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Dunbar Heat Shrinkable Tubing crosses: Raychem, Sumitomo,
3M, Canusa, Insul-Tab and Alpha.
*
(On most orders placed by 1 pm PST, 2 pm
MST, 3 pm CST and 4 pm EST)
| | Frequently Asked
Questions
- What is the
difference between Minimum Shrink Temperature and Operating Temperature?
The minimum shrink temperature is that temperature at which the tubing begins
to recover. Continuous operating temperature is the temperature range
at which the tubing performs optimally while maintaining its integrity.
- What equipment can
be used for printing on Dunbar Heat Shrinkable Tubing?
The Dunbar Advanced Printing System (APS) Thermal Transfer Printer can be used
for making markers.
- Why is MIL-I-23053/5
Class 2 (Clear) neither UL Recognized Nor CSA Certified?
Both regulatory agency standards UL 224 and CSA 198 specify a requirement
known as the "All Tubing Flame Test". No 23053/5 Class 2 product is flame
retardant and therefore will not pass these minimum flame test requirements.
- Do I check
dimensions of Heat Shrinkable Tubing in the supplied or recovered form?
Both the wall thickness and inner diameter of Heat Shrinkable Tubing are
checked in the recovered form only. Wall thickness and inner diameter
dimensions are not specified in the supplied form.
- What does the term
"minimum supplied diameter" mean?
This refers to the inside diameter, or I.D., of the tubing as supplied by the
manufacturer. Typically it reflects a minimum value so that the tubing will
readily slide over the object to be covered.
In the case of tubing that is supplied as a ½-inch, minimum supplied I.D. and
a 2:1 recovery (this means it shrinks to about one-half of its supplied size),
the supplied tubing is always supplied with a minimum I.D. of 0.500-inches.
- What does the term
"maximum recovered I.D." mean?
This refers to
the final inner diameter of the tubing after the tubing has been fully shrunk,
or recovered, through the careful application of heat. A maximum value is
specified to ensure that the tubing will fit snuggly about the object being
covered.
In the case of a tubing that is supplied as ½-inch minimum supplied I.D.
tubing, with a 2:1 shrink ration, the recovered I.D. will always be
0.250-inches. While this tubing may "recover" to fit a 0.240-inch item
snuggly, it will always recover to provide a snug fit to an object
0.250-inches.
- What happens to the
tubing wall thickness when the tubing is recovered?
After recovery,
the tubing wall thickness increase to some extent. Because of some
variability, the recovered wall thickness is generally specified as a nominal
value.
- What size of
Heat Shrinkable Tubing should I use for my application?
The basic answer is that it depends upon the specific application.
A practical approach to determining the size of tubing to use is simply to use
one that will shrink to about 70% of the minimum supplied I.D. For example, to
cover a cylinder of diameter ¾-inch, a tubing with a minimum supplied diameter
of 1-inch should be used. To cover a ½-inch bar, a ¾-inch tube should be used.
Now, for this latter case a 2:1 shrink ratio tubing could be used if one
wished to maximize the recovered wall thickness.
- What is the best way
to recover Dunbar Heat Shrinkable Tubing?
There are several
methods to recover heat shrinkable tubing depending on the type of tubing; open flame,
low velocity torch, high heat light sources to precision hot air sources, the most
common being the standard heat gun. If done properly, any of these sources will result in good tubing recovery; done improperly, each will
provide poor recovery at best and tubing damage at worst.
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