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.