Abstract: This paper evaluates the energy efficiency and control response of traditional band-heaters compared to a new non-contact induction heating technology for injection molding barrels. It reviews quantitative results from laboratory and bench-top tests, considering factors like barrel diameter, surface condition, and thermocouple depth.

Background: The injection molding industry has improved energy efficiency with electric machines, but further energy savings are needed. Conventional barrel heating is inefficient, with significant energy lost to radiation and convection. Band-heaters also have slow temperature control responses due to their thermal mass and contact resistance.

New Induction Barrel Heating Technology: The nXheatTM system uses high-frequency induction with a thermal insulating layer, generating heat directly within the barrel and eliminating coil thermal mass. This approach achieves near 100% heating efficiency and improved temperature control.

Overview of Tests: Tests compared energy efficiency and control improvements using band-heaters and induction on a laboratory injection molding machine and bench-top setups. Induction showed significant energy savings and faster control response.

Molding Machine Test Procedure: Tests on a Toshiba machine with specific barrel dimensions used both band-heaters and induction. Power consumption and temperature control were monitored, showing induction's superior efficiency and control.

Barrel-segment Test Procedure: Tests on different barrel sizes with MICA and ceramic band-heaters assessed efficiency and control. Induction provided immediate energy input and cessation, unlike band-heaters which had significant lag.

Results: Induction consumed 31% of the power used by band-heaters and provided better temperature control. Band-heaters showed efficiency between 40-60%, decreasing with higher temperatures and over time due to surface darkening.

Conclusions: Induction heating with insulation significantly improves efficiency and control response, reducing sensitivity to thermocouple depth and enhancing predictability.