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by CrystalGamma 3187 days ago
> And good plastics are plastic in the traditional sense of the word: if you drop them, they'll absorb the force by deforming and then spring back into place.

That's not what I was taught plastic meant. I was taught both plastic and elastic materials deform under force, but the elastic ones (not the plastic ones) return to their original form once the force is gone …

3 comments

"Plastic" actually stands for "thermoplastic", meaning they can be easily deformed when hot. At normal temperatures, a thermoplastic material can be pretty elastic.
If you drop an iPhone hard enough it wil dent. Drop a polycarbonate phone: no problem. Windows phone wasn't a great OS, but the Lumia line were absolute tanks.
PC is a very impact resistant material, but you can also form it cold, a bit like mild steel, actually.
So is nylon. But nylon is hydroscopic, and thus not well suited for electronics applications.

I do prefer ABS-PC or ASA for a lot of my more-adverse condition cases. They're much more heat resilient, and chemical/UV resistant in ASA's case.

Well, a great many connectors (even, or rather, especially industrial ones) are made from PA6 or 66 with some glass fiber fill; including the actual contact carriers (if they are a separate part). FR4 is somewhat hygroscopic as well; moisture expansion causes real problems for some applications. Never heard of issues with PA connectors.
In mechanical engineering, plastic deformation does refer to permanent/non-reversible changes (as opposed to elastic deformation) past the elastic limit. That said, plasticity is more commonly used to suggest malleability.