Bending 1/2" plastic sheet

[Bobbydog]

Hello all.. I was just wondering if anyone has any experience bending 1/2" plastic HDPE in 4X8 sheets. I'm using a home made jobby at the moment, but I'm looking to buy a good quality professional bender. The ones that Laramy make with the "sword" adapter look like they might do the trick nicely. I could put together a break to fit them in. If anyone has any suggestions, I would really appreciate some input. Thanks in advance. Peace.

Bobbydog

 

[EdClymer]

Greetings

What you need is localised strip heating: we have used an element from a 3 kW fire, stretched and located into suitable hard, heat resistant fibre board groove. Then (in our case) 240 V applied.

The sheet is placed on the heater and turned when one side is hot (or maybe more than once).

Then the sheet is bent through the angle and clamped against a former: cold water soaked towels are used for cooling.

Advantage in using a shallow say 3 mm x 3 mm sawcut on the bend line, to prevent the 'banana' effect due to differential expansion.

Try experimenting with off-cuts.



Ed Clymer
Resinfab & Associates
England

 

[EvOne]

As Ed mentioned you could use localized heating to good effect. Does the bend have to be sharp or could you use a small radius bend? How about a thick walled tube containing a quartz heating rod, nicrome heat strip, even circulated hot water for the inner bending die and a flat heated die for the outside of the bend? This way you would be heating both sides simultaneously and controllably and not get too much thinning (especially if using a radius bend). Could imbed nichrome into one of the heat resistant moldable plaster like products to make the flat die, maybe teflon sheet it for smooth texture and low friction.

David Chapman
Arizona Electropulsion / Fine-Junque

http://www.stores.ebay.com/theworldoffinejunque