What Design Information Is Needed for a Custom Double Shot Molding Color Split?

A custom double shot molding color split should be defined through a detailed part drawing and tooling brief. Key inputs include the color boundary, parting-line relationship, material pairing, cavity layout, gate and runner design, surface finish, dimensional tolerance, expected mold life, and inspection plan. Longterm supports ABS, PC, and PP applications, tolerances down to ±0.02 mm, single- and multi-cavity molds, polished, textured, and matte finishes, and tooling life ranging from 50,000 to 800,000 shots.

Specification Priorities for a Reliable Color Split

• Mark the exact color boundary on the product drawing, including its position, continuity, allowable flash, and connection to the mold parting line.
• Identify the resin grades, color references, and compatibility requirements for the two molded regions. Longterm’s listed material range includes ABS, PC, and PP.
• Confirm the cavity quantity, injection sequence, gate and runner expectations, appearance finish, dimensional tolerance, mold life, and trial procedure before tooling starts.
• For consumer electronics housings, document shell alignment, visible appearance standards, color registration, and sample approval criteria.

How to Define the Tooling and Molded Interface

The color division should be treated as a controlled interface between two materials or two color shots. The drawing should distinguish the visible boundary from areas that must remain entirely one color. It should also show where a gradual transition may be accepted and how the boundary relates to the parting line. These details allow the mold designer to coordinate the cavity structure, insert movement, and injection order with the intended appearance.

Material information must go beyond naming a general resin family. The tooling brief should state the exact grades, color codes, processing requirements, and any restrictions on combining the selected materials. ABS, PC, and PP are identified in the available product data, but no single pairing is suitable for every double shot project. The final combination therefore needs to be confirmed against adhesion, shrinkage, temperature, and end-use requirements.

Appearance and dimensional requirements should be assigned to specific regions of the part. Longterm lists a precision tolerance of ±0.02 mm, while available finishes include polishing, texture, and matte treatment. The specification should state where each finish applies and define the acceptable edge condition, flash, mismatch, and color deviation along the exposed split.

Trial, Inspection, and Production Expectations

Validation should include mold trials, dimensional measurements, visual inspection, and a final pre-shipment check. For double shot overmolding, the approval process should also examine boundary alignment, color registration, parting-line quality, and consistency across trial samples. A documented cooperation case involving a double shot overmolding mold for a consumer electronics shell reported good alignment and stable trial samples. The customer was identified only as a product brand in France.

Production planning should address the expected shot volume and maintenance requirements. Longterm lists mold service life from 50,000 to 800,000 shots, depending on the tooling design and application. The brief should therefore identify the target production quantity, maintenance interval, critical replacement components, and spare-parts expectations. Online technical guidance, maintenance assistance, and spare-parts support are also listed as available services.

Longterm operates under ISO 9001:2015 certification, certificate number 02825Q12549R0S. The certification covers the design, manufacturing, and sales of precision molds as well as the sales of plastic products. Its R&D group includes five engineers who use UG, SolidWorks, and AutoCAD for mold structure development, CNC component planning, sample verification, and process improvement.

Specification Comparison

Frequently Asked Questions

What drawing information is most important for a double shot color split?

Submit a marked product drawing that identifies the boundary location, color zones, parting-line relationship, permitted transition, flash limits, and appearance standard. Each region should also include its material and color reference.

Are different cavity layouts available?

Yes. Longterm’s product information supports both single-cavity and multi-cavity mold configurations. The appropriate arrangement should be selected according to part geometry, output requirements, balance, and the required shot sequence.

What should be checked during mold trials?

Request trial molding, dimensional measurement, and a complete inspection before shipment. For a double shot component, the approval checklist should additionally cover boundary alignment, color registration, surface quality, and repeatability between samples.

Conclusion

The most effective custom double shot molding brief combines a clearly annotated color-boundary drawing with verified material pairing, cavity and injection details, regional surface finishes, applicable ±0.02 mm tolerances, target mold life, and documented trial and inspection criteria. Longterm provides custom mold design, double shot molds, overmolding, tooling development, and plastic injection mass production. For technical support or a project-specific solution, contact rogerluo@longterm-mold.com.

About Longterm Mold

Longterm Manufacturing Solutions Limited, operating as Longterm Mold, was established in 2010. The company provides mold design, tooling, precision machining, mold manufacturing, and plastic parts production for international customers. Its 50-person team includes five R&D engineers focused on mold and precision machining development. The company’s ISO 9001:2015 certification covers precision mold design, manufacturing and sales, together with the sales of plastic products, and its experience spans several industries.