Ultrasonic Welding Your Custom Plastic Components: Joint Variations

Ultrasonic Welding Overview

There is no better way to join your custom plastic components than ultrasonic welding. Fusing parts together with vibration and heat creates a much more secure bond than glues or solvents. But before we explore the different joint variations, here’s a quick overview of the ultrasonic welding process.

What Is The Ultrasonic Welding Process?

The ultrasonic welding process uses a solid-state weld, created under pressure, to join injection molded, custom plastic components. There are no soldering materials, glues, solvents, bolts or nails. Sonic pulses resonating from the vibrating tool, or horn, cause the two parts to vibrate against each other. The vibrations simultaneously fuse and heat the parts, creating a nearly unbreakable bond.

Why Are Joints Important?

Custom plastic components are fused at joints. The joint’s variation and design depends upon the component itself, the plastic’s thickness and type of plastic used. The joints are engineered into the design of the custom plastic components. This is critical to a reliable bond when the joint is welded to its corresponding part.

Joint Designs Commonly Uses In Ultrasonic Welding

Mash Joint – The mash joint is best used with semi-crystalline plastic with thin walls. This joint has a large jointing distance and produces an airtight, high strength weld.

Double V Joint – The double V joint’s design is best used in very precise injection molding with parts that have a 1.5 mm wall thickness or less. A correctly adjusted joint is key, because this joint requires accurately centered components. However, once centered, this weld is incredibly strong.

Step Joint – The step joint is one of the easier joints to weld. It works especially well with amorphous plastics and is visibly flawless, strong and airtight. This design absorbs shear and tensile stress and its components are self-centering.

Tongue And Groove Joint – The tongue and groove joint is, by far, the strongest joint design. However it’s recommended that your parts have thin walls. The gap dimensions of the tongue and groove joint have very small clearances, which creates a capillary effect. This causes the melt to penetrate throughout the whole joint area.

The Importance Of Melt Encapsulation When Welding Your Custom Plastic Components

Melt encapsulation is measured in how evenly the melt or weld is distributed throughout the joint. A well encapsulated joint should be airtight and free of burns. Amorphous plastics are more viscous when melted, so they can be welded without checking for encapsulation. All other materials need at least partial encapsulation to maintain maximum strength.

Baytech Plastics, A Trusted Name In Ultrasonic Welding

No matter the size of your custom plastic components or the material you choose to use, you can trust Baytech Plastics with all of your ultrasonic welding needs. We help you every step of the way, from choosing the right materials to designing the right joints for the most seamless joint weld possible. Contact us to learn more about our ultrasonic welding services