In general, you can glue the material using binders such as nails and screws. It is suitable for iron metal, tree wood, fabric, and plastic. For many types of plastics, adhesives are used. The adhesive forms a chemical bond between the adhesive itself and the surface of the adhered plastic material. The metals can be joined with each other by heating other types of metals as an adhesive, like an electrically connected lead solder.
History of ultrasonic welding machines
The first practical usage of ultrasonic welding to bind and weld plastics was ended in the start of the mid-twentieth century.. At that time, the hard plastic was used to be welded only. Soloff, who was the founder of Sonics and Material Company and the lab manager for Branson Instruments, where he used an ultrasound probe to weld thin plastic films into bags and tubes.
He, without any desire, approached the probe to the plastic tape seller and observed the half of the dispenser welding. He felt that it was not necessary to manually move the probe around the part and that ultrasound energy could be transmitted through and around hard plastic to weld the entire joint.
Ultrasonic welding of metal was developed in the second half of the twentieth century as the electronics technology used in the tech instruments became more efficient. Around this time, this technology also came to be applied to plastic, and it became widespread in earnest.
Ultrasonic welding machine parts and their working
The ultrasonic welding machine gets a 50 Hz supply input from the main power supply. Then, it increases the frequency of electrical energy to 20k Hz with a special electronic circuit. The converter converts electrical energy into mechanical vibration by means of piezoelectric crystals. The frequency remains 20 kHz.
Then, with a component known as a booster, the amplitude of vibration increases or decreases depending on the ultrasonic application. This is because thermoplastic materials have different melting temperatures and body structures. Using the amplitude that is appropriate for the process you are performing will change the result of your work.
The frequency that reaches the desired value is transmitted to the plastic parts to be welded.. Vibration stops when the parts of the plastics that rub against each other 20k times per second under pressure reach the melting point temperature. The parts are cooled by waiting for a some time while while being pressurized. This time is smaller than one second for most applications.
Basic parts of Ultransonic welding machines
The ultrasonic welding machine has the following basic and important parts:
Power supply
It receives input of 50Hz alternating current signal. This may be 110-220V in differnet countries. This input is ma ust to work this machine.
High Frequency Generator,
Then an electronic circuit converts this 50Hz frequency i=signal into 15-20khz. This is the highest frequency that helps this machine work the best.
Transducer
The high-frequency signal of 15-20,000 Hz is then converted from electrical frequency to sound frequency. This is done by a circuit known as a transducer, which performs this task.
Horn
These ultrasound signals come in contact with another mechanical part known as a horn. This horn then directly comes in contact with the two plastics or thin metals that need to be joined.
The Horn generates vibrational heat at 20,000 times per second. This is focused on a small part. Hence, the heat generated melts the part, which allows it to cool, and then the weld is created upon cooling them.
Ultrasonic welding machine working mechanism
For joining complex parts of thermoplastic materials made by injection molding, the equipment for ultrasonic welding can be customized to meet the exact specifications of the welded parts. The details are placed between a fixed-form socket (anvil) and a sonotrode (horn) connected to a converter, and low-amplitude acoustic vibrations with a frequency of ~20-70 kHz are emitted [reference needed] When welding plastics, the interface of the two parts is specially designed to concentrate the melting process.
One of the materials usually has a spike or a rounded energy director that contacts the second plastic part. Ultrasonic energy melts the point contact between the parts, creating a compound. Ultrasonic welding of thermoplastics leads to local melting of plastic due to absorption of vibration energy along the welded joint. In metals, welding is due to high-pressure surface oxide spraying and the local movement of materials. Although there is heating, it is not enough to melt the main materials
Features of welding machines
- No fuel needed
- At low temperature
- Vheaper process
- Time-saving process
- High safety
- No flammable process
Shortcomings of Ultrasonic welding
- NO heavy metal
- Not applicable for building materials
- NO welds large parts
Types of Ultransoic welding machine
Ultrasonic can use t weld thin metals and the thermoplastic material. So on the basis of its usage, it has two types:
Ultrasonic thermoplastic welding
As the name implies, it is especially for welding plastics, which are heat sensitive. Hence, it can be used to manufacture shoes, automobiles, and in the aerospace industry.
Ultrasonic thin metal welding
This type is best for thin metals to weld. But it cannot weld the heavy metals, so we cannot use it to weld the heavy metals. Thus, only thin metals can be welded using this welder.
Can we weld heavy metals using ultrasonic welding?
No, you cannot weld the heavy metals using the Ultransonic welding. As its horn cannot rub the heavy metals to generate enough heat to weld them.
Is ultrasonic welding better than MIG and TIG welders?
It depends upon the usage. For example, for working with thermoplastic material, the Ultrasnonc is good. But if you want to work with heavy metals and other heavy work, you would need a MIG or TIG welder.
Conclusion
Ultrasonic welding is an effective welding process that provides quality welding joints, ease of operation, and safety. Although useful, it requires high precision, accuracy, and technical expertise. In this regard, this article talks about the process and its application in the manufacture of parts