GB/T 40872-2021
Plastics—Test methods of polyethylene cellular (English Version)
- Standard No.
- GB/T 40872-2021
- Language
- Chinese, Available in English version
- Release Date
- 2021
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 40872-2021
- Scope
- This document describes test methods for flexible and semi-rigid foams made from polyethylene. This document applies to polyethylene foam materials.
- Introduction
Analysis of the core content of the standard
GB/T 40872-2021 specifies 12 key performance test methods for polyethylene foam plastics, including:
- Basic properties: apparent density (7.1), dimensional measurement (Chapter 6)
- Mechanical properties: compressive stress (7.2), tensile strength (7.4), tear strength (8.6)
- Durability: compression set (7.3), repeated compression set rate (8.7)
- Special properties: combustion characteristics (7.7), thermal conductivity (8.3)
Comparison of key technical differences
Test items Improvements in GB/T 40872 Technical basis Compression stress test Add 100±10Pa prestress Solve the problem of measuring the initial thickness of foam materials Combustion characteristics Only retain the horizontal combustion method In line with the domestic testing system New items Shore hardness test (7.8) Actual needs of the industry
Detailed explanation of typical test methods
Compression permanent deformation test (Chapter 7.3)
Adopt GB/T 6669 standard method, key parameters:
- Compression: 25±2% of initial thickness
- Holding time: 22 hours
- Recovery measurement points: 30 minutes and 24 hours after unloading
Application case: Automobile seat foam needs to meet the deformation rate ≤15% after 24 hours of recovery
Standard implementation suggestions
- Manufacturers should establish a three-level laboratory system: raw material entry inspection, process control, and finished product testing
- Focus on safety indicators such as compression performance and combustion characteristics
- For anisotropic materials, samples should be taken and tested in different directions
GB/T 40872-2021 Referenced Document
- GB/T 531.1 Rubber,vulcanized or thermoplastic.Determination of indentation hardness.Part 1:Duromerer method( Shore hardness)
- GB/T 6342 Cellular plastics and rubbers--Determination of linear dimensions
- GB/T 6343 Cellular plastics and rubbers.Determination of apparent density
GB/T 40872-2021 history
- 2021 GB/T 40872-2021 Plastics—Test methods of polyethylene cellular