Meaning
Manufacturing limits for recycled polymeric materials specify the maximum allowable fraction of reprocessed plastic that can be blended with virgin resin for structural components. Sourcing departments define the regrind tolerance to control the mechanical properties of injection-molded battery cell spacers and module housings. This limit ensures that the parts do not become brittle or lose their flame-retardant properties due to thermal degradation during recycling.
Material Performance
Reprocessing plastic scrap through granulating and re-molding breaks the polymer chains, which reduces the molecular weight and lowers the tensile strength of the material. If the regrind tolerance is exceeded, the molded spacers may crack under the mechanical pressure exerted by swelling battery cells. To avoid these failures, material specifications often restrict the regrind fraction to less than fifteen percent by weight.
Laboratory testing verifies that the blended resin still meets the required impact resistance and thermal stability standards.
Cost Optimization
Using regrind material helps manufacturers reduce production costs and lower the carbon footprint of the battery assembly. It allows factories to reuse sprue and runner scrap directly on the production line. However, this must be balanced against the risk of component failure during the vehicle lifetime.
Sourcing Specifications
Procurement contracts require polymer suppliers to submit certificates of analysis detailing the regrind ratio used in each batch. Automotive companies audit these suppliers to ensure that the actual regrind fraction matches the approved engineering drawings. This traceability is required for maintaining consistent part quality across different production runs.
