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Old 11-24-2012, 03:51 PM
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ogilvyspecial ogilvyspecial is offline
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Location: Michigan
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jeffshead, I spent a few years working in Buick's plastic plant and the
"scalloped" look that you are seeing above the switch area we called
"flash" and, per our parameters, always had to be trimmed off.

There were a few reasons this happened, first was that the high,
or low, injection pressure on the machine wasn't set properly.

The other, most common, cause was when a press went down for a few minutes,
or longer. While the process was sitting idle the plastic would heat up in the
system and, as a result, would become thinner (melted more than the norm)
so it flowed better and could work itself out around the edges of the die.

With that said, some dies were better than others and, in some cases, the
parts always had some flash when they came out of the press, which we had to
trim off. I can't speak to CT's process, maybe that's an acceptable amount
of flash, or maybe the person who was responsible for checking the parts
after they came out of the press simply didn't trim it off, or missed it entirely.

With that said, based on your close-up photo, my guess is that your part came out
of a press that had been down a little while and this was one of the first parts that
came out that looked like they were getting things back in sync. In addition to the
plastic heating up too much, the surfaces of the die are also cooler (after sitting idle)
than when a press is "pumpin' 'em out." So, what you end up with is plastic that
wants to flow "too much" and a cooler die surface that slows it down "too much."

I'm sure that your grips are serviceable, but, if it were
me, I'd send them back and see what they said about it.
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