Yuyao Jiantai Plastic Machinery Co., Ltd.

New pelletizing machine improves polyethylene granule quality

With the growth of demand for plastic products, the quality requirements of polyethylene particles are also increasing. Traditional granulators have problems such as uneven particle distribution and poor surface finish, which cannot fully meet the needs of high-end applications for granule quality. To this end, we have developed a new type of polyethylene particle granulator, through optimized design and precise control of process parameters, the sphericity and surface luster of the particles have been greatly improved.

The new granulator adopts a unique twin-screw quantitative feeding structure, which can accurately measure and transport the melt, ensure the uniform distribution of raw materials in the screw hole and die hole, and effectively reduce the fluctuation of particle weight and size. At the same time, we have developed an advanced mold temperature control system to achieve precise control and quick response to the mold temperature, so that each mold hole can be kept at the optimal granulation temperature, which greatly improves the surface smoothness of the granules and reduces the defect rate.

In addition, the new granulator adopts a high-precision electronic proportional drug removal device, which can accurately measure and add various additives to meet the requirements of different formulas for the ratio of additives. With the advanced automatic control system and human-machine interface, the operator can easily monitor and adjust every key process parameter to ensure long-term stable operation.

Through a series of performance tests and comparative experiments on the new granulator, the results show that: compared with the traditional granulator, the particle size distribution range of the new model is reduced by 30%, the weight fluctuation is reduced by 25%, the surface glossiness is increased by 40%, and the defective particle rate is reduced by 20%. This will greatly enhance the processing properties and applicability of the pellets.

The superior quality granules produced by the new polyethylene granulator have better fluidity and more uniform dispersion in subsequent processing processes such as injection molding, extrusion and blow molding, which can reduce mechanical damage and burrs, and improve the surface quality of plastic products. Especially in high-end applications such as multi-layer co-extrusion and thin-walled articles, uniform and stable particle sphericity and lustrous surface are crucial to ensure product quality.

In addition, high-quality spherical particles will also directly improve the quality of recycled materials, reduce heat loss and pollution during the regeneration process, and achieve more efficient recycling. In general, the application of the new polyethylene particle granulator will promote the further development of plastic processing technology, meet the needs of users for high-performance plastic products, and create greater environmental and economic benefits for enterprises.

Looking to the future, with the upgrading of consumption and the popularity of green environmental protection concepts, the market's demand for customization and personalization of plastic products will become stronger. This requires the development of plastic granule production equipment in a more intelligent and flexible direction to achieve rapid switching of parameters such as particle size, shape, and formula. We will also continue to research and develop new technologies, and develop multi-functional and modular pellet production lines to achieve rapid response to changing market demands.

At the same time, combined with digital and automation technologies, intelligent sensing and optimization of each production link will become a trend, further improving output, quality, and flexibility. We will actively cooperate with experts inside and outside the industry to establish efficient data collection and analysis systems, researching and developing more advanced spherical pellet production solutions to meet the needs of tomorrow's circular plastic economy.

Working principles and applications of plastic pellet granulators

Plastic pellet granulators are important equipment in the plastics processing industry. They can continuously produce plastic pellets with uniform size and smooth surface from plastic raw materials. The pellets can be easily transported and fed into various processing machines for making plastic products. This article will introduce the working principles, structural features, operational parameters, and applications of different types of plastic pellet granulators.

The pelletizing process consists of three main steps - melting, extruding, and cutting. The plastic raw materials are first fed into the barrel and melted by the heaters. The molten plastic is then conveyed forward by the rotating screw and forced through the die face under pressure. The extrudate is finally cut into pellets of equal length by the rotating knives mounted on the die face.

According to the number of screws, pelletizers can be divided into single-screw and twin-screw types. Single-screw granulators are simple in structure and suitable for most thermoplastics. Twin-screw granulators provide more positive feeding and mixing and are used for processing PVC and other shear-sensitive materials. The screw geometry, screw speed, die temperature are key factors affecting pellet quality.

Based on the cutting manner, there are two types of pelletizers - strand and hot-face pelletizers. For strand pelletizers, the extrudate is cut after leaving the die face. Cooling water is applied to solidify the strands before cutting. The cut length depends on the rotating speed of blades. For hot-face pelletizers, cutting is done at the die face while the melt is still hot. No cooling water is needed and cut length depends on die hole dimensions.

Underwater pelletizing technology has become more popular recently. The main advantage is immediate water cooling and hardening after pellet cutting, which results in very smooth surface and tight tolerances of the pellets. It is ideal for processing PET, nylon and other polymers. But it requires higher initial capital investment.

In addition to screw extruder pelletizers, ram extruder pelletizing systems are also used for PVC and engineering plastics when precise temperature control and low-stress processing are needed. The ram pushes the melt through the die holes in a pulsating manner without excessive shearing flow.

Besides conventional small pellet sizes around 3-5mm, micro-pelleting and nano-pelleting technologies have been developed to produce pellets in the size range of 0.5-2mm and 0.2-0.5mm respectively. The ultra-small pellets improve end product quality by increasing uniformity of polymer melting and mixing.

Pelletizers are widely used in various plastics processing fields. The produced uniform pellets significantly increase the productivity and quality consistency of plastic products like films, pipes, profiles, sheets and molded articles. They are also ideal for plastic recycling industry to upgrade waste plastics into high-quality regranulated pellets.

Advanced intelligent control systems are now integrated with pelletizers for easy parametric control, real-time monitoring, diagnosis and quality prediction. IoT technologies enable remote monitoring and troubleshooting. These will become future trends to further assist the plastics industry in efficient and sustainable production of consistent high-quality pellets and products.