This story appeared in the Winter 2020 edition of Plastics Recycling.
An Estonian company has invented a system to turn mixed, dirty plastics into boards that can be used to make landscaping products, furniture, noise barriers and building materials.
The system from Rolan Investment OÜ, Tallinn, Estonia, includes equipment for removing metal contaminants and incorporating additives and an extruder that melts and foams the mixed plastics in a continuous process. Additionally, the system includes a two-phase cooling stage, a controlled pultrusion process and cutting equipment.
To stabilize the production process, “the devised temperature curves and pressures caused by extrusion are monitored and controlled. … In contrast with the known solutions, the calibration matrices are divided into several parts. This ensures a stable extrusion process that can be controlled and directed,” according to the patent.
The system uses unsorted, unidentified and dirty, mixed plastics to make products that can be milled, sawed and nailed and are weatherproof and maintenance-free, the patent states.
Patent 10,486,352; issued Nov. 26, 2019