Heat shrinkable tube and its principle

Heat shrinkable materials, also known as polymer shape memory materials, such as polyethylene, polyene hydrogen and other materials are usually linear structures, after radiation or chemical action into a network structure, it is called cross-linking, after cross-linking A new type of polymer functional material manufactured by the principle of "memory effect"

The so-called "memory effect" is the heating of crystalline or non-crystalline polymeric materials such as radiation cross-linked polyethylene.

Above the melting point, although the crystal grains are melted, they do not have a flowing state, but have elasticity such as rubber. If the polyethylene is expanded at this time, the expanded state can be maintained after cooling and setting, if the expanded polyethylene is re-established Heating to the crystallization melting temperature, the polymer material will "memorize" its original shape when it expands and re-shrink to return to its original state, so it is called "shape memory effect"

Use

Heat-shrinkable materials are available in a variety of structures, types, and specifications: tubes, belts, sheets, and shaped parts, which are widely used in automobiles, home appliances, telecommunications, electric power, petrochemicals, and military industries. As an electronic device protection, wire terminal, branch connection, joint insulation, waterproof, zero device anti-corrosion, fixing, etc.

Contraction method

The shrinkage temperature index reaches the lowest temperature at which the heat shrinkable tube begins to shrink. Generally, the material shrinks rapidly. It is recommended that the shrinking ambient temperature should be higher than the shrinkage temperature by 10 ° C to 30 ° C.

Precautions for use

1. In order to ensure the waterproof, sealing and insulation functions of the product after heat shrinking, when using the heat-shrinkable tube, a heat-shrinkable tube of sufficient length should be selected. When heating the double-layer heat-shrinkable tube, the hot-melt adhesive should be overflowed from the casing. The end is better, the size of the heat-shrinkable tube should be reasonable and should not be too large or too small.

2. When heating the heat-shrinkable tube, the stress should be uniform, and the time should not be too long. When it reaches the full shrinkage, local overheating should be avoided to prevent the heat-shrinkable material from aging and becoming brittle, resulting in cracking of the casing.

Storage, storage, transportation

Heat-shrinkable materials should be kept away from direct sunlight during storage, storage and transportation. The ambient temperature during storage, storage and transportation should generally not exceed 50 °C to avoid natural shrinkage of heat-shrinkable materials.