Selection Tips for Heat Shrinkable Cable Sleeves: 4 Key Points

2025-06-25 13:49:39

Although small, heat shrink tubing plays a crucial role in cable insulation, sealing, and protection. Choosing the wrong one can result in either electrical leakage or accidents. Based on engineering practice and technical standards, this article extracts five key scientific selection points to help you make the right choice in one go.   

1、 Accurate matching application scenario: environment determines material

-High temperature scenario (>125 ℃):

-Engine compartment/industrial equipment: Fluororubber heat shrink tubing (continuous temperature resistance -65 ℃~200 ℃) is selected, which can withstand corrosion from engine oil and diesel, and has a flame retardancy of V0 level (self extinguishing in 15 seconds).   

-Case: TE Connectivity's BATTU double wall heat shrink tubing is designed specifically for battery Terminals and is resistant to high temperatures of 130 ℃ and automotive liquid corrosion.   

-Chemical corrosion environment:

-Chemical plants and offshore platforms prefer PTFE (polytetrafluoroethylene) casing, which is resistant to strong acids and alkalis, and resistant to salt spray corrosion (such as repairing offshore wind power cables).   

-Dynamic mechanical stress scenario:

-Railway and ship cables require thick EPDM heat shrink tubing (wall thickness ≥ 1.2mm) to resist bending fatigue and pass an axial tension test of 700N.   

>Tip for avoiding pitfalls: Double wall heat shrink tubing with adhesive (inner layer of hot melt adhesive ensures waterproof sealing) must be selected in humid environments, and single wall tubing is only suitable for dry environments.   

2、 Size calculation rule: Outer diameter and shrinkage ratio are the core

-Key indicators:

-Shrinkage ratio: commonly 3:1, 4:1  high shrinkage ratio suitable for irregular objects.   

-Wall thickness selection: For underground buried cables, choose a wall tube with a thickness of ≥ 1.5mm, and for electronic harnesses, choose a thin-walled tube with a thickness of 0.5mm.   

3、 Material performance benchmarking: data-driven comparison

The key performance differences of heat shrink tubing made of different materials are as follows:

>Upgrading trend: EU RoHS prohibits the use of halogens, with preference given to C5-PFK environmentally friendly alternatives (replacing chlorine containing materials).   

4、 Special scenario solution: cost reduction through selection

-Quick Cable Repair:

-Heat shrink tubing kit (such as Mindong WLS series): suitable for 35kV high-voltage cables, suitable for temperatures ranging from -30 ℃ to 60 ℃.  

-Narrow space area:

-Thin walled pre expansion tube (wall thickness 0.5mm): used for PCB board Connectors, with a shrinkage temperature of only 70 ℃ (to avoid damaging components).   

-Ultra high voltage insulation:

-3.3kV digital isolation sleeve: replacing traditional optocouplers, leakage current ≤ 5 μ A (SiC material).   

Mastering the above four points can avoid 90% of the hidden dangers in selection. Technical parameters are the foundation, and scenario adaptation is the soul - in the wave of new energy and intelligence, heat shrink tubing has been upgraded from a "protective component" to a "critical component of safety systems", and scientific selection is the ultimate responsibility for the engineering life.