Heat shrink tubing is a type of polyethylene pipe that shrinks when heated, forming a protective layer around wires, cables, connectors, and joints. Heat shrink tubing is widely used in the electrical, mechanical, and communication industries to protect circuits from the effects of short circuits, faults, and fire hazards.
In this article, we will carefully study the production and use of heat shrink tubing to fully understand its working principle.
Select materials based on specific applications
Polyolefin is the most commonly used material for heat shrink tubing due to its wide range of applications, chemical corrosion resistance, and heat resistance. It can be single-walled or double walled.
The second commonly used material is polyvinyl chloride, abbreviated as PVC. Although this material is cost-effective, it is not as convenient to use as other materials and may burn when overheated.
No matter what material you choose, make sure it has the necessary electrical authority certification, such as UL or CSA.
Heating and extruding materials to expand their diameter
Heat shrink tubing is manufactured using extrusion molding technology. This process involves heating the substrate to form a cylindrical shape under the action of a mold (also known as a die or nozzle). Heating causes the extruded pipe to expand to a larger diameter.
Unlike other extruded products such as window frames and sealing strips, heat shrink tubing undergoes electron beam irradiation during the manufacturing process. This will change the performance of the pipe, improving its strength and heat resistance.
Set aside and let the expanding tube cool at room temperature.
After reaching the desired pipe size, remove the cylinder from the mold assembly and cool it to shape it into the final shape and size of the pipe.
The final result is obtained by cooling the material at room temperature.
Wrap the heat shrink tubing around the component
The final product of extrusion process is heat shrink tubing. Usually, the size of heat shrink tubing is divided based on the shrinkage ratio.
The shrinkage rate of the selected heat shrink tubing is determined by the known expansion diameter of the tubing before heating and the recovered diameter, which is the size required for a tight fit.
Wrap the heat shrink tubing around the wires and cables to ensure a secure connection. To select the correct size, please choose the maximum diameter that can still fit tightly after being completely contracted by the heat source.
Heating causes the tube to shrink and soften
After installing the heat shrink tubing in place, use a hot air gun or other heat source to heat it up. Be sure to use the specific temperature range recommended by the heat shrink tubing manufacturer. The electric heating tools or miniature butane spray guns sold by G-APEX can be used with good results.
Using custom printed heat shrink tubing, heating will not affect the readability of text or images printed on the inner and outer surfaces of the tubing.
Heat the tube from one end to the other while rotating it to ensure even heating. Slowly slide the hot air gun over the tube, maintaining a moderate distance to ensure even heating. After heating is completed, wait for the tube to cool down before proceeding with subsequent operations.
For double walled heat shrink tubing with adhesive, continue heating until some adhesive is observed flowing out from both ends of the tubing.
Cover the circuit or component with a protective layer.
Conventional and custom sized heat shrink tubing can be used to wrap wires, connectors, fittings, and terminals. If there is no protective cover, these products may be damaged due to various environmental factors.
Heat shrink tubing is a flexible shielding layer that serves to insulate, protect, and organize wires and cables. Heat shrink tubing is waterproof, durable, and resistant to chemical corrosion and ultraviolet radiation.
