Thermoplastic Weld Compatibility
Not every plastic welds to every other plastic. As a rule, amorphous resins can often be joined to chemically similar amorphous resins, while semicrystalline resins (nylon, acetal, polypropylene, PEEK) generally weld only to themselves. Melt temperature, polarity, and molecular structure all have to line up. Use the checker below to test a material pair for ultrasonic welding and for vibration or spin welding, or scan the full matrices further down.
Full compatibility matrix
Hover or tap any cell for the pair rating.
Material reference
| Code | Chemical name | Common trade names | Structure | Moisture absorption |
|---|
Hygroscopic resins absorb moisture from the air. Absorbed moisture turns to steam in the weld zone and causes porous, weak joints, so materials rated moderate or high should be welded straight from sealed packaging or dried first. Nylon (PA) is the classic offender.