Plastic Enclosures and Temperature Ratings

I’ll let you in on a secret: when it comes to chocolate, I can take it or leave it. Ok, not really a secret to those who know me, but news to you. Now, if there’s peanut butter involved, all bets are off. You’re likely to lose a limb if you try to come between a Reese’s and me. My good friend bought me one of those HUGE Reese’s peanut treats (it’s approximately 6 servings in one bar), which I slipped into my purse for later consumption. I did not notice that while I was driving, it decided to slip itself OUT of my purse. The next day, I attempted to retrieve it from my purse but when I found it wasn’t there, I went to the car and there it was in the back seat. When I lifted it, I discovered it had melted in the extreme temperatures inside the car. Oh the heartbreak.

I could only imagine how I would feel if I were a plastic design engineer testing a product for the interior of an automobile, and found my new product melted around my board. Let me clarify that statement, plastic is not going to melt back to a molten form inside a car, but at certain temperatures the material does become malleable and the slightest bit of pressure can create compression marks or even make the entire enclosure collapse.

Have you experienced temperature-related set backs in your projects? I’d love to hear about your adventures and what options you used to resolve any issues.

Take ABS for instance. The melting point is approximately 176 degrees F (80 degrees C). This means that when exposed to temperatures near 176 degrees ABS material will begin to soften. This is sort of like roasting chicken in the oven for an hour. It doesn’t immediately reach 175 degrees internally at the 60 minute mark, but it does slowly heat up to temperature. You can roast the chicken at 345 or 350 or even 360 and within a few minutes on either side of an hour, you will have cooked chicken. Similarly, when ABS is exposed to hot enough temperatures, the material begins to degrade and soften; leave it long enough and you’ll have a cooked enclosure.

So what do you do if you want to use your Polycase where temperatures may exceed 176 degrees F? Stay tuned to the next post for available options.