Heat Shrink, invented by the Raychem Corporation, is a tube that shrinks in diameter when heat is added. The diameter and thickness can vary, but they are all rated according to their expansion ratio. Heat shrink comes in a variety of colors for easier color coding of wires and connections. Heat tubing insulates cables and wires and offers abrasion resistance as well as environmental protection for conductors, connections, and provides a snug fit over irregular shaped joints. It also offers protection from dust, solvents, and other foreign materials.
Usually heat-shrink tubing is manufactured from polyolefin fluoroplymer (FEP, PTFE, KYNAR), PVC, Neoprene, Viton or Silicone Elastomer. These materials are often cross-linked to help the tubing maintain its shape, before and after shrinking. Tubing that is meant to be used outdoors is generally treated with a UV stabilizer.
Currently the leading global producers are Tyco, 3M, and Sumitomo Electric Industries.
Heat Shrink Rations:
- 2:1 - Shrinks to half of its original diameter.
- 3:1 - Shrinks to a third of its original diameter.
- 4:1 - Shrinks to a fourth of its original diameter.
- 6:1 - Shrinks to a sixth of its original diameter.
Types of Heat Shrink:
- Thin Wall: used in confined and tight spaces to bundle, insulate or identify cables.
- Medium Wall: ideal for direct burial of heavy duty electrical cable, or where environmental protection is needed.
- Thick or Heavy-duty Wall: great for electrical insulation, waterproofing and mechanical protection of tubes or wires.
- Heat Shrink Kits: varity of sizes and colors to suit most applications.
- Heat Shrink End Caps: shaped like small mugs, may be used to insulate cut ends of wires and cables, as well as provide extra protection against moisture and abrasion.
- Specialty Heat Shrink: PTFE (offers the lowest coefficient of friction), Neoprene (exceptional fluid and solvent resistance), Viton (ideal for cable bundling and protection)
How to Use:
Generally the tubing is positioned over the connection to be protected and then heated with an oven, heat gun, or hot air. There are other methods to shrink the tubing such as using a soldering gun or open flame, but they are less effective. Car should be given when using heat tubing as it can melt or catch fire like any other plastic.
Heat shrink tubing is used to insulate wires and cables, as well as to protect them from minor abrasions. It is also used to repair wires, bundling, and create seals for cable entries and connections. Heat shrink is used in home electrical systems, aerospace, military, telecom, computers, aviation and more.