Washing Resistance Testing

Washing resistance testing mainly conducts scientific testing and analysis on the colour fastness to washing of the textiles, washing resistance of the bonding fastness of the coated or laminated fabrics, washing stability of the garment accessories, dimensional stability, appearance retention after washing, and washing resistance of the functional finishes, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Colour fastness to washing of the textiles: This item mainly evaluates the ability of the textile fabrics and finished garments to resist the colour change (fading) and resist the colour staining onto the other fabrics (staining) during the simulated domestic or commercial washing process. This is one of the most important indicators for evaluating the intrinsic quality of the textile, and is directly related to the service performance of the product and the consumer experience.

Washing resistance of the bonding fastness of the coated or laminated fabrics: This item is aimed at the functional composite fabrics, such as the fabrics laminated with the waterproof and moisture-permeable films and flocked fabrics. It tests whether the bonding strength between the layers of the materials (such as the film and base fabric, and the fluff and backing fabric) decreases or the phenomena such as the delamination and blistering occur after multiple washes.

Washing stability of the garment accessories: This item detects the performance changes of the accessories on the garments such as the zippers, buttons, tapes, interlinings and embroidery threads after washing. Including the evaluation of the zipper smoothness, whether the buttons crack or fall off, whether the interlinings shrink and deform, and whether the embroidery threads fade.

Dimensional stability (dimensional change after washing): Measures the dimensional changes in the length and width directions of the textile (especially the garments and home textiles) after the washing and drying under the specified conditions. This indicator is the key to measuring whether the product "shrinks", and directly affects the fit and appearance of the garment.

Appearance retention after washing: This item comprehensively evaluates the overall appearance changes of the textile after washing, not limited to the colour. Specifically including whether the pilling, surface abrasion, distortion, seam smoothness changes, printing pattern blurring or falling off occur.

Washing resistance of the functional finishes: For the textiles with the special functional finishes, such as the antibacterial, UV protection, antistatic, waterproof (non-coated type) and flame retardant. Through the washing resistance testing, the persistence of these functional finishing effects is evaluated, that is, whether the functions are still effective after multiple washes.

Testing Scope

Various apparel textiles: Including all the daily wearing garment products such as the underwear, shirts, outerwear, trousers and skirts made of the woven, knitted and nonwoven fabrics. The different categories of garments correspond to the different testing standards and washing severity grades.

Home textiles: Covering the bed sheets, quilt covers, pillowcases, curtains, sofa covers, tablecloths, towels and shower curtains. These products have frequent contact with the human body, and the washing cycles are relatively fixed, with the higher requirements for the colour fastness to washing and dimensional stability.

Industrial textiles: Some industrial fabrics that need the regular cleaning, such as the hotel fabrics, reusable medical textiles and catering workwear, also need the washing resistance testing, to ensure that they can still meet the use requirements after multiple cleanings.

Shoes and luggage materials: The lining fabrics, interlinings, washable canvas uppers of the shoes, as well as the linings and removable washable parts of the luggage, whose washing resistance affects the service life and hygiene condition of the products.

Infant and children's textiles: The infant and children's garments and products (such as the diapers, bibs and bedding) need to be frequently and vigorously washed to maintain the hygiene, and have the extremely high safety requirements, so their colour fastness to washing (especially the staining) and dimensional stability standards are usually stricter.

Fabrics with the coating or special processes: Such as the flocked, hot stamped, digital printed and composite fabrics. The washing resistance testing of these products needs to focus on the adhesion fastness of the special process layers and the appearance changes.

Testing Methods

GB/T 3921-2008 "Textiles — Tests for colour fastness — Colour fastness to soaping": A Chinese national standard, specifying the test method for the colour fastness to soaping of the textile. During the testing, the specimen is sewn with the specified adjacent fabrics, placed in the soap solution, agitated in the washing colour fastness tester at the specified temperature and time, and then rinsed and dried. Finally, the grey scales are used to rate the colour change of the specimen and the staining grade of the adjacent fabrics.

ISO 105-C10:2006 "Textiles — Tests for colour fastness — Part C10: Colour fastness to washing with soap or soap and soda": An International Organization for Standardization standard, a widely recognized test method globally. Its principle is similar to the national standard, but provides the various test conditions from mild to severe (such as the temperatures from 40 ℃ to 95 ℃, with or without the steel balls to increase the friction), to adapt to the requirements of the textiles for the different uses.

