Heat Shrink Tubing
Introduction
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, Silicone Rubber and PVC.
Single v/s Dual Heat Shrink
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.
Importance
Heat Shrink tubing has many uses. Some are listed below:
- 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
Why should we use heat shrink tubing instead of traditional insulation?
Heat shrink tubing provides extensive durability and heat resistance. In most cases, it outperforms basic insulation. Additionally, heat shrink tubing is built to provide the perfect fit and will not come off with age or use (the same cannot be said for electrical tape). Heat shrink tubing is also generally easy to install. Some heat shrink tubing requires costly heat shrink machinery, but some tubing can be installed manually.
Additional Information
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 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.
Heat Shrink Insulated Terminals
These terminals offer superior performance over standard crimp terminals. After crimping, the hot-melt glue lined heat shrink sleeve is heated and shrunk down onto the cable. This increases the mechanical strength of the termination and its resistance to corrosion, as the melted glue effectively seals the joint.
