The Marlyand Plastics Injection Molding contest

Together with Maryland Plastics we will have a contest to see if the creativity of our community can lead to excellent design in injection molded tableware. The winner of the contest will receive $300 in 3D printing from Shapeways.

The top 3 entries will then be evaluated by Maryland Plastics and if the designs meet their exacting standards they will offer the designer a buy out fee. This could mean an additional fee of $2000 for example. But this would depend on the design being injection moldable.. The design has to be injection mold able and fit into Maryland Plastics Crystalware line. You can enter the contest by uploading a model with the tag: injection molding to Shapeways. Your design will remain  your own property unless you decide to accept an offer from Maryland Plastics for the rights to the design.

So tired of all this boring unique, one of a kind stuff? Injection molding, is about millions of copies.

Rules to be Injection Mold able:

The easiest thing to do is pick up something that is made in plastic. You can even look through the Maryland Plastics Catalogs and see how it works. In most cases, a Mold is 2 pieces of steel, that are held together at high pressures, and liquid plastic is injected in the cavities. Then the 2 pieces of steel are pulled apart and the plastic pieces fall out. This can be seen on any injection molded piece. If you look at a plastic fork, there is a seam that runs along the entire perimeter of the fork. This is where the pieces of steel meet. On a plastic bowl or plate, it is usually along the brim. This seam is very important in your design. You must leave a way for the steel to escape.

 For example, this punch bowl shape. Think of 2 pieces of steel. How would you have two pieces of steel to make this design, and then be able to remove the plastic piece? It would require extra moving pieces and be extremely expensive. And when you go to buy plastic stuff, you don’t want expensive. In some cases a 3 piece mold is required.  


In the case of a coffee cup or pitcher, a 3 piece mold is acceptable. It is had to design a handle in a product that wouldn’t require a third piece. If you think about how the steel would need to escape from the plastic, you would see that one piece of the mold would be for the inside of the cup. Then you would need 2 pieces to move in from the sides of the cup to make the handle. If you just had a 2 piece mold, the steel would not be able to pull out from the handle.

Rules for Crystalware:

When you look through the Crystalware catalog, you will see many items ranging from platters to pitchers to plates. What we are looking for is one of two things. Something that will fit along with the items we already have. Or a design of it’s own that would look good in clear plastic. For example you like the design on the pitcher. You could make say cups that compliment the design. Or if you hate the design on the pitcher, and you think another design would look better.

Good luck guys!


  1. Mendel

    Oh, this is a very nice contest!
    Is there a deadline or something like that?

    1. Joris

      The 7th of Febuary. oops, was in the newsletter.

  2. Eric Finley


    Another question, to add to Mendel’s… are we submitting the *mold(s)* or the *model*?

    If we’re just submitting the model, then it seems like an awfully difficult task to assess whether it’s injection moldable. Would there be any way to get feedback from the folks at Maryland on submitted designs, so that there are no “Surprise! You could have won, but it would have required a complicated mold.” moments right at the end.

    1. Joris


      There will be the possibility to ask questions and get feedback. The idea is to have a design that ultimately can be easily turned into an injection mold. So a 30 part design will not work. I’d model the final item and then we can always work with you to help you turn it into a mold after the contest. Try to remain close to the criteria as described above, I think that this is paramount.

    2. Mike

      All you need is the Model. We send that off to the Mold makers and they design the mold around the model.

      Like the description says. Look at anything plastic (well other then 3D printed, blown, or thermoformed) like the fork with the seam. If you look at the top of the fork there are no “undercuts”. That means there is no place that requires a piece of the mold the move in then out to not hit the part as it exits. It’s kind of hard to explain but look over some plastic items you have around and look for extra seams. Those items required more complex molds.

  3. Fx

    I have got some additional questions:
    - Is it required to create the design in U.S. measure units (most of the world use metric system) ?
    - What is the minimum wall thickness ?

    Thanks for the answers !

    1. Mike

      Create it in your native units, I can convert it over to English standard.
      For wall thickness, it depends on the size. I’d say to look at different plastic items. The thinner it is the less expensive to produce, but for this line of products, a little thicker and heavier is needed as this is a higher end line. Overall thickness isn’t going to be too important as weight and thickness are things I can modify usually fairly easily. The main goal here is design.

  4. Anonymous

    hi, just curious what the maximum build envelope is for this design

  5. Mike

    By build envelope, you mean the max size? For this we are completely open.

  6. Fx

    Just to clarify: the newsletter says the limit for this contest is the 10th of february. Joris says in this thread the end is the 7th of february. Which deadline is the right one ? Thank you for the answer !

    1. Joris

      I’m an idiot. I guess we make it the 10th just in case.

  7. Shapeways Blog

    We had a number of great entries for the Maryland Plastics injection molding contest. You can check out the entries here in the special injection molding theme gallery. The people of Maryland Plastics carefully looked and evaluated each model. They said

  8. Tommy Lewis

    I need a manufacturer that can make custom molded, 3D, relief maps with 4 color complete printed surface on one side. It will not be for any structural function – it will be just for display.

    Think map of Texas or Florida…thin like a Halloween mask – but maybe twice as thick – it needs to hang flat on a wall and not bend. I would also like an option where I could suspend the map from 1-2 “strings”
    It would be nice if the factory was in North America – Asia is fine if costing justifies timing.

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