PP/PE & Soft Plastics Single Screw Pelletizing Line

Custom-Engineered Single Screw Extrusion Solutions for Clean & Pre-Washed Plastic Scraps.

Raw Material Note: Kairong Machinery specializes in extrusion pelletizing and melt filtration hardware. Our systems are designed for clean industrial scraps, factory edge-trim, or pre-washed plastic materials. While our heavy-duty screen changers filter minor impurities, highly contaminated waste requires pre-cleaning prior to extrusion.

Compatible Raw Materials

Processing Scope: Our two stage single screw extruder are specially engineered to process a wide variety of clean, pre-washed polyolefin and soft plastic scraps—including PP, PE (HDPE/LDPE), EVA, etc.

Common Feedstock Forms:

Films & Sheets:Agricultural greenhouse films, stretch wraps, packaging films, and factory roll edge-trims.
Woven & Industrial Packaging:PP woven bags, FIBC jumbo/ton bags, and cement sacks.
Pre-Crushed Flakes:HDPE milk bottles, detergent jugs, PP crates, and battery shells.
Specialty Soft Scraps:EVA foaming off-cuts, sheet trims, and clean manufacturing waste.

Primary Solution — Two Stage Single Screw Extruder (Tandem System)

For recycled plastic films, soft packaging, and light scraps, our Two stage single screw extruder system is the most reliable and engineered solution for high-quality pelletizing.

Why Choose a Two Stage Single Screw System?

For recycled plastic films and soft plastics, the main challenge is not simply melting the material. Material waste is often lightweight, bulky, and irregular in shape, while recycled feedstock may contain moisture, ink, dust, or minor contaminants. A single extrusion stage may therefore have to handle too many tasks at the same time.

A two stage (tandem) extrusion system strategically separates these tasks into two optimized phases:

The First Stage (Mother Extruder):Focuses on feeding, melting, plasticizing, and homogenizing the recycled material. It provides maximum melting capacity while effectively removing volatiles and trapped moisture through multi-vent vacuum degassing ports.
The Second Stage (Baby Extruder):Receives the already-melted material and focuses purely on stable melt conveying, fine filtration, pressure building, and smooth pelletizing. Because the material is fully plasticized before entering the second stage, the second extruder operates under much more controlled, stable conditions.

Engineering Expertise Matters:

A tandem system is not simply two extruders connected together. Both stages must be precise-matched in screw design, output capacity, pressure balancing, thermal control, and filtration requirements. The first stage provides sufficient melting and degassing, while the second stage maintains a smooth, consistent melt flow for filtration and pelletizing.

The result is an extrusion process that is vastly easier to control, providing superior melt stability and bubble-free pellets—even when incoming material conditions vary.

Heavy-Duty Melt Filtration & Non-Stop Screen Changing

To complement our two stage system, the secondary extruder is equipped with advanced hydraulic non-stop screen changers (Plate / Double-Column / Continuous Type):

Continuous Operation:Allows screen replacement in seconds without stopping the main drive motor or interrupting melt flow.
Impurity Removal:Efficiently strains out residual fibers, paper bits, and un-melted foreign particles, ensuring clean, high-density final pellets.

Alternative Solution — Single-Stage Single-Screw Line

A two-stage system is not necessary for every film recycling application.

When the incoming material is relatively clean and easy to process, and the requirements for degassing, filtration, or melt quality are not particularly demanding, a single-stage single-screw extruder may provide a simpler and more economical solution.

It can also be a practical choice when the project has a limited budget or when the required output is relatively modest. With fewer processing stages and a more compact configuration, the initial investment and system complexity can be reduced.

The key is to match the extrusion system to the actual material and recycling requirements rather than choosing a two-stage system simply because it is more advanced.

For relatively simple film waste, a well-designed single-stage line may be all you need. For more demanding materials requiring stronger plasticization, degassing, filtration, or process stability, a two-stage (tandem) system may be the better choice.

One Machine for Everything?

It is common for customers to look for one extrusion machine that can process many different materials. In practice, however, no single-screw or twin-screw extruder can be optimized for every material and every process at the same time.

Different materials can have very different melting behavior, viscosity, temperature requirements, feeding characteristics, and pelletizing requirements. A machine can usually be designed to handle a certain range of materials, but when the requirements become too broad, compromises in screw design, processing conditions, output, or final pellet quality may become unavoidable.

For projects involving multiple materials, we usually recommend identifying the main material first. The extrusion system can then be designed around the primary material and process requirements, while considering whether the other materials can also be processed on the same machine with reasonable adjustments.

If you already have a specific combination of materials or a particular processing idea in mind, feel free to contact us and share your materials, target output, and main requirements. We can evaluate the application and suggest a practical extrusion and pelletizing solution based on your actual project.

Projects

Country：China

Customer Code：036 Country：China Capacity：400 kg/h Pelletizing system：water ring pelletizing system Extruder：HMS-180 Material：HDPE film recycling

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