A discontinuation notice, an allocation or a force majeure can leave you without the resin your part, process and customer approvals were built around. The way through is the same every time: buy time, define what really has to match, then qualify a replacement before the old material runs out.
1. Buy time
Ask your current supplier how much inventory is left and whether there is a last-time buy. Secure enough bridge inventory to cover qualification, often several months, and store it sealed and dry.
2. Pull the full picture
- The technical data sheet for the old grade.
- Your incoming COAs, which show the actual values your process is tuned to.
- Your process settings.
- Any approvals tied to the grade: customer drawings, PPAP, UL listings, FDA or medical documentation.
3. Separate must-match from nice-to-match
List the properties that make the part work: usually melt flow, density, impact, heat resistance, filler type and level, flame rating, color and regulatory status. Mark which ones are critical. That list is your spec for the replacement.
4. Build a candidate list
Look for grades in the same polymer family with the same filler and level, close melt flow and density at the same test conditions, and the same certifications. Read data sheets carefully: ISO and ASTM values, and different specimen thicknesses, aren’t directly comparable. See how to compare melt flow.
5. Sample, then trial
Run a sample on your actual process, measure and test parts, then run a small production trial before you approve it.
6. Document the approval
If your customer or a regulator approved the old grade, get the new one approved too, and keep the paperwork.
7. Qualify a backup while you’re at it
You’re already doing the work. Approving two candidates instead of one means the next disruption is a phone call, not a crisis. How a backup source works →
How ResinBridge helps
Send us the discontinued grade name and a recent COA. A polymer chemist will identify candidate equivalents, tell you plainly how close each one is, and price them. ~50 lb samples are available upon credit approval. Start here →