How to test the color fastness of polyester-brocade interwoven socks?

How to test the color fastness of polyester-brocade interwoven socks?

Introduction
Color fastness is a key quality indicator in the production and procurement process of socks. For polyester-brocade interwoven socks, the quality of their color fastness will directly affect the appearance and service life of the product, as well as customer satisfaction. If you are an international wholesale buyer, it is crucial to understand how to test the color fastness of polyester-brocade interwoven socks. This article will give you a detailed introduction to the test methods for the color fastness of polyester-brocade interwoven socks to help you better control product quality.

1. Basic concept of color fastness
Color fastness, also known as dyeing fastness, refers to the resistance of the color of textiles to the influence of various external factors during processing and use. For polyester-brocade interwoven socks, they may be affected by various factors such as light, washing, friction, sweat stains, etc. during wearing and washing, so various color fastness tests are needed to evaluate the stability of their color.

2. Common color fastness test methods for polyester-brocade interwoven socks

(I) Soap-resistant color fastness test
Principle
This simulates the color fastness of socks during daily washing. Sew the polyester-nylon interwoven socks sample and the standard adjacent fabric together, put them in soap solution, wash them under the specified temperature, time, bath ratio and other conditions, then rinse and dry them, and finally use gray cards or instruments to evaluate the discoloration of the sample and the staining of the adjacent fabric.
Steps
Prepare the sample: Cut a sample of appropriate size from the polyester-nylon interwoven socks, generally about 20cm×20cm, to ensure that the sample has no obvious defects and uneven color. At the same time, prepare the standard adjacent fabric, the material and color of which should meet the requirements of relevant standards.
Sewing the sample: Stack the sample and the standard adjacent fabric together, sew them along the edge with a sewing machine to make a combined sample.
Prepare soap solution: Prepare the soap solution according to the specified concentration and method. The commonly used soap solution concentration is about 5g/L, and the pH value is in the neutral or weak alkaline range.
Washing: Put the combined sample into the soap solution and wash it at the specified temperature, such as 40℃±2℃ or 60℃±2℃. The washing time is generally about 30 minutes, and the sample must be fully tumbled and rubbed in the soap solution to simulate the mechanical action in the actual washing process.
Rinse and dry: After washing, remove the combined sample from the soap solution and rinse it with running water to remove the residual soap solution. Then separate the sample and the flat adjacent fabric and dry them separately under dry conditions, and the drying temperature is generally not higher than 80℃.
Rating: Use a gray card or a color fastness tester to rate the discoloration of the sample and the staining of the adjacent fabric. The color change rating is to evaluate the degree of color change by comparing the sample with the original unwashed sample, and the staining rating is to observe the depth of color stained on the adjacent fabric.
Precautions
Pay attention to controlling the temperature and time during washing, because different washing conditions will affect the test results. For example, too high a temperature may cause excessive shedding of the dye, and too long a time will also increase the discoloration of the sample and the degree of staining of the adjacent fabric.
When preparing soap solution, ensure that the concentration and pH value of the soap solution are accurate to avoid affecting the test results due to soap solution quality problems.

(II) Friction color fastness test
Principle
This test is mainly to evaluate the color fastness of polyester-nylon interwoven socks when subjected to friction. By using a friction fastness tester, fix the sample on the instrument, apply a certain pressure to the sample with a standard friction white cloth and rub it, and then observe the staining on the friction white cloth to evaluate the color fastness.
Steps
Prepare the sample: Also cut a sample of appropriate size from the polyester-nylon interwoven socks, generally about 10cm×10cm.
Fix the sample: Fix the sample flatly on the workbench of the friction fastness tester to ensure that there are no wrinkles or loose parts in the sample.
Prepare the friction white cloth: Select a standard friction white cloth that meets the standard requirements. Its material is generally cotton fabric and the size is generally about 5cm×5cm.
Rubbing: Fix the friction white cloth on the friction head, then start the friction fastness tester and rub the sample according to the specified pressure and number of frictions. Generally, the pressure of dry friction is about 9N, the pressure of wet friction is about 5N, and the number of frictions is usually 10 round trips.
Rating: After the friction is completed, remove the friction white cloth and compare it with the gray card for staining. The color fastness grade is evaluated according to the depth of staining.
Notes
When conducting a wet friction test, ensure that the moisture content of the friction white cloth is appropriate, generally about 65%±5%. Too high or too low a moisture content will affect the accuracy of the test results.
During the friction process, ensure that the movement of the friction head is smooth and uniform to avoid uneven friction or excessive friction.