Frame Material Question

**EyeCon** · 03-11-2005, 09:34 AM

I'm an old salt-pan guy myself, but I prefer hot air units for sports frames due to the fact there are temperature adjustment dials which are more effective in controlling the degree of heat than hot pans...in my earlier days I've cooked my share of frames and poly lenses before I realized frames are made of various materials...but lets get to the question!...Which frame material CANNOT be adjusted using H E A T?...Is it Zyl, Propionate, Nylon, or Polycarbonate?

I've searched past threads for a definitive answer but came up short...I even came across my old nemises...Optyl.

Thanks all,
John Stevenson
a.k.a. Eyecon

**Chris Ryser** · 03-11-2005, 11:07 AM

Originally Posted by EyeCon

.............but lets get to the question!...Which frame material CANNOT be adjusted using H E A T?...Is it Zyl, Propionate, Nylon, or Polycarbonate?
...I even came across my old nemises...Optyl.

If I remeber right , it is NYLON............can not be formed or changed under heat or cold.

Optyl can be formed but you have to hold it until cold and hard or it goes back to the old shape.

Here are some technical details on thermoplastics:
Thermoplastics can be moulded into a shape many times. On heating, they will soften, on cooling they will set. In theory, the process could be repeated an infinite number of times; in practice, slow degradation of the hot plastic renders it inadvisable to carry the process out more than half a dozen times. (Pg. 23 Plastics Technology: Theory, design, and manufacture)

In general, thermoplastic materials will not withstand high temperatures. Teflon is one exception. Thermosetting materials, in general, will not burn, but will char and disintegrate. Thermoplastic materials melt if heated to a high enough temperature. Thermosetting plastics are brittle, whereas thermoplastic materials exhibit varying degrees of ductility.

**Oha** · 03-11-2005, 11:20 AM

I haven't dispensed much nylon lately, but I seem to remember adjusting it by first soaking it in warm to hot water.

**GOS_Queen** · 03-11-2005, 11:28 AM

Nylon doesn't budge ....

PRO-pianate is "pro" heat ...

POLY-aminde doesn't like heat and shrinks ...

(that's how I remember the difference between those two) ..

I just wish it was easier to tell them apart ...