A buyer has approved a China-sourced PC/ABS or ABS/ASA candidate. What should be checked on every production shipment before it is released to molding?
Release a shipment against an agreed control plan, not against a familiar trade name. Match the purchase order, packaging and certificate of analysis to one traceable lot; verify the few properties and documents that can change the finished part; and use representative sampling with a written disposition rule. The exact checks, methods and limits must be agreed for the commercial grade, application and destination market.
Information that changes the recommendation
- Exact commercial grade, color, reinforcement or flame-retardant system, revision level and approved application
- Lot or batch number on each bag, pallet label, certificate of analysis and packing list
- Agreed reportable properties, test methods, specimen condition, units, tolerances and reporting frequency
- Incoming-sample method, retained-sample quantity, re-test rule and who can release, hold or reject a lot
- Current safety, regulatory, transport and customer documents required for the destination and intended use
- Packaging condition, net weight, moisture protection and storage time before drying or molding
- A molded-part comparison plan when the application is sensitive to impact, appearance, warpage, flame performance or chemical exposure
Start with a grade-control sheet that is owned by both buyer and supplier. Put the full grade name, color, additive or reinforcement status, revision, process, mandatory tests and document list on one page. A generic data sheet can describe a product family; it does not identify the material in a particular shipment. The certificate of analysis should identify the actual lot and the agreed reportable results, while the purchase order and packaging labels should point to the same identity.
Choose release tests from the risk to the finished part. For example, a PC/ABS housing program may need a controlled check of color, melt-flow behavior and the specific impact method used in approval, plus representative molded-part review. An ABS/ASA outdoor part may need an agreed color and appearance check and a defined weathering or retention validation plan. Do not substitute a typical data-sheet value, a different test method, or a result from another specimen thickness for the agreed requirement. ISO 180:2023 makes clear that Izod impact results depend on defined specimen and test configurations.
Use sampling as a documented decision process. ISO 2859-1:2026 provides attribute-sampling schemes for lot-by-lot inspection; it can be a useful reference when the item being judged is pass/fail, such as label correctness, bag damage or document completeness. It does not set your product-specific property limits, and it is not a shortcut for demonstrating a continuous material property. State the sampling location, number of bags, composite or individual sample method, conditioning, laboratory method and accept/hold/reject action in the control plan.
Separate commercial release from regulatory confirmation. A safety data sheet can carry information on hazards, handling, disposal, transport and exposure controls, but whether an SDS, declaration or other document is required depends on the material and destination rules. ECHA explains the REACH context for SDS information in the EU; importers must still confirm the exact legal obligations for the formulation, intended use and destination. Never assume that a supplier certificate, a prior shipment or a product-family statement covers every market or customer requirement.
Keep a retained reference and a change-control trail. For an approved lot, retain the certificate, labels or photographs, inspection record and enough material or molded plaques for the agreed comparison period. Require advance notice for changes to raw-material source, additive package, pigment, manufacturing site, process, packaging or test method. A stable supply relationship is easier to manage when a deviation has a documented baseline, rather than when a later molding issue has to be reconstructed from memory.
Step-by-step evaluation
- 01Before ordering, agree one grade-control sheet with the required documents, reportable tests, limits, methods, sampling rule and release authority.
- 02At receipt, quarantine the shipment until purchase order, pallet or bag labels, lot number, quantity and certificate of analysis reconcile.
- 03Inspect packaging and collect samples using the agreed bag locations and method; label every retained sample with lot, date and collector.
- 04Review the certificate against the agreed methods and limits. Hold the lot when identity, units, method, result, revision or document date cannot be confirmed.
- 05Run the selected incoming tests and, where risk warrants it, mold representative plaques or parts under the approved process window.
- 06Release, conditionally release, return or investigate the lot using the pre-agreed disposition rule; record any deviation and corrective action.
- 07Trend results by lot and review proposed supplier changes before the changed material reaches routine production.
What to record before approval
- Write the required test designation in full, including specimen type, thickness, notch or conditioning when applicable. A property name alone is not a test specification.
- Use a batch-specific certificate of analysis for incoming release; a technical data sheet is supporting information, not a lot record.
- For color-controlled or weatherable ABS/ASA, agree the instrument, illuminant, geometry, sample preparation and permitted difference before comparing numbers.
- If an AQL plan is used, define what counts as a defect and the inspection level, AQL, lot size and disposition rule. Do not present an AQL as a guarantee of a material property.
- Confirm customs, chemical, food-contact, electrical, construction or other destination requirements for the exact grade and intended use before shipment; requirements can change and may be customer-specific.