Injection Molding Defect Log Template for Buyers

Most organizations manage molded-part defects via email: a photo, a complaint, and a reply. Six months later, no one can definitively say whether the splay issue has improved or worsened.

A defect log replaces scattered correspondence with a rigorous quality record. Every event occupies a single row. This page provides the template and the operational rules to make it effective. When communicating a logged event to a supplier, assemble the required data using the Defect Evidence Generator.

The Value of the Log

A meticulously maintained log converts anecdotal complaints into verifiable trends (“This is the third flash event this quarter, all on the second shift”). It transitions supplier conversations from adversarial debates to factual reviews.

The log anchors updates to your acceptance standards in historical data. If a dispute escalates or a mold transfer becomes necessary, the log serves as the definitive record of supplier performance. Furthermore, suppliers invariably increase their process discipline when they know the buyer tracks defects systematically.

The Log Template

Copy these columns into a spreadsheet. Log one defect event per row.

Field	Required Data
Log ID / Date	Sequential identifier and the date the defect was identified.
Part & Revision	Part number and active drawing revision.
Lot / PO	Production lot number, delivery date, or PO reference.
Cavity	Cavity number (critical for multi-cavity tools).
Defect Type	Standardized name (e.g., sink, short shot). Use the defect guides for definitions.
Location	Specific zone or feature (e.g., Gate area, Boss #3, A-Surface).
Severity	Categorized per your quality standard (e.g., Critical, Major, Minor).
Quantity & Rate	Number of defective parts found versus total parts inspected.
Photo Reference	File name or link to the defect photograph. Always photograph the defect.
Supplier Notified	Date of notification and supplier contact name.
Supplier Explanation	The stated root cause. Evaluate it using the Supplier Defect Review Sheet.
Corrective Action	Specific tooling or process changes implemented, by whom, and by when.
Verification	Method used to confirm the fix (e.g., re-inspection, mechanical test, next-lot verification).
Disposition	Accept, Accept with Deviation, Rework, or Reject/Scrap.
Status	Open, Monitoring, or Closed.

Rules for Maintaining the Log

Log immediately. Record the event when the defect is found, not at the end of the month. Delay degrades the accuracy of severity and rate data.

Isolate defects. One defect type equals one row. If a part exhibits both splay and flash, log them separately. Clean categorization is required for accurate trend analysis.

Standardize terminology. Use the exact same defect names every time. Consistent nomenclature makes the log filterable. Refer to the defects overview for a stable vocabulary.

Require photographic evidence. A year after the event, the photograph is the only objective evidence that remains.

Close rows only on verified fixes. A status of “Supplier adjusted parameters” remains in the Monitoring state. Only change the status to Closed when the corrective action is proven across subsequent lots.

Review data quarterly. Extracting rate trends by defect type and by supplier provides the return on the administrative effort of keeping the log.

Integrating the Log into the Program

T1 and Tool Trials: Historical defect data from similar parts sharpens the focus of the T1 checklist walkthrough.

Acceptance Standards: Recurrent disputes highlighted in the log dictate where the quality standard requires tighter, more explicit limits.

Supplier Performance Reviews: Open-row counts and time-to-close metrics provide objective, unarguable measures of supplier responsiveness.

Future RFQs: Include the defect history of a part family in the next RFQ package so bidders can engineer preventive measures into their tooling quotes.

Disclaimer

PlasticsTechnologyAlliance.com is an independent buyer resource. This template supports, but does not replace, your formal quality management system. Severity definitions, part dispositions, and record retention rules must comply with your internal procedures and industry regulations.