Injection Molding Defect Log Template for Buyers

Most teams manage molded-part defects by email: a photo, a complaint, a reply. Six months later, nobody can say whether the splay issue got better or worse.

A defect log replaces that scatter with one quality record. Every event gets a row. Use the template and rules below. When you send a logged event to a supplier, assemble the package with the Defect Evidence Generator.

The Value of the Log

A maintained log turns anecdotes into trends (“third flash event this quarter, all on second shift”). Supplier talks move from argument to facts.

The log anchors updates to your acceptance standards in history. If a dispute escalates or a mold transfer starts, the log is the performance record. Suppliers also tighten process discipline when they know you track defects systematically.

The Log Template

Copy these columns into a spreadsheet. 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 when the defect is found, not at month end. Delay weakens severity and rate data.

Isolate defects. One defect type equals one row. If a part has splay and flash, log them separately. Clean categories are required for trend analysis.

Standardize terminology. Use the same defect names every time so the log filters cleanly. Use the defects overview vocabulary.

Require photographic evidence. A year later, the photo is often the only objective evidence left.

Close rows only on verified fixes. “Supplier adjusted parameters” stays Monitoring. Move to Closed only when the fix holds across later lots.

Review data quarterly. Rate trends by defect type and by supplier are the return on keeping the log.

Integrating the Log into the Program

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

Acceptance Standards: Recurring disputes in the log show where the quality standard needs tighter, clearer limits.

Supplier Performance Reviews: Open-row counts and time-to-close are objective responsiveness measures.

Future RFQs: Put the defect history of a part family in the next RFQ package so bidders can price prevention into tooling.

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.