Injection Molding Defect Log Template for Buyers

Most programs handle defects by email: a photo, a complaint, a reply, and six months later nobody can say whether black specks are getting better or worse. A defect log fixes that with one discipline—every event gets a row. This page gives you the template and the usage rules; copy the table into a spreadsheet and start with the next event. When you reply to the supplier about an event, build the request list with the Defect Evidence Generator.

Why Keep a Log

A maintained log converts anecdotes into trends (“third splay event this quarter, all Mondays”), makes supplier conversations factual instead of adversarial, anchors acceptance-standard updates in history, and becomes decisive evidence if a dispute or a mold transfer ever arrives. Suppliers also behave differently when they know events are logged—quietly, quality attention rises.

The Template

Copy these columns; one row per defect event:

Field	What to record
Log ID / date	Sequential ID and date found
Part & revision	Part number + drawing revision
Lot / PO	Production lot, delivery, or PO reference
Cavity	Cavity number if marked (multi-cavity tools)
Defect type	Use consistent names—link the site’s defect guides for definitions
Location on part	Zone or feature (gate area, boss #3, A-surface)
Severity	Critical / Major / Minor (define per your standard)
Quantity & rate	How many found, out of how many inspected
Photo reference	Filename or link—always photograph
Supplier notified	Date + contact
Supplier explanation	Their stated cause (review it with the Supplier Defect Review Sheet)
Corrective action	What was changed, by whom, by when
Verification	How the fix was confirmed (re-inspection, test, next-lot check)
Disposition	Accept / accept-with-deviation / rework / reject-scrap
Status	Open / monitoring / closed

Usage Rules That Keep It Useful

• Log at the event, not at month-end. Memory rewrites severity.
• One defect type per row. A part with splay and short shot is two rows—trends need clean categories.
• Use the same defect names every time. Consistent naming is what makes the log filterable; the defects overview provides a stable vocabulary.
• Always attach the photo. A year later, the photo is the event.
• Close rows only on verified fixes. “Supplier adjusted parameters” is monitoring, not closed.
• Review quarterly. Rate trends per defect type per supplier are the output that pays for the discipline.

What the Log Feeds

• T1 and trial reviews — prior-event history sharpens the T1 checklist walkthrough.
• Acceptance standards — recurring dispute zones tell you where the standard needs explicit limits.
• Supplier reviews — open-row count and time-to-close are fair, factual performance measures.
• RFQs — known defect history on a part family belongs in the next RFQ package so bidders quote the real job.

Evidence Box

This buyer review note was developed from recurring shop-floor troubleshooting patterns, injection molding process principles, and buyer-side mold trial review logic. Where specific technical claims affect supplier evaluation, material handling, tooling decisions, or production approval, they should be verified against the actual mold design, material grade, supplier processing guide, process sheet, and sample inspection data.

This page is a buyer-side review aid, not a final engineering diagnosis, supplier certification, or guaranteed fix.

Related PTA Resources

• Injection Molding Defects (overview)
• Supplier Defect Explanation Review Sheet
• T1 Sample Review Checklist
• Inspection & Acceptance Standards

Disclaimer

PlasticsTechnologyAlliance.com is an independent buyer resource. This template supports—but does not replace—your quality system. Severity definitions, dispositions, and retention rules should follow your own procedures and industry requirements.