Twin Screw Compounding Extruder For Recycled Plastic - Nanjing Jieya Extrusion Equipment Co., Ltd.

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Extruders For Recycled Plastic

Recycle Waste Plastic Into New Pellets

Plastic waste can be a widely term.Different in shape and size, different properties and characteristics, they also come in different colors.

All these differences lead to some plastic waste being rather easy to recycle, while other waste is not. For example, a PET bottle, such as those storing our soft drinks, is a piece of plastic that can be quite easy to recycle. A rule of thumb is this: the purer and cleaner plastic waste, the easier to recycle.

^_S ^_ymbol	^_Name	^{_{Collected from}}	^{_{Recycled into}}
	PET	Water bottles, soft and fizzy drink bottles, pots, tubs, oven ready trays, jam jars	fiber, tote bags, furniture, carpet, paneling, straps, bottles, and food containers
	High density	household and kitchenware, cable insulation, carrier bags, food wrapping material	oil bottles, pens, floor tiles,benches,doghouses, picnic tables, fencing and shampoo bottles.
	PVC	Blister packaging, wire jacketing, siding, windows and piping	Decks, paneling, mud flaps, roadway gutters, flooring, cables, speed bumps and mats.
	Low density	Squeezable bottles; frozen food, dry-cleaning and shopping bags; tote bags; and furniture.	Trash can liners and cans, compost bins, shipping envelopes, paneling, lumber, landscaping ties and floor tiles.
	pp	syrup and medicine bottles; bottle caps, and battery cases.	Signal lights, battery cables, brooms, brushes, auto battery cases, ice scrapers, landscape borders, bicycle racks, rakes, bins, pallets and trays.
	PS	Toys and novelties, rigid packaging, refrigerator trays and boxes, cosmetic packs, and costume jewelry.	Insulation, light switch plates, egg cartons, vents, rulers, foam packing and carryout containers.

Recycling Process

Mechanical recycling
In the recycling process of thermoplastic wastes, it is necessary to subject them to two rounds of melting in order to obtain compounds. Traditional recycling is known as ‘mechanical recycling’ which physically breakdowns the plastic but does not alter the chemical structure .Mechanical recycling uses grinding, washing, sorting, and reprocessing to repurpose plastic material.The present work involved the construction of a tandem recycling process, wherein molten waste polymers were immediately introduced into a co-rotating twin screw extruder.A process-dependent screw configuration has been devised for the twin-screw system employed in the delivery of molten material. The product derived from 80% waste thermoplastic was thereafter compared to the original product as an outcome of the aforementioned procedure. Properties similar to those of pure Polypropylene were seen in some physical and chemical characteristics.The plastic recycled can then be converted into other products substituting for the use of virgin plastics.Mechanical recycling is a great method to make sure applications with lower material requirements do not need to be made from virgin plastics.

Chemical recycling
Chemical recycling is the process of recycling plastics through the chemical change of the polymer structure forming a raw material that can be used to manufacture new products. This technology means mixed batches of all types of plastic can be recycled – even back into food-grade packaging.

Compounding And Pelletizing Recycled Plastic

Compounding & Pelletizing is an essential step of the mechanic recycling process that leads to a very-high-quality recycled plastic granules by using specific technologies. Either single screw of twin screw extruder is the core compounding extrusion machine used in this process.Only the co-rotating twin screw compounding extruder has the unique opportunity to impart fillers or reinforcements to the recyclate.

how it works :

1.To melt the plastic material and furthermore mix with fillers, additives to improve properties. It can be a single screw or twin-screw extruder or both ,according the requirements for the end product.

2. To purify the material and remove any remaining organic residues by screen changer and vaccum degassing unit added into the whole compounding production line.

Picture from Mumbai-India-Environmental-NGO-Earth5R

A Twin-Screw Compounding Extrusion (TSE)system for recycled plastic might include:

1. Individual loss-in-weight (LIW) feeders for reclaim, fillers and additives;
2. Metal contaminant ejection system at TSE feedthroat;
3. Twin screw compounding extruder with extended L/D and configured for early-stage venting and downstream filler feeding via a side stuffer;
4. Specialty vacuum-venting system for high-level water removal;
5. Oversized screen changer and melt-flow diverter;
6. Underwater pelletizing system with classifier.

Challenges For Recycled Plastics Compounding

Feeding regrind
Regrinds present special feeding challenges in terms of bulk density and consistency.
The challenge is to ensure how consistently they can feed the different regrind shapes, sizes, and bulk-density variations. Here is where we can help with designing the correct feeder configuration.

Vacuum Degassing
Extruder degassing is to remove the gaseous components incorporated in the material itself, which are generated by the presence of inks or contaminants. By doing so, an excellent result can be guaranteed.
Proper degassing can be reached by changing the number, position and geometry of the degassing ports.
The degassing process is most effective when used over a conveying section after a mixing section on the extruder.

Filtration
The more homogeneous and the less contaminated the resulting material is, the better the result will be.
Filtering of contaminants in plastic extrusion has always played a key role in producing and selling top-quality equipment. For highly polluted post-consumer materials, installation of a screen changer is mandatory .According to different requirement for target pellets, we could configure different screen changers.

Benefits of Jieya Twin Screw Compounding System

Modular design

Segmented screw element and barrel are designed for different tasks in every operating units. In this way, the whole process are accurate controled,which ensure reliable performance of extrusion.

Low Cost, Long Lifetime of Spare Parts

Equipped with CNC machining centers, our factory produces screws and barrels are manufactured by ourselves, enabling a tight control of quality and cost.

Reliable service

What we provide is not only a twin screw extruder,but a systematic solution from the very beginning preparation of material to final pelletizing.

We hope to create more values for our customers by continous improvement.

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