What is 3D Molding?

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By Jeremy Losek, Nov 17th, 2020

3D molding is a method of injection molding that utilizes a plastic mold made by a 3D printer. While a traditional steel or aluminum injection mold is ideal for mass production, a 3D mold may be an alternative for prototypes or projects that require lower volumes. Read on to discover if 3D molding is the best choice for your job.

Why Use a 3D Printed Mold?

A traditional injection mold is a hollow shell with a cavity that is used to create the shape of the product being produced. Injection molds are usually made of metal like steel or aluminum. These molds are made using a CNC machine, which can be costly. 3D printed molds are seen as an inexpensive and flexible alternative to the traditional injection mold and are seen as a way to DIY injection molding.

How is a 3D Printed Mold Made?

A 3D printed mold is first designed using CAD software and saved as an STIL and then sliced in G-Code. A 3D printer then prints the mold. Some common materials used to make a 3D mold are ABS, nylon, polypropylene, thermoplastic elastomers, and more.

Before a 3D printed mold can be used with a plastic injection molding machine, it must be supported by a metal frame. This is because the 3D printed mold on its own cannot withstand the pressure and heat used during injection molding. Since the metal frames can be used with other molds, it is easy to alter or switch out the 3D mold used. If the entire mold is 3D printed, more material and time is necessary.

What are the Advantages and Disadvantages of 3D Molding?

A 3D printed mold is an alternative to traditional injection molding, particularly when your projects have a smaller budget and lower volumes. 3D printed molds can be useful when making prototypes if the exact material is not critical and you need a part simply to test the form and fit. A traditional injection mold can be used to produce millions of products and requires precise machinery, time, and expertise to produce and as a result, has a higher up-front cost and lowers unit cost as more parts are made. In contrast, 3D printed molds will not last as long as traditional injection molds, so their up-front cost is considerably cheaper. This can be an asset for jobs with low to medium volume production requirements. Additionally, 3D printed molds take less time to design and produce and are generally easier to alter the design as needed.

There are some downsides to using 3D printed molds. First, since the plastic material used to make the mold has a longer heating and cooling phase when compared to steel, aluminum, or other metals used by traditional injection molds, it can take longer to produce products. This can drag out overall production time, result in lower volumes, and increase production costs. To counteract these thermal conductivity issues, an additive can be added to the mold materials. 3D printed molds, like other 3D printed objects, can suffer from shrinkage during cooling, which can present a major issue for jobs that require precision. Lastly, unlike metal injection molds, plastic 3D molds cannot handle high pressure or temperatures for long periods. The degradation can be negated by adding a protective coating of metal, ceramic, and oxides on the 3D printed injection mold.

Whether or not you will benefit from using 3D molding largely depends on your project requirements. If you are on the market to produce a smaller batch of parts and have a limited budget or time, then 3D molding may be right for you. Please contact ICOMold today at (419) 867-3900 if you have any further questions about 3D printing.

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