PE Film Compacting & Pelletizing Case Study: ACSS Two-Stage Solution for Recycled PE Pellets

PE film recycling is different from the recycling of rigid plastics.
The low bulk density of film makes it difficult to feed directly into a conventional extrusion system.
During recycling, PE film may also contain:
• Moisture 
• Printing ink 
• Dust 
• Paper residues 
• Organic contamination 
• Other foreign materials 
If these factors are not properly controlled, they can lead to:
• Unstable feeding 
• Fluctuating extrusion pressure 
• Gas and bubble formation 
• Melt contamination 
• Increased filter loading 
• Reduced pellet quality 

The ACSS system addresses these challenges through a combination of cutter compaction, two-stage extrusion, vacuum degassing, and continuous melt filtration.

The ACSS two-stage compacting and pelletizing system can be applied to various PE film materials, including:

• LDPE film 
• LLDPE stretch film 
• HDPE film 
• Packaging film 
• Agricultural film 
• Industrial PE film 
• In-house factory film scrap 
• Printed PE film 
• PE bags 
• Flexible PE plastic waste 

The actual configuration should be selected according to the material condition, contamination level, moisture content, required throughput, and final pellet application.
For washed PE film, an appropriate dewatering and drying process should be completed before the pelletizing stage.

1. Low Bulk Density
PE film is lightweight and occupies a large volume compared with its weight.
Feeding loose film directly into an extruder can therefore result in unstable feeding and low feeding efficiency.
Film Tends to Bridge and Tangle
Flexible film can bridge inside the feeding system or wrap around rotating components.
A suitable compaction and feeding system is therefore important for continuous operation.

2. Moisture and Volatiles
Washed film can retain moisture, while printed and post-consumer film may contain volatile substances.
These materials can generate gas during extrusion if they are not effectively removed.

3. Contamination
PE film may contain dust, ink, paper residues, and other contaminants.

Continuous melt filtration is therefore important when processing materials with a certain level of contamination.

The ACSS system integrates the major stages required for PE film pelletizing into one continuous production line.
The main configuration for this application includes:

The combination of a large-volume compactor and two-stage extrusion is designed to provide stable feeding and controlled melt processing of PE film.

The complete process is:

PE Film → Belt Conveyor + Metal Detection → 800 L Compactor → First-Stage Ø120 Extruder → Vacuum Degassing → Continuous Piston-Type Melt Filtration → Second-Stage Ø150 Extruder → Melt Filtration → Water-Ring Pelletizing → Vibrating Dewatering → Recycled PE Pellets

Each section performs a specific function in the recycling process.

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The PE film is transferred to the pelletizing system through a belt conveyor.
A metal detector is integrated into the feeding system to help identify metallic contaminants before they enter the extrusion equipment.
Stable and controlled feeding is important because loose PE film has a low bulk density and can otherwise cause fluctuations in material flow.
The automatic feeding system reduces the need for manual feeding and supports continuous operation.

The PE film enters the 800 L compactor before extrusion.
The compactor reduces the apparent volume of the loose film and increases the bulk density of the material.
This provides several benefits:
• Improved feeding stability 
• Higher material density 
• Better continuous feeding into the extruder 
• Reduced bridging and feeding interruptions 
• More stable extrusion 

The compactor is particularly important for lightweight film materials that are difficult to feed directly into an extruder.

After compaction, the material enters the first-stage extruder.

Main Specifications
• Screw diameter: 120 mm 
• L/D ratio: 42 
The relatively long first-stage screw provides sufficient processing length for:
• Melting 
• Plasticizing 
• Mixing 
• Homogenization 
• Initial degassing 

The material is progressively heated and plasticized as it moves through the screw.
The screw design is configured to provide stable plasticization while minimizing unnecessary thermal degradation.

A vacuum degassing system is installed during the extrusion process.
The vacuum system helps remove:
• Moisture 
• Entrained air 
• Low-molecular-weight volatiles 
• Residual gases 

This is particularly useful when processing PE film containing printing ink, residual moisture, or other volatile substances.

Effective degassing helps reduce:
• Bubbles 
• Voids 
• Pellet surface defects 
• Melt instability 
and supports more stable downstream pelletizing.

After initial plasticization and degassing, the polymer melt passes through a continuous piston-type melt filter.
The filtration system removes solid contaminants from the molten PE.
Typical contaminants may include:
• Paper 
• Fine dirt 
• Aluminum or other foreign particles 
• Unmelted polymer 
• Other solid impurities 

The continuous piston-type design helps maintain production while the filter is serviced or regenerated.

Key benefits include:
• Continuous operation 
• Stable melt pressure 
• Effective contaminant removal 
• Reduced production interruptions 
• Improved filtration efficiency 
This is particularly valuable when recycling PE film with a certain level of contamination.

After the first filtration stage, the material enters the second-stage extruder.
Main Specifications
• Screw diameter: 150 mm 
• L/D ratio: 12 
The second-stage extrusion section is mainly responsible for melt homogenization and pressure stabilization before pelletizing.
The two-stage extrusion configuration separates the main plasticizing and degassing functions from the final melt stabilization stage.
This provides greater flexibility for processing PE film containing moisture, volatile substances, and impurities.

