What Is the Granulation Process?
Knowledge

What Is the Granulation Process?

Plastic granulation technology is mainly used in plastic product manufacturing and resource recycling to make various plastic products or plastic raw materials, and has both environmental and economic benefits.
Published: Aug 12, 2021
What Is the Granulation Process?

What Is the Plastic Granulation?

Plastic granulation is the process of taking plastic and size reducing it so that it can be used in to plastic manufacture. The manufacturing capabilities of injection mold machines in the plastics industry is limited. During injection, plastic product can form cooling spots and skinning. The injection system may not have an exhaust device which can lead to bubbles and radial flow patterns in the products. One solution which can just make up for the shortcomings of the injection molding machine is a twin-screw extruder used in granulation, which has a strong plasticizing ability and has an exhaust device. After the material is plasticized by the twin-screw extruder, the material can reach molecular level dispersion, and the vacuum exhaust device can draw away the excess water and impure gasses caused by decomposing material.

What Is the Extrusion Granulation?

The extrusion granulation process generally has two granulation methods, hot cutting, and cold cutting. Which granulation method is used depends on the properties of the material. Polyethylene and polypropylene generally use cold cutting, and PVC generally uses hot cutting. With the cold cutting method, the material is plasticized by the extruder and extruded into a round strip. The round extruded material is drawn to the pelletizer and cut into cylindrical particles after water cooling. The hot cutting method is to directly cut the newly extruded round plastic into pellets by attaching a rotating blade to the die plate. PVC granulation for injection molding is suitable for granulation by the hot-cutting method.

The hot-cutting granulation is mainly composed of a twin-screw extruder, die head, pelletizing device, pellet conveying device, and cooling fan. The kneaded material is sheared and plasticized by a twin-screw extruder, and then extruded to the desired shape through a fixed-shape die. The extruded material is cut into a fixed shape by a pelletizing device and is cooled by a fan during the conveying process to complete the pelletizing process.

Crushing Granulation Technology

Crushing and granulation technology involves collecting waste plastics and using crushing, cleaning, drying, pelletizing, and other procedures to recycle them. The most important step is the sorting step. With magnetic separation equipment, metal-containing impurities can be removed, and mixed plastic waste can be further sorted. Various types of single plastic recycled materials can be divided into two types; simple plastic, and composite plastic, according to the recycled plastic components.

Application of Twin-Screw Extruder Granulator

Twin-screw extruders are widely used for physical modification of polymers: blending, filling, and fiber reinforcement batching or mixing, and can also be used for extrusion of molded products. In addition, the twin-screw extruder has good feeding characteristics and is suitable for powder processing. It has better mixing, exhaust, reaction, and self-cleaning functions than the single-screw extruder, and it can process plastics and blends with poor thermal stability. The material time shows its superiority.

  1. Production of Masterbatch
    The mixture of plastic particles with a high proportion of additives is the masterbatch. Additives include pigments, fillers, and functional additives. They are usually powdery and easy to agglomerate. The twin-screw extruder is the key equipment of the masterbatch production line, used for the homogenization, dispersion, and mixing of additives in the polymer matrix.
  2. Blending Modification
    Reinforcing materials provide the best performance between the matrix and additives, fillers, and reinforcing materials. Glass fiber is the most important reinforcing material, but other fibers can also be combined with polymer-carriers. By adding fibers and combining them with polymers, a material with high strength and high impact resistance can be obtained.
  3. Exhaust
    Due to the mutual meshing of the two screws, the shearing process of the material at the meshing position continuously updates the surface layer of the material. This improves the exhaust effect, giving the twin-screw extruder better performance than the exhausted single-screw extruder. Exhaust performance. A threaded conveying element with a large lead is used in the exhaust section. A ring dam or reverse threaded element is usually used to build pressure in the first metering section. The melt that has passed the ring dam enters the exhaust section, the pressure is released, and the volatiles can escape.
  4. Reactive Extrusion
    Reactive extrusion is a special process in which monomers are bonded during the extrusion process. The twin-screw extruder is very suitable for reactive extrusion due to its excellent mixing performance. The liquid raw materials are added to the twin-screw extruder according to a determined proportion. The polymerization reaction occurs under the action of mixing and meshing, and the excess reaction heat is dissipated through the barrel. At the outlet, a gear pump is usually used to directly input the product into the water ring granulator for granulation.
  5. Direct Extrusion
    As the requirements for product dimensional uniformity are not high for granular extruded plastics, about 95% of granular products use twin-screw extruders for final mixing, devolatilization, and reactive extrusion. Through the use of specific heads and appropriate downstream equipment, finished products such as films, plates, pipes, and so on, can be produced in a more efficient manner. Direct extrusion can omit the steps of cooling, pelletizing, reheating, and melting, as the material is subjected to less thermal and shear stress. The entire process can save energy, and the formula can be easily adjusted. It has been used in the production of PE, TPE/TPO/TPV, PVB, wood fiber composites, foamed products, nylon, and biodegradable plastics. A gear pump is usually added to reduce pressure fluctuations in the materials and provide stable pressure for the machine head.

