Plastic Welding

What is plastic welding?

Plastic welding is the process of heating two pieces of plastic and pressing them together until they fuse. There are several different types of plastic welding. Each technology differs in how they apply heat and pressure to the parts, but the basic steps are the same — add heat, apply pressure, and cool. Plastic welds are strong molecular bonds. Depending on which welding technology is used, the weld is hermetically sealed.

Hot-Plate Welding

Hot-plate welding is the process of welding two plastic parts together using a heated tooling plate. A weld rib or bead on each component is brought into contact with the hot plate. Heat conducts into the weld rib causing it to melt. The heated tool is then removed and the parts are pushed together until they bond to one another.

Technology Examples:

  • Rapid Conductor
  • Compact FUSION

IR Welding

IR welding is the non-contact welding process that joins two plastic parts together with IR energy. IR emitters heat a weld rib or bead on each component. The IR source is removed and the parts are pushed together until they are welded.

Technology Examples:

  • InfraGuide
  • Quartz IR
  • Metal Foil IR

Laser Plastic Welding

Laser welding uses a precise IR laser beam that is directed through a transmissive material and penetrated into an absorptive material. The two materials are held in tight contact with each other and the joint between them heats up and melts as energy from the laser is absorbed. The result is a clean weld with minimal flash.

Technology Examples:

  • Extol configures laser welding machines around the application


Plastic staking is a method of joining components together using a molded stud or boss to mechanically retain a mating component. Heat is applied to the boss, softening it, and a forming tool is used to reshape the material into a cap or stake.

Technology Examples:

  • nanoSTAKE
  • InfraStake
  • Ultrasonic Staking
  • Hot-Air Staking

Spin Welding

Spin welding is a method of joining plastic components together with surface friction concentrated in a circular weld joint. One part is spun relative to another and force is applied, causing the material to heat and melt. The spinning process stops and the parts continue to be pressed together while they bond together.

Technology Example:


Through-Transmission IR Welding

Innovative through-transmission infrared welding in a compact package. This technology uses focused IR light energy to replace adhesives. Useful in both linear and spot welding applications.

Technology Examples:

  • InfraWeld

Hybrid Vibration Welding

Two components are vibrated in shear against each other, generating heat from friction. Vibration stops and pressure is maintained while the components bond to one another. Hybrid vibration welding adds an IR preheat at the beginning of the cycle to soften the rib and reduce the amount of particulate flash generated from the vibration cycle.

Technology Examples:

  • CEMAS Vibration Welders

Ultrasonic Welding

Ultrasonic welding uses high-frequency vibration to melt and weld plastic. A tool vibrates at ultrasonic frequencies and causes concentrated molecular vibration in the weld joint. The friction between the molecules heats and melts the plastic. Once the vibration is stopped, the tool maintains a holding pressure on the joint to create a bond.

Technology Examples:

  • Dukane Ultrasonics
  • Branson Ultrasonics
  • Herrmann Ultrasonics

Blog posts about plastic welding and plastic staking

Advantages of Servo-Driven Hot Plate Welders

Advantages of Servo-Driven Hot Plate Welders

Servo-controlled hot plate welders completely revolutionize the hot-plate welding process. Take it from Extol, we started the servo movement with the Rapid Conductor hot plate welder. Our welders use servo-motors to control the platens and weld strong, repeatable parts.

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Laser Welding Reflections

Laser Welding Reflections

Humans have been fascinated by reflections for millennia. Narcissus was bewitched by his reflection in a pool of water and mirrors have magic powers in fairy tales. Speaking of mirrors, they are simply smooth surfaces with shiny, dark backgrounds.

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