Heat Shrink plastic tubing is expanded, extruded plastic sleeving that is designed to
contract when heated. It is commonly used to provide sealing, termination,
identification, insulation, and strain relief for cables. It has many uses in
electrical, electronic, telecommunications, cable management, and virtually all
other industries, and there are many variations to meet different needs: economical
options for light, unexposed use, general purpose and high temperature versions for
automotive, aerospace and military applications, and adhesive lined heat tubing for
tight seals that keep out dust and moisture.
The most common method for contracting heat shrink is the heat gun. Heat guns range
from moderate heat, fixed temperature versions for general use to variable
temperature models with digital readouts. The heat shrink oven is a costlier and
less portable option, but is more energy efficient.
In addition to heat shrink tubing and heat gun/hot air tools, this section also
features heat shrink connectors you need to take your heat shrink project from start
to finish, including heat shrink labels and high temperature specialized heat
Heat Shrink Tubing: How It Was Invented, and Why We Use It
Sure, heat shrink tubing is cool and fun to use, but have
you ever wondered how it came about, what makes it work, or how many uses it
actually has? If so, CableOrganizer.com can help – just have a quick read
through our FAQs, and you'll be an expert on heat shrink tubing in no time.
Who invented heat shrink? What's the history behind it?
Heat shrink tubing was originally developed by Raychem Corporation in the late 1950s,
when Raychem's chemical engineer founder, Paul Cook, made use of radiation
chemistry (from which his company's name is derived) to develop the two
main products that Raychem was originally known for: lightweight aircraft cable, and
heat-shrinkable tubing. While Raychem pioneered heat shrink polymers, today they're
produced by many different manufacturers, including 3M, Sumitomo, Alpha, Canusa, and
What is heat shrink tubing made of?
Heat shrink tubing can be made of any one of a range of thermoplastics, including
polyolefin, polyvinyl chloride (PVC), Viton®
(for high-temp and corrosive environments), Neoprene®,
polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) and
Kynar®. In addition to these
polymers, some types of special-application heat shrink can also include an adhesive
lining that helps to bond the tubing to underlying cables and connectors, forming
strong seals that can often be waterproof. Another material that is sometimes added
to heat shrink tubing is conductive polymer thick film, which provides an electrical
connection between the two or more conductive objects that are
being joined by the tubing – without the need to solder them first.
What makes heat shrink tubing shrinkable?
You've probably noticed that most plastics you come in contact with won't just shrink
down if they're heated – so what makes heat shrink tubing different? The
answer is cross-linking, the process of exposing a polymer to radiation in
order to create covalent bonds between that polymer's atoms. Following World War II,
it was discovered that radiation was capable of altering the molecular structure of
certain plastics so that they wouldn't melt or develop a flowing consistency, no
matter what temperatures they were exposed to. Covalent bonds also give polymers
plastic memory, which means that once a polymer has been cross-linked and
stretched into an expanded shape, it will automatically shrink back to its original
dimensions when a certain amount of heat is applied.
Does all heat shrink tubing shrink the same amount?
Each type of heat shrink on the market is labeled with a shrink ratio, or
the measurement of how small the tubing becomes when shrunken in comparison to its
original expanded size. For example, heat shrink tubing with a 2:1 shrink ratio has an expanded
diameter that is twice the size of its shrunken diameter. Likewise, a 6:1 ratio indicates that a piece of heat shrink
is capable of shrinking to 1/6th of its expanded size. These, of course, aren't the
only shrink ratios out there; a wide variety is available on the market, but their
ratios can all be interpreted as easily as the two examples just given.
What is heat shrink tubing used for?
Likely to be found just about anywhere there are cables and wires, heat shrink is
extremely useful, both for protection and cosmetic enhancement. It can be used to:
Seal water and dust out of cable splices
Insulate cables and wires against extreme heat in aircraft, boats, and military vehicles
Provide a barrier between cables and corrosive chemicals