Additional plastics joining Processes
Additional plastics joining processes available at EWI, include:
- Vibration welding
- Spin Welding
- Hot gas (air)
- Extrusion welding
- Dielectric or RF welding
- Induction implant welding
- Resistive implant welding
Vibration Welding
How it works: A frictional process that involves rubbing two thermoplastic parts together in a linear or orbital fashion while under pressure at a specific frequency and amplitude to generate sufficient heat for melting and welding
Advantages: Relatively fast cycle times, suitable for medium to large assemblies, welds most types of thermoplastics
Limitations: Capital equipment cost is high, weld joints must be nearly planar, thin-walled weld joints must be supported, noise
Application examples: Automotive dash boards, intake manifolds, carpet to door panel application, lighting assemblies
Spin Welding
How it works: A frictional process that involves rotating one thermoplastic component relative to a stationary mating component while under pressure at a specific velocity
Advantages: Relatively fast cycle times, low capital equipment cost, welds most types of thermoplastics
Limitations: Weld joint must be round, requires specific joint design
Application examples: Pressure vessels, floats, most any round assemblies
Hot Gas (Air) Welding
How it works: Usually a manual process, hot gas or air is directed simultaneously at a prepared weld joint and a filler rod of the same thermoplastic material to create a weld in a similar fashion to metal stick welding. Pressure is typically applied using a feature built into the tip of the handheld hot air gun. This process is also commonly found in a more automated setting for staking and swaging type joining processes.
Advantages: Economical, suitable for very large, one-of-a-kind structures and for repair work
Limitations: Slow, weld quality is operator dependent
Application examples: Large tank liners, storage vessels, environmental pond liners, automotive body and fender repair, piping
Extrusion Welding
How it works: Similar to hot gas welding, extrusion welding pumps a fully molten bead of polymer from the heated gun tip which also directly contacts the structure being joined to create melt on the weld joint surfaces.
Advantages: “Same as hot gas welding”
Limitations: “Same as hot gas welding”
Application examples: “Same as hot gas welding”
Dielectric (RF) Welding
How it works: Also referred to as radio frequency (RF) welding, this process generates heat electromagnetically by passing high frequency AC current through two plies of thermoplastic film or sheet that are pressed together by positive and negative electrodes.
Advantages: Fast cycle times, heats internally at the weld joint interface
Limitations: Suitable only for films and thin sheet, and thermoplastic materials having high dielectric loss and high dielectric breakdown voltage properties
Application examples: Waterbed mattresses, 3-ring binder covers, blister packs, consumer packaging
Induction Implant Welding
How it works: Another electromagnetic welding process, induction implant welding involves using an electromagnetic (induction) field to generate heat in a conductive implant that is placed in the weld joint.
Advantages: Relatively fast cycle times, selective (localized) heating of the implant only, can be re-heated for disassembly
Limitations: High capital equipment cost, may require a consumable component (implant), may not be able to weld internal features
Application examples: Sealing of food packaging, pallets, medical devices, loudspeaker cabinets
Resistive Implant Welding
How it works: This welding process involves passing AC or DC current through a conductive implant that is placed between two components and where heat is generated via resistance heating. In the plastic pipe industry, this process is called electrofusion welding
Advantages: Inexpensive capital equipment costs, relatively simple process, may be re-heated for disassembly, possible to weld complex geometries
Limitations: Relatively slow cycle times, requires a consumable implant
Application examples: Gas and water distribution pipes, carbon fiber based composites, automotive truck bed liners
For help in selecting the best joining option for your plastics assembly challenge, contact EWI.
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Joining Processes
