GB/T 33338-2016 in English

1. Background and significance of standard formulation

GB/T33338-2016 "Test method for twist of dipped yarn, cord and cord" is an important national standard for dipped fiber products in China, aiming to unify and standardize the determination method of twist of dipped yarn, cord and cord in the industry.

With the development of the rubber industry, dipped products are increasingly used in the fields of automobiles, aerospace, etc., and twist is a key indicator affecting product quality and performance, and its accurate measurement is crucial. The formulation of this standard fills the technical gap in the industry and provides a scientific basis for product quality control.

2. Comparative analysis of standard frameworks

3. Detailed explanation of standard implementation steps

Test environment control:According to GB/T6529 standard, the test is carried out under the conditions of temperature (20±2)℃ and humidity (65±5)%RH.

Sample preparation requirements:

• Impregnated yarn and cord: At least 20 meters must be pulled off the outer layer of the sample, and a sample of more than 600mm must be cut.
• Dipped cord: Samples should be taken at a distance of more than 200mm from the edge of the cloth, and two cord samples should be taken for each cloth.

Pre-tension and clamping length: See Table A.1 for specific parameters. The test conditions for common materials are as follows:
- Dipped polyester yarn: (0.050±0.005) cN/dtex, clamping length 500mm

4. Implementation suggestions and precautions

Equipment selection: It is recommended to use a twist meter that meets the requirements of GB/T33338, ensure an accuracy of 1mm, and have a pre-tension device.

Staff training: Operators need to undergo professional training and be familiar with standard requirements and test procedures to avoid data deviations due to improper operation.

Data recording and analysis: Calculate the twist value strictly according to the standard formula (see formula 1), and do a good job of data rounding to ensure that the results meet the requirements of GB/T8170.