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 developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 2374-2007 Dyestuffs - General rules for dyeing test. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 2374-2007:
——the title and expression of fiber are modified (see 3.3; 3.3 of Edition 2007);
——the structure and expression of dyeing depth are modified (see 5.1; 5.1 of Edition 2007);
——the title and expression of dyed fiber are modified (see 5.2; 5.2 of Edition 2007);
——the expression of standard gradient selection is modified (see 5.3.3; 5.3.3 of Edition 2007);
——the expression of dye bath ratio is modified (see 5.4; 5.4 of Edition 2007);
——the expression of dosage calculation for reagent and auxiliaries is modified (see 5.5.1; 5.5.1 of Edition 2007);
——the title, structure and expression of visual evaluation are modified (see 7.1.1; 7.1.1 of Edition 2007);
——the expression of instrument measurement is modified (see 7.1.2; 7.1.2 of Edition 2007);
——the recommended color difference limit is added for determining whether the color light is qualified in instrument measurement (see 7.1.2);
——the "result judgment" is moved to 7.1.1 "visual evaluation" (see 7.1.1.5; 7.3 of Edition 2007).
This standard was proposed by China Petroleum and Chemical Industry Association.
This standard is under the jurisdiction of Technical Committee on Dyestuff of Standardization Administration of China (SAC/TC 134).
The previous editions of this standard are as follows:
——GB 2374-1980, GB/T 2374-1994 and GB/T 2374-2007.
Dyestuffs - General rules for dyeing test
1 Scope
This standard specifies the requirements for materials and reagents used in dyeing (or printing) test, requirements for instruments and equipment, basic requirements for dyeing test, dyeing process control and evaluation of dyeing result.
This standard is applicable to the dyeing (or printing) inspection and test of various dyestuffs.
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 4841.1-2006 Colour cards of standard depths for dyeing with dyestuffs 1/1
GB/T 4841.2-2006 Colour cards of standard depths for dyeing with navy blue and black dyestuffs
GB/T 4841.3-2006 Colour cards of standard depths for dyeing with dyestuffs 2/1, 1/3, 1/6, 1/12, 1/25
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB/T 6688-2008 Dyestuffs - Determination of relative strength and color difference - Instrumental method
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 25811 Standard bleached polyester fabric used for dyeing test
GB/T 25812 Standard bleached cotton fabric used for dyeing test
GB/T 25813 Standard bleached cotton yarn used for dyeing test
3 Requirements for materials and reagents
3.1 Reagents
The chemical reagents and dyeing auxiliaries used in dyeing test shall be formal products of the factory and meet the corresponding standard requirements. The chemical reagents shall be at least chemically pure. For chemical reagents or other auxiliaries that are not currently regulated by national or professional standards, the specifications shall be specified in detail in the method standards or product standards for various dyestuffs.
3.2 Water for test
The water used in the dyeing test process, including the water for pretreatment and post-treatment of fabrics (except rinsing water), water used for preparing solution of dyestuffs and dyeing reagents, etc., shall meet the requirements for Grade 3 water specified in GB/T 6682-2008.
3.3 Fiber
Yarns or fabrics used for dyeing test shall conform to corresponding standards or quality specifications. The specific variety requirements are as follows:
a) cotton yarn: 14 tex/2(42 S/2) scouring and bleaching 42 double-stranded yarns, meeting the requirements of GB/T 25813;
b) cotton cloth: 25 tex/28 tex(23 S×21 S) scouring and bleaching muslin, meeting the requirements of GB/T 25812;
c) pure cotton knitted fabric: scouring and bleaching knitted fabric;
d) wool fanlidine: scouring and bleaching cloth;
e) wool yarn: scouring and bleaching 219 woolen yarn;
f) polyester fabric: 13 tex/13 tex(45 S×45 S) pure polyester plain-weave fabric, meeting the requirements of GB/T 25811;
g) polyester yarn: 50 three-strand staple fiber yarns;
h) polyester knitted fabric;
i) acrylic bulked yarn: 26 double-stranded yarns;
j) acrylic fanlidine;
k) nylon fabric: plain-weave fabric or nylon knitted fabric;
l) silk: mulberry silk plain-weave fabric;
m) others: if necessary, it shall be specified in detail separately in product standards according to specific conditions.
4 Requirements for instruments and equipment
Various instruments and equipment used in the dyeing test process, including dyeing equipment, balance, glass measuring device, etc., shall be subjected to regular metrological verification and may only be used after passing the verification.
