What About Textiles With Unqualified Ph Value?

PH value is a very important quality index of textiles. It is the mandatory target for GB18401-2010's "basic safety technical specification for National Textiles". The pH value is also the most common quality problem in the textile processing and production trade. It has attracted more and more attention. This article will discuss with you how to control the pH value of textiles.

1, the definition of pH value:

The pH value is pH value, and the human skin is weak acidic. Under this environmental condition, the invasion of germs can be prevented. Therefore, if the pH value of textiles is beneficial to human health, it will help to protect human health. Otherwise, if the pH value is too high or too low, the skin's balance and resistance will be destroyed, which may cause skin allergy or induce infection and lead to the invasion of germs.

2, pH limit requirements:

3. The source of pH anomaly:

Mainly for textiles in dyeing and finishing process pH control is not enough, after acid treatment is not sufficient, or not thoroughly cleaned, easy to cause pH abnormal dyeing and finishing process is mainly alkali reduction, polyester printing water washing, reactive printing water washing, cotton cloth desizing, scouring and mercerization.

4. Comparison of different methods for determining the pH value of textiles:

(1), China Standard (GB/T 7573-2009)

3 specimens of 2 + 0.05g were selected and cut into 5 x 5. A small piece of MM is placed in a flask containing 100ml distilled water, shaking the flask to make the sample fully wetted, and shaking the flask on the oscillator for 2 hours + 5min. At the room temperature, the pH value of the water extract (fabric free) is directly measured by pH. every sample is tested for 3 times, and the average value of the second and third samples is taken as the final result, and the accuracy is 0.1.

(2), European Union standard (EN 1413-1998)

3 specimens of 2 + 0.05g were selected and cut into 5 x 5. A small piece of MM is placed in a flask containing 100ml potassium chloride solution (0.1mol/L) or 100ml distilled water, shaking the flask to make the sample fully wetted, and shaking the flask on the oscillator for 2 hours. At the room temperature, the pH value of the water extract (fabric free) is directly measured by Ph. every sample is tested for 3 times, and the average value of the second and third samples is taken as the final result, and the accuracy is 0.1.

(3), Japanese standard (JIS L 1096-1999)

A sample of 5 + 0.1g was made and cut into 1 * 1mm pieces. After boiling in 50ml distilled water for 2 minutes, the sample was placed in the flask. The flask was shaken and the sample was fully soaked. The samples were removed for 30 minutes at room temperature, and the pH value of the water extract was directly measured by the pH meter at the temperature of 25 + 2 C.

(4), American Standard (AATCC 81-2001)

Weighing 10 + 0.1g samples, cut them into small pieces, boil them in 250ml distilled water and keep them for 10 minutes. Put the sample into the flask and shake the flask to make the sample thoroughly soak. Continue boiling for 10 minutes. After cooling to room temperature, remove the sample and directly measure the pH value of the water extract with pH meter, accurate to 0.01.

PH values of aqueous extracts of cotton fabrics under different determination criteria:

5, how to deal with the unqualified pH detected in textiles?

PH is not qualified for fabric or garment, and pH is adjusted by acid and alkali neutralization principle. PH unqualified is mostly alkaline, there are many kinds of acid that can be used to adjust. The most common are two kinds of glacial acetic acid and citric acid. Glacial acetic acid has volatile and pungent odor. Citric acid regulates pH more stable. Therefore, it is generally recommended to use citric acid to adjust more appropriately, but it is necessary to pay attention to controlling dosage, excessive will affect the handle, and easily cause yellowing.

For example, if the fabric is measured with pH value of 9-10, the pH value of the citric acid solution can be adjusted to 4-5, then soaked for 10 minutes, and then dried. Send regular inspection structure tests to customers before confirming qualified, reduce trade risk.

6, the control method of pH value:

Only by analyzing the causes of unqualified pH value and prescriping the right remedy can we effectively reduce the unqualified rate of textile pH value:

(1) fabric enterprises should enhance the quality awareness of the quality control personnel and the training and training of textile standards, and correctly understand the requirements of textile pH. Garment processing enterprises should also select suitable surface and accessories according to their own requirements and safety categories, and provide accurate requirements and standards to fabric suppliers. From the source to quality control, we can avoid trade disputes caused by pH unqualified.

(2) the relevant personnel in dyeing and finishing enterprises should take the initiative to learn the knowledge of ecological textile safety, familiarity with the standard requirements, take the initiative to pay attention to the inherent quality of printing and dyeing products, optimize the production process and take the initiative to raise the level of technology.

(3) laboratories or laboratories should be tested strictly in accordance with the inspection standards to ensure that the inspection data are fair and accurate, and avoid incorrect testing data due to improper operation and other human factors.