1. Scope This standard specifies the technical requirements and test methods of nylon pre-oriented yarns, which are used to guide production and are the basis for product inspection and rating. This standard applies to all specifications of elastic yarn (DTY) produced by our company. Mainly: semi-extinction, full-extinction, light elastic yarn of circular section and special-shaped section, the linear density is 22dtex-222dtex (20D-200D).
2. Terms and definitions The following terms and definitions are applicable to this standard 2.1 This standard uses the terms and definitions in GB/T3291, GB/T11965 and GB/T4146, and cites some clauses in FZ/T54007-1996. 2.2 Product specifications are expressed by linear density and the number of monofilaments. Considering the usage habits of downstream users, the linear density is expressed in denier (Den) on the product packaging label, such as 70D/24F. 2.3 The batch number of the product is determined according to the company's "DTY Product Batch Numbering Method".
4 Test methods
4.1 Inspection of physical performance indicators and dyeing performance indicators
4.1.1 The linear density test shall be in accordance with GB/T14343.
4.1.2 The test of breaking strength and elongation at break shall be specified in GB/T14344.
4.1.3 Boiling water shrinkage test shall be carried out according to GB/T6505.
4.1.4 The dyeing uniformity test shall be regulated by FZ/T50008.
5.1.5 The test of crimp shrinkage and crimp stability shall be specified in GB/T6506.
4.1.6 The oil content test shall be in accordance with GB/T6504.
4.1.7 Numerical rounding off: The numerical rounding off of each test result shall be in accordance with the provisions of GB/T8170, and the number of decimal places shall be reserved in Table 1.
4.2 Visual inspection
The appearance inspection is carried out one by one, and the light adopts 40W double-tube fluorescent lamp, the illumination is required to be greater than 400lx, the observation distance is 30-40cm, and the two inclined surfaces and cylindrical surfaces of each package are visually inspected. During inspection, the surface height of the package should be parallel to the line of sight.
5 Sampling regulations
5.1 Inspection of physical indicators, sampling according to GB/T6502.
5.2 The dyeing uniformity test is to sample the hosiery one by one for dyeing.
6 Evaluation of inspection results
The grade of the product is determined by the grade of the lowest index in the physical index and appearance index
7 Packaging and Identification
7.1 Put a small label on the inner wall of each bobbin, indicating the product specification, batch number, production date, machine and spindle number, and twist direction (twist direction is not marked for plied yarn).
7.2 The inspected products shall be marked on the inner wall of each bobbin, and different grades shall be distinguished by different markings.
7.3 The packaging materials used must meet the requirements of the company's "Technical Indicators for Raw and Auxiliary Materials".
7.4 Each wire cylinder is packed with plastic bags and packed according to different varieties, batch numbers and grades. The label on the outside of the box clearly indicates the product type (semi-matte, full-matte, glossy), specification, batch number, grade, production date, number of filament tubes, net weight, twist direction (ply yarn does not mark twist direction) and other information.
8 Storage
8.1 The product should be stored in a dry, ventilated and dark warehouse, and the storage environment temperature should be less than 35℃.
8.2 The packing box is allowed to stack up to 10 layers.
