How ultrasonic welding compares to other plastics joining methods

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.