Introduction
Non-Arc Welding Processes
• Resistive heating, chemical reactions, focused
light and electrons, sound waves, and friction
can also be used to join materials
–
–
–
–
–
–
–
Resistance welding
Oxy-Fuel Welding
Friction welding (&Solid State)
Laser and electron beam welding
Brazing and soldering
Plastics joining
Adhesive bonding
Welding of Plastics
Joining Plastics
• Polymer - a single
building block (mer) is
repeated to form a long
chain molecule
– Thermoplastic polymers
soften when heated,
harden when cooled
• 2-liter bottles
– Thermosetting polymers
don’t soften when heated
• Car tires, caulking
compound
(Poly)ethylene
H
H
C=C
H
H
add H2O2
HH
··· -C-C- ···
HH
Hot Plate, Hot Gas, Infrared
• Advantages
– Provide strong joints
– Reliable
– Used on difficult to join
plastics
• Limitations
– Slow
– Limited temperature
range
0.1.1.2.5.T23.95.12
Welding of Plastics
Hot Plate, Infrared Welding
Hot plate welding
Welding of Plastics
Hot Gas Welding
• Thermoplastics
(hotmelts)
– Adhesive is heated
until it softens, then
hardens on cooling
• Hot gas softens filler
and base material
• Filler is pulled or fed
into the joint
Vibration
• Advantages
– Speed
– Used on many
materials
• Limitations
– Size
– Requires fixturing
– Equipment costly
0.1.1.2.5.T24.95.12
Ultrasonic
• Advantages
– Fast
– Can spot or seam weld
• Limitations
– Equipment complex,
many variables
– Only use on small
parts
– Cannot weld all
plastics
0.1.1.2.5.T25.95.12