Plastic Drying and Cleaning Systems

Plastic Drying and Cleaning Systems: Maximum Moisture Control Before Pelletizing

One of the most critical stages of the plastic recycling line is the complete drying of wet and damp flakes emerging from the washing processes before they enter the pelletizing machine. Plastic Drying and Cleaning Systems are integrated solutions that ensure the removal of water from the material using mechanical or thermal methods. Raw material with high moisture content leads to evaporation issues in the pelletizer, reduced product quality, and significant capacity losses. Produced with Oğuz Makina's advanced engineering standards, our drying units guarantee the highest raw material quality by achieving low moisture levels ranging from 1% to 8%.

1. Drying Technologies and Working Methods

Drying technologies are divided into two main categories based on the form of the plastic (film or rigid flake). Selecting the correct system is vital for energy efficiency and operational profitability.

Mechanical Squeezing and Dewatering (Film Group) Materials like LDPE and PP film, bags, and sacks trap water within their spongy structures. Standard dryers are insufficient for these materials.

• Horizontal Squeezing Machines: These machines mechanically expel water by compressing the material within a high-pressure screw (screw-barrel) system. This process provides both drying and pre-compaction, increasing the capacity of the pelletizing machine.

• Mechanical Efficiency: Since it does not require thermal treatment, energy consumption is significantly lower compared to thermal drying systems.

Centrifugal Drying (Rigid Plastic and Flake Group) Centrifugal force is the most effective method for HDPE, PET, and PP rigid flakes.

• High-Speed Centrifuges: Due to the high rotational speed of the rotor, plastic particles are thrown against special perforated screen walls. While water is expelled through the screens by this impact and centrifugal force, the plastic material is dried and conveyed to the next stage.

• Surface Cleaning: The centrifuge process does more than just dry; thanks to high friction, it also cleans the final dust and micro-particles remaining on the material.

2. Drying Requirements Based on Material Type

Each polymer type has different surface tension and water retention capacities, necessitating a specialized drying strategy:

• PET Recycling: PET flakes have very low moisture tolerance during the pelletizing stage. Therefore, thermal drying towers are usually used in PET lines as a supplement to high-speed mechanical centrifuges.

• LDPE and PP Film: The best results in this group are obtained with "Squeezing Machine" technology. The squeezing method physically discharges water trapped in the pores of the film.

• Rigid Plastics (Crates, Pipes, Drums): Generally, a single drying centrifuge is sufficient to bring the material's moisture to levels suitable for the pelletizing process.

3. Technical Advantages: Energy Savings and Production Quality

Oğuz Makina drying and cleaning systems are equipped with technological features that increase the total efficiency of the facility:

• Low Moisture Rate: Thanks to improved rotor and screw designs, materials can be dried down to the 1-5% range.

• Energy Efficiency: Our mechanical dewatering systems provide up to 70% energy savings compared to traditional heated ovens.

• Heavy-Duty Design: Units operating under continuous vibration and dynamic loads offer long-lasting use with high-strength steel chassis and balanced rotors.

4. Advanced Cleaning and De-dusting

Another function of our drying systems is to clean fine dust and label residues from the raw material. Integrated with pneumatic conveying systems and de-dusting units, these dryers directly improve the clarity and physical properties of the final granule.

5. Critical Tips for Investors

When setting up an efficient recycling line, the choice of a drying unit should be based on:

• Output Moisture Rate: The target moisture level should be at a point that does not decrease the capacity of your pelletizing machine.

• Maintenance and Screen Cleaning: Centrifuge screens should be resistant to clogging and easy to clean.

• Volume Reduction (Compacting): Especially in film recycling, the ability of the squeezing machine to densify the material is key.

Frequently Asked Questions (FAQ)

• What should be the moisture content of the material coming out of the dryer? For efficient pelletizer operation, a moisture content of 4-8% for film plastics and 1-2% for rigid plastics is ideal.

• Should I prefer a squeezing machine or a centrifuge? If you are processing LDPE film, bags, or sacks, you must use a squeezing machine. If you are processing rigid flakes and PET, high-speed drying centrifuges are the right choice.

• How do drying systems affect energy costs? Mechanical drying systems (centrifuge and squeezing) consume significantly less electricity than thermal drying systems. Choosing the right system directly increases the profitability of the facility.

• How often should machines be cleaned? Drying screens should be checked periodically based on the contamination rate of the material. Our self-cleaning rotor designs minimize this need, but regular maintenance extends machine life.

• How can I solve the dust problem? Air separation and dust collection units (cyclones) that can be integrated into our drying systems provide a cleaner production environment by separating fine dust within the raw material.