Secondary raw material (a used LDPE film) is taken to the processing point and checked by a responsible employee of a company for visual defects. Also, it is ensured that there are no impurities of hazardous waste or other waste that is not used in the processing. Secondary raw materials are weighted and accounted. They are discharged in a designated place.
Secondary raw materials which are accepted into the production unit are thoroughly checked. Impurities are manually removed from plastic packaging and plastic waste, i.e. other types of packaging, such as paper, cardboard, metal, etc., that come in between plastic packaging and plastic waste. Also, plastic waste that is contaminated with grease, food residues or other hazardous materials is considered unsuitable for use. Waste is sorted out and separated by type, colour and other criteria.
Packaging and waste that are not used by Granulės JSC in the production process are handed over to the companies handling such packaging or waste.
Plastic packaging and plastic waste are transported to a shredder with a belt conveyor for shredding. Shredded secondary raw materials are fed into washing devices – centrifuge with a conveyor belt for cleaning highly contaminated raw materials and a wash basin containing precipitated waste that is heavier than the film and that cannot be processed.
During the washing process, secondary raw materials are washed with cold water. Soil, dust and other impurities are washed away.
After washing, secondary raw material enters the drainage system and finally a processing line (extrusion – granulation).
A washed and rinsed shredded raw material goes to a centrifuge which separates water with the centrifugal force. When water is separated, raw material goes to a centrifugal hot air dryer with the help of vacuum.
Clean and dry raw material goes to a granulation warehouse.
A shredded, washed and dried raw material moves through a pipe into a storage hopper by using compressed air. From there, with the help of a belt conveyor, a raw material goes to a heating tank. A heated raw material goes to an extruder. In the extruder, a raw material is melted into a homogeneous mass separating the contaminated plastic from the extruder – plastic and rubber by using a filter. The molten mass, separated by using a filter, goes into a mass cooling and shredding device.
During this production process, plastic pellets are produced.
The pellets are further cooled with water which is then removed by centrifugal force, and dry and cooled pellets go to a storage hopper. From the storage hopper, they are put into big bags which are placed in a special warehouse area.