What Is Polyolefin Heat Shrink Tubing?

Polyolefin (a family of polyethylenes) is the leading material for heat-shrink tubing—valued for its flexibility, thermal resistance, electrical insulation, and durability. It’s manufactured via extrusion, then cross-linked (typically by radiation), expanded, cooled, and stored in that expanded form—ready to shrink back snugly around substrates when heated.

Materials & Cross-Linking

• Base Polymers: Includes LDPE, LLDPE, MDPE, HDPE, and EVA variants

• Cross‑Linking Methods: Typically, radiation (electron beam, gamma) at ~50–150 kGy, which links polymer chains into a 3D network. This improves heat resistance, chemical resistance, elasticity, and mechanical stability.

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  Heat Shrink Dual Wall Tubing

  

  Heat Shrink Sleeve Red

  

  Heat Shrink Sleeve Black

Benefits of Radiation Cross‑Linking:

Feature	Benefit
Heat tolerance	Sustains continuous ~125 °C and short bursts to ~150 °C.
Chemical/abrasion resilience	High resistance to chemicals, oils, solvents; abrasion down to ISO 4649 < 0.5 mm
Shape memory	Reverts to original size uniformly for reliable insulation

Shrink Ratios, Temperatures & Specs

• Common Ratios: 2:1 is standard; 3:1 and 4:1 are used for irregular shapes

• Shrink Activation Temps: Begin between 70–100 °C; typical shrink occurs near 90 °C; full recovery ~125 °C .

• Operating Range: Usually –55 °C to +135 °C, sometimes up to +150 °C briefly

• Wall Types: Available in standard, thin-wall, heavy-wall, and adhesive-lined configurations.

Applications

• Electrical insulation: Heat Shrink Joint and Termination Kit, Insulation Protection for Bus Bar Sleeve.

• Mechanical defense: abrasion and strain relief in automotive, aerospace, and industrial settings.

• Environmental protection: seals out moisture, oil, solvents; adhesive-lined variants give waterproof integrity .

• Colour‑coding & marking: available in black, white, red, blue, clear, etc.

• High‑performance sectors: aerospace, military-spec, demanding outdoor or high-voltage uses.

Benefits Overview

1. Thermal & electrical insulation across wide temp ranges.

2. Chemical resistance to acids, oils, solvents; flame-retardant

3. Mechanical strength: abrasion resistance, tensile strength (~1500 psi).

4. Versatile shrink ratios fit various geometries.

5. Secure seals with adhesive liners — dual‑wall options protect from moisture.

6. UV stabilisation possible for outdoor use (usually black).

   
   

Variants & Specs

• Heat Shrink Thin-Wall Sleeve  2:1 

• Heat Shrink Medium Wall Sleeve 3:1

• Heavy‑Wall Sleeve High‑Voltage 3:1

• Dual Layer 3:1

Name of Tubing Use

• Heat Insulating Sleeve 

• Heat Shrink Bus Bar Sleeve

• Heat Shrink Anti Tracking Sleeve

• Heat Shrink Outer Jacketing Sleeve

• Heat Shrink Stress Control Sleeve

• Heat Shrink Cable Repair Sleeve

• Heat Shrink Dual Layer Sleeve (Dual Wall Tubing)

• Heat Shrink Triple Layer Sleeve (Triple Wall Tubing)

• Heat Shrink Oil Barrier Sleeve

Choosing the Right Tubing

1. Shrink Ratio: 2:1 for standard; 3:1/4:1 for irregular fits.

2. Wall Thickness: thin for flexibility; heavy for mechanical or high-voltage needs.

3. Adhesive-Lined vs. Standard: choose adhesive for waterproofing.

4. Operating Conditions: pick materials rated for extreme temperatures, UV exposure, or high voltage.

   
   

Practical Tips

• Use a hot-air gun, LPG gas gun or oven; avoid open flames to prevent scorching .

• Select correct expanded ID based on the largest part to cover.

• Even heat yields uniform recovery; avoid hot spots.

• Watch temperature: exceeding recommended temps can degrade integrity.

Conclusion

Polyolefin heat‑shrink tubing delivers a powerful blend of thermal stability, electrical insulation, chemical resistance, and mechanical toughness. With variants ranging from adhesive-lined to heavy-wall heavy-duty and shrink ratios from 2:1 to 6:1, it’s the go-to solution for wiring, harnessing, sealing, and protecting electronics across industries—from consumer electronics to aerospace, power distribution, transmission and auto.

Let me know if you'd like a detailed comparison chart, sizing guidelines, or sourcing recommendations!