How to choose heat shrink tubing for custom wire and cable assemblies?

06/08/2021
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Our commonly used heat-shrinkable tubes are PVC heat-shrinkable tubes with a shrinkage rate of 2:1 and double-walled tubes with glue with a shrinkage rate of 3:1.

You can easily complete the shrinkage with a lighter, a hairdryer, or a heat gun.

Heat shrink tubing — also called electrical shrink tubing — is a critical protective and organizational product used in various electrical arrays. This blog post will answer the question: What is heat shrink tubing used for?

Benefits of Heat Shrink Tubing

Versatile and easy to use, heat shrink tubing offers many unique benefits, including:

  • Protection against abrasion, low impacts, and sharp cutting edges
  • Defense against water, chemicals, dust, and other intrusive contaminants
  • Organization of wires and cables into easy-to-handle bundles
  • A smoother texture and finished appearance
  • Electrical and thermal insulation
  • Enhanced structural support for less strain on wires, connectors, and components
  • Compatible with color additives to aid wire identification

Heat Shrink Tubing Materials

Heat shrink tubing can be manufactured from a wide range of thermoplastic materials and is often combined with additives to enhance specific characteristics. Common materials used for heat shrink tubing include:

  • Polyolefin: Polyolefin is the most popular material for shrink tubing due to its thermal resistance. It is more expensive than PVC but capable of withstanding temperatures as high as 125-135°C. This property makes it ideal for manufacturing, industrial, and mechanical applications with high operating temperatures.
  • Adhesive-Lined Polyolefin: To provide a more secure tube that will not slip in critical conditions, manufacturers have created a polyolefin heat shrink tubing with an adhesive inner layer that melts and adheres to the wires and components inside the tube to fill voids and ensure a close fit. An added adhesive offers more support and increased protection from moisture and harsh conditions.
  • PVC: PVC is less expensive than polyolefin but has a lower temperature threshold of approximately 105°C. PVC is durable, strong, and highly abrasion-resistant. It can be manufactured with high clarity, bright colors, and flame-retardant qualities, making it a highly versatile and cost-effective option for low-temperature applications.

Other materials used for heat shrink tubing include PTFE, FEP, elastomers, silicone rubber, etc. The best material type depends mainly on the conditions in which the equipment will operate and the shrink needed to create the desired seal.

Method of calculating the required size of heat shrinkable tube

  • Round object: The diameter of the circle is the diameter of the heat-shrink tube. For example, a 2mm diameter heat shrinkable tube is sufficient for a 2mm diameter wire.
  • Cuboid: Diameter = (length + section) *2/π
  • Cube: Diameter=Side Length*4π
  • Flat object: diameter = flat size *2/π

Quality Heat Shrink Tubing

We provide heat-shrinkable tubes in various colors, sizes, and materials to meet the needs of customers for almost any application.

To learn more about the best heat shrink tubing for your application or to ask about our selection of quality electronic components, contact us today.