SAN DIEGO — Hudnut Industries Inc. of Portland, Ore., has developed a densification system for volume conversion of industrial resin scrap and recycled thermoplastics into production-ready materials. The ReCyclotron RC-30 plastic densifier costs about $145,000 and can process expanded polystyrene, polypropylene and low density and high density polyethylene at a rate of 250-400 pounds per hour.
"The densifier allows you to recapture your waste stream and turn it into a profit stream," said Carl Goehner, vice president of engineering. Goehner was interviewed during EPS Expo, held March 7-9 in San Diego.
The machine accepts ground particle-size foam or film and, relying on an Allen Bradley programmable-logic controller, conveys the material on a high-speed airstream to an agitator-equipped hopper.
The controller oversees continuous-process monitoring and runs start-up and shutdown cycles.
The system causes material to float in a hot air bath until the foam cells collapse or the film shrivels.
Trapped butane or other volatile blowing agents escape into a reaction chamber, where they are diluted with air.
The system controls the rate of air turnover and diminishes the concentration below the low acceptable limit for a material to be regarded as volatile.
The system retains most of the heat. An advanced burner can use natural gas, propane or methane.
Custom designs can dry, and then densify, wet plastics.
Unlike batch-feed balers and tub grinders, the system operates as long as ground plastic remains in the hopper. Minimal operator time is required.
In technology extensions, Hudnut Industries is developing other industrial machinery such as electrically heated models, larger capacity plastic reclamation and recycling systems, advanced air-drying machines, and sorting systems for organic and inorganic materials.
Northwest Thermal System Co. of Portland fabricates the ReCyclotron and also handles production for Hudnut Industries' thermal energy projects involving oxidizers, burners and blowers.
Hudnet Industries used a 1997 grant of $400,000 from the Department of Energy in developing the densifier. A manufacturer and fabricator of pipe insulation and pool toys in the East began using the first commercial system in late 1998.