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Unread 24-01-2017, 11:27
GreyingJay GreyingJay is offline
Robonut
AKA: Mr. Lam
FRC #2706 (Merge Robotics)
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Re: Polycarbonate/Plexiglass Ruling

Quote:
Originally Posted by FrankJ View Post
One easy test to tell acrylic from poly. Hit a piece hard against a table top. If it cracks or shatters it is probably acrylic. Wear your safety glasses. So in the robot world. Lexan=polycarbonate=good. Plexiglass=acrylic=bad.
The test I was taught (not sure how accurate) is to look into the cross section. If it's clear, it's acrylic. If it's dark, it's polycarbonate.

I have also done an experiment for a non-FRC related group of kids. I took two identically sized pieces of polycarbonate and acrylic plastic (about 2" by 12"). (Fun note: polycarbonate is easy to cut with woodworking power tools like miter saws. Acrylic, I scored with a knife and snapped.)

To the eye, other than the cross section, both pieces look very similar. Then I folded the polycarbonate in half like a sheet of paper. You end up with a nice 90-degree bend. Then I tried the same with the acrylic, and it shatters into pieces (wear gloves). Insert your favourite object lesson here about things looking the same but being very different inside, don't judge inward strength by outward appearances, looking OK on the outside but handling stress and pressure very differently on the inside, etc.
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