Power controller for industrial infrared lamps in the plastic injection process cycle

• Application: To control SWIR lamps according to the plastic injection process cycle and full integration with the machine control system
• Solution: GFX4-IR 4 channel power controller to perform control of SWIR (Short Wave Infra Red) lamps in a preheating oven for composite materials components for Aerospace industry

Composite materials have evolved over the years. Adding glass and carbon fibers to the thermoplastics have reached the characteristics of stiffness and strengths to meet the request of components for the aerospace and automotive industry; replacing the usage of metals.
The benefit of composite materials is maximizing mechanical performance while reducing the weight of the component.
The hybrid molding is one of the processes applied in the composite production technology.
It consists of inserting a preheated composite laminate component (called organ–sheet) inside the mold of typical injection plastic process.

The production process is practically a plastic injection machine line with one or more SWIR lamps ovens to perform two main steps:

• Preheating of the laminate composite material to be inserted in the mold
• Over molding with thermoplastic resin, the inserted laminate component

Considering the rapid injection process cycle, the pre heating phase is based on SWIR (Short wave infrared) lamps technology, having a quick thermal response and heat directly the substrate of the laminated composite.
The SWIR lamps are a non-linear electrical load (resistance depends on the temperature of the filament) from cold to hot state and the peak current can reach up to 5-6 times of its nominal current.
The IR lamps are connected in parallel 3 phase configurations and the machine is controlled through PLC.

GFX4-IR SCR Power controller

• 4 channel control for a total of 80KW load – compact and effective design for reduced foot print
• Max 40 A per channel
• Configurable SCR control mode: Phase angle, Burst firing, Half single cycle, Soft start – Flexibility to suit different load Characteristics
• Specific SWIR Soft start and current over peak limiter – protects and enhances life of heaters
• Partial and full load break alarm – give early indication for heater replacement – reduces machine down time
• Embedded 4 channel Fuse and CT – reduces additional components and wiring in the panel
• Factory automation Field bus Ethernet – makes it compatible with most PLCs

The GFX4IR 4 channel power controller resulted as the most effective solution for the application.

The 4-channel power controller has a specific SWIR soft start feature (figure 2) to enable a gradual warm up of the lamps at the process start and in combination with the current over peaks limiter (figure 3) preserve the lamp from thermal stress of the filament and extend the lifetime.

The applied SCR control mode is a combination of Soft start in PA (phase angle) and HSC (Half single cycle) in Zero crossing mode – this is to avoid EMC noise and flickering effect on the lamps.

Maintenance and Diagnostic

The HB alarm function detects a partial or full interruption of the load for the benefit of a correct heating effect on the laminated material treated when a lamps failure occurs.
The product has on board 4 protection rapid fuses to preserve the product itself from short circuits.
The ODVA and PI conformant certification (Figure 4) of these products guarantees their complete compatibility and integration with PLCs supporting Ethernet/IP and ProfiNET.