Plastic welding joins thermoplastic parts without adhesives or mechanical fasteners, creating strong, hermetic, and cosmetically clean joints. The right welding method depends on material, joint geometry, production volume, and cost constraints.
High-frequency (15-40 kHz) vibration creates frictional heat at the joint interface. Fast cycle times (0.5-2 seconds). Best for small to medium parts in amorphous materials (ABS, PS, PC). Requires energy director design on the part. Not suitable for large parts or high-moisture materials.
Linear friction welding using low-frequency (100-240 Hz) vibration. Accommodates larger parts and complex joint geometries. Works with both amorphous and semi-crystalline materials. Cycle time: 3-15 seconds. Higher capital cost but more versatile than ultrasonic.
Contactless welding using a laser beam transmitted through the upper part and absorbed by the lower part. Produces cosmetically perfect joints with minimal flash. Ideal for medical devices and electronics. Requires one transparent and one dark absorbing part. Cycle time: 2-10 seconds.
Parts are pressed against a heated platen, then pressed together after platen removal. Simplest and most robust method. Works with all thermoplastics. Cycle time: 10-60 seconds. Suitable for large parts and high-volume production. Platens require regular cleaning to prevent contamination.
One part rotates against a stationary part under pressure, generating frictional heat. Only suitable for circular joints. Fast cycle times (1-5 seconds). Common applications: filters, bottles, containers, and ball-shaped assemblies.