Automated Dynamics (Schenectady, N.Y.) reports that it has developed a laser-based resin heating technology for automated fiber placement of thermoplastic or thermoset prepregs. Called Laser Heating System (LHS), it replaces infrared (IR) heating systems normally used when placing thermoset-based prepregs, and hot gas heating systems normally used when placing thermoplastic-based prepregs. Zack August, project engineer at Automated Dynamics and developer of LHS, says the system offers several improvements over traditional heating systems:
- Better process stability
- Fiber placement rates three to five times faster (up to 0.5 m/sec for engineering thermoplastics and 1.2 m/sec for thermosets)
- Closed loop process temperature control based on actual material surface temperature
- Tighter process temperature control: ±10°C for thermoplastics and ±3°C for thermosets
- Better heating efficiency, which means more heating energy is transferred directly to the prepreg.
Because laser energy is applied more efficiently to the prepreg, and because the closed loop control is able to keep surface temperature within a relatively small window, Automated Dynamics says overall energy consumption of the LHS is about 60 percent less than hot gas heating systems. The technology, says August, has been proven in a production environment in the lab; actual production testing is taking place now. The LHS will be a standard option on all Automated Dynamics fiber placement systems, and the company is working with other fiber placement system manufacturers to offer it as a retrofit option on their machines as well. Automated Dynamics has already designed one LHS for Lockheed Martin for use at its facility in Palmdale, Calif. Lockheed is using the LHS for experiments associated with a military aircraft, including processing of Cytec’s MTM45 prepreg (out-of-autoclave epoxy ). Lockheed reports it has achieved a processing rate of approximately 1.2 m/s.