Test method for color fastness to rubbing of leather surface

1 Subject content and scope of application this standard specifies the method to determine the color fastness of leather surface or service surface when dry and wet friction This standard is applicable to light leather 2 Reference standard GB 406 technical requirements for natural color cotton cloth GB 251 grey sample card for assessment of staining GB 4689.1 leather laboratory sample part and mark GB 4689.2 leather air conditioning of test piece for physical property test 3 Terminology 3.1 The gray sample card uses the contrast method to judge the degree of staining 3.2 the white cloth used to wrap the friction head White cloth is required to meet the requirements of 5.3 3.3 friction head refers to the part that directly rubs the sample See 5.1b for the requirements 4 Principle: in the process of back and forth friction of leather surface under the specified pressure, part of the color of leather surface is transferred to the lining, and the gray sample card is used to determine the grade by visual inspection 5 Apparatus, equipment and materials 5.1 color rubbing fastness test of leather surface (main parts of the instrument are shown in Fig 1) A the parts that move the friction head to and fro at the speed of 30 ± 2 times / min to the compound screw rod One way travel of reciprocating motion is 100mm B the weight of the friction head is 250 ± 2G, and the radius of the end face of the friction head is 10 mm There is a spring groove 20 mm from the end face to fasten the lining cloth with spring ring C The holder can firmly fix the sample without affecting the free movement of the friction head 5.2 gray sample card according to GB 251 5.3 the white cloth specified in gb406 shall be used as interlining The white cloth shall be desized before use and cut into a circle with a radius of 35mm The interlining can only be used after air conditioning for 24 hours according to GB 4869.2 5.4 distilled water for chemical analysis 6 Sample 6.1 the sampling part of the sample shall be used as the leather sample of this test method according to the 10th and 11th samples specified in gb4689.1 6.2 the sample shall be air conditioned according to the requirements of GB 4689.2 Note: when air conditioning is not carried out, the actual site conditions shall be recorded 7 Test method and result judgment during test, the instrument shall be placed on the felt horizontally 7.1 dry wipe 7.1.1 the use face of the sample shall be upward, and it shall be stretched flat and wrinkle free when put into the sample holder Clamp the sample clamp, place it between the long hole (length: 100mm, width: 30mm) of the instrument base and the felt, and fix the sample clamp with the screw on the long hole of the instrument base 7.1.2 wrap the lining cloth tightly on the friction head end and fix the lining cloth in the spring groove of the friction head with spring 7.1.3 put the friction head wrapped with lining cloth into the base 7.1.4 start the instrument and stop it after 25 reciprocations, and remove the lining 7.1.5 compare the color depth transferred from leather surface to interlining with the gray sample card specified in 5.2, and judge the grade by visual inspection Judge the light source: the natural light of the North window 7.2 wet rubbing operation is the same as that in 7.1 Wet rubbing shall be carried out on the adjacent parts of dry rubbing 7.2.1 the friction times are 20 reciprocations 7.2.2 the interlining is soaked with distilled water as specified in 5.4, and its sand content is 70% ~ 75% measured by balance 7.2.3 after wet wiping, the interlining shall be placed in the backlight and the air with constant humidity for natural drying, and then the gray sample card shall be used for judgment according to the provisions of 7.1.5 Note: it is allowed to test the whole leather at 61 specified positions 8 The test report includes the following contents: 8.1 various characteristics of the sample 8.2 whether it is tested according to this standard 8.3 results of each test 8.4 special cases in measures