What’s heat shrink tubing?

[ad_1]

Heat shrink tubing is a type of plastic tubing that shrinks in diameter when heated. The materials used to make heat shrink tubing vary, but include complex polymers and similar materials. Heat shrink tubing is most commonly used in electrical applications to protect, insulate, or repair wires, terminals, and other types of electrical connections. Extend the life of these items and ensure their good performance.

Depending on the exact type of material used, there are two main ways heat shrink tubing can work. Pipes may be specially treated during the manufacturing process to shrink when heated. This type of pipe is said to be based on expansion. When it is made, it is heated near its melting point and stretched to expand its diameter. It is then rapidly cooled to help it hold its shape. When heated later in consumer use, the tube will shrink to the size it was before it was first stretched.

There is some suggestion that heat shrink tubing may be made through a process that involves a change in the chemical structure of the material itself. In this type of tube, many monomers — individual molecules of a given compound — will group together into chains when heated. This process is called polymerization. As the monomers stick together more tightly, the material actually shrinks. However, the difference in size before and after curing isn’t dramatic, so it seems likely that nearly all heat shrink tubing is at least partially based on expansion.

Each type of heat shrink tubing on the market has its own shrink ratio, i.e. degree of shrinkage. Pipes with a shrink ratio of two to one, for example, will shrink to half their original size. One that has a shrink ration of six to one will shrink to one-sixth of its original size. The shrink ratio needed will depend on the specific application the hose is being used for. Heat shrink tubing has a number of common uses, such as insulating outdoor wires and cables against the elements, bundling multiple wires together, and color-coding wires for easy identification.

Raychem Corporation was the original developer of heat shrink tubing in the 1950s. While all plastics shrink when heated, the company has developed a way to treat plastics to shrink, but not melt or degrade, even at very high temperatures. They found that when some polymers are exposed to radiation, they develop stronger internal chemical bonds. This process became known as cross-linking and gives the pipe the ability to shrink down to its original size as well as imparting very high strength and durability.

[ad_2]