Polypropylene Extrusion Machine

This equipment is a high-performance twin screw extruder specially designed for polypropylene (PP) modification and PP granulation processes. Nanjing Kelongwell Chemical Machinery Co., Ltd. has optimized the screw structure and temperature control strategy for the rheological properties of polypropylene materials, such as high flow sensitivity and shear sensitivity. This PP extruder is suitable for pure resin granulation of homopolymer polypropylene and random copolymer polypropylene, as well as for processing PP modified formulas such as high filling and high reinforcement. While ensuring high output, it precisely controls the melt temperature to avoid material thermal degradation, making it an ideal choice for polypropylene blending production lines.

·Customized screw combination: Based on the characteristics of PP granulation process, low shear and high dispersion threaded elements are used to effectively maintain the length of glass fibers, reduce polymer chain breakage, and improve the mechanical properties of the final product in glass fiber reinforced or high filled calcium carbonate formulas.
·High torque transmission system: equipped with a high torque gearbox, it can withstand the high back pressure of polypropylene melt during high-speed extrusion, ensuring stable operation of the twin screw extruder when processing high viscosity or high filling materials, with minimal output fluctuations.
·Segmented precision temperature control: The barrel adopts multiple independent heating/cooling sections, which can achieve steep process temperature curves and accurately match the temperature requirements of polypropylene from the feeding section to the head section, preventing the formation of "fish eyes" or black spots due to overheating.
·Multi stage vacuum exhaust: Equipped with an efficient exhaust system, it effectively removes moisture, residual monomers, and low molecular weight volatiles from polypropylene raw materials, making the particles obtained from PP granulation dense and pore free, and improving the surface quality of downstream products.
·High wear and corrosion resistance: The inner lining of the barrel is made of bimetallic alloy, and the screw is made of nitride steel or optional wear-resistant coating, which easily meets the abrasion challenge of glass fiber and mineral fillers on the PP extruder and extends the service life of the equipment.

Polypropylene Extrusion Machine

Why choose this twin screw extruder for polypropylene materials instead of a regular plastic granulator?

Compared with single screw extruders, co rotating twin screw extruders have strong conveying and excellent distribution/dispersion mixing capabilities, making them particularly suitable for materials such as polypropylene that are sensitive to shear heat. Ordinary plastic granulators are prone to problems such as melt slip and large temperature fluctuations when processing PP, resulting in uneven particle density or color differences. And through modular screw design, this device can use "soft" mixing elements in the melting zone to maximize the retention of glass fiber length in the glass fiber reinforcement process, making the impact strength much higher than that of materials processed by ordinary extruders.

In addition, the large free volume design of the PP extruder enables stable feeding of high filling formulas (such as calcium carbonate filling up to 80%) without bridging or yield fluctuations, which many general-purpose granulation equipment cannot achieve.

This PP granulation unit is widely used in the following industries and materials:
·Automotive industry: Long glass fiber reinforced polypropylene (LFT), thermoplastic polyolefin (TPO), used for components such as bumpers and instrument panels;
·Packaging materials: thin-walled injection molding special materials, high transparency food containers, BOPP film raw materials;
·Non woven fabric: special resin for spunbond and meltblown polypropylene, used for sanitary materials, masks, etc;
·Modified blending: functional masterbatch, halogen-free flame-retardant PP, wood plastic composites (WPC);
·Recycling and Regeneration: The recycling and granulation of post consumer and industrial polypropylene waste to restore melt index and achieve high-value reuse.

Nanjing Kelongwell Chemical Machinery Co., Ltd. provides comprehensive OEM/ODM services and customizes PP extruder production lines according to customer formulas and process requirements:
·Customization of screw components: Design specialized kneading blocks and mixing components based on polypropylene formulas (high glass fiber, high filling, flame retardant, etc.);
·Customization of barrel structure: flexible configuration of the position and quantity of side feeding, liquid injection ports, and vacuum exhaust ports;
·Automation control: Optional full PLC control system, supporting remote monitoring and data acquisition, meeting the intelligent needs of different factories;
·Selection of cutting methods: We provide various PP granulation forms such as water ring cutting, underwater cutting, and strip cutting to meet different melting and cooling requirements.

Q1: What are the specific irreplaceable advantages of twin screw extruders compared to single screw extruders in PP processing?
A: Polypropylene is very sensitive to shear history. Twin screw extruders rely on forced conveying and precise component combinations to achieve mixing, rather than solely relying on shear heat generation. This avoids the common problems of melt slip and temperature runaway in single screw extruders, making the PP granulation process more stable, resulting in narrower particle molecular weight distribution and better color consistency.

Q2: Can this PP extruder process high content calcium carbonate or glass fiber?
A: Absolutely possible. The PP extruder we designed adopts a modular screw combination, which allows for the addition of high proportion fillers or glass fibers downstream through side feeding after the polypropylene is completely melted. The maximum filling amount of calcium carbonate can reach 80%, and the glass fiber content can reach 60%, which not only reduces screw wear but also ensures reinforcement effect. This is a mature solution optimized specifically for PP modification.

Q3: How to avoid material thermal degradation when processing PP?
A: The thermal degradation temperature of polypropylene is about 280 ℃. To prevent degradation, Nanjing Kelongwell Chemical Machinery Co., Ltd. adopts segmented precision temperature control and high torque low-speed strategy on the twin screw extruder. It is usually recommended to have a length to diameter ratio of 36:1 to 40:1. With sufficient mixing, local overheating should be avoided to prevent the formation of "fish eyes" or black spots.

Q4: Which is more suitable for PP granulation, water ring granulation or strip granulation?
A: For high melt index (MFI>10) polypropylene, water ring cutting or underwater cutting can quickly cool the particle surface, prevent adhesion, and are more suitable for large-scale PP granulation. For high filling or glass fiber reinforced PP, due to the high melt strength, it is also feasible to pull and cut the particles. We will recommend the most suitable cutting method based on your specific material characteristics and production requirements.

Q5: Can this equipment be used for both new material modification and recycled material granulation?
A: Sure. Our PP extruder has the ability to mix new materials and recycle PP pellets. When used for recycling materials, an efficient filtration and screen replacement system and strong vacuum exhaust can be configured to remove impurities and volatiles, effectively restore the melt index of recycled materials, and meet the standards for re injection molding or extrusion molding.