Injection Molding

Over Molding

HQC has the specialized skill and equipment to do overmolding. While over molding can be and is done on standard horizontal injection molding presses, you might find using rotary presses to load parts to be more cost-effective.

With HQC, you gain a production advantage because when we work on projects that require overmolding, we look at the direct cost implications to you. Depending on your capital and price targets, we evaluate the overmolding process to either fit into our horizontal machines or, if we determine it will achieve lesser cost and a quicker return, use our rotary process. In some cases, because we have the multiple pieces of necessary equipment, we have even used both procedures to reduce expenses even more.

A rotary press allows the part-loading to take place while the other mold with the inserted parts is molding.

Once the molding is done, the mold opens and the other mold with loaded inserts rotates into position to start the process. This saves time, increases consistency and provides you with greater production value. Our great familiarity with both commodity and engineering-grade materials as well as thermoplastic elastomers further allows us to guide you to the most efficient and least expensive process.

At HQC, we look at your project as if it was an HQC project we would do ourselves. We review all of your options, including the designs and costs, for arriving at a product with the best and longest-lasting quality and value. As we communicate and collaborate with you, your knowledge and our manufacturing experience combine to deliver an excellent product to market.

One thing to keep in mind is that overmolding and insert molding are often referred to as the same process. However, overmolding differs in that it takes one plastic material and molds over it with another plastic material. A main reason for this is that thermo bonding can occur when one material melts at a higher temperature than the other. Part design will often dictate what material is inserted into a mold to have the other material molded onto or into it. Overmolding thermoplastic elastomers over other resins or materials can give a soft-touch feel.

Overmolding differs from two-shot molding as well. Two-shot molding requires special injection molding machines and specialized molds. While being cost-effective for large-quantity parts made from two different plastics or colors, two-shot molding must have a high-enough volume to justify its greater expense.

From the start of production, HQC plastic overmolding integrates the necessary quality testing and requirements to ensure a quality product as well as consumer safety and satisfaction.

We currently use our overmolding with an ultrasonic bonding process for medical-device manufacturing that provides the customer with a three-component soft-touch product. The product is also decorated using lean manufacturing to make it highly cost-competitive.