use iodine solution to check whether the desizing of the sample cloth is clean. If not, continue to cook until the desizing is clean. Until it is clean, use a glass rod to remove the sample cloth and rinse it with clean water.

4. Open the oven, lay the sample cloth flat on the oven partition and bake for 1.5-2.0 hours. Weigh the dried sample cloth with a balance and calculate the weight of the sample cloth.Dry weight of gray cloth without pulp.

5. Since there is fiber loss during the desizing and cleaning process, use the loss coefficient to correct it and calculate the pulp-free dry weight of the gray cloth: