Who Pays the Retest When a Bulk Batch Fails
When a bulk batch fails primary testing, the mill pays for accredited retests if counter-sample analysis confirms non-compliance under contract terms.
Composite Retest
Aggregate Validation Procedure
Quality control protocols involving the combination of multiple individual samples into a single test unit provide a broader assessment of a production lot. A composite retest is performed when initial results show borderline compliance or when the original sampling was deemed unrepresentative. It involves blending specimens from different parts of a shipment to create a new, unified sample for laboratory analysis.
This method smooths out local variations to determine if the bulk material meets the average requirements.
Sampling Strategy
Technicians collect small portions of material from at least ten percent of the total number of rolls or bales. These portions are thoroughly mixed to ensure the final composite reflects the overall composition of the delivery. If the test involves chemical properties, such as pH value or formaldehyde content, the blended sample provides a reading of the total risk.
This strategy is useful for commodities where high variability is expected between individual units.
Decision Logic
Results from the combined specimen often serve as the final word on a disputed batch. If the composite retest passes, the lot is typically accepted, even if one original individual sample failed. This logic assumes that the single failure was an outlier and that the overall material is safe for production.
However, if the composite sample fails, the entire shipment is usually rejected or earmarked for secondary sorting. The cost of this additional testing is often shared between the buyer and the mill depending on the outcome. Clear rules in the quality manual define when a composite approach is appropriate.
Technical Limit
Aggregation can hide specific defects that only appear in concentrated areas. While the average might be acceptable, a single highly contaminated roll could still cause problems in the finished garment. Practitioners use this method for bulk properties rather than for identifying localized flaws.
It balances accuracy with the cost of testing.