5 Basic requirements for dyeing test
5.1 Dyeing depth
5.1.1 Expression of dyeing depth
5.1.1.1 Dyeing depth in dyeing test
Dyeing depth shall be indicated where color light and intensity or color fastness or other application properties are tested. The dyeing depth in dyeing test is expressed as follows:
——dip dyeing: calculated by the fraction of dyestuff mass relative to fabric mass, expressed in % (owf);
——pad dyeing: calculated by the ratio of the dyestuff mass of dye liquor to the volume of dye liquor, expressed in g/L;
——printing: calculated by the fraction of dyestuff mass of printing paste relative to the mass of printing paste, expressed in %.
5.1.1.2 Standard dyeing depth
In the test of color fastness and some application properties, in order to facilitate comparison, standard dyeing depth should be adopted. The standard dyeing depth is in accordance with GB/T 4841.1-2006, GB/T 4841.3-2006 and GB/T 4841.2-2006, expressed as 1/1, 2/1, 1/3, 1/6, 1/12, 1/25, light navy blue, dark navy blue, light black and dark black.
5.1.2 Selection of dyeing depth
5.1.2.1 Color light and intensity
In the test of color light and intensity of dyestuffs, the dyeing depth shall not only meet the requirements of grading clarity and suitability for evaluating color light and intensity, but also the appropriate reduction of operation error shall be considered. Therefore, the dyeing depth is generally between 1/3~1/1 standard dyeing depth specified in GB/T 4841.1-2006 and GB/T 4841.3-2006. For navy blue and black dyestuffs, the dyeing depth shall also be selected to ensure that it reflects the true color of dyestuffs.
5.1.2.2 Color fastness
In the test of color fastness, one or several grades of depth may be selected for test according to the specific application needs of each dyestuff. The selected dyeing depth for each grade shall meet the requirements of GB/T 4841.1-2006 or GB/T 4841.2-2006 or GB/T 4841.3-2006. Generally, 1/1 or 1/3 standard dyeing depth may be selected, while light navy blue or light black standard dyeing depth may be selected for navy blue and black dyestuffs.
5.1.2.3 Other dyeing properties
The dyeing depth for testing other dyeing properties of dyestuffs shall be specified in standards or test methods. Unless otherwise specified, 1/1 standard dyeing depth specified in GB/T 4841.1-2006 is generally adopted.
5.2 Dyed fiber
5.2.1 Selection of fiber
Appropriate fiber categories are selected according to the properties of dyestuffs to be tested. Yarns or fabrics are selected according to the test purpose. The selected yarn or fabric must meet the corresponding quality specification standards or requirements. Generally, detailed requirements are specified in the method standards or products of various dyestuffs.
5.2.2 Weighing of yarn or fabric
Yarn or fabric used for dip dyeing test shall be weighed to at least 0.01g.
Fabric for pad dyeing and printing may be cut to a suitable area as required without weighing.
5.2.3 Pretreatment of yarn or fabric
Various yarns or fabrics shall be treated before dyeing test, and the treatment methods and conditions shall be specified in detail separately in inspection methods of dyestuffs.
The treated and washed yarn or fabric shall be thrown out with excessive water for later use. The water brought into dye vat together with the yarn or fabric is not included in the volume of dye liquor.
5.3 Dyestuffs
5.3.1 Weighing
Dyestuffs for dip dyeing shall be accurately weighed and accurate to 0.000 2g; dyestuffs for pad dyeing and printing shall be accurately weighed and accurate to 0.001g. During pad dyeing and printing, the dyestuffs standard sample and specimen shall be weighed one by one. During dip dyeing, in order to reduce the effect of weighing error on dyeing result, unless otherwise specified, mother solution with higher concentration shall be prepared in advance, and then a certain volume shall be pipetted from the fully shaken dyestuff mother liquor for preparing dye bath one by one according to the specified dyeing depth requirements, and the volume of the pipetted dyestuff mother solution shall be accurate to 0.1mL.
5.3.2 Preparation of dyestuff test solution
The preparation of dyestuff test solution shall be based on the principle that the dyestuff is fully dissolved or fully and evenly dispersed. The specific preparation method shall be specified in detail separately in the inspection methods of various dyestuffs. Generally, dyestuff test solution shall be used immediately after preparation.
5.3.3 Standard gradient
In the test of color light and intensity of dyestuffs, the standard sample shall be dyed at 3 different depths, i.e. graded dyeing, and the interval of dyeing depths of the three grades is generally 5 points (5%). If the specimen is dyed at two or more depths, the interval of dyeing depths is also 5 points (5%). The color depth of the specimen shall be selected so that the color depth of the dyed sample is within the color depth range of the dyed sample of the standard sample, so as to evaluate the color light and intensity.
Foreword i
1 Scope
2 Normative references
3 Requirements for materials and reagents
4 Requirements for instruments and equipment
5 Basic requirements for dyeing test
6 Control of dyeing process
7 Evaluation of dyeing result
