TWI Knowledge Summary
Weldability of thermoplastics
Introduction
The ability to weld a plastic component is governed by:
- Physical and mechanical properties of the materials to be joined
- Welding parameters, e.g.
- - time
- - temperature
- - pressure
- Design of the joint and component
- Design of the welding equipment
The table below gives an indication of the weldability of some common thermoplastic materials for five common welding processes.
Table 1. Weldability of Thermoplastic materials
| Material | Welding Process | |||||
|---|---|---|---|---|---|---|
| Generic | Specific type | High Frequency | Hot Gas | Ultrasonic | Hot Plate | Vibration |
| ABS | X | ? |
|
|
|
|
| Acetal | ? | ? |
|
|
|
|
| Acrylic | X |
|
|
|
|
|
| EVA | ? | ? | ? |
|
|
|
| ECTFE | X |
|
? |
|
? | |
| FEP | X |
|
? |
|
? | |
| PE | LDPE | X |
|
? |
|
|
| LLDPE | X |
|
? |
|
|
|
| MDPE | X |
|
? |
|
|
|
| HDPE | X |
|
? |
|
|
|
| XLPE | X | ? | ? | ? | ? | |
| UHMWPE | X | ? | X | ? | ? | |
| PA | PA11 | ? |
|
|
? |
|
| PA12 | ? |
|
|
? |
|
|
| PA4,6 | ? |
|
|
? |
|
|
| PA6 | ? |
|
|
? |
|
|
| PA6,10 | X |
|
|
? |
|
|
| PA6,12 | X |
|
|
? |
|
|
| PA6,6 | ? |
|
|
? |
|
|
| PA 6,6-6 | ? |
|
|
? |
|
|
| PA6,9 | ? |
|
|
? |
|
|
| PB | X | ? |
|
|
|
|
| PBT | X | ? | ? |
|
|
|
| PC | X |
|
|
|
|
|
| PEEK | X | ? |
|
|
|
|
| PEI | X | ? |
|
|
|
|
| PES | X | ? |
|
|
|
|
| PFA | X |
|
? |
|
? | |
| PPO | X |
|
|
|
|
|
| PPS | X | ? | ? |
|
|
|
| Polystyrene | X |
|
|
|
|
|
| Polysulphone | X | ? |
|
|
|
|
| PTFE | X | ? | X | ? | X | |
| PVC | pPVC |
|
|
? |
|
? |
| uPVC |
|
|
? |
|
|
|
| PVDF | X |
|
? |
|
? | |
| SAN | X |
|
|
|
|
|
| TPX | X | ? | ? |
|
|
|
|
- This material can be readily welded by this process
X - This material can not be welded by this process ? - This material can be welded by this process, but only under certain conditions. |
||||||
Further information
Related content which covers weldability aspects of thermoplastics includes:
Friction welding of thermoplastics - a guide to best practice. Section 4. Material weldability and process parameters
Welding techniques for thermoplastics
Hot bar and impulse welding of plastics (August 2000)
Laser welding of plastics (August 2000)
Microwave welding of plastics (August 2000)
Plastics joining - Friction welding techniques
Plastics joining - Hot Gas Welding technique
Plastics joining - Hot Plate Welding technique
Plastics joining - Radio Frequency Welding technique
Plastics joining - Ultrasonic Welding technique
You can use the Weldasearch literature database to supplement what you find in JoinIT.
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