Ultrasonic welding is a process that uses high-frequency sound waves to weld two pieces of metal together. The sound waves create heat, which melts the metal and joins it together. Ultrasonic welding is often used to weld thin pieces of metal together, because it is a relatively fast and precise process. It can also be used to weld plastic and other materials.
The human ear can hear mechanical vibrations in the frequency range of 16 Hz to 16 KHz. Inaudible frequencies below 16 Hz are known as infrasound and those between 16 KHz and 100 GHz are known as ultrasound. Frequencies above 100 GHZ are known as hyper sound. The process is “green” in that it does not use solvents, adhesives, or mechanical fasteners. Its advantages over other assembly processes are that it is clean, efficient, and repeatable. Assemblies are cycled quickly making it an economical assembly process.
Applications of Ultrasonic Welding:
Ultrasonic welding is a process that uses high-frequency sound waves to weld materials together. It is used in a variety of industries, including automotive, medical, and aerospace. Ultrasonic welding offers many advantages over traditional welding methods, including:
- Increased speed
- Increased accuracy
- Reduced manufacturing costs
- Reduced environmental impact
- It is used for the assembly of thermo plastic material
- Alternative to using solvents or heat as bonding method
- It is used in automotive, appliance, medical, textile, packaging, electronics and toy production such as
Appliance: Steam iron, Pump Housing, Vacuum cleaner, Dishwasher spray arm
Automotive: Lenses, filters, valves, glove box door, instrument cluster, air diverter, mass airflow sensor, headlamp parts, dashboards, buttons, seat belt locks, and air ducts etc
Consumer appliance: assembly for ribbon cartridges, audio and video cassettes, watches, blister packs, pouches, tubes, storage containers and carton spouts
Electrical and Electronics: Wire splicing, Wire Termination, Flex cable Termination, Tube sealing, Batteries, Heat sinks, Solar Panels, Coils, Contacts, Sensors, Data storage keys, Switches etc.
Medical: Arterial filter, catheters, medical garments, masks, cardiometry reservoir, blood / gas filter, face mask and IV spike / filter
Advantages of Ultrasonic Welding:
1. It is a very fast process
2. The process requires fairly rigid materials
3. It is attainable to affix dissimilar metals also, provided each have same melting temperatures.
4. It produces high strength, pressure tight hermetic seals.
5. It is best to spot weld plastic sections.
6. Glorious electrical, mechanical, and thermal connections between similar and dissimilar metals
7. Ultrasonic Metal Welding is that the ideal method for bonding conductive materials likes copper, aluminium, brass, gold and silver.
8. Excellent welds are achieved with otherwise difficult applications, such as welding materials that are dissimilar in thickness and composition.
9. The process is environmentally green as no solders, flux or braze material are required.
10. Low heat build up during the ultrasonic process (no annealing of materials)
11. Very little or no energy is being spent. A typical weld uses below 2000 watts and is completed in less than one-half second.
12. The process is a cold weld so that components are not annealed and no harmful intermetallic are formed during welding.
13. The ultrasonic weld is extremely reliable with built-in process monitoring to help assure zero rejects.
14. Compensation for normal surface variations of the material
15. Ability to clean surface oxides and contaminants prior to welding.
16. Ability to weld thin materials to thick materials.
17. Weld tooling typically lasts for several hundred-thousand cycles with no maintenance.
18. Large weld areas of up to 150 mm sq. can be produced with 6000 watt power supply.
Disadvantages of Ultrasonic Welding:
- Large joints (>250 x 300 mm) cannot be welded in a single operation
- Specifically designed joints are required
- Ultrasonic vibrations can damage electric components
- Tooling costs for fixture are high
- Sound generation, which is typically of 90-95 dB