Multi-component processing
Areas of application

The term "multi-component technology" describes a variety of methods employing specially designed mold and machine features. Essentially, they all use two or more injection units to inject two or more materials onto each other or in between each other. Injected onto each other, the components will either form an integral molding (an automotive taillight) or a split molding (a closure with a seal ring). If injection is with a shot in between the other shots, referred to as the sandwich technique, a laminated structure is obtained with a soft skin and a hard core (typically, regrind may be used for the core and virgin material to provide a high-quality surface).

Processing techniques at a glance

• Bi-injection:
  simultaneous or sequenced injection of two components into one cavity 
   
• Core-back technique:
  injection of two components into one cavity one after the other, the space for the second component being accessed by shifting a valve
   
• Transfer technique:
  the preform is transferred into the second cavity or second machine manually or by means of a robot
   
• Rotary technique:
  transfer is by axial or vertical rotation with the rotary function provided for in the machine or in the mold
   
• Sandwich technique:
  a laminated structure is produced with a skin-core structure