The Startup’s Guide to Injection Molding

The Process for Having Your Part Injection Molded                            

Like any manufacturing process, preparing to have your product injection molded starts well before you are ready for manufacturing. In short, there are five major stages that occur.

1. Initial Product Design

This varies from product to product. For some, this can be the sketch on a napkin, while others begin with a more detailed CAD drawing. Either way, the initial design, with dimensions, functional, and quality requirements is the starting point for your injection molded part.

2. Prototyping

Before you can begin manufacturing, there needs to be some level of prototyping. Before you hit this stage, it is best to consult with potential injection molding partners. They will be able to guide you in selecting various methods and suppliers for prototyping. For some, this may be 3D printing sample parts, while others may need prototype tooling and manufacturing of a small number of parts to understand product risks and functionality.

3. Design for Manufacturing

The design for manufacturing (DFM) phase is one of the most critical in your injection molding process. During this phase, your injection molding expert will work with your team and your product design to prepare it for manufacturing.

Design for Manufacturing includes reviewing a detailed DFM checklist and product requirements outline. Injection molding design requires expertise in understanding risks, product aesthetics, and user interface. This step will help in material selection and mold selection as well.

4. Tool Building

All injection molded parts require its own unique mold or tool. This is an aluminum or steel mold that is specially made for your product. Selecting the right mold is crucial for your immediate and long-term project success.

Your mold is what goes inside the injection molding machine to create your part. It is one of the largest upfront costs in your injection molding process. Depending on which mold you select, this can create anywhere from thousands to millions of parts for you. Your injection molding partner may have an in-house mold builder or will use trusted suppliers to make sure you have a tool that will last you into the future.

5. Manufacturing – Injection Molding

After all that, you are finally ready to manufacture your part. Your mold will be installed in an injection molding machine and parts will begin to be produced. After your parts are manufactured, you will work with your contract manufacturer on any assembly, packaging and shipping needs.

It is also during this stage that you will receive detailed quality outlines of your part, including first article inspection reports (aka dimensions and outlines of the first officially manufactured parts), and additional quality specs depending on your application. Depending on the number of parts you need, you will have parts beginning to ship to you shortly after you begin your production run.