Plastic Injection Molding: Overmolding

The overmolding process is slightly different from insert molding in that it involves creating a single part using a combination of two or more plastic or elastomer materials. Plastic overmolding can help reduce production time because the second piece is molded directly onto the original part rather than having to completely manufacture the two pieces separately and then assemble them. Overmolding is a difficult process, but Stack Plastics has the capabilities to adhere to the very tightest of tolerances.

Your #1 Source for Quality Overmolded Plastic Parts

Springboard (Stack Plastics) is an FDA registered plastic molding company with ISO 13485 certification and IQ, OQ, and PQ validation. We specialize in low to mid volume production of simple to complex plastic parts for our customers in the medical, automotive, military industries, and more. Request a quote to begin discussing your overmolding project today. Contact us for more information. 

Specialized Overmolding Services to Meet Your Design Requirements

Stack Plastics offers end-to-end overmolding services to ensure your project is a success. From design to final fabrication and packaging, our team of experts will work with you every step of the way to create the ideal solution for your exact needs. With a variety of materials at our disposal and the precise capabilities of our equipment and facilities, Springboard Manufacturing provides highly customizable overmolding services for all your project needs. 

Medical Overmolding

While overmolding can be used to create a variety of products for a variety of industries, it is quickly becoming a staple in medical device manufacturing due its ability to cater to demanding design, aesthetics, and functionality requirements.

Overmolding is often used to create a textured or comfort grip surface on metal components, known as soft touch overmolding. By utilizing this technology, Stack Plastics can create soft-hard, multicolor, nonslip designs for a range of medical devices, housings, and other high performance equipment. Contact us for more information regarding our precision medical overmolding capabilities.

Overmolded Parts Manufactured to ISO 13485 Medical Standards

When it comes to medical device manufacturing, quality is non-negotiable. Our personnel receive training on the following quality standards to ensure the products we produce conform to the stringent requirements of any industry:

  • ISO 13485:2016 certified for comprehensive quality assurance management in the manufacturing of medical components and subassemblies
  • FDA registered
  • IQ, OQ, & PQ validation, demonstrating our facilities & equipment meet current set by the pharmaceutical, medical, and clinical industries

Advantages of Injection Overmolding for Your Application

Plastic overmolding can help reduce production time because the second piece is molded directly onto the original part rather than having to completely manufacture the two pieces separately and then assemble them. Additional benefits of plastic overmolding for demanding applications include:

  • Improves grip and ergonomics
  • Provides electrical insulation
  • Creates a waterproof seal
  • Absorbs sounds/dampens vibrations

Material Combinations Used in the Overmolding Process

Since the materials we use shrink as they cool, special considerations are made during the tooling and development process to accommodate for changes in dimensional tolerance. Because we use several different materials with different cooling/shrinking properties, we can create our molds to match the specific properties of the material(s) being used. Overmolding material options include, but are not limited to:

  • ABS: High resistance to heat, chemicals & impact with a tensile strength between 6,1000 & 6,500 psi.
  • PEEK: FDA-approved, versatile material commonly used to replace metal. Provides high chemical resistance at elevated temperatures, withstands autoclave sterilization, & maintains excellent harness, stiffness, & strength.
  • Acrylic Thermoplastics: Provide excellent weatherability and resistance to UV fading. They feature high tensile strength and are scratch-resistant. Acrylics are also available in FDA-approved grades for use in food and medical applications.

When deciding on material combinations for your overmolding process, it’s important to consider certain properties such as thickness, hardness, coefficients, friction, and more to ensure compatibility between materials. We have extensive knowledge of plastics and exotic resins to help you select the best material for your specific part.

Contact Stack Plastics for Custom Plastic Overmolding Services Today

Stack Plastics provides the end-to-end overmolding molding services you need to stay ahead of the game. Our Springboard stable of state-of-the-art tooling and design capabilities combined with over 300,000 square feet of on-site production space allows us to create high quality molded parts designed to your project’s exact specifications . Read about our other plastic molding capabilities here. Request a quote today to begin discussing your overmolding requirements. Contact us with any questions.