Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is drafted in accordance with the rules given in the GB/T 1.1-2009.
This Standard replaces GB/T 18886-2002 Textiles — Tests for Colour Fastness — Colour Fastness to Saliva in whole. The following technical deviations have been made with respect to the GB/T 18886-2002 (the previous edition):
— in Normative References, replacement of obsolete standards GB 7564 to 7568 and GB 11404 with GB/T 7568.1 to 7568.8; and addition of GB/T 6151, GB/T 6682, GB/T 13765, GB/T 32598 and GB/T 32616 (see Clause 2; Clause 2 of Edition 2002).
— addition of allowable tolerance for the pressure of test apparatus.
— "Test solution preparation" is incorporated into "Equipment and materials"; modification of the formulation of artificial saliva; addition of the pH control index and preparation method of artificial saliva (see Clause 4; Clause 7 of Edition 2002).
— addition of “Note: Other types of fibres can be used with reference to homogeneous or similar fibres” in the requirements of lining fabrics” (see 4.4.2).
— addition of some equipment and materials (see 4.7 to 4.11).
— addition of “Note: For each test equipment, conduct the test with at most 10 combined specimens simultaneously, and each test specimen shall be separated by a plate (11 plates in total). If test specimens less than 10 pieces, remain use 11 plates to maintain the pressure unchanged” in the test procedure (see 6.1).
— addition of the placement of the combined specimen (see 6.2).
— addition of the optional assessment method for the change in colour of each specimen or the staining of adjacent fabric(s) instrumentally (see 6.4).
— addition of items a), b), d), e), f), and g) in test report, and addition of instrument rating results and instructions for rating methods in item c) (see Clause 7).
This standard was proposed by China National Textile and Apparel Council.
This standard is under the jurisdiction of the National Technical Committee 209 on Textiles of the Standardization Administration of China (SAC/TC 209).
The previous editions of the standard replaced by this standard are as follows:
— GB/T 18886-2002.
Textiles — Tests for Colour Fastness — Colour Fastness to Saliva
1 Scope
This standard specifies the test method for determining the colour fastness to saliva of textiles.
This standard is applicable to various textiles.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 250 Textiles — Tests for Colour Fastness — Grey Scale for Assessing Change in Color
GB/T 251 Textiles — Tests for Colour Fastness — Grey Scale for Assessing Staining
GB/T 6151 Textiles — Tests for Colour Fastness — General Principle of Testing
GB/T 6682 Water for Analytical Laboratory Use — Specification and Test Methods
GB/T 7568.1 Textiles — Tests for Colour Fastness — Specification for Standard Adjacent Fabric
GB/T 7568.2 Textiles — Tests for Colour Fastness — Standard Adjacent Fabrics — Part 2: Cotton and Viscose
GB/T 7568.3 Textiles —Tests for Color Fastness — Standard Adjacent Fabrics — Part 3: Polyamide
GB/T 7568.4 Textiles — Tests for Colour Fastness — Specification for Polyester Adjacent Fabric
GB/T 7568.5 Textiles — Tests for Colour Fastness — Specification for Acrylic Adjacent Fabric
GB/T 7568.6 Textiles — Tests for Colour Fastness — Specification for Silk Adjacent Fabric
GB/T 7568.7 Textiles — Tests for Colour Fastness — Standard Adjacent Fabrics — Part 7: Multifibre
GB/T 7568.8 Textiles — Tests for Colour Fastness — Standard Adjacent Fabrics — Part 8: Secondary Acetate
GB/T 13765 Textiles — Tests for Colour Fastness — Specification for Standard Adjacent Fabric of Linen and Ramie
GB/T 32598 Textiles — Tests for Colour Fastness — Method for the Instrumental Assessment of the Degree of Staining of Adjacent Fabrics
GB/T 32616 Textiles — Tests for Colour Fastness — Instrumental Assessment of Change in Colour of the Specimen
3 Principle
A specimen in contact with the specified adjacent fabrics is immersed in artificial saliva; and then the excess test solution is removed and the sample is placed between two plates under a specified pressure in a test apparatus; kept under a prescribed condition for a certain period of time. The specimen and the adjacent fabrics are dried separately. The change in colour of the specimen and the staining of the adjacent fabrics are assessed by comparison with the grey scales or instruments.
4 Equipment and Materials
4.1 Test apparatus
Each group of test apparatus composed of a stainless steel rack and matching heavy hammer with the mass of 5 kg and the bottom area of about 115 mm × 60 mm, and accompanied with glass or acrylic resin plates with the size of about 115 mm × 60 mm × 1.5 mm. when combined specimen, in (100 ± 2) mm × (40 ± 2) mm, is clamped between plates, the pressure of composite sample is (12.5 ± 0.9) kPa. During the test, the structure of test equipment shall be able to ensure the pressure of test sample remain constant after heavy hammer is removed.
If the dimension of combined specimen isn't in (100 ± 2) mm × (40 ± 2) mm, the nominal pressure, applied by heavy hammer, of composite sample remain at (12.5 ± 0.9) kPa.
Other devices may be used provided that comparable results are obtained.
4.2 Thermostat
Maintaining the temperature at (37 ± 2) ℃.
4.3 Artificial saliva
4.3.1 Formula composition
The reagents used are chemically pure, and the test solution shall be prepared with Grade 3 water (4.12) before use.
Each liter of test solution contains:
Magnesium chloride hexahydrate (MgCl2·6H2O): 0.17 g
Calcium chloride dihydrate (CaCl2·2H2O): 0.15g
Dipotassium hydrogen phosphate trihydrate (K2HPO4·3H2O): 0.76 g
Potassium carbonate (K2CO3): 0.53 g
Sodium chloride (NaCl): 0.33 g
Potassium chloride (KCl): 0.75 g
The pH value of the test solution shall be adjusted to 6.8 ± 0.1 with 1% hydrochloric acid solution.
4.3.2 Preparation method
Dissolve the prescribed amount of potassium and sodium salts in 900 mL Grade 3 water (4.12), add magnesium chloride and calcium chloride, stirring constantly, until it is completely dissolved. Immerse the calibrated pH meter (4.11) electrode in the solution, slowly add 1% hydrochloric acid solution, stirring gently, until the pH value of the solution reach 6.8 ± 0.1. Add grade 3 water (4.12) to 1 000 mL, shake well and keep away from light.
4.4 Adjacent fabrics (see GB/T 6151)
Choose either 4.4.1 or 4.4.2.
4.4.1 A multi-fibre adjacent fabric complying with the requirements of GB/T 7568.7.
4.4.2 Two single-fibre adjacent fabrics, complying with the requirements of GB/T 7568.1 to GB/T 7568.6, GB/T 7568.8 and GB/T 13765.
The first piece is made of the same fibre as the specimen, and the second piece is made of the fibre specified in Table 1. In the case of blends, the first piece shall be made of the predominating fibre, and the second piece made of the fibre second in order of predominance, or as otherwise specified.
Note: Other types of fibres can be used with reference to homogeneous or similar fibres.
Foreword II
1 Scope
2 Normative References
3 Principle
4 Equipment and Materials
5 Test Specimen
6 Test Procedure
7 Test Report
