Subject:
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Re: Melting Point of ABS (Re: Strengthening Gears)
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Newsgroups:
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lugnet.technic
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Date:
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Tue, 5 Mar 2002 18:45:14 GMT
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Highlighted:
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(details)
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4756 times
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The "service" temperature is the limit at what you should operate it at.
The "mold" temperature is how LOW the mold has to be cooled to get a good
shot.
The "processing" temperature is the temperature the plastic has to be when
it enters the mold.
There are very different materials used in LEGO -- they are not a single
type. The standard bricks may be ABS, but the gears are almost certainly a
different material or grade even of ABS. The trees are certainly different,
the corrugated tubes, etc. Different molding methods require different
blends. I am sure LEGO spends a lot of money on plastic and can get custom
blends for just about anything they want.
I just wish the axles were made of stainless steel.
--Jack Gregory
Thomas Avery <thomas.avery@intec-hou.com> wrote in message
news:GsI76v.GED@lugnet.com...
> In lugnet.technic, David Schilling writes:
> > A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> > has a melting point of 103-128°C. Since water boils at 100°C, I don't • have
> > any doubt that you would see some deformation by that point.
>
> There are different grades of ABS, each having different mechanical
> properties. I found an extensive resource on materials at: • http://www.matweb.com
>
> The ABS property data can be found here:
> http://www.matweb.com/abspolymer.htm
>
> I picked 3 grades of ABS that seemed likely to be the type(s) that Lego
> uses, but I'm not sure:
>
> ABS, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1100
> max service temp in air: 140 - 223 F
> mold temperature: 109 - 149 F
> processing temperature: 399 - 500 F
>
> ABS, Impact Grade, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1103
> max service temp in air: 167 - 365 F
> mold temperature: 111 - 149 F
> processing temperature: 410 - 487 F
>
> ABS, Extruded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1106
> max service temp in air: 140 - 212 F
> mold temperature: 136 F
> processing temperature: 392 - 486 F
>
> I'm not sure what the different terms mean, exactly. I can tell you all
> about steel, but nothing about plastic :-)
>
> What I think they indicate (please, someone correct me if I'm wrong) is • that
> the actual melting point is difficult to pick because of the gradual
> softening of the material. I think the actual melting point, or rather the
> point at which the material experiences permanent deformation, is • dependant
> on the applied stresses.
>
> Obviously, there will be a point at which the material deforms under its • own
> weight, and that is perhaps the classic definition of melting. There will
> also be a point at which the material can be safely molded by applied • forces
> without fracturing the material. This point is perhaps the "mold
> temperature". The mold temperature will be much less than the "classic
> melting point".
>
> So, what use is this information? Will Lego pieces melt or not in boiling • water?
>
> The answer is: NO, they will not melt. However, they WILL permanently • deform!
>
> Boiling water (212 F) is much higher than the mold temperatures given • above.
> Therefore it is possible that the self weight of the material, and also
> handling the material in and out of the water, will apply enough stress to
> permanently deform (or "remold" if you like) the bricks.
>
> The experiences that others have stated in the thread reinforces this.
>
> TJ
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Message is in Reply To:
 | | Melting Point of ABS (Re: Strengthening Gears)
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| (...) There are different grades of ABS, each having different mechanical properties. I found an extensive resource on materials at: (URL) ABS property data can be found here: (URL) picked 3 grades of ABS that seemed likely to be the type(s) that (...) (23 years ago, 5-Mar-02, to lugnet.technic)
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