Capillary Rheometer End Correction Data Processing Workflows
End-corrected capillary rheology isolates entry losses and non-Newtonian wall shear rates to establish accurate melt viscosity curves for compounding quality control.
Lot Acceptance
Meaning
Quality assurance procedures determine whether an incoming shipment of raw material or a batch of finished components complies with the engineering specification. This decision-making process relies on statistical sampling plans to inspect a representative subset of the batch rather than testing every individual unit. A structured lot acceptance program defines the allowable number of defects within the sample before the entire shipment must be rejected and returned to the vendor.
Establishing clear acceptance criteria protects the manufacturing line from receiving substandard materials that could cause equipment damage or product failures in the field.
Inspection Protocol
Sampling plans are structured around standardized statistical tables that define the required sample size based on the lot volume. Technicians execute measurements on these selected parts to verify dimensional accuracy, mechanical strength, and material composition. If the number of non-conforming items falls below the defined threshold, the shipment passes lot acceptance and is released to the production floor.
Production Outcome
Rejecting an entire batch due to a few non-conforming samples can disrupt the manufacturing schedule. The supplier must be notified immediately to arrange for sorting, rework, or replacement of the failed lot. This operational disruption is often minimized by establishing safety stock or running secondary audits.
Risk Allocation
Balancing the risk of accepting bad lots against the risk of rejecting good lots is the fundamental challenge of sampling plan design. If the sample size is too small, defective material may slip through the audit and enter production, leading to high warranty costs. A larger sample size reduces this risk but increases the time and labor cost of the inspection process.