AATCC 61 "Colorfastness to laundering: Accelerated": An American Association of Textile Chemists and Colorists standard. This method uses a small rotating cylindrical washing machine to simulate the effects of multiple (such as 5, 10 and 20) domestic or commercial washes in a short time (such as 45 minutes), and is an accelerated test method.

AATCC 135 "Dimensional changes of fabrics after home laundering": This standard is specially used to determine the dimensional stability of the woven or knitted fabrics after home laundering. The test uses a standard household washing machine, detergent and the specified washing procedures, precisely measures the distances between the marked points before and after washing, and calculates the dimensional change rate.

ISO 6330 "Textiles — Domestic washing and drying procedures for textile testing": This standard specifies in detail the standardized washing and drying procedures used for the tests such as the dimensional stability and appearance retention, including the combinations of the different types of washing machines (front-loading and top-loading), water temperatures, spin speeds and drying methods (line drying, tumble drying and ironing), ensuring the comparability of the test results.

Customer-defined test protocols: Many brand owners or purchasers will formulate the internal stricter test standards or custom test conditions according to the positioning and actual use of their own products. For example, specifying the particular detergents, increasing the number of washes, and combining the particular drying methods, to simulate the washing situation of the whole life cycle of the product.

Testing Standards

Domestic Standards:

1. GB/T 3921-2008, Textiles — Tests for colour fastness — Colour fastness to soaping

2. GB/T 8629, Textiles — Domestic washing and drying procedures for testing

3. GB/T 8630, Textiles — Determination of dimensional change after washing and drying

International Standards:

1. ISO 105-C10, Textiles — Tests for colour fastness — Part C10: Colour fastness to washing with soap or soap and soda

2. ISO 6330, Textiles — Domestic washing and drying procedures for textile testing

3. ISO 5077, Textiles — Determination of dimensional change on washing and drying

4. AATCC 61, Colorfastness to laundering: Accelerated

5. AATCC 135, Dimensional changes of fabrics after home laundering

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Washing colour fastness tester: One of the core equipment, usually with a rotating cylindrical tank structure. The test tanks can be heated at the constant temperature and rotate at a uniform speed, and the specimen, steel balls (optional) and washing liquor are placed inside the tank. It can precisely control the washing temperature, time and mechanical force, such as the SW-12 type and Wascator models that meet the standard requirements.

Standard household washing machines and dryers: Used to execute the dimensional stability and appearance tests specified in the standards such as the ISO 6330 and AATCC 135. The laboratory needs to be equipped with the standardized front-loading drum washing machines (commonly used in the European standards) and top-loading agitator washing machines (commonly used in the North American standards), as well as the corresponding tumble dryers, to ensure the consistency of the washing conditions.

Standard light source cabinet: Used for the objective rating of the colour changes of the specimens after washing. Under the standard light sources such as the D65 (average daylight) and TL84 (shop lighting), the trained rating personnel use the grey scales to compare the colour differences of the specimen before and after washing and the staining degree of the adjacent fabrics, giving the fastness ratings of grades 1-5 (grade 5 is the best, and grade 1 is the worst).

Digital fabric thickness gauge and electronic balance: Used to test the physical property changes of the fabric before and after washing. The thickness gauge can measure whether there is the thickness loss or indentation of the coated fabric after washing; the electronic balance can be used to measure the mass changes after washing, assisting in the evaluation of the abrasion or shedding.

Standard multi-fibre adjacent fabrics and single-fibre adjacent fabrics: The key consumable materials. In the colour fastness testing, they are washed together with the specimen, used to evaluate the staining of the specimen onto the different fibre types (such as the acetate, cotton, nylon, polyester, acrylic and wool). The multi-fibre adjacent fabric contains the strips of the various fibres, and the single-fibre adjacent fabric is a single-fibre fabric.

Standard detergents and ballast: The testing requires the standard ECE or AATCC detergents without the fluorescent brightening agents and enzymes, to ensure that the results are not interfered with by the additives. The ballast (such as the standard bleached cotton fabric or the specified fabric load) is used to achieve the specified liquor ratio in the testing, simulating the actual washing load.