Geekery: How Injection Molding Works

plastic pellets

How do these plastic pellets become parts for our favorite games and hobby?

Plastic injection molding is used to create millions of different products. In this video Bill Hammack –  a chemical engineering professor at the University of Illinois – details the key engineering principles underlying plastic injection molding, and the technology’s history.

Bill runs a science centered YouTube channel – take the time to check it out. To learn more about how billiards went from using ivory to using plastic check out this fascinating article.


Did you learn anything new?

  • Severius_Tolluck

    Neat, I lived not too far from there for a while.

  • dave long island

    Huh… who knew? I always thought science was to blame for nukes, chemical and biological weapons.. But it’s given us plastic crack too. So it all kinda balances out, ultimately..

  • Bran D

    So what we’ve been calling sprues this whole time are actually runners.

    • Exactly what I took away as well

    • petrow84

      Same here.

    • jazeroth

      yep apparently

    • draekus

      Yup. Its basically the stuff that gets cut off and regrinded for all other plastic products. When it comes to model kits, the runners/sprues are part of the final product.

  • pokemastercube .

    the gunpla kits are kinda the pinicle of plastic injection molding and design personally

    • euansmith

      Have you seen the Unicast stuff from AR? It is some sort of “resin” rather than HIPS, but looks like science so advanced as to be indistinguishable from magic. Single piece models with insane undercuts.

      • draekus

        I got some of the new Prodos Space Crusader models recently. I can definitely say the casting is superb. I was shocked. Much better than FW.

  • Damon Sherman

    he looks so uncomfortable in that chair.

  • petrow84

    Awesome, thanks fo sharing.

  • Admiral Raptor

    Very cool video!

  • AdeptusAstartes

    Dad-crush – will you be my surrogate Dad, Mr. Hammack, Sir?!