JB/T 14514-2024 in English

Analysis of the core content of the standard

Detailed explanation of key technical requirements

The standard stipulates that the heat shrinkable end cap adopts a double-layer structure design: the outer layer is a radiation cross-linked polyolefin heat shrinkable layer (Shore hardness ≥70), and the inner layer is a hot melt adhesive sealing layer (thickness tolerance ±0.20mm). Key performance indicators include:

• Dimensional accuracy: After expansion, the inner diameter tolerance band is ≤±0.3mm (taking Φ6.4 as an example)
• Mechanical properties: Tensile strength ≥12MPa and elongation at break ≥300%
• Electrical properties: Volume resistivity ≥1×10¹²Ω·m

Test method specification

Recommendations for the implementation of the standard

1. Material selection: Radiation cross-linked materials that have passed 158°C thermal aging verification are preferred
2. Process control: The expansion process needs to monitor the concentricity of the wall thickness (≤1%)
3. Acceptance criteria: S-3 sampling scheme is adopted according to GB/T2828.1, AQL=4.0

Technology evolution analysis

Compared with the earlier version, this standard adds:
1) Quantitative indicators for the thickness of the hot melt adhesive layer (such as the Φ12.7 specification requires 1.24±0.20mm)
2) Clarify the corresponding relationship between the dimensions before and after expansion
3) Introduce optical projectors as controversial measurement methods