Ultrasonic welding is generally a clean, fast and reliable method of joining plastics but in some cases other joining methods should be considered, particularly if the limitations of ultrasonic plastic welding make it unsuitable for a particular application. Here some other (non-ultrasonic) techniques are listed along with their likely advantages and disadvantages compared to ultrasonic welding.
Method
|
Advantages
|
Disadvantages
|
Mechanical fasteners
|
- Usable on any materials
- Low capital cost - good for prototypes and small batches
|
- Multiple small components to assemble - extra cost, labour intensive.
- Appearance may be unsightly.
- May loosen in use.
- Potential for consumer to disassemble.
|
Adhesive bonding
|
- Adhesives may be available for materials not compatible for welding
- Low capital cost - good for prototypes and small batches
|
- Longer time to join - parts may need to be clamped or held together until bonded.
- Possible safety issues with emissions.
- Possible problems recycling mixed materials.
|
Spin welding
|
- Capacity for larger components than ultrasonic
|
- Relatively complex equipment.
- Only suitable for axi-symmetric welds.
- Limited to same chemically-compatible material combinations.
|
Vibration welding
(low frequency) |
- Capacity for larger components than ultrasonic
|
- Relatively complex equipment.
- Limited to same chemically-compatible material combinations.
|
Hot plate welding
|
- Capacity for larger components than ultrasonic
- Good for thin, conductive materials eg. laminated metal-plastic foils.
|
- At least one component must be thin to permit heat transfer.
- Limited to same chemically-compatible material combinations.
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