W14-PETT-DECISION — PET Toughener vs IV Modifier vs Process Fix
1. What decision is the buyer trying to make?
Whether PET brittleness or drop failure should be solved with a toughener, an IV modifier / chain extender, or a process/drying fix.
2. Which variables actually matter?
- rPET % and its IV history
- Failure signature (cold drop vs flex fatigue vs edge crack vs splay)
- Moisture level at extrusion
- Cost impact per kg of finished part
- Regulatory scope
3. Which variables are commonly misunderstood?
- "Toughener fixes everything" — it does not fix hydrolytic degradation.
- IV drop looks like brittleness but is a molecular-weight problem, not an impact-modifier problem.
- Under-dried PET creates defects that mimic impact failure.
4. What should the buyer investigate next?
A controlled diagnostic: measure IV, moisture, and cold-impact separately before choosing an intervention.
5. What should be included in the RFQ?
PET grade + IV · rPET % · process · failure mode · test conditions · optical constraint · regulatory scope · volume · benchmark grade.
Ending — Decision Graph Completeness
- Learned: brittleness in PET has three distinct root causes.
- Investigate next: which one is actually yours.
- RFQ prep: 9 items above.
Bridges
- W14-PETT-ECO · W14-PETT-PRODUCT
- W11 Problem-First · W13-A-005 Virgin vs Recycled Carrier