PVC Heat Shrinkable Tube
PVC Heat Shrinkable Tube is a thin-wall thermoplastic shrink tube rated -40℃~+105℃, supplied mostly in blue, ID Φ12–Φ600 mm. It recovers at roughly 90–120℃: low enough for lithium battery packs and finished assemblies that cannot take polyolefin's higher shrink heat. Its main uses are non-electrical: wrapping Li-ion packs, finishing component bundles and protecting cable abutments. It is not primary electrical insulation for power cable. Send the pack or bundle dimensions and we return the size.
Specification
| Material | PVC (polyvinyl chloride) |
|---|---|
| Operating temperature | -40℃~+105℃ |
| Shrink ratio | ≥4:1.5 |
| Wall type | Thin wall |
| Colors | Mostly blue |
| Size range | ID Φ12~Φ600mm; for Li-ion packs etc. (non-electrical) |
What it is and how it recovers
PVC shrink tube is a thermoplastic product, not cross-linked. The tube is extruded, then stretched (oriented) while warm and cooled in the expanded state; the orientation is frozen into the amorphous polymer. Heating (typically 90–120℃, within reach of a simple heat gun or shrink tunnel) lets the oriented molecules relax and the tube contracts back toward its extruded size. Recovery temperature is much lower than polyolefin or fluoropolymer tubes, which is why PVC suits battery packs and assemblies that cannot tolerate high process heat. The recovered wall is a snug cosmetic and protective wrap, not a thick dielectric barrier.
Where PVC Heat Shrinkable Tube is used
Primary applications: Li-ion pack insulation, component finishing, cable abutment. On battery packs the tube is the outer wrap over the cell stack, giving a smooth blue surface and edge coverage. On component builds it finishes bundles and covers abutments where two diameters meet. None of these duties ask the tube to carry voltage. That positioning is deliberate, and substitutions into electrical insulation duty fail for the reasons listed below.
How to select the right size
Three inputs decide the tube:
- Pack width and height. For battery packs the tube is usually supplied flat; send the pack width x height and we convert to the flat width and lay-flat size.
- Shrink allowance. The tube shortens slightly during recovery : order length with margin.
- Process heat. Confirm the assembly tolerates ~90–120℃ shrink temperature; most pack builds do, and that low heat is the reason PVC is specified.
Send the pack or bundle dimensions, colour and quantity and we return the size and format.
Common Failure Modes & How to Prevent Them
These are the issues specific to thin-wall PVC shrink tube in pack and component work, with the root cause and the prevention or fix for each.
The wrap loosens after weeks near a heat source
Root cause: PVC is thermoplastic, not cross-linked. Sustained temperature near the top of the -40~+105℃ range lets the oriented wall relax further, and the recovered fit goes slack.
Fix: Log the real sustained temperature at the tube location, not just ambient. Zones sitting close to cells, FETs or joints that run hot should move to cross-linked polyolefin; keep PVC in zones inside the rating.
The wall scorches or discolours during shrinking
Root cause: A thin PVC wall reacts fast to concentrated heat. A gun held in one spot, or an open flame, burns the surface before the whole circumference reaches recovery temperature.
Fix: Shrink at 90–120℃ with the heat source moving, centre outward, or run packs through a shrink tunnel. The low recovery temperature needs less heat than polyolefin, and less tolerance for uneven technique.
Folds and wrinkles on large diameters
Root cause: At the upper end of the Φ12–Φ600 range, recovering around a corner or against a rectangular pack edge, the thin wall folds instead of conforming evenly.
Fix: Size so the supplied ID slides freely and the recovered ID grips. For rectangular packs, specify by lay-flat width from the pack perimeter instead of forcing a round size over a rectangle: send the width x height and we convert.
The wrap comes up short in length
Root cause: Like every stretched tube, PVC shortens along its axis during recovery. A piece cut to the exact pack length loses coverage at the ends.
Fix: Order length with margin past the pack ends. The expected longitudinal shrink is published with the size table so the cut length is right the first time.
Specified into an electrical insulation duty
Root cause: This tube is a thin cosmetic and protective wrap. Used where a dielectric wall is required, it has neither the thickness nor the tracking performance of insulation-grade tubing, and the substitution usually surfaces only at test or in the field.
Fix: Treat it as non-electrical: pack wrapping, bundle finishing, abutment protection. For insulation duty use polyolefin or the material-specific tubes; for medium-voltage joints use the dedicated accessory kits.
The wall splits when pulled over corners in a cold workshop
Root cause: Thin-wall PVC is stiffer when handled below room temperature. Forcing it over a sharp pack edge can split the wall before any heat is applied.
Fix: Warm the tube or the room before fitting, ease the leading edge over corners, and let heat do the final conforming instead of pre-stretching by hand.
Frequently asked questions
What is PVC Heat Shrinkable Tube made of, and how does it shrink?
It is made of PVC (polyvinyl chloride): a thermoplastic, not a cross-linked polyolefin. The tube is extruded, stretched while warm to orient the polymer, and cooled with that orientation frozen in. Heating to roughly 90–120℃ relaxes the orientation and the tube contracts back toward its extruded size. This is why it recovers at a lower temperature than polyolefin or fluoropolymer tubing and suits assemblies that cannot take high process heat.
Does it hold up across the -40℃~+105℃ range?
The rated continuous range is -40℃~+105℃. Because the material is not cross-linked, the wall is at its softest near the top of that range: PVC is a wrap, not a rigid shell. Where a zone sits permanently above the rating or must stay firm when hot, cross-linked polyolefin is the better wall; tell us the sustained temperature at the tube location and we confirm.
How do I size it for a rectangular lithium battery pack?
PVC shrink tube in these large sizes is supplied flat. Send the pack width × height and we convert to lay-flat width and supplied size; the ≥4:1.5 ratio gives room to slide on and still grip after recovery. Order length with margin: the tube shortens along its axis during recovery, and the exact figure comes with the size table.
Can I use it as electrical insulation?
No. This tube is specified for non-electrical work: Li-ion pack wrapping, component finishing and cable abutment protection. Its thin wall is a cosmetic and protective layer, not a dielectric barrier. For insulation duty use polyolefin or another insulation-grade tube, and for medium-voltage joints use the dedicated cable-accessory kits.
What colours and compliance documents come with it?
The tube is supplied mostly in blue. Flame class and RoHS status depend on the grade and are confirmed at order. We do not publish a flame class until it is verified. Certificates are issued per batch; tell us your target market and we align the documentation.
When does PVC beat polyolefin on a pack build?
When the assembly cannot tolerate polyolefin's higher shrink temperature: PVC recovers at about 90–120℃, within reach of a heat gun or a low-temperature tunnel, and the size range runs to Φ600 mm for full-pack wrapping in blue. Where the duty needs higher temperature or a dielectric wall, polyolefin or fluoropolymer stays the right choice. The two are selected by process heat and function, not by price.
Request a quote for PVC Heat Shrinkable Tube
Send the pack or bundle dimensions (width x height or diameter), length, colour and quantity. We return the lay-flat size or ID, and lead time.
Size range & specification notes
ID Φ12–Φ600 mm; used for battery-pack wrapping and other non-electrical protection jobs.