There are three main ways to join plastic parts: mechanical, adhesives, and welding. Mechanical processes – such as screws, rivets and snap-fit – are perfect for products that will need to be disassembled during their lifetime or for low-volume runs. Adhesives – such as glue – form a more permanent bond and are great at adhering two dissimilar materials. Welding processes are permanent and do not use consumables, instead using a combination of heat and pressure to fuse the parts together. Ultrasonic welding services use sound waves to fuse two or more plastic parts of the same material together. Ultrasonic welding is the perfect solution for plastic components and assemblies that cannot feasibly be molded into a single piece.
How Does Ultrasonic Welding Work?
Ultrasonic welding uses high-frequency vibrations to heat and bond parts under pressure. The term “ultrasonic” refers to the fact that the high-frequency vibrations are generally outside the range of human hearing. First used in the toy industry, ultrasonic welding services are now used in medical, electronics, packaging, and automotive industries, among others. Ultrasonic welding is widely used in microelectronic devices and electronic aerospace electrical packaging.
Advantages of Ultrasonic Welding
- High-strength welds
- Easily automated
- Fast (no cure or dry time and welds in less than a second)
- No consumables (fasteners or adhesives)
- Provides tamper-proof hermetic seals
- Clean and precise
- Can vibrate contaminates out of packaging seals
- Great for volatile or heat-sensitive products
- Visually appealing (no visible seams to detract from the finished piece)
- Doesn’t introduce impurities or thermal distortion to the components being joined
Ultrasonic welding does have some limitations that should be kept in mind when choosing your secondary operations:
- There is a limited weld depth
- The parts should be small and not contain complex geometry
- It is limited in combinations of certain plastics
Using Ultrasonic Welding to Solve Problems
An LED hardscape lighting manufacturer approached us with a design problem. Their new product needed a channel cavity to house the LED board, but the injection molding process required two through holes to hold the cavity core in place during molding. These holes needed to be sealed before assembly to withstand the elements and the heat from the LED lights.
Our solution was to create a cavity in the mold that produced a tapered plug that could then be ultrasonic welded into the hole after welding. With our ultrasonic welding services, we were able to produce strong, reliable welds in the thermoplastic material and ensure the integrity of the product.
Ultrasonic Welding Services from Proto-Cast
At Proto-Cast, we take pride in the quality of our work and uphold ISO 9001:2015 standards. Ultrasonic welding is a quick, clean, and cost-effective way to bond plastic parts. If you want to learn more about the advantages of ultrasonic welding, call us today at 610-326-1723.