Heat Shrinking Tubes And Pvc

You might be wondering what the connection between heat shrink wrap and PVC is, but both are widely used materials in modern day construction. In particular, both have a connection for use in electrical engineering.

Polyvinyl Chloride (PVC) is commonly used to create the tubing which protects electrical wires. PVC is formed by polymerizing the monomer vinyl chloride, creating a rigid chain of carbon atoms. For its application as insulation for electrical wires, PVC needs to plasticized. With plastic additives PVC becomes flexible enough to protect the wires even when they bend. However, the plastic additives can become a cause for concern.

In construction the major concern with electric wires that have plastic additives is the release of HCL gas when fires destroy a building. However, in areas where smoke is a major hazard, PVC free insulation is preferred. So long as air is cool enough to be breathed the HCL breaks down onto surfaces, making it unavailable for inhalation.

Despite the concerns inherent with burning PVC, the insulation is also prized because it is more flame retardant than other materials. Like PVC, heat shrink tubing has a certain degree of heat resistance. Where shrink tubing differs from PVC is in the result of heating it up.

When heat is applied to shrink tubing two different things can happen. In one instance, a material with many monomers will be heated until they polymerize. When the monomers polymerize the material's density increases as the volume decreases, causing the material to shrink around whatever it is insulating. In the opposite instance tubing is heated, expanded, and then allowed to cool after being mechanically stretched over the material being insulated. Thus when the material returns to its pre-heating size it will be tight around the insulated material.

The most common applications for heat shrink tubing are as insulation for small electrical wires in electrical components and also for computers. Many custom computers feature tower casings with windows and to make the wiring more aesthetically pleasing, manufacturers will use the heat shrink tubing to clean up the appearance of the computer insides a bit, thus preventing a seemingly random winding of wiring.

The tubing can also be used to protect conductors, protect exposed ends of wires, and also protect joints and terminals in electrical engineering applications. Since it can be used for so many different applications the tubing will often be color coded to facilitate easy of system identification when servicing components or computers.