How to Handle High-Moisture Plastic Film Before Pelletizing

Industry Background

Plastic film recycling has become an increasingly important part of the circular economy, particularly for materials such as LDPE agricultural films, packaging films, shopping bags, and industrial stretch films. In a typical recycling process, plastic films undergo shredding, washing, friction cleaning, and rinsing before entering the pelletizing stage.

However, one common challenge remains throughout the industry: high moisture content after washing. Excess water retained in soft plastic films can negatively affect downstream pelletizing operations, resulting in unstable feeding, increased energy consumption, and inconsistent pellet quality.

As recycling plants pursue higher efficiency and more stable production, effective moisture reduction before extrusion has become a critical consideration.

Typical Challenges of Wet Plastic Film Materials

Unlike rigid plastics, flexible films tend to retain water between folds and layers after washing. Even after conventional centrifugal dewatering, a significant amount of moisture may remain trapped within the material.

Common operational issues include:

• Material bridging inside feeding systems

• Irregular feeding rates to the extruder

• Steam generation during melting

• Increased extrusion pressure fluctuations

• Reduced pellet consistency

• Higher drying energy requirements

These challenges are especially noticeable when processing agricultural films and post-consumer packaging films that have undergone intensive washing procedures.

Equipment Structure and Technical Considerations

A plastic squeezer pelletizing machine is designed to combine mechanical dewatering, densification, and continuous discharge into a single process.

Mechanical Squeezing Principle

The machine uses a screw compression structure to gradually squeeze water from washed plastic film materials. During compression, moisture is forced out through drainage openings while the material becomes denser and more compact.

Typical design features may include:

• Heavy-duty screw shaft

• Wear-resistant barrel structure

• Continuous compression zone

• Water drainage section

• Adjustable discharge system

Moisture Reduction and Material Densification

Compared with thermal drying systems, mechanical squeezing focuses on physical water removal.

Key considerations include:

• Feedstock moisture level

• Film thickness variation

• Material contamination level

• Screw compression ratio

• Discharge temperature control

The densified material produced by the squeezing process is generally easier to feed into downstream extrusion systems than loose washed films.

Capacity Matching

When integrating a squeezer into a recycling plant, capacity should be matched with the washing line and pelletizing line.

Factors influencing capacity selection include:

• Washing line output

• Type of plastic film

• Desired pellet production rate

• Material bulk density

• Operating hours per day

Proper equipment matching helps maintain stable production flow throughout the recycling system.

Integration in PP PE Film Recycling Lines

In a complete PP PE film recycling line, the squeezer pelletizing machine is typically installed after the washing and dewatering stages and before the extrusion pelletizing system.

A typical process flow may include:

Film Shredder → Washing Tank → Friction Washer → Dewatering Machine → Squeezer Pelletizer → Extruder → Pellet Cutting System

Within this arrangement, the squeezing machine performs several important functions:

• Reducing moisture before extrusion

• Increasing bulk density of washed films

• Improving material transport efficiency

• Stabilizing extruder feeding conditions

• Lowering fluctuations during pellet production

As a result, downstream pelletizing equipment can operate under more consistent conditions.

Selection Recommendations for Different Feedstock Conditions

Agricultural Film Recycling

Agricultural films often contain soil, sand, and organic residues. For these materials, a robust squeezing system with strong compression capability is generally recommended.

Post-Consumer Packaging Films

Packaging films usually have lower contamination levels but may contain mixed thicknesses and varying material compositions. Flexible adjustment of compression parameters can help accommodate these variations.

Industrial Film Scrap

Industrial film waste is often cleaner and more uniform. In these cases, capacity matching and continuous operation capability may become the primary selection factors.

Woven Bags and Raffia Materials

For woven polypropylene materials, equipment should be selected according to fiber structure and material density to ensure stable feeding performance.

Conclusion

As plastic film recycling operations continue to expand worldwide, controlling moisture before pelletizing remains a key factor in maintaining stable production.

Mechanical squeezing technology provides an effective method for combining dewatering and densification into a continuous process. By reducing moisture levels, improving material density, and stabilizing downstream feeding conditions, squeezer pelletizing machines can play an important role in modern PP PE film recycling lines.

When selecting equipment, recyclers should evaluate feedstock characteristics, production capacity requirements, and overall process integration to achieve reliable and efficient recycling performance.