Setting Defect Limits and Claims for Plastic Molded Parts

To prevent disagreements over molded parts, define acceptance criteria and claim procedures before tooling or production starts. Put the approved drawing, dimensions and tolerances, resin, surface finish, cavity details, inspection steps, and remedies in the purchase order or its technical specification. For an electronic housing mold, the stated quality checks include mold trials, dimensional inspection, and a complete pre-shipment check.

Set Acceptance Criteria Before Production

Each requirement should have a clear reference and a way to verify it. The available project options include P20, 718H, or 1.2738 mold steel; ABS, PC, or PP resin; single- or multi-cavity tooling; and polished, textured, or matte finishes. A precision tolerance of plus or minus 0.02 mm and a mold life of 50,000 to 800,000 shots are also listed. Specify the options and performance requirements that apply to your project rather than relying on a general product range.

Approve a trial sample before mass production and keep it as the visual and technical reference for later inspections. Record the dimensions checked, applicable tolerances, surface requirements, and trial conditions in the order or specification. When reporting a nonconformity, identify the part location and cavity, provide the measured result and inspection method, and show how it differs from the approved requirement.

Define Defects and the Claim Process

Separate acceptance criteria into categories so that each type of issue can be assessed consistently. Dimensional defects should be judged against specified measurements and tolerances. Surface defects should be compared with the selected finish and approved sample. Material claims should refer to the agreed resin, such as ABS, PC, or PP, while functional issues need their own stated test or performance requirement. If a limit is missing from the drawing, specification, or sample approval, agree on it before production instead of applying an undocumented standard after delivery.

Write down how and when claims must be submitted, what evidence is required, and who is responsible for investigating and correcting a confirmed issue. A useful claim record identifies the affected quantity and production lot, includes measurements and relevant photographs, notes the cavity where applicable, and describes the requested resolution. The listed after-sales services include online technical guidance, mold maintenance, and spare parts support. For mold-related problems, the procedure can also cover technical review, adjustment or maintenance, replacement support, and approval of new trial samples.

Inspection and Project Scope

The stated inspection sequence for the electronic housing mold comprises mold trial testing, dimension inspection, and a full check before shipment. Specify when each check takes place, which records are retained, and how any rejected result is handled. Also make the scope of the order explicit: it may cover mold making alone, tooling with injection molding, precision mold development, or mold development combined with mass production.

Longterm lists consumer electronics and home appliances among its application areas. Its cooperation examples include a handheld-device housing mold and a home-appliance component mold. Reported evaluation factors included dimensional accuracy, surface quality, sample conformity, technical support, communication, and delivery timing. These can inform project-specific criteria, but should not be treated as universal defect limits.

Acceptance Criteria at a Glance

Frequently Asked Questions

Should defect limits be included in the mold order?

Yes. The order or attached specification should identify the applicable dimensions and tolerances, resin, surface finish, cavity configuration, approved sample, inspection method, and remedy for accepted claims.

What information should a buyer provide with a claim?

Include the affected parts or inspection records, measurements, photographs when useful, quantity, production lot and cavity details where available, and a comparison with the agreed requirement. State the corrective action being requested.

Which quality checks and support services are listed?

The stated checks are mold trials, dimensional inspection, and a full pre-shipment check. Available after-sales support includes online technical guidance, mold maintenance service, and spare parts.

Recommendations

Make every acceptance limit traceable to a drawing, technical specification, approved sample, or inspection record, and agree on claim deadlines and remedies before production. For the electronic housing mold, the listed basis includes P20, 718H, or 1.2738 mold materials; ABS, PC, or PP compatibility; a plus or minus 0.02 mm precision tolerance; a specified surface finish; and trial, dimensional, and pre-shipment inspections. Available project models range from custom mold making to tooling with molding, precision and overmolding projects, and development with mass production. Longterm's ISO 9001:2015 certification supports a documented quality process, while the project documents define the actual acceptance limits. For technical solutions or support, contact rogerluo@longterm-mold.com.

About Longterm

Longterm Manufacturing Solutions Limited was established in 2010 and serves customers in the United States, Europe, Australia, and other international markets. Its 50-person team provides mold design, tooling, precision machining, mold manufacturing, and parts production. The company lists production capacity of approximately 15 to 20 injection molds each month and more than 120,000 precision-machined components per year. It holds ISO 9001:2015 certification and serves customers in multiple industries.