1. Heat-shrinkable materials: Based on plasticity linear polymers or polymer alloys, polymer molecular chains are partly crosslinked by high-energy irradiation or chemical methods to obtain elastic "memory effect". After being heated and expanded to a specific size, they are cooled and shaped. When heated to a suitable temperature, they shrink to the shape and size before expansion. This material is called heat. Shrinkage material.
2. Heat-shrinkable sleeve: The tubular intermediate product of specified size can be obtained by extrusion forming of the above polymer or polymer alloy. After irradiation (or chemical) crosslinking, the tubular product with certain size can be heated and expanded, and then cooled to form a heat-shrinkable sleeve.
3. Definition of Cold and Heat Shock Test for Copper Exhaust Heat Shrinkage Pipe
Cold-thermal shock test, also known as temperature shock test or high-low temperature impact test, is used to check the adaptability of copper heat-shrinkable tube to the rapid change of ambient temperature. It is an indispensable test in routine test in batch production stage, and can also be used in environmental stress screening test in some cases. It can be said that the frequency of application of cold and hot shock test box in verifying and improving the environmental adaptability of copper heat exhaust shrinkage tube is second only to vibration test and high and low temperature test.
4. Common Implementation Standards
(1) GJB 150-86 Environmental Test Method for Military Equipment
(2) GB 2423 "Basic Environmental Test Rules for Electrical and Electronic Products"
(3) US Military Standard MIL-STD-810F Environmental Engineering Considerations and Laboratory Tests
5. Purpose of cold and hot shock test
In fact, as a tool, the cold and hot shock test box is used in different stages of product development for different purposes:
(1) The engineering development stage can be used to discover the design and process defects of copper heat-shrinkage tube.
(2) Providing the basis for the finalization or design appraisal of copper heat-shrinkable tube and the acceptance decision-making at the batch production stage;
(3) As an application of environmental stress screening, the aim is to eliminate the early failure of copper heat-shrinkage tube.
Therefore, when compiling the environmental test outline or screening outline, test report or screening report at different stages of the development process, the test purpose of cold and heat shock test should be specified, and it is not appropriate to express ambiguous or general.