Subject:
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Re: how odd!!!!
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Newsgroups:
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lugnet.general
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Date:
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Sun, 27 Apr 2003 19:10:59 GMT
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Viewed:
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677 times
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In lugnet.general, Thomas Stangl writes:
> The tannish bricks are raw ABS with no pigmenting, so they were probably snuck
> out of one of the plants, or someone threw them in a trash bin instead of
> shredding them. They were most likely test runs of a mold or the entire >molding process - why use expensive pigmented ABS if you have raw ABS laying >around?
They do indeed appear to be raw ABS. The company I work for has one
customer who wants parts made in antimicrobial ABS with the intent of
painting them afterwards, so we decided not to waste money on having the
sheet colored. It all comes in this milky light beige sort of color, and
we've noticed that a couple sheets that were left in our drybox (kept at
about 140F) for a few months started to develop darker brownish spots, which
could explain why the uncolored bricks are not of a uniform shade. Then
again, we can't really be sure it's not the antimicrobial additive breaking
down.
As for TLC using uncolored plastic...I remember hearing at one point
that they purchase their proprietary formula of ABS resin from another
company, which leaves me unclear as to whether they would receive raw ABS
seperately of the coloring agents, or if they would only receive pre-colored
ABS (we work with extruded sheet, not resin pellets). If it's the latter,
black should actually be the cheapest, since it can be colored with carbon
powder (i.e. coal). Anyways, most injection molding companies tend to use
whatever's loaded into the barrel at that specific time, since it's still
cheaper to use more expensive colors than it is to purge the barrel and load
it up with the cheapest color available. Of course, things change, so even
if they get pre-colored resin now, it doesn't mean they always did in the past.
> Or as someone else noted, they may have been some hand-molded tests, and they
> used liquid ABS mix instead of melting pellets.
There's no such thing as liquid ABS. It's an amorphous plastic, which
means it gets gooey if you get it hot enough, but it never actually melts
like a crystalline or semi-crystalline plastic will. The closest it gets to
being a true liquid could be compared to well-chewed gum. Even then, you'd
still really need to have some sort of injection molding machine to force
the gooey ABS into the mold. It's not the sort of thing you can really do
by hand, unless you plan to carve the piece out of a large chunk of ABS.
And as for the mixed-color bricks, there was an Ask Redini where
someone asked if there are any two-color bricks. You can find that question
here:
http://club.lego.com/ask/archive.asp#04_multicolorbrick
I've actually got one light-grey 12-tooth double-bevel gear with a very
small patch of white on the side of two teeth, but other than that the only
two-color bricks I've ever seen are the Bohrok faceplates.
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Message is in Reply To:
 | | Re: how odd!!!!
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| The tannish bricks are raw ABS with no pigmenting, so they were probably snuck out of one of the plants, or someone threw them in a trash bin instead of shredding them. They were most likely test runs of a mold or the entire molding process - why (...) (22 years ago, 22-Apr-03, to lugnet.general)
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