Meaning
Ratio between the number of missed detections and the total number of actual positive samples in a data set. A high false negative rate in a resin inspection lab means that contaminated batches are being accepted as clean material. This failure typically occurs when the detection limit of the test is higher than the regulatory threshold for a restricted substance.
The error leads to the production of parts that contain prohibited heavy metals or banned flame retardants despite passing the initial screening.
Detection Reliability
Sensitivity of the analytical method is the primary driver of this statistical error. If a sensor is not tuned to the specific wavelength of a contaminant, the signal remains below the noise floor. Improving the equipment reduces the frequency of these missed detections and protects the supply chain.
Compliance Failure
Regulatory audits often uncover hidden issues when the testing frequency is too low. A shipment of medical-grade polycarbonate might be rejected by a customer if a later test finds a chemical that the supplier missed. This creates a liability for the moulder who has already converted the resin into finished goods.
Economic Consequence
Scrap costs and product recalls are the direct results of a failure to identify bad material. Rebuilding customer trust after a safety failure is more expensive than investing in higher-quality testing protocols. Companies avoid these losses by setting strict validation requirements for all incoming polymer lots.
