ApplicationsHeat and Bend Plastic Toy Parts

Application: 

A toy manufacturer bending plastic to produce three-sided toy barns.

Problem: 
  • Cost - One of the two bends in the plastic was produced when the part was molded. Cost requirements dictated that the second bend be produced after the part was molded.
  • Poor Quality - The existing method of heating the plastic with a heat knife prior to bending left stress marks in the finished toy barns.
  • Excessive Scrap - The poor quality of the bend resulted in an excessive number of the toy barns being scrapped.
  • Long Heating Time - Each plastic piece had to be heated for 10-15 seconds with the heat knife, limiting production output.
  • Extensive Training Required - With the existing process, operators required extensive training on how to heat and make the bend in the plastic.
Solution: 
  • Heat - Two Model 5194-16 Infrared Line Heaters were used to precisely heat the plastic from the top and bottom before it was bent.
  • Power Control - The power to the each Infrared Line Heater was controlled by a Model 5620 Phase Angle SCR Power Controller.
  • Automated Fixture - Placement of the part in the heating station closed a switch to automatically activate the SCR Power Controllers and apply power to the Infrared Line Heaters.
  • Timed Heating - The SCR Power Controllers timed the heating process and shut off the power to the Infrared Line Heaters when the heating cycle was complete.
  • Instant On/Off - The Infrared Line Heaters heated up and cooled down instantly based upon signals received from the SCR Power Controller.
Benefits: 
  • Improved Quality - The heating characteristics of the Infrared Line Heaters eliminated the stress marks in the bend area, significantly improving the quality of the finished toy barns.
  • Reduced Scrap - The improved quality of the bend virtually eliminated the need to scrap finished toy barns due to stress marks in the bend area.
  • Faster Heating Time - The heating time was reduced from 10-15 seconds to 3 seconds per bend with the Infrared Line Heaters.
  • Reduced Operator Training - Operators required less training to learn how to bend the plastic using the new heating method. Reduced Energy Consumption - The instant on/off capabilities enabled to manufacturer to operate the Infrared Line Heaters only when they were required to heat the plastic, reducing overall energy consumption for the process.
  • Repeatable Heating Process - The timer function of the SCR Power Controllers, combined with the instant on/off and precise heating capabilities of the Infrared Line Heaters, made the heating process repeatable and consistent.
  • Cost Effective - Using the Infrared Line Heaters controlled by the SCR Power Controllers provided the manufacturer with a cost-effective method of producing the bend after the parts had been molded.