This standard specifies the method of comparing the performance of laundry detergents by washing white cotton control cloth in multiple cycles. This standard is applicable to the performance comparison test of various types of laundry detergents, including powder, liquid and paste products. GB/T 15815-1995 Comparative test of laundry detergent performance by washing white cotton control cloth in multiple cycles GB/T15815-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Comparative test of performance for laundry detergents+--Cycle of washing unsoiled cotton control cloth procedure1 Subject content and scope of application
GB/T 15815-1995
This standard specifies the method of comparing the performance of laundry detergents by washing white cotton control cloth for multiple cycles. This standard is applicable to various types of laundry detergents, including performance comparison tests of powdered, liquid and paste products. 2 Reference standards
GB/T13174 Determination of detergency of laundry detergents 3 Method summary
The detergent for comparative test (test sample and reference sample) is prepared into a washing liquid of specified concentration with water of specified hardness, and a certain amount of carbon black oily liquid is added. The specified number of white cotton control cloth test pieces are washed with the specified (load) liquid ratio, and the same series is continuously washed for a specified number of cycles (generally more than 20 times).
After cyclic washing, the white cotton control cloth test pieces are evaluated for appearance (roughness), softness, sensory whiteness, and the deposited ash (burning method) and whiteness retention (calculated from the whiteness before and after washing) are measured. These criteria are compared to evaluate whether the performance of the test detergent is better or worse than that of the reference detergent.
4 Reagents and materials
4.1 White cotton control cloth, using white cloth for stain removal test (non-fluorescent), cut into pieces of cloth about 10cm×10cm and weighing about 1g, and write the number on the corners of the cloth with indelible ink or embroider with colored thread. Prepare 6 pieces of cloth for each stain removal test bottle. 4.2 Artificial carbon black oil liquid, prepared according to the provisions of 5.2 and 5.3 of GB/T13174. 4.3 Standard detergent, in accordance with the provisions of Chapter 7 of GB/T13174. 4.4 Test water: tap water (water hardness equivalent to 250 PPm) or prepared in accordance with the provisions of Article 5.6 of GB/T13174. 5 Instruments
5. 1 Decontamination test machine, Launder-0-meter type or Terg-o-Tometer type. 5.2 Whiteness meter (ZBN33012).
5.3 Porcelain cup, 2000 mL.
5.4 Porcelain plate.
5.5 Porcelain crucible, 50 mL, with cover.
5.6 High temperature furnace, capable of controlling the temperature at 800 ± 10°C. Approved by the State Bureau of Technical Supervision on December 8, 1995, 300
Implementation on August 1, 1996
6 Test procedure
6.1 Cycle washing
GB/T15815—1995
Mix the detergent for the fabric to be tested and the test water for the reference detergent (Article 4.4) into a washing solution with a concentration of 0.2% (if the detergent for the fabric to be tested is concentrated, a washing solution with a concentration of 0.1% should be prepared), and then add 0.3% artificial carbon black oily liquid. For the same sample, use 3 to 4 decontamination test bottles. Pour 300mL of prepared detergent solution into each decontamination test bottle. After preheating to 43℃ in the preheating tank, put 6 pieces of white cotton control cloth that have been numbered and pre-measured for whiteness into each bottle. Then put the decontamination test bottle into the bottle rack of the decontamination test machine and wash in a 45℃ water bath for 15min. Then use tweezers to clamp the 6 pieces of cloth in each decontamination test bottle into 1000mL of hard water (4.4) in a 2L Tang porcelain jar, swing 5 times to rinse off the foam attached to the cloth pieces, clamp them up and drain slightly, then put them into the decontamination test bottle containing 300mL of clean hard water (4.4) preheated to 43℃, put the decontamination bottle into the bottle rack of the decontamination test machine and rinse at 45℃ for 2min. Take out the cloth pieces, wring them out and lay them flat on the Tang porcelain plate to dry, which is one wash. In this way, wash 20 times continuously. 6.2 Post-washing cloth test
6.2.1 Whiteness measurement and calculation of whiteness retention
Before the cycle washing, the whiteness of the white cotton control cloth should be measured first, and then the whiteness of the dried cloth should be measured after every 5 cycles of washing (the average whiteness of the six cloths is taken). The whiteness retention of the corresponding number of cycles of washing is calculated according to formula (1): Whiteness retention (%) (n times) -
n=5,10,15,20.
6.2.2 Determination of the amount of deposited ash
Average whiteness of the cloth after n cycles of washing
Average whiteness of the white cotton control cloth before washing
After 20 cycles of washing, take out 4 pieces of cloth from each parallel decontamination test bottle of the sample and reference detergent in the same series of tests for the determination of the amount of ash deposition (the remaining 2 pieces are reserved for sensory evaluation). Mark the clean crucible (5.5) in advance, burn it in a high-temperature furnace at 800℃ for 2h, move it into a desiccator, cool it to room temperature, and weigh it. Take the four pieces of cloth obtained from the same decontamination test bottle as a group, remove the fibers that are easy to fall off on the edge of the cloth, put it into a 105℃ oven to dry for 4h, move it into a desiccator to cool it, take it out, put it into a small plastic bag of known weight, and weigh it (because dry cloth pieces are very easy to absorb moisture, otherwise it is difficult to weigh accurately). Repeat the drying, cooling and weighing in this way, and take the lowest mass of the cloth piece. Clamp the weighed cloth piece with a clean glass rod, ignite it above the weighed crucible to carbonize it, so that the carbonized product after combustion falls into the crucible without loss, and then burn the crucible in a high-temperature furnace at 800℃ for 6h, move it into a desiccator, cool it to room temperature, and weigh it. The percentage of deposited ash is calculated according to formula (2):
Deposited ash (%) =
6.2.3 Sensory evaluation
Ash mass
Cloth massbzxz.net
Center
...(2)
More than 5 experienced judges visually and tactilely compare the other 2 pieces of cloth left in each decontamination test bottle to judge whether the whiteness (black and white), appearance (roughness/smoothness) and softness of the cloth pieces after cyclic washing with the sample detergent are better or worse than those of the cloth pieces washed the same number of times with the reference detergent.
7 Result judgment
Based on the whiteness retention and deposited ash measurement values ​​of the white cotton control cloth after cyclic washing with the comparison sample and the reference detergent and the sensory evaluation, the performance of the sample detergent is comprehensively judged to be better or worse than that of the reference detergent. 301
Additional Notes:
This standard is proposed by China Light Industry General Association.
GB/T15815---1995
This standard is under the jurisdiction of the National Surfactant Detergent Standardization Center. This standard was drafted by China Daily Chemical Industry Research Institute. The main drafters of this standard are Zhang Jiayong, Hu Zhengyu, Liu Junfang, Liu Ming and Liu Xiaoying. 302
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