What is Urethane Casting?

Watch our video on Urethane Casting:

Urethane Casting is a process of printing a “master pattern” using PJ3D or SLA to create a mold of silicone gel, which will then be used to cast identical parts using a urethane. Parts manufactured with this process require tooling, a master pattern, and the urethane part material.

Ordering Urethane-Casted parts?

After uploading your 3D CAD file to our instant quoting page, we factor in all the tooling, master pattern, and Urethane Cast parts into the final cost of the total quote. Low quantities are primarily a tooling and pattern fee where larger quantities have those fixed costs amortized among the lot.

Urethane cast parts typically ship in 2-4 weeks with first articles often available earlier.

Tolerances for Urethane Casting

  • We can offer urethane casted parts as large as 30” long.
  • Our typical tolerance on Urethanes is +/- 0.010" + 0.003" per inch. Irregular or overly-thick geometries may cause deviances to normal tolerances due to shrinkage.
  • A shrinkage rate of +0.15% can be expected due to thermal expansion of the liquid, and the response of the flexible mold. 

Possible Finishes

Urethane-Casted parts can be either rigid, flexible, or even rubber-like depending on the composition of the Urethane used. We offer Urethane in a wide variety of color options such as: transparent (standard), black, and color matching. Parts may also be applied with a standard, smooth finish, or a custom finish, which includes adding hardware installations and painting.

How it’s made!

First a master pattern is printed in either PolyJet 3D (PJ3D) or Stereolithography (SLA) to provide an accurate silicone mold. Sometimes tape is placed on flat surfaces to allow for crisp, clean removal of the cast part during post-processing.

Next, the master pattern is encased in liquid silicone to form an accurate mold. After the mold cures it is cut into distinct halves and the pattern is removed. This cavity is used for casting the end product.

A photo of the split pattern. Note that features that may fatigue, such as through holes, are replaced with dowels.

Once the mold tool is created our production will use urethane and other resins to fill the voids. The material will cure and be removed from the tool. This process repeats until the project is finished!

Urethane parts have great end-use applications and can often bring a project to its next level for end-user testing or short run production.

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