Contamination Fault Investigation
topic
Contamination investigation: (1) Identify the foreign material: fibre type (polypropylene = PP, identifiable by burning test — melts and beads without ash vs cotton: grey ash), colour origin (dyeing or printing contamination vs raw material contamination). (2) Trace lot history: which bales, which carding batches, which ring frame. (3) Identify source: raw material (bale inspection), floor contamination (packing material, operator clothing), or mechanical contamination (synthetic lubricant drip). (4) Implement controls: contamination screens on openers, clean room protocols, and packing material change.
Role
Contamination investigation is the quality activity with the highest urgency and commercial consequence in premium yarn production. A single contamination event detected in garments — a white polypropylene fibre in a black cotton sweater — can trigger rejection of an entire seasonal collection, with claims in the millions. Understanding investigation methodology and contamination source tracing allows engineers to respond to customer complaints quickly and credibly, minimising commercial damage.