Guide to Plastic Film & Woven Bag Recycling Machines

Why Recycle Plastic Films?

PP (polypropylene) and PE (polyethylene) plastic films and woven bags are widely used flexible plastic materials, commonly found in daily life and industrial applications. PE films include agricultural mulch films, greenhouse films, cling wrap, shopping bags, and garbage bags made from Low-Density Polyethylene (LDPE) and Linear Low-Density Polyethylene (LLDPE). PP films, on the other hand, are frequently used in packaging materials such as BOPP films and composite flexible packaging layers.

Plastic woven bags, primarily made from PP woven yarn, are extensively used for packaging bulk goods like grains, animal feed, fertilizers, and cement. This includes standard woven bags as well as jumbo bags or bulk bags (FIBC bags). Due to their high usage, short lifecycle, and diverse sources—from agricultural fields (mulch film waste), industrial and logistics sectors (packaging films and woven bags), to consumer usage (shopping bags and courier bags)—these materials become widespread waste. Being difficult to naturally degrade, these discarded soft plastic materials persist in the environment, causing significant "white pollution" and resource wastage if not properly recycled.

With rapid advancements in recycling technologies, professional plastic film recycling machinery now enables efficient processing and conversion of these previously challenging materials into high-quality recycled pellets. These recycled pellets can be reintroduced into the production of new plastic products. This process effectively reduces dependency on virgin plastics, promotes circular utilization of plastic resources, and contributes significantly to environmental sustainability.

What Can Be Recycled?

Our plastic film recycling lines provide efficient and reliable sorting and washing solutions for various soft plastic materials, including LDPE, HDPE, PP, PE, and more. We offer flexible and customizable recycling processes tailored to different production capacities and types of raw materials (such as plastic bags and films), fully meeting the needs of both small-to-medium operations and large-scale industrial recycling plants.

Typical recyclable materials include:

How Does a Plastic Film Recycling Machine Work?

Depending on the cleanliness of the raw material, plastic film recycling processes generally follow two distinct pathways:

1. Heavily Contaminated Material Process (e.g., agricultural films with up to 80% sand content) This requires a complete "Shredding → Washing → Contaminant Removal → Drying" process: Suitable Materials: Agricultural mulch films, municipal waste films, woven bags with heavy oil contamination, etc.

2. Clean Material Direct Process (e.g., industrial offcuts or clean packaging films) Cleaner materials can bypass washing and go directly to pelletizing systems: Suitable Materials: Industrial offcuts (unused packaging films, pallet protection films), BOPP printed films without oil or dirt contamination.Clean raw material after treatment in the plastic washing line

Recycling Process: Film Woven Bag Washing Pelleitizing Line

The PP/PE film and woven bag recycling line generally includes pre-treatment, shredding, washing, drying, melting, and pelletizing. The fundamental principle involves mechanically and water-assisted removal of impurities from waste plastics, followed by drying and extrusion through a pelletizing machine to produce high-quality recycled plastic pellets suitable for downstream applications.

Typical Recycling Process:

1. Material Collection & Pre-treatment:

Collect dispersed waste films and woven bags, then remove non-plastic contaminants (labels, metals) either manually or mechanically. Separate incompatible materials (like PVC), and preliminarily clean large impurities such as sand and soil.

2. Shredding (Coarse & Fine):

Large plastic films and woven bags are shredded into smaller pieces using shredders or crushers (single/double-shaft). Specialized machinery (e.g., Boxin Machinery crushers with water spray) simultaneously crushes and pre-washes materials, reducing dust and removing some sand and impurities.

3. Washing:

Shredded plastics are thoroughly cleaned using multiple washing stages. First, friction washers use high-speed rotating blades to remove stubborn dirt. Next, float-sink tanks separate heavier contaminants (sand) and lighter plastics. Hot washing processes (using hot water and detergents) can remove ink, adhesives, and oil, enhancing the purity and value of the recyclate.

4. Dehydration & Drying:

After washing, the plastic fragments contain significant moisture and are dehydrated using centrifugal dryers (vertical or horizontal). Residual moisture is further reduced by hot-air dryers to below 5%. Advanced processes may use squeezing dryers, which mechanically remove moisture and partially melt plastics to improve subsequent pelletizing efficiency.

