The Beginning of the Plastic Injection Molding Process

Tooling and plastic injection molding. You cannot have one without the other. With the proper tool design, your plastic parts scale properly, and this can save you a great deal of time and money during production. The Tool Room offers this expert advice about how tooling and injection molding work together.

Tooling, also called the mold, refers to the negative cavity space into which melted plastic resin is injected to create a specific part. Excellent quality and high quantity parts require exacting standards in tooling. Tool design is complex, and this is where your capital investment is most prominent. You will also need to allow for enough time before expected production to create an effective tool.

The tooling design process begins with prototype development. Low volume prototypes are necessary for developing, troubleshooting, and validating tooling design during the pilot production phase. This phase, though it may seem redundant, is vital to reduce errors in the manufacturing and assembly process. If your parts are going into high volume production, it is cost beneficial to invest into production tooling for long-term use. Prototypes are beneficial for lower volume runs.

Essential parts of a tool/mold are:

• The cavity half is the side of the tool typically attached to the side of the molding machine. It is immobile.
• The core half is the side of the tool that opens and closes with the molding machine against the cavity half. The core half opens as it is removed from the tool.
• Cooling lines are channels that control cooling of the plastic part.
• The ejector system includes pins on the core half of the tool that push the cooled part out of the tool after molding completion.
• The runner is the flow path for the plastic resin injected into the mold.
• Side actions are the moving pieces within the cavity that allow for undercuts in the part.

Whether your project needs a simple or an intricate simple part, the tooling determines the ultimate quality of the plastic injection molding process and the components created from it. As the foundation of plastic molding, tooling design requires time and expertise. This starts with mold material. Most plastic injection molds are made of steel, aluminum, or alloys. Material choice depends on the complexity and application of the component, as well as production volume and budget.

The plastic injection molding and tooling process also involves acquiring components and machinery needed for the job, including gauges, jigs, fixtures, and other equipment. The effort placed in this phase greatly impacts the quality and cost of the resulting part. Once your tooling has passed rigorous testing and produces the expected result, the mold can enter a regular production schedule.

The Toolroom is your partner in rubber and custom injection molds, plastic molding, machining services, and tool design. We are ready to advise your business on the best choice in injection molding methodology. We are completely committed to providing world-class service and superior quality. The experts at The Toolroom know everything about plastics injection molding so you don’t have to. Our experienced team utilizes leading edge technology for long term tooling solutions. For your next project, call The Toolroom at (573) 437-4154.