Dual wall heat shrink tubing is manufactured by co-extrusion of polyolefin(PE)and a hot-melt adhesive inside, also name dual wall tube or heat shrink double wall tube. With properties of excellent insulating, nvironmental sealing, and resistant to impact and abrasion. Dual wall heat shrink tubing widely used electronic equipment waterproof, wire branch corrosion protection, cable repair, even for Pump and submersible pump waterproof.

First,usually shrink ratio is 3:1, but also have 4:1 for special request. Since the big shrink ratio, dual wall tube suit for many irregular shape products’insulation and sealing, it has diameter from 3.2mm-50mm. For packing, sizes over 9.5mm are pack in piece(standard is 1.22m/pc), because its flexible is not allow to pack in rolls. Since with inner adhesive, Dual wall tubing is thicker than halogen free heat shrink tubing but lower flexible(outer PE material is flexible).

Secondly,Black is standard color, special red, blue, white and yellow are available on request. Also supply clear one but non-flame retardant jacket. middle thickness, can be applied to cable repair and splice waterproof, which under 10KV voltage. Its inner adhesive can sealing material like plastic, rubber, metal,etc.

lastly, it starts shrink at 80degree, fully recovery temperature 120degree, inner adhesive melt from 80degree to 100degree, working temperature is -45degree to 125degree. PE material should be flame-retardant and envovironment.

When choose dual wall heat shrink tubing, you need sure size, shrink ratio and color. Black is first concide, Since usually used in bad condition, Colors are not so necessary, and it is more expansive(need add masterbatch), but color is depend on customer’s request. For the size, usually supply 3.2, 4.8, 6.4, 7.9, 9.5, 12.7, 15, 19.1,25.4, 30, 39, 50mm. If you cable out diameter is 7mm, you need choose 9.5mm or 12.7mm one, big one is more easy to cover and more thick after shrink. Small one maybe has some difficult to execute but more cheaper. Its flame-retardant depends on the property of BFRs and percentage.