In the process of manufacturing each twin-screw extruder, we are committed to meeting high standard performance requirements. Each extruder undergoes strict quality control in the manufacturing process. The equipment and all components have been strictly audited and fully inspected. From design, procurement to production, we pay attention to every detail.

Published by Aug 12, 2021 Source :kknews, Source :twgreatdaily, Source :riw

Further reading

You might also be interested in ...

Headline
Knowledge
Essential for Precision Machining: A Complete Guide to Tungsten Carbide Center Drills
In modern manufacturing, precision is the core standard by which product quality and performance are measured. From aerospace components to medical devices, even a minor deviation can lead to serious consequences. When it comes to precision drilling, a critical challenge is ensuring that a drill bit can be accurately positioned at the start of a cut while maintaining stability during high-intensity operations. The tungsten carbide center drill is the professional tool engineered specifically to solve this problem.
Headline
Knowledge
From Cavitation Effect to Industrial Applications: The Secrets of Ultrasonic Cleaning
When your glasses, tableware, or electronic components are stained with stubborn dirt, what can you do? Traditional methods often require vigorous scrubbing or even harsh chemical solvents, which are not environmentally friendly and may scratch the item. At this moment, ultrasonic cleaning acts like an “invisible little helper”, reaching deep into grooves and gaps to gently yet effectively remove contaminants.
Headline
Knowledge
The “Spark Magician” of Metalworking
Electrical Discharge Machining (EDM) is a non-traditional machining process that removes metal through electrical sparks. Unlike conventional methods, it is not limited by material hardness and can precisely create deep cavities, micro-holes, and complex structures in hardened steel, tungsten carbide, or superalloys. The three main types of EDM include wire cutting, die-sinking, and hole drilling, which are widely applied in mold making, aerospace, automotive, and medical industries. Although EDM has a slower processing speed, works only with conductive materials, and requires consideration of electrode wear and surface treatment, its advantages in high precision, zero cutting force, and superior surface finish make it an indispensable technology in precision manufacturing. Moreover, it continues to evolve in line with the trend toward smart manufacturing.
Headline
Knowledge
Press Brake vs Shearing Machine: Functional and Technical Comparison of Industrial Processing Equipment
Press Brake and Shearing Machine are two essential types of equipment in the field of machine tools, widely used in the processing of metal, wood, and other materials. They play critical roles in manufacturing, enabling efficient and precise material forming and cutting. This article introduces the definitions, functions, technical features, and applications of folding and cutting machines, offering neutral and practical knowledge sharing.
Headline
Knowledge
Master Chuck Types & Selection: The Essential Guide for Machinists
In the world of precision manufacturing, every minute detail can determine the quality of the final product. The chuck is a critical yet often overlooked component—it's not just a tool for holding a workpiece, but the very heart of ensuring machining accuracy, efficiency, and safety. This article will take you on a deep dive into the diverse universe of chucks, covering their operating principles, design philosophies, common types, and how to select the right jaws and chucks for different needs. Whether you're new to the industry or a seasoned engineer, this guide will unlock the intricate secrets of chucks, helping you master every detail on your path to manufacturing success.
Headline
Knowledge
An Overview of Electrical Discharge Machining (EDM)
Electrical Discharge Machining (EDM) is a non-traditional manufacturing process that utilizes electrical sparks to remove material from a workpiece. Unlike conventional machining methods such as milling or turning, which rely on physical contact between a tool and the material, EDM operates without direct contact, making it ideal for processing hard or brittle materials that are difficult to machine otherwise. The process involves generating a series of rapid electrical discharges between an electrode and the workpiece, submerged in a dielectric fluid, which erodes the material through thermal energy. This technique has revolutionized precision manufacturing by enabling the creation of complex geometries with high accuracy.
