Thermoplastic Welding Process, Fast, Computer-Controlled Accuracy, Chemical / Adhesive Free, Low Cost, High Speed

SINCERE TECH is an injection mold china company that provides a variety of services to the world, including custom plastic mold making, custom injection molding service, and Ultrasonic Welding, one step to complete your project. Ultrasonic Welding is used to bond two pieces of plastic together.

Ultrasonic welding is probably the most commonly used thermoplastic welding process because it is very fast (fractions to a few seconds) and usually produces welds that are relatively free of flash. In addition, ultrasonic welding is suitable for high volume production.

Ultrasonic Welding: A Brief Explanation

Ultrasonic welding uses the potential energy within the plastic itself, converting it to heat and sound. In plastic ultrasonic welding the parts are vibrated toward and away from each other. This heats and softens them. The continued motion heats and softens the plastics, then mixes the softened surfaces of the plastic together. This forms both a physical, and if the plastics are selected correctly, a chemical bond between the parts.

A sonic horn oscillates vertically, contacting the plastic part at a variable distance from the projection point, depending on the application, delivering the energy where it’s needed. The part on the other side of the joint area rests on an energy-dampening anvil, ensuring the sonic energy remains in the weld zone.

Tongue & groove joint design and location is very important in ultrasonic welding. Interference, or shear types of joints, involve welding a slightly larger part into a smaller one. Shear joint designs are commonly used for semi-crystalline polymers, or when watertight seals or high joint strengths are needed.

Ultrasonic Welding: Benefits & Advantages

Rapid development of the ultrasonic welding machine has occurred in the last ten years. Basic functions are now computer-controlle

d for greater accuracy and reliability, such as:

  • Weld energy
  • Collapse
  • Trigger force
  • Pressure

Ultrasonic welding of plastics has many advantages over other plastic-joining processes, including:

  • Lower cost – eliminates the costs of consumables, produces repeatable, error-free results
  • Higher speed – welding usually occurs in less than a second.
  • Cleaner process – no consumables required, less risk of contamination
  • Greater reliability – adaptable to clean-room environments as well as high-volume production situations

Unlike most other methods of plastics joining, ultrasonic welding uses no caustic chemicals and produces few fumes. The only restriction on welding plastics is that the parts must have relatively close melting points, or else one will melt completely before the other begins to soften.

Ultrasonic Welding: Applications & Uses

Ultrasonic assembly is ideal for assembling all types of medical products, such as:

  • Filters
  • Instruments
  • Fluid vials
  • Masks
  • Surgical garments

Ultrasonic welding has a wide variety of additional uses and applications, including:

  • Sealing containers and bags
  • Attaching plastic components
  • Inserting metal components into plastics (see Ultrasonic Insertion)
  • Corrugated containers – eliminates the need for staples or adhesives
  • Plastic Tubes and pumps – will not contaminate contents