Invented in the late 50’s and early 60’s by Paul M Cook of Raychem, the original patent for heat shrink tubing describes extruding and stretching plastic/polymer tubes (up to 400 – 800% times larger) then treating or curing the tubing in such a way that when heated (usually by a heat gun) to a certain temperature, the tubing shrinks back to the original size. This shrinking is basically caused by the heat disrupting or melting the crystalline structure that upholds the expanded size. So basically, it’s not really shrinking, it’s returning an enlarged tube back to its normal size.
But it’s so much easier to say heat shrink tubing.
Cold shrink tubing is cold in the sense that it doesn’t activate by use of heat and instead shrinks by way of removing the central support tube. There isn’t as much information online about the origin of cold shrink as there is with heat shrink tubing, but it appears that with cold shrink you have an expanded tube made of various rubbers, and rubber compounds, but it’s kept enlarged by the support column. When the support is removed, the tube again returns to the normal size. It’s regarded as slightly more cost and time efficient solution in that it works without heat and generally goes a little quicker. Just make sure to select the correct size to ensure a proper seal, the previously linked video seems to show that it doesn’t seal well when compared to heat shrink and it could be that they used too large of a piece in that video. Cold shrink tubing is also different from heat shrink in that is typically made of rubber elastomers whereas heat shrink tubing is made of thermoplastics like PVC, Viton, polyolefin, neoprene and more. Each type of shrink tubing works best in certain situations and knowing which one to use is preference or specified by the job you’re doing and the tools you have available.
Presently, in addition to the other brands of shrink tubing we carry, we’re carrying the full catalog of 3M heat shrink and cold shrink tubing and to help you find the right one, you can check out these 3M brochures that get incredibly technical for hot and cold shrink tubing. The brochures get into the available sizes and potential uses for each type of shrink tubing and the heat shrink tubing brochure categorizes the tubing as described below. If you don’t see a part number listed on our site be sure to let us know and we can help you get it.
The heat shrink tubing products made by 3M come in a variety of styles, each intended for different uses. The single-wall polyole heat shrink tubing which is a thin and flexible tube that is somewhat flame resistant. This style is used for insulation, wire marking and strain relief, among other things. The adhesive-lined polyolefin heat shrink tubing features an inner wall that melts some adhesive to promote a secure bond. Heavy-duty heat shrink tubing (including bus and bar tubing) has thicker and tougher walls to protect against abrasions and they may or may not have adhesive as labelled. Specialty polymer tubing is made for especially sensitive wiring or extreme environments such as high heat, locations near petroleum or other volatile chemicals.
In addition to these varieties, 3m also makes heat shrink tubing kits which feature an assortment of colored varieties or just plain black. We currently carry the Scotchlok heatshrink terminal kit and the assorted black kit. The kits are a convenient and affordable way to get a lot of common-sized heat shrink tubing.
For a technology that’s been around for just 60 years, heat shrink and cold shrink tubing has become an invaluable and essential tool to keep around. Useful for protecting, organizing, stabilizing, lifehacks, and more, 3M heat shrink tubing will help you with any of the jobs you’ll need it for.