Ultrasonic Weld Types & Weldability
Near Field Weld (Direct): Refers to a weld where the contact surface of the horn is 1/4" or less away from the joint surface.
It is important that the horn fits exactly the contour of the part to be welded.
Far Field Weld (Indirect): The distance between the contact surface of the horn and weld between the contact surface of the horn and weld joint is more the 1/4".
Ultrasonic energy is transmitted through the upper portion of the part to the joint surface.
Factors Influencing Weldability in Ultrasonics
- Amorphous vs. Semi-crystalline resins
- Mold release agents
- Moisture content
- Lubricants
- Pigments
- Plasticizers
- Resin grade
- Fillers
Ultrasonic Weldability of Plastics
EASE OF WELDING EASY MEDIUM COMPLEX DIFFICULT
- Resin Polystyrene/PS
- Acrylic
- ABS
- SAN
- PMMA
- PC-ABS Blends Polycarbonate/PC
- PC-ABS Blends
- PPS
- Polysulfone/PSO
- PVC
- ASA
- PPO
- PC-PBT Blends
- Polyester
- Ryton
- PET
- Polyamide Co-polymer (Nylon 6-3-T)
- Valox Polyamide/Nylon 6
- Polyamide/Nylon 6/6
- PBT
- PP
- PE
- Polyacetal
- Ultem
20kHz Peak to Peak Amplitude 35 to 45 microns 45 to 55 microns 55 to 80 microns 80 to 100 microns
Joint Design Energy Director
90 - 0.7 mm Energy Director (60 /0.8mm)
For low strength mechanical assembly only
Shear Joint
(0.5 - 0.6 mm) - (1 - 2 mm)
for higher strength or hermetic assembly Shear joint
0.4 mm wide -
(0.8 - 1.4 mm) Shear joint
0.4 mm wide -
(0.8 - 1.4 mm)