The melt is filtered again before entering the pelletizing system.
The final filtration stage provides additional removal of remaining solid contaminants.
This helps protect the pelletizing section and improve the consistency of the recycled PE pellets.
The actual filtration configuration should be selected according to:
• Raw material contamination 
• Required filtration fineness 
• Production capacity 
• Final pellet application

After melt filtration and pressure stabilization, the molten PE is transferred to the water-ring pelletizing system.
The water-ring pelletizer cuts the molten polymer into pellets and simultaneously provides initial cooling.
The pelletizing system is designed to produce:
• Stable pellet formation 
• Consistent pellet shape 
• Efficient cooling 
• Continuous production 
The actual pellet dimensions depend on the pelletizer configuration and operating conditions.

After pelletizing and cooling, the pellets are separated from the process water through the vibrating dewatering screen.
The dewatering system removes surface water from the recycled PE pellets and prepares the pellets for collection or further handling.
The final pellets can then be conveyed to a storage or packaging system.

The 800 L compactor increases the bulk density of loose PE film before extrusion.
This helps overcome one of the most common feeding problems associated with flexible film recycling.

The ACSS system uses two independent extrusion stages:

Ø120 × L/D 42 First Stage
Ø150 × L/D 12 Second Stage

The first stage focuses on melting, plasticizing, mixing, and initial degassing, while the second stage provides melt stabilization before pelletizing. 

Vacuum degassing helps remove moisture, air, and volatile substances from the polymer melt.
This can be particularly important when processing printed PE film or washed film with residual moisture.

The continuous piston-type melt filter helps remove solid contaminants while maintaining continuous production.
This reduces the need for frequent production shutdowns caused by conventional screen replacement.

The water-ring pelletizing system provides continuous cutting and cooling of the molten PE.
The combination of stable extrusion pressure and controlled pelletizing supports consistent pellet production.

The complete system is controlled through an intelligent PLC system.
The control system monitors and manages key operating parameters such as:
• Temperature 
• Pressure 
• Feeding 
• Extrusion 
• Pelletizing 
• Equipment status 
• Fault conditions 
The touchscreen interface also allows operators to monitor the production process and adjust operating parameters.

The ACSS pelletizing system can be used for different PE film recycling applications.

1. Clean Industrial PE Film

For relatively clean in-house production scrap, a washing process may not be necessary.
The material can potentially be processed through:
PE Film → Compaction → Pelletizing → Recycled PE Pellets
The actual process depends on the cleanliness and condition of the material.

2. Washed PE Film

For post-consumer or contaminated PE film, washing and drying should normally be completed before pelletizing.
The process becomes:
Waste PE Film → Shredding / Washing → Dewatering & Drying → Compaction → Pelletizing → Recycled PE Pellets
The pelletizing system then handles the final conversion of clean PE film into pellets.

3. Important Note on Moisture

For washed PE film, the moisture content entering the pelletizing system is an important design parameter.
The required dewatering and drying equipment should therefore be selected according to the material condition and the requirements of the pelletizing system.

The recycled PE pellets produced from this type of system can potentially be used in a range of downstream applications, depending on the raw material quality and pellet properties.
Typical applications include:
• Garbage bags 
• Packaging films 
• Agricultural films 
• Plastic bags 
• Pipes 
• Injection-molded products 
• Blow-molded products 
• Construction products 
• Plastic composite products 
The final application should be selected according to the recycled pellet's properties, including contamination level, color, melt flow characteristics, and mechanical performance.

The overall recycling route can be summarized as:
PE Film Waste → Feeding + Metal Detection → Compacting → Plasticizing → Vacuum Degassing → Melt Filtration → Second-Stage Extrusion → Final Melt Filtration → Water-Ring Pelletizing → Dewatering → Recycled PE Pellets

The ACSS system integrates these stages into one continuous pelletizing line.
The combination of compaction, two-stage extrusion, vacuum degassing, filtration, and water-ring pelletizing is designed specifically to address the feeding and processing characteristics of PE film.

This PE film recycling application demonstrates the use of the ACSS Two-Stage Compacting & Pelletizing System for converting PE film waste into recycled PE pellets.
The system is configured with an 800 L compactor, Ø120 × L/D 42 first-stage extruder, Ø150 × L/D 12 second-stage extruder, vacuum degassing, continuous piston-type melt filtration, water-ring pelletizing, and vibrating dewatering.
The process is designed to address several typical challenges associated with PE film recycling:
• Low bulk density 
• Unstable feeding 
• Moisture 
• Volatile substances 
• Printing ink 
• Solid contamination 

The complete process is:

PE Film → Compaction → Two-Stage Extrusion → Degassing → Melt Filtration → Pelletizing → Dewatering → Recycled PE Pellets

For relatively clean industrial film, the pelletizing system can be used as the main recycling stage.
For washed post-consumer or contaminated PE film, the appropriate washing, dewatering, and drying system can be installed before pelletizing.
This provides a flexible approach for producing recycled PE pellets according to different raw material conditions and downstream requirements.

ACERETECH provides PE film recycling and pelletizing solutions based on the characteristics of the incoming material and the requirements of the finished recycled pellets.

The ACSS Two-Stage Compacting & Pelletizing System integrates:
Compacting → Two-Stage Extrusion → Vacuum Degassing → Melt Filtration → Pelletizing → Dewatering

It is suitable for a wide range of PE film recycling applications, from relatively clean industrial production scrap to washed PE film requiring enhanced degassing and filtration.
Contact ACERETECH to discuss your PE film recycling project and determine the appropriate pelletizing configuration.