Choosing a Double Shot Molding Process for Reliable Two-Material Bonding

Selecting a double shot molding process starts with matching the material pair to the part specification. Then evaluate how accurately the materials must align, whether the tool needs multiple cavities, and how trial parts perform. Longterm’s custom overmolding molds support combinations such as ABS+TPU and PP+TPE. Before authorizing production, review the mold trial and dimensional inspection results.

Key Selection Considerations

• Verify the material combination: ABS+TPU and PP+TPE are among the listed hard-and-soft pairings.
• Determine the required alignment precision and whether a multi-cavity configuration suits the design and production volume.
• Assess the tooling and samples through a mold trial, dimensional checks, and pre-shipment inspection.
• Consider the application: double shot molds can be used for consumer electronics parts, including housings and accessories.

How to Evaluate the Mold Design

1. Confirm material compatibility

Begin by checking the specified materials against the part’s functional and design requirements. Longterm lists ABS+TPU and PP+TPE as supported combinations. Because the available product information does not include a material-pair testing matrix, ask the mold supplier to confirm the proposed pairing for your specific application.

2. Define alignment and cavity requirements

Review the part geometry and production targets to determine alignment tolerances and cavity count. The custom mold offering includes high-precision alignment, with multi-cavity configurations available as an option. The listed mold steel is 718H / 1.2738, and the stated service life is up to 800,000 shots; confirm that these specifications meet your project needs.

3. Approve samples based on inspection results

Use the mold trial, dimensional testing, and pre-shipment inspection to assess both the tooling and molded parts. Longterm’s custom mold quality checks also include first-article inspection, full-dimension measurement, and mold running tests. A reported double shot overmolding project for a consumer electronics shell in France received customer feedback noting good alignment and stable trial samples.

Longterm holds ISO 9001:2015 certification covering the design, manufacture, and sale of precision molds, as well as the sale of plastic products.

Selection Points at a Glance

Frequently Asked Questions

Recommendation

Choose the process by confirming the material pair, setting alignment and cavity requirements, and approving trial parts against dimensional results before production begins. Longterm provides custom mold making and injection molding, including mold development with plastic injection mass production; the mass-production MOQ is negotiable. For technical information or assistance, contact rogerluo@longterm-mold.com.

About Longterm

Longterm Manufacturing Solutions Limited was established in 2010 and serves international customers with mold design, tooling, precision machining, mold manufacturing, and parts production. Its R&D team includes five engineers focused on molds and precision machining. Capabilities include injection mold structural design, precision CNC component solutions, sample verification, and process optimization. The company is ISO 9001:2015 certified and has worked with customers across multiple industries.