Heat shrink tubes in recyclable materials | Global Sources

by Vianie Li & Cecile de Veyra

Heat shrink tubes insulate, protect or reinforce wires, cables and components, shielding them from abrasion, pulling and bending stresses, chemicals and weather conditions. They can also be used to organize and color-code for easy identification. These sleeves are made of recyclable plastics such as PVC and PET.

PVC tubes are usually available in shrink temperatures of 85 and 105 C and diameters of 2 to 200mm. PET variants, however, are better than their PVC counterparts in terms of thermal resistance, electrical insulation and mechanical properties. They are also nontoxic and easier to recycle.

In China, both materials are widely used, in addition to PE and EVA, while R&D work continues to explore other options that suit more rugged applications but are just as recyclable. One alternative, released by Dongguan G-Apex, is made of polyimide. This tubing, which can recover in 180 to 330 C, is rigid and designed for the electronics, chemical, communications and military fields. It can withstand temperatures as low as -196 C, considerably below the -40 to -80 C of conventional products.

Mainstream heat shrink tubes from Chinese manufacturers have a shrink ratio of 2:1, 3:1 or 4:1, flammability rating of VW-1 and operating temperature range of -55 to +125 C. They are made in various colors, with black, red, yellow, green, blue, white, purple and gray widely available. Double-wall types are available, usually used for home appliances, vehicles and electronic equipment. These offer greater protection against corrosion, abrasion, UV and water ingress.

Companies in China ensure their heat shrink tubes comply with UL and RoHS requirements. For materials, they usually source from domestic suppliers.