When it comes to plastic welding, perhaps the first thing that comes to mind is ultrasonic welding. This is the fastest plastic welding technology. But just because it's popular, doesn't mean it's the best choice for every application. It has many benefits, but also some disadvantages. What should you do if ultrasonic welding isn't your best option?
                                        
Advantages of ultrasonic welding

■ Medium-sized parts: There are size restrictions for ultrasonic welding. Can you easily hold the part in your hand? Is it easy to join the two parts together? Is it too big or too small? Unable to handle with hands and fingers, ultrasonic welding may not be your best choice.

■ Spot welding with robots: Ultrasonics are fast but require expensive generators to drive each drop point. With a corner on the end of the robot, you can move from point to point quickly since each weld only takes a few seconds.

■ Tight budgets: In certain applications, ultrasonic welding can be a cost-effective method of joining plastics together. The technology has matured and competition has driven down component prices.

                                      
Disadvantages and Alternatives to Ultrasonic Welding

■ Cleanliness requirements: Because ultrasonic welding is a vibrating process, it often produces fine dust. This is also known as particulate matter. If your welding application requires cleaning, laser welding may be a better choice.

■ Sensitive components: For sensitive components such as PCBs, small fluid channels, and precision optics, controlling welding depth and energy is critical. If too much energy is applied to a part, it can break, small fluid channels can fill up, and precision optics can become inaccurate. In these precision applications, ultrasound is difficult to control. This time laser welding provides enough precise control and allows you to enter the weld as quickly or slowly as desired.

■ Soft materials: Ultrasonic welding works by vibrating and creating molecular friction in the joined parts. This can be a challenge if the parts are soft, such as polypropylene (PP), polyethylene (PE). Polymer materials such as soft materials have poor dissolution effects after vibration. You can try hot plate welding or plastic laser welding equipment.

■ Large parts: Due to the limitations of ultrasonic grinding tools, ultrasonic welding cannot weld large parts. There are several alternatives better suited for large parts such as laser welding, hot plate welding.