Shredding and Recycling Rigid Plastics

Machines in the WLK series are ideally equipped for a wide range of plastics tasks. The machine design is characterized in particular by its durability and robustness. Thanks to the conveyor belt cut-out, all machines can be seamlessly integrated into any production line. They also offer a wide range of options in terms of drive and cutting geometry.

With rotor lengths of 1,400 to 2,200 mm, the shredders in the W5 series shred large-volume plastic tanks and plastic garbage cans with ease. The hydraulically upward pivoting screen basket and the inspection flap allow foreign objects to be removed quickly and facilitate maintenance. Large quantities of plastic flakes can be removed via the wide conveyor belt cut-out.

Voluminous plastic parts, such as IBCs and canisters, are particularly suitable for shredding with four-shaft shredders from the ZM series. The plastic containers are shredded between the two cutting discs and pressed through the cutting gaps between the cutting discs by the two clearing discs. The screen placed underneath defines the grain size of the shredded material.

The machines in the PowerLine series can be used universally. Variable equipment and sizes enable precise adaptation to your specific requirements. The counter knives are user-friendly adiustable from the outside and protected by an additional cover plate.

Rigid plastics are large, rigid plastic waste that cannot be disposed of in the yellow bag. These bulky plastic scraps can usually be disposed of free of charge at recycling centers. Thanks to their stable shape, they are durable, light and easy to produce. The biggest advantage is that they are very easy to recycle if they are collected separately. In the USA, rigid plastics also include a lot of rigid packaging such as cups, trays or transport boxes for food.

• Water barrels, canisters, tubs
• Bottles, fruit crates, folding baskets
• Composters, garden furniture, watering cans
• Sandpit toys, Bobby cars, clothes hangers
• Plastic pallets, containers, IBCs
• Big boxes, paloxes, window frames
• Trunk, child seat

Rigid plastics are mainly made of thermoplastics such as polyethylene (PE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyamide (PA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS) and polyvinyl chloride (PVC). (PC), acrylonitrile butadiene styrene (ABS) and polyvinyl chloride (PVC). Around 65% of rigid plastic waste is made up of polyolefins such as PP, PE and HDPE. These plastics are particularly easy to recycle. Rigid plastics are manufactured using various processes such as injection molding: e.g. for toys, car parts, blow molding e.g. for bottles, canisters, containers and rotational molding e.g. for large hollow bodies such as barrels and tanks.

In contrast to flexible packaging such as tubes, pouches or films, rigid plastic packaging protects the contents much better. They offer leak protection for liquid products, which is particularly important for to-go, take-away and delivery services. Sensitive or fragile goods are also often transported in rigid plastic packaging. In the USA, smaller packaging such as yogurt pots, plastic bottles, milk and juice cans and caps are also categorized as rigid plastics. There, all recyclable consumer plastics are collected together and recycled, provided they are disposed of correctly in recycling containers.
Awareness of the circular economy is growing steadily: in 2016 alone, consumers in the USA recycled over 660,000 tons of rigid plastics.

Source: Recycling Today

The recycling of rigid plastics often results in a mixture of different polymers, which must first be sorted and separated into unmixed fractions. Due to joint collection, many plastic wastes are heavily soiled or contaminated - for example with soil, sand or food waste. In addition, many products contain metals such as aluminum, copper or iron, which must be removed during recycling. A typical example is a toy car with rigid iron axles, which are separated from the plastic before further processing.

Hard plastics can be fed loose or in bales directly into the hopper of a WEIMA single-shaft shredder by conveyor belt, crane, wheel loader or forklift. A hydraulic pusher presses the material in a controlled manner against the rotating rotor, which processes the plastic into homogeneous ground material. The screen size - usually 40 to 80 mm for hard plastics - defines the particle size. The shredded material is then transported by conveyor belt to the next process step, such as washing, drying or extrusion.

After shredding, the hard plastic is cleaned in a washing system and sorted using the sink-float method. Metal separators or metal detectors remove impurities such as iron or aluminum. The sorted plastic flakes can then be processed into regranulate in the recycling extruder. This regranulate serves as a raw material for new products, such as waste garbage cans, buckets, pallets or containers.