What is heat shrinkable tubing, aka “heat shrink”, aka “shrink tube”, aka “shrink wrap”?
An expanded plastic tube, which when heated shrinks. Since plastics have a memory, the tube is attempting to return to its original size when heated.
What are the common uses of heat shrink tubing?
Typically the tubing is used to repair or cover wires. It’s an ideal alternative to electrical tape providing a professional appearance and durability. Quality heat shrink is an approved (CSA/UL) electrical insulator generally rated for up to 600 volts. Other applications generally are to cover or protect, taking advantage of the tube’s ability to conform to the shape of the item its covering. NOTE: The tubing must be able to slide on.
Are there different types of heat shrink tubing?
The tubing is available in a variety of colors, formulations, diameters, wall thicknesses, various flexibilities, with an adhesive lining and without. Shrinkshop’s heat shrink tubings are never made from PVC, only polyolefin. PVC tubing may melt, burn and release hazardous gases.
Why doesn’t the plastic melt or burn?
The polyolefin tubing is extruded, expanded then passes through an electron beam as part of the manufacturing process. This effectively modifies its molecular structure. This is described as being “cross linked”. The result is a very stable material which will not burn or melt if heated properly.
The most common “shrink ratios” are 2:1, 3:1 and 4:1. When heated, the original inner diameter will shrink to a maximum of 1/2, 1/3, and 1/4 of its original size respectively. There is virtually no shrinkage in the length of the cut tubing.
What is the smallest and largest diameter of tubing available?
This depends on the specific type but the smallest tube Shrinkshop has in stock is 3/64” BEFORE shrinking and the largest is 5”.
What is the difference between “single wall” and “dual wall” or “double wall” heat shrink?
Dual or double wall shrink is called such because the product has an outer wall of the polyolefin and an inner wall of dry adhesive. When heated the inner wall melts and flows to surround and protect electrical connections. There are various types of inner linings, some actually bond to the copper and provide a waterproof, environmental seal. A good way of distinguishing the two types is single wall for indoor and the adhesive-lined for outdoor applications.
Are there any health or safety issues related to the heating of the tubing
Although SDS (safety data sheets) are available for Thermafix ® Heat Shrinkable Tubing, the product is not considered non-hazardous. Of course whenever using a heat gun or torch, caution and safety must be taken into consideration.