The art of recycling
lies in technology
Our technology is unique in the Czech Republic in terms of what it is capable of. We have modern facilities and are always adapting our technology to current challenges on the waste market.
The Plastic Union group’s recycling technology is unique in that this is the only company in the Czech Republic to process composite plastics from yellow bins in such a way that they can be separated into single-type materials. This results in single-type, homogenised regrind and regranulate of up to 99% purity, i.e. it contains only negligible traces of other materials. Thanks to its modern recycling technology, the group can handle plastics from start to finish: purchase, manual sorting, grinding, dirt removal by washing, separation by type and colour, regranulation, and subsequent sale of the resulting regranulate.
First, the incoming material is manually sorted on a conveyor belt. Here, workers help to remove impurities from the material. One of the first pieces of technology involved in the process is a magnetic separator, which removes all metallic impurities, including any that have escaped visual detection.
The next stage is grinding. This relies on a large dredge crusher capable of grinding large plastics and bales of pressed plastic packaging. The maximum dimensions of these input raw materials are 1,400 x 1,200 mm. The output is plastic regrind with granulation of 40 mm, in which metallic impurities are again separated. It is moved via a conveyor system towards the washing line.
The first stage purifies the water on a vibrating screen, and the second treats the water technologically. The technology meets the highest demands placed on the ecology of operation. The unique system of multiple washing with hot, cold and lukewarm water removes all dirt and any residues of cleaning agents that may have remained in plastic containers. At the start, it first separates coarse impurities on the rotary screen and then grinds the plastic to a granulation of 20 mm.
After washing, the mixture is divided by a basic sedimentation method into floating lighter types of plastic, i.e. polypropylene [PP] and high-density polypropylene [HDPE], and non-floating heavier types of polymers, i.e. polyethylene [PET]. Excess water is removed from the still wet plastic regrind, by now divided into floating and non-floating parts, with the help of a centrifuge and friction washer. That water flows into a wastewater treatment plant. The regrind is then dried to the moisture required for the next part of the recycling process, ground to a granulation of 6 mm, and cleaned with a dust and light particle separator. Both of these separated segments of the plastic recycled mixture, in the form of clean flakes, are subsequently filled into large-capacity transport bags.
The next part of the recycling technology is a device for the variable type-based separation of selected types of polymers. The input is dry material (with a maximum surface moisture of ≤2%) that has granulation of 2-8 mm and is free of metal particles. This equipment, which operates on the principle of a static charge obtained from the surface of plastic fragments, allows the level and intensity of the static charge to be adjusted to distinguish between the mixed plastics contained in the regrind. Electrostatic separation results in two types of regrind: polypropylene [PP] and high-density polypropylene [HDPE]. These market-ready materials can be further colour sorted and granulated.
An optical separator is used to remove the colour or approximate colour mix required by customers for their production process from the plastic regrind. The higher the degree of separation, the higher the sale price for the customer.
Plastic regranulate is the final stage in the ecological recycling and processing of plastic waste. The regranulation line is a technological unit for the processing of washed and dry regrind. The technological unit has a silo installed at its entry point and an automatic storage system for the continuous feeding of the extruder.
The extruder is filled by an unmanned gravimetric dosing system, which can accurately dose up to three formula items to enrich (with fillers or additives) or colour the output granulate.
The extruder is fitted with a melt filtration system so that it can be continuously operated without any interruption in production. A liquid ring granulating set with rotary blades for hot granulate production is compactly connected to the mouth of the extruder chamber.
The produced granulate is carried by the water of a closed-circuit cooling system through an anti-corrosive vibrating screen. This cooling circuit features a basic used-water filter with heat exchanger.
The cooled granulate that has passed through the vibrating screen is then centrifuged in a centrifugal fan and transported to a filling station that has been installed for two large-capacity transport bags to be attached to it.