Heat-shrink tubing
Description
A type of plastic tubing that will shrink with heat to encapsulate and protect an object placed in its core. Heat-shrink tubing is constructed to shrink radially but not horizontally. Heat is applied using an oven or hot-air gun. Heat-shrink tubing provides a layer of protection or isolation for the interior component. Options available for heat-shrink tubing include single wall or dual wall. The single wall tubing is thinner and easier to slip over another material while the dual wall contains an adhesive liner that will provide a stronger seal. Additionally heat shrink tubing is classified by its shrink ratio defined as the diameter of the original tubing compared to its diameter after shrinkage). The most common types are 2:1 (shrinks to half) and 3:1 (shrinks to one-third). The 2:1 tubing is more flexible and easier to slide over irregular shapes and connectors, while 3:1 tubing is provides a tighter, more secure fit due to the greater reduction in size.
Many thermoplastic polymers can be used, including Polyolefin, Polyvinyl chloride (Tygon), fluoropolymers (Teflon, Kynar), elastomers (Neoprene, silicone), or Viton.
Comparison Table
| Classification | Specific types | Description | Shrink Ratio | Operating Temp | Physical Properties | Cost | Recorded tests Brand name: number (dates) See note below. |
|---|---|---|---|---|---|---|---|
| Polyolefin | An organic thermoplastic with a waxy texture that is odorless, non-porous and non-toxic; adhesive-lined dual-wall available | 2:1 or 3:1 common | to 135°C | Good chemical resistance; excellent abrasion and tear resistance; very flexible | $$ | * McMaster Carr polyolefin: 2 (2011) * DWP 125: 2 (2014) * Ezishrink: 2 (2014) * RNF 100: 2 (2014) | |
| Polyvinyl chloride | PVC, Tygon | A polymer thermoplastic composed of 57% chlorine and 43% carbon; the common plastics has a low cost and is available in many colors, good with irregular shapes | 2:1 common | Up to 105°C; | Fair chemical resistance; excellent tensile strength and abrasion resistance; flexible | $ | * n/a |
| Fluoropolymer | FEP, PTFE, Teflon, Kynar | A fluorocarbon-based polymer with multiple carbon-fluorine bonds; 40% thinner walls than most polyolefin heat shrink; high clarity | 2:1 common | Up to 200°C | Excellent chemical resistance; most have low flexibility; very low coefficient of friction, i.e. non-stick | $$$$ | * n/a |
| Elastomer | Silicone, Neoprene, Viton | A polymer with rubber-like viscoelastic properties; additional properties based on formulation; Neoprene is commonly used in industrial settings; Silicones are used in medical because they can be sterilized | Varies | Depends on formulation | Good resistance to most fluids and solvents; very resistant to abrasion; very flexible, even at low temps | Varies | * n/a |
- Note: The AIC Materials Testing Results page provides information on Oddy tests that were completed on these materials. Access their database, then use the search box to locate materials of interest.
Synonyms and Related Terms
heat shrink tubing
Applications
- Coating metal mounts to provide separation and padding for an object
Risks
- Uneven heat sources, such as a lighter, can result in uneven shrinkage.
- Overheating can cause the plastic to melt or catch fire
Working Properties
Resources and Citations
- Wikipedia: Heat-shrink tubing Accessed Feb. 2025
- Grayline Inc.: Heat Shrink Users Guide
- WKK Fixation Materials: Everything to know about heat shrink tubing
- RS: A Complete Guide to Heat Shrink Tubing
- GTSE: The difference between 2:1 and 3:1 Heat Shrink Tubing