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As we receive many inquiries/requests for welding of plastic bumpers, helmets, etc., we would like to inform you that our technology does not allow such welding and unfortunately we cannot help you.
Ultrasonic welding of plastics - is a technology suitable for serial production where it is necessary to fast and quality join 2 plastic parts. A special machine is used - an ultrasonic welding machine (we have Telsonic and Branson machines available). Further, it is necessary to have a specially tool - sonotrode - which transmits the oscillating motion to one of the parts, while the other one is fixed in the fixture. Frictional heat is generated between the parts, which locally melts the two parts at the contact point and presses the parts together.
principle of ultrasonic welding
- the electrical energy is converted in the welding machine into oscillating motion at high frequency (usually 20,000 Hz or 40,000 Hz)
- this motion is transmitted by a special sonotrode (made specifically for the parts to be welded) to the parts
- the parts vibrate and heat up by friction and the material is plasticized
- by pressing the parts together with the welding machine and cooling the parts, the weld is created
cycle
- inserting parts into the jig and starting the welding cycle
- the sonotrode goes down to the part and an ultrasonic pulse is started (usually in tenths of a second)
- after the welding process is complete, the clamping force is increased
- cooling
- the sonotrode moves back to the starting position
- removal of the assembly
advantages of ultrasonic welding
- when used correctly, material changes outside the welded zone are minimized
- very precise and repeatable process
- welding of visual parts is also possible
- faster due to thermal welding
- lower process cost
disadvantages of ultrasonic welding
- higher cost of investment - for each assembly, a fixture and sonotrode must be made
- as a rule, it is not possible to weld different types of plastics (if the difference in melting temperatures is higher than 10-15°C)
- parts must be designed for ultrasonic welding - i.e. they must have "weld edges"
other applications of this technology
- this technology can be used to insert metal parts into plastic
- this technology can also be used to join parts together by riveting - one of the parts is made of any material and the other of plastic, designed for ultrasonic riveting