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How to Use 3D Printing for Injection Molding

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The majority of plastic products in the world today are manufactured by injection molding. However, fabricating molds can be prohibitively expensive and time-consuming. Fortunately, molds don’t always need to be machined out of metal—they can be 3D printed.

Stereolithography (SLA) 3D printing provides a cost-effective alternative to machining aluminum molds. SLA parts are fully solid and isotropic, meaning that they can withstand the pressure of low-volume injection molding.

Download the Formlabs white paper to learn how to create 3D printed injection molds.

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White Paper

Moldmaking with 3D Prints: Techniques for Prototyping and Production

Interested in other applications of 3D printed molds? Download our white paper that also covers thermoforming and casting with elastomers.

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3D printed injection molds in an aluminum frame with the finished injection molded part.

With affordable desktop 3D printers, tempererature resistant 3D printing materials, and injection molding machines, it is possible to create 3D printed injection molds in-house to produce functional prototypes and small, functional parts in production plastics. For low-volume production (approximately 10-100 parts), 3D printed injection molds save time and money compared to expensive metal molds. They also enable a more agile manufacturing approach, allowing engineers and designers to prototype injection molds and test mold configurations or to easily modify molds and continue to iterate on their designs with low lead times and cost.

Formlabs stereolithography (SLA) 3D printers using High Temperature Resin can produce completely solid, smooth parts that can withstand the temperature and pressure of desktop injection molding. 3D prints produced by SLA are chemically bonded such that they are fully dense and isotropic, producing functional molds at a quality not possible with any other desktop 3D printing process.

Formlabs partnered with Galomb, Inc., which manufactures affordable desktop injection molding machines, to test molds printed on a Formlabs SLA 3D printer. The 3D printed injection molds were able to consistently produce small plastic parts, and showed no surface deterioration after 25 shots of low-density polyethylene (LDPE) plastic.

In the white paper, we discuss:

  • The steps and results of our test with a Galomb desktop injection molding machine
  • Recommendations and best practices for injection molding with 3D printed molds
  • Suggestions for designing and 3D printing injection molds

Download the white paper to learn more about how to create 3D printed injection molds for low-volume, in-house injection molding.

Download the White Paper