Headline
Knowledge
Applications of Machine Tools in the Aerospace Industry
The aerospace industry is a highly specialized and technology-driven sector, encompassing the design, manufacturing, and maintenance of aircraft, spacecraft, satellites, and related equipment. Machine tools play a critical role in this field, enabling the precision machining of complex metal and composite material components. These tools enhance production efficiency while ensuring the accuracy and reliability required to meet the stringent safety and performance standards of aerospace. This document outlines the key applications, technologies, benefits, and future trends of machine tools in the aerospace industry.
Headline
Knowledge
Smart Healthcare Uncovered:How AI Is Transforming Clinical Practice?
With the rapid rise of artificial intelligence (AI), the healthcare industry is undergoing a disruptive transformation. AI is significantly improving diagnostic accuracy and treatment efficiency while profoundly redefining healthcare professionals’ roles and patient experiences. A comprehensive understanding of the core technologies and clinical applications behind this transformation is essential for grasping the future trends and strategic directions of smart healthcare.
Headline
Knowledge
Principle and Applications of Laser Cutting Machines
As the global manufacturing industry advances toward higher precision and efficiency, laser cutting technology has become a key enabler of industrial upgrading. Compared with traditional shearing, stamping, and mechanical cutting, laser cutting offers non-contact processing, higher accuracy, and greater flexibility. It significantly improves productivity while reducing secondary finishing. Today, it is widely adopted in metalworking and increasingly applied in electronics, aerospace, medical, and architectural design industries.
Headline
Knowledge
Why Are High-Quality Cutting Fluids Critical for Machining Quality?
In CNC and metalworking, cutting fluid is no longer just a coolant—it plays a critical role by providing lubrication, chip removal, and corrosion protection. With the right formulation and concentration, it can reduce cutting heat, minimize friction, extend tool life, and maintain workpiece accuracy. High-pressure cooling further enhances efficiency in deep-hole and high-speed machining. The pairing of tool material with the proper cutting fluid is equally crucial; correct selection and maintenance ensure process stability, prolong equipment life, and improve the overall work environment. Cutting fluid has become an indispensable investment in modern precision manufacturing.
Headline
Knowledge
Introduction to Emerging Printing Technologies: Opening New Horizons for the Future of Printing
With rapid technological progress and increasingly diverse market demands, traditional printing techniques are no longer sufficient to meet modern industry’s requirements for precision, efficiency, and sustainability. As a result, emerging technologies such as UV printing, 3D printing, and Nanoimprint Lithography (NIL) have risen to prominence, offering solutions with higher precision, broader applications, and lower production costs. These innovations have already demonstrated value across packaging, advertising, healthcare, semiconductors, and construction. In the following sections, we will explore their technical features and real-world applications, highlighting the advantages and future potential of these cutting-edge printing technologies.
Headline
Knowledge
The Core Standard for Life-Critical Systems: A Complete Guide to IPC Classification
In high-risk fields such as medical, aerospace, and automotive, IPC classifications determine PCB reliability and safety. Class 3 represents the highest standard, requiring zero tolerance for defects, complete via filling, adequate copper annular rings, and rigorous inspections to ensure operation under extreme conditions, while Class 2 suits long-term use in non-critical equipment with minor cosmetic flaws allowed. Class 3’s strict criteria cover component placement, soldering, plating thickness, and environmental testing—adding cost and production time, but far outweighing the risks of failure in life- or safety-critical systems. Thus, defining high-risk equipment as Class 3 during design is essential, making IPC classification a core safeguard rather than an option.
Agree