Cold-Forming Plastic Looks Like Acrylic, Bends Like Metal

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By Sean Michael Ragan
Posted 2011/09/30 @ 9:00 am
Category Craft, Education, Science

UK educational supply ~~center~~ centre Mindsets online sells variously-sized 3mm thick sample sheets of Eastman’s Spectar copolyester at not-completely-outlandish prices. Spectar supposedly looks and handles much like acrylic, but with the surprising property that it can be cold-formed without breaking or whitening, and exhibits a memory effect, holding a cold bend until reheated. Chemically, Spectar is similar to the PETE used to make disposable drink bottles, and is commonly abbreviated as PETG. Mindsets is the only online vendor I’ve found, so far, selling small samples of Spectar to consumers.

BY Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.

In the Maker Shed

9 Responses to Cold-Forming Plastic Looks Like Acrylic, Bends Like Metal

nessie on September 30th, 2011 at 4:14 pm said:

You can cold-bend polycarbonate using sheet-metal tools as well, and it doesn’t whiten or discolor. Thick sheets are really tough to bend though, but you can get really nice corners if you’re careful.

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- Bob Darlington on September 30th, 2011 at 5:26 pm said:
  
  This is absolutely not true. You must heat the polycarbonate before bending. It is brittle and will crack if bent cold. Don’t take my word for it, try it for yourself! I work with the stuff daily and it would make my life easier if this were true.
  
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  Frank Wentzel on October 1st, 2011 at 1:19 pm said:
  
  I have made a number of projects from 1/4″ lexan by cold-bending it in a sheet metal bending break. The secret is to flex th lexan a number of time (4 or 5) at ever increasing amounts till you get to the desired angle.
  
  /// Frank ///
  
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- Tim Kemp on October 1st, 2011 at 12:09 am said:
  
  Have you ever tried folding a CD? Bob is right, polycarbonate will crack violently when bent.
  
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Christopher Morse on October 3rd, 2011 at 12:54 pm said:

PETG is not hard to come by. McMaster Carr has it: http://www.mcmaster.com/#standard-petg-sheets/=ebv98b
I didn’t know it has so easy to cold form in thicker sections. That’s good to know. I’ve used it because it is thermoformable at low temperatures. Throw it in boiling water and it’s spaghetti.

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Christopher Morse on October 3rd, 2011 at 12:54 pm said:

PETG is not hard to come by. McMaster Carr has it: http://www.mcmaster.com/#standard-petg-sheets/=ebv98b
I didn’t know it has so easy to cold form in thicker sections. That’s good to know. I’ve used it because it is thermoformable at low temperatures. Throw it in boiling water and it’s spaghetti.

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Christopher Morse on October 3rd, 2011 at 12:54 pm said:

PETG is not hard to come by. McMaster Carr has it: http://www.mcmaster.com/#standard-petg-sheets/=ebv98b
I didn’t know it has so easy to cold form in thicker sections. That’s good to know. I’ve used it because it is thermoformable at low temperatures. Throw it in boiling water and it’s spaghetti.

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Christopher Morse on October 3rd, 2011 at 12:54 pm said:

PETG is not hard to come by. McMaster Carr has it: http://www.mcmaster.com/#standard-petg-sheets/=ebv98b
I didn’t know it has so easy to cold form in thicker sections. That’s good to know. I’ve used it because it is thermoformable at low temperatures. Throw it in boiling water and it’s spaghetti.

Reply ↓
Christopher Morse on October 3rd, 2011 at 12:54 pm said:

PETG is not hard to come by. McMaster Carr has it: http://www.mcmaster.com/#standard-petg-sheets/=ebv98b
I didn’t know it has so easy to cold form in thicker sections. That’s good to know. I’ve used it because it is thermoformable at low temperatures. Throw it in boiling water and it’s spaghetti.

Reply ↓