5 .Melt Extrusion:

Cleaned and dried plastic flakes enter pelletizing extruders, where they're heated and melted. Single-stage or double-stage extruders equipped with automatic temperature control and vacuum degassing systems melt the flakes uniformly and remove residual moisture and volatile substances. Melt filters ensure purity before extrusion.

6. Cooling & Pelletizing:

The melted plastic is cooled and cut into pellets using either water-ring pelletizers (hot die-face cutting) or strand pelletizers (strand cutting). Water-ring pelletizers, preferred for PE/PP, quickly cool pellets after cutting. Strand pelletizers extrude and cool plastic strands, then cut them into uniform cylindrical pellets. Final pellets, typically 2-5 mm, undergo vibration screening or air sorting to remove fines and are then stored in silos for downstream use.

Throughout the recycling process, water recycling and wastewater treatment are crucial. Washing generates substantial wastewater containing detergents and solids, which must be recycled via sedimentation and filtration systems to minimize environmental impact. Modern recycling lines integrate automated controls for continuous operation, enhancing productivity and reducing labor intensity.

Core Equipment and Technology Modules

A complete soft plastic recycling line includes several essential modules working together to ensure efficient recycling:

	Conveyors: Horizontal and inclined conveyors transport materials between stages, minimizing manual handling and enhancing workflow continuity.
	Shredders/Crushers: Specially designed shredders handle soft plastic materials, breaking down large bundles into manageable sizes suitable for washing and pelletizing.
	Friction Washers: High-speed rotating blades mechanically scrub and detach contaminants from plastics, significantly enhancing cleanliness.
	Float-Sink Tanks (Washing Tanks): Separate plastics from impurities using density differences, effectively removing heavier contaminants.
	Centrifugal Dryers: Rapidly remove water from plastic fragments, reducing moisture content to facilitate efficient pelletizing.
	Hot-Air Dryers: Further dry washed plastics to optimal moisture levels (<5%), preventing defects during extrusion.
	Extruders (Plasticizers): Melt and homogenize cleaned flakes, crucially preparing plastics for stable pelletizing.
	Pelletizing Systems: Convert molten plastic into uniform pellets via water-ring or strand pelletizing techniques.
	Cooling and Conveying Equipment: Ensure rapid cooling and transfer of pellets to storage facilities, maintaining pellet integrity and quality.

Continuous improvements in these core components, such as enhanced wear-resistant blades, optimized water flows, and advanced melt filtration technologies, have significantly increased productivity, energy efficiency, and operational stability.

Applications and Downstream Uses

Recycled PP/PE pellets have diverse downstream applications, their usability influenced by raw material sources and processing techniques. Typical applications include:

• Film Products: Garbage bags, shopping bags, agricultural mulch films. Quality may vary; recycled agricultural films often yield black mulch films or lower-grade packaging.

• Injection-Molded Products: Household items, storage boxes, buckets, pallets, appliance parts, toys, automotive components, etc. Recycled pellets significantly reduce production costs.

• Fibers and Woven Products: Recycled PP pellets for woven bags, ropes, and geotextiles. PE pellets can also be spun into short fibers for nonwoven materials.

• Pipes and Profiles: Recycled HDPE commonly used for agricultural irrigation pipes, conduit pipes, drainage pipes, and profiles for composite decking, fences, and window frames.

• Modified and Blended Materials: Pellets blended with elastomers or additives produce specialty materials like shoe soles, flame-retardant plastics, and road construction additives, broadening recycled plastic applications.

The purity and quality of recycled pellets directly influence their final applications. High-quality pellets can enter more demanding markets, including indirect food packaging and appliances. Mid-grade pellets typically serve durable consumer goods, construction materials, or packaging. Lower-grade pellets are suitable for wood-plastic composites or non-demanding products, or further processed into fuel oils through chemical pyrolysis.

Overall, recycled PP/PE pellets cover a significant proportion of plastic production, used extensively in film blowing, injection molding, extrusion, and other manufacturing processes. Everyday products made from recycled plastics include bags, containers, furniture, and numerous industrial components. By appropriate modification and blending, recycled plastics can even enter high-end industries like textiles, automotive, and electronics, effectively replacing virgin plastics, reducing production costs, and significantly contributing to environmental sustainability.