Heat Shrink Tubing
Heat Shrink Tubing is a shrinkable plastic tube used to insulate wires and provide abrasion resistance. It is also used to bundle groups of wires, or provide identification. Heat shrink tubing will shrink its diameter when heated to a specific temperature, with little or no shrinkage along its length.
Polyolefin is the most commonly used heat shrink tubing material. It is used by military, automotive, railway and aerospace industries.
Other materials include PTFE, Viton, Silicon Rubber and PVC.
Single vs. Dual Heat Shrink
Basic 2:1 Single / Thin wall tubing is the most common. This tubing provides a good seal against water and other contaminants. It also strengthens connections, reducing the likelihood they can pull apart. However it achieves this through friction only and typically does not bond with the material it shrinks to.
“Dual” Wall or Adhesive Lined tubing features an adhesive lining. It melts as the tubing contracts forming a truly sealed connection. It also dramatically increases the strength of connections, even making it stronger than the wires themselves.
When to use:
Heat Shrink tubing has many uses. It can be found just about anywhere there are cables and wires. It has functions both for protection and insulation as well as cosmetic.
- Seal water and other contaminants out of wire connections
- Provide electrical insulation
- Insulate against extreme heat
- Color code wire for easy identification
- Bundle multiple wires together
- Cleanly terminate ends of braided sleeving
- Improve the overall look of large amounts of wiring
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Heat Shrink Terminals:
To take advantage of the benefits of heat shrink tubing in wire connections it used to have to be a separate process. You’d have to remember to place a section of tubing on the wire before connecting it. That isn’t the case anymore. You can now create a connection and seal with heat shrink in one process, thanks to Heat Shrink Terminals. These use heat shrink tubing as the insulation on crimp, solder, and crimp and solder terminals.
Curious about how Heat Shrink is made? Here is an excerpt from Wikipedia:
"Heat shrink tubing was invented by Raychem Corporation. It is manufactured from a thermoplastic material such as polyolefin, fluoropolymer (such as FEP, PTFE or Kynar), PVC, neoprene, silicone elastomer or Viton.
The process for making heat-shrink tubing is as follows: First the material is chosen based on its properties. The material is often compounded with other additives (such as colorants, stabilizers, etc.) depending on the application. A starting tube is extruded from the raw material. Next, the tube is taken to a separate process where it is cross-linked, usually through radiation. The cross-linking creates a memory in the tube. Then the tube is heated to just above the polymer's crystalline melting point and expanded in diameter, often by placing it in a vacuum chamber. While in the expanded state it is rapidly cooled. Later, when heated (above the crystalline melting point of the material) by the end user, the tubing shrinks back to its original extruded size.
The material is often cross-linked through the use of electron beams, peroxides, or moisture. This cross-linking creates the memory in the tubing so that it is able to shrink back to its original extruded dimensions upon heating.
For external use, heat shrink tubing often has a UV stabilizer added." See the whole article HERE.