Textile Soap Wash Fastness Test

In people's daily life, basically all textiles must be washed. Under the action of washing liquid at a certain temperature, the dyes will fall off from the textiles, and finally the original color of the textiles is changed to be called discoloration. At the same time, the dyes that enter the washing liquid will be contaminated with other textiles, and will also cause the color of other textiles to change, which is called staining. The colorfastness of textiles to soaping refers to the fastness of the dyestuffs to resist the washing of the soap solution. The quality of the color fastness to soaping is reflected by the degree of discoloration of the textile itself and the degree of staining of other fabrics. It is to evaluate textile dyeing. The important indicator of fastness.

(I) Test standards

GB/T3921-2008 "Color fastness to textiles, colorfastness to soaping".

(b) Scope of application

This standard stipulates methods for determining the fastness to washing of all types of textiles used in conventional households, including five trials ranging from easing to severely different washing procedures.

This standard is only used to determine the effect of washing on the colour fastness of textiles and does not reflect the results of a comprehensive laundry procedure.

(b) Test methods

Methods for determining the fastness to washing of fastnesses of all types of textiles used in conventional households, including 5 trials ranging from mild to severe different washing procedures. The textile sample is sewn together with one or two pieces of the specified standard lining fabric, placed in a liquid soap or a mixture of soap and anhydrous sodium carbonate, mechanically agitated at the specified time and temperature, and then cleaned and dry. As a reference sample as it is, a sample card or instrument was used to assess the discoloration of the sample and staining of the lining fabric.

(D) Testing Instruments and Materials

(1) Test equipment

Wash fastness tester: It has multiple stainless steel containers with a capacity of (550 ± 50) ml, with a diameter of (75 ± 5) mm and a height of (125 ± 10) mm. The speed of the shaft and the container is (40 ± 2) r / min, the bath temperature is controlled by the thermostat, so that the test solution is maintained within the specified temperature of ± 2 °C.

2 corrosion-resistant stainless steel beads: diameter of about 6 mm.

3 Balance: accurate to ± 0.01g.

4 Mechanical stirrer: Ensure that the contents of the container are fully dispersed to prevent sedimentation.

5 Heat the soap dispenser.

(2) Soap: Based on dry weight, the moisture content does not exceed 5% and meets the following requirements

Free base (calculated as Na2CO3) ≤0.3%

Free base (as NaOH) ≤0.1%

Total fat ≥850 g/kg

Preparation of Soap Mixed Fatty Acids Freeze Point ≤30°C

Iodine value ≤ 50

Soap should not contain fluorescent brighteners.

(3) Anhydrous sodium carbonate (Na2CO3).

(4) soap;

1 Methods A and B: Soap 5g/L

2 Methods CDE: Soap 5 g/L

Anhydrous sodium carbonate 2 g/L

(3) Third-grade water: It conforms to the provisions of GB/T6682.

(4) The lining fabric conforms to the provisions of GB/T6151.

1 Multi-fiber interlining fabric (in line with GB/T7568.7.IS0105-F07 regulations): DW type (containing six fiber components of acetate fiber, bleached cotton, polyamide fiber, polyester fiber, polyacrylonitrile fiber and wool) For 40 °C and 50 °C test, such as for 60 °C test, need to be specified in the test report; TV type (containing three vinegar fiber, bleached cotton, polyamide fiber, polyester fiber, polyacrylonitrile fiber and Six fiber components of viscose are used for the 60°C test and the 95°C test.

2 Single-fiber lining fabric (according to GB/T7568.1 ~ 7568.6, GB/T13765, IS0105-F01 ~ F06): The first piece is made of fibers of the same kind as the sample, the choice of the second single fiber lining fabric As shown in Table 9-5. If the sample is blended or cross-fabricated, the first piece is made of a major amount of fiber and the second piece is made of a minor content of fiber.

(8) Gray sample card: used to assess discoloration and staining, in line with GB/T250 and GB/T251; or spectrocolorimeter, according to (7) a piece of dyeing fabric (such as polypropylene), if needed .

GB/T8424.1.FZ/T01023 and FZ/T01024 assessed discoloration and staining.

(five) sample preparation

1. Fabric

The sample was a fabric and a composite sample was prepared according to one of the following methods. Take a piece of 100mm x 40mm piece:

(1) The front is fitted with a multi-fiber lining fabric of the same size and sewn along a short side.

(2) Sandwiched between two single-fiber lining fabrics of the same size and sewn along a short side.

2. Yarn or loose fiber

(1) The yarn can be knitted into a fabric and tested according to the manner of the fabric.

(2) Take the yarn or loose fiber approximately equal to 1/2:1 of the total mass of the lining fabric sandwiched between a 100mm x 40mm multifiber lining fabric and a fabric of the same size not dyed and sewn along the four sides. 2 Clipped between two single-fiber lining fabrics of 100mm x 40mm and sewn along four sides.

3. Bath ratio

The mass of the combined sample was measured to facilitate accurate bath ratios.

(VI) Test procedure

(1) Preparation of soap based on the test method used

(2) After the washing is completed, the combined samples are taken out, washed twice in tertiary water, and then rinsed in flowing water until clean. (2) Put the combined sample and the specified number of stainless steel beads into the container, and inject the required amount of soap solution that is preheated to the test temperature of ±2°C according to the table, so that the bath ratio is 50:1, and close the container. Wash under the test conditions and start timing.

(3) Extrude excess water from the combined specimen by hand. If necessary, leave a suture on the short side and unfold the combined specimen.

(4) The sample is placed between two filter papers and squeezed to remove excess moisture, and then suspended in air not exceeding 60° C., and the test lining and the lining are connected by only one suture.

(7) Test results

Using a gray card or instrument, compare the original sample to assess the discoloration of the sample and staining of the lining fabric.

(8) Precautions

(1) Clearly separate the containers used for the test containing the fluorescent whitening agent and the non-fluorescent whitening agent.

(2) Test strictly according to the dissolution ratio of 50:1.

(3) Determine the corresponding soap resistance test method in combination with the product standard.