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It’s rather obvious that Lego bricks are made from plastic, but there are many kinds of plastic.

Is the recipe for LEGO bricks plastic secret?

Zhaph - Ben Duguid
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mikl
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  • Very similar to http://bricks.stackexchange.com/questions/155, but potentially different enough ;) That question notes that the Transparent bricks are made from a different type of plastic. – Zhaph - Ben Duguid Oct 26 '11 at 12:39

2 Answers2

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Actually, it depends on the part.

Most parts are indeed ABS as it's a very sturdy plastic, but sometimes it's not suitable, or downright impossible to use. I've seen a presentation on quality issues given by a LEGO employee in LEGOworld a few years back, and as far as I remember there were between 10 and 20 sorts of plastic in use. The ones I remember are:

  • ABS (acrylonitrile butadiene styrene) for most regular bricks
  • PC (polycarbonate) for transparent bricks, as ABS can't be made transparent. Polycarbonate parts on the other hand have too much friction when in contact with other polycarbonate parts, making them extremely hard to disassemble. LEGO designers are forbidden to have some PC parts put together in models.
  • Rubber for tires and rubbery things - that's kinda obvious
  • A less sturdy plastic (can't remember the name) for parts which are more subject to being bent, for example studless technic beams.
  • As of 2018 plant elements will be made from a polythylene sourced from sugar cane.

And the list goes on. I know the presentation hadn't been made public, but some people took pictures, so if I ever find it back I'll add a link.

EDIT: still can't find it, but I know it was given at LEGOworld in 2006 by Bjarke Schønwandt who was Global Quality Manager at LEGO at the time (he may still be, I have no idea).

Zhaph - Ben Duguid
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Joubarc
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    "Polycarbonate parts on the other hand have too much friction when in contact with other polycarbonate parts, making them extremely hard to disassemble. LEGO designers are fobidden to have PC parts put together in models." Details like this are exactly the kind of information I'm looking for on this site. Thank you! –  Oct 26 '11 at 13:19
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    Rubber for tires - Really? Actual tree rubber? – fredley Oct 26 '11 at 13:25
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    @Fredley I honestly don't know about that (I had forgotten rubber can be natural) but it's most certainly synthetic. Let's not forget LEGO is the first tire producer in the world (in terms of tires produced per year) – Joubarc Oct 26 '11 at 13:30
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    I'm pretty sure that the tyres are not made from real rubber, but some of the elastic bands used with Technic might be. Natural rubber does degrade over time, so I wouldn't be surprised to learn that it's another synthetic compound. – mikl Oct 26 '11 at 13:39
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    LEGO tires do degrade over time. Well, at least in GBC modules they do. – Joubarc Oct 26 '11 at 13:40
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    @mikl Indeed - most of my original black rubber bands have degraded, although some of the newer sets have a different style of rubber band that seems slightly firmer, and are circular in their cross-section rather than square. – Zhaph - Ben Duguid Oct 26 '11 at 13:55
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    Polypropylene is typically used for "living hinge" molded parts. I can find a cite for this. – Erik Olson Oct 26 '11 at 20:44
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    ABS is not just one plastic: it is a copolymer and is extremely customizable by varying the inputs. There are frequently used commercial formulations though. – Erik Olson Oct 26 '11 at 20:47
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    It's also worth recording that most clones are polystyrene, which is roughly half the cost and can't be made as elastic as ABS. – Erik Olson Oct 26 '11 at 20:50
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    I love legos too :D –  Dec 30 '14 at 12:32
  • The rubbery parts are now made with some sort of butylated material. So, pretty much synthetic rubber. –  Feb 20 '16 at 14:08
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According to a letter from a LEGO representative posted at this site:

Tires and elastic materials found in some LEGO sets are manufactured from Styrene-Butadiene Styrene (SBS), a material commonly found in vehicle mud guards and shoe soles.

62Bricks
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