Over 10,000+ customers' choice, Focus on screening industry 40+ years
1. Screening Differences Among Multiple Rubber and Plastic Materials
The screening difficulty of plastic pellets is usually not reflected in a single particle size, but in the differences between materials.
Pellet shape and particle size distribution. Cylindrical, spherical, flake-shaped, and irregular pellets have different movement states on the screen surface. Pellets with regular shape and relatively good flowability easily form a uniform material layer. Flake-shaped pellets, burred pellets, or pellets with a high proportion of linked pellets easily remain, bridge, or wedge into screen openings. For materials with a relatively wide particle size distribution, top-layer interception and middle-layer classification need to be reasonably configured to prevent oversize pellets from entering the finished product.
Fine powder and pellet cutting debris content. Fines and cutting debris may be generated during pelletizing, conveying, and packaging. Materials with a relatively high fine proportion easily generate dust during screening and may also adhere to the screen and the inner wall of the screen frame. For products requiring relatively high pellet surface cleanliness, fines removal is part of finished product quality control.
Static tendency. Some plastic pellets easily generate static electricity after friction. Fine powder adheres to the screen, screen frame, and areas near the discharge outlet, affecting screening and cleaning. For materials with relatively strong static electricity, attention should be paid to equipment grounding and screen cleaning method.
Hygroscopicity and caking tendency. Some engineering plastics or modified plastics may absorb moisture during storage, and pellet surfaces may become sticky or form caked material. Screening equipment needs to provide enclosed moisture-proof conditions and work in coordination with material drying and workshop dehumidification measures.
Material and hygiene requirements. General industrial plastic pellets have relatively conventional requirements for equipment materials. Food-contact grade, medical-grade, or high-value plastic pellets have higher requirements for contact materials, surface treatment, and cleaning accessibility.
These differences indicate that a plastic pellet rotary vibrating sieve cannot cover all materials with one fixed configuration. Screens, parameters, screen cleaning, and materials need to be adjusted according to material category.
2. Adaptation Logic of the Rotary Vibrating Sieve: Movement Mode and Multi-Layer Configuration
The Gaofu S49 Series Rotary Vibrating Sieve uses a vertical vibration motor to drive upper and lower eccentric weights, causing the screen surface to generate horizontal, vertical, and inclined compound motion. Material moves in a spiral trajectory on the screen surface, spreading from the center to the edge, completing stratification and screening. For plastic pellets, this movement mode has several points of adaptability.
Spiral tumbling motion imposes relatively gentle impact on pellets. Compared with straight-line jumping motion, the spiral tumbling of the rotary vibrating sieve makes pellet movement on the screen surface more continuous, with relatively less mechanical impact. For thermoplastic plastic pellets, this helps reduce pellet breakage and secondary fine generation. For flake-shaped or irregular pellets, the movement state is relatively controllable, but amplitude and inclination still need to be adjusted to avoid accumulation.
Multi-layer screens can complete interception, classification, and fines collection simultaneously. The equipment can be equipped with 1 to 5 screen layers, simultaneously performing 2 to 6 grades of separation or filtration. For plastic pellets, a common configuration is 2 to 3 layers: the top layer intercepts linked pellets, oversize pellets, and packaging debris; the middle layer is set according to the target particle size, and qualified pellets pass through to the lower layer; the bottom layer collects fines and cutting debris. Each layer’s discharge outlet is set independently, and coarse material, qualified pellets, and fines are discharged separately, reducing repeated transfer and mixed grades.
Adjustable vibration parameters. Amplitude can be adjusted through the eccentric block angle, and screen surface inclination can be adjusted within a certain range. For pellets with relatively good flowability and regular shape, amplitude or inclination can be appropriately increased to improve screening efficiency. For flake-shaped, irregular, or static-prone pellets, parameter adjustment needs to balance dispersion and screening, avoiding pellet accumulation or excessive bouncing on the screen surface. Specific parameters need to be determined based on material testing and operating observation.
Screen mesh selected according to pellet specifications. Plastic pellet screening usually does not require high mesh. The focus is on intercepting oversize pellets, controlling fines, and stabilizing particle size distribution. Screen mesh should be determined according to pellet size specifications, downstream processes, and finished product standards. The mesh of the top, middle, and bottom layers should be calculated as a whole to avoid one layer becoming a bottleneck. The Gaofu S49 Series Rotary Vibrating Sieve has a reference screening accuracy of up to 600 mesh (0.02 mm), a reference filtration accuracy of up to 5 microns, a reference grading efficiency of 90% to 98%, and a reference normal service life of 15 to 20 years. The above parameters are for reference only. Actual selection should be confirmed based on material characteristics, capacity targets, and site conditions, and is subject to actual equipment selection.
3. Configuration Priorities for Different Rubber and Plastic Material Categories
General-purpose plastic pellets (such as PE and PP). Pellets have relatively regular shape and relatively good flowability. Screening mainly removes linked pellets, oversize pellets, and fines. A two-layer or three-layer configuration can be used: the top layer intercepts linked pellets and foreign matter, the middle layer controls finished pellet size, and the bottom layer collects fines. Vibration parameters can be appropriately increased, and bouncing-ball screen cleaning can be used. Material can be carbon steel or 304 stainless steel according to final use.
Engineering plastic and modified plastic pellets. Some materials have relatively strong hygroscopicity or obvious static tendency. During screening, attention should be paid to enclosed moisture prevention and electrostatic grounding. Screen tension needs to be maintained. The screen cleaning method can be selected between bouncing balls or evaluated ultrasonic screen cleaning according to fine powder adhesion conditions. 304 stainless steel is recommended, with polished inner walls to reduce material residue.
Masterbatch and compound pellets. Multi-product and multi-color changeovers are frequent, so the equipment structure should be easy to disassemble and clean. The screen uses a quick-release mesh frame. The screen frame and discharge outlet should be easy to open and inspect, and seals should be easy to replace. The cleaning SOP should specify disassembly, cleaning, reassembly, and inspection steps to reduce color mixing and cross-contamination.
Recycled plastic pellets. Sources are mixed, and the proportions of fines, linked pellets, and irregular pellets are relatively high. Static problems may be more prominent. During configuration, attention should be paid to top-layer interception capability, screen cleaning performance, and electrostatic grounding. For working conditions with relatively high fine content, an ultrasonic screen cleaning system or combined screen cleaning method can be evaluated. Material can be carbon steel, 304 stainless steel, or 316L stainless steel according to the final use of the recycled material.
Food-contact grade and medical-grade plastic pellets. There are higher requirements for contact materials, surface treatment, and cleaning verification. Parts in contact with the material are recommended to use 304 or 316L stainless steel, with polished inner walls, treated welds, and a structure without dead corners for easy cleaning and inspection. Seals should be made of food-grade materials and should be easy to replace regularly.
4. Coordination of Screen Cleaning, Enclosure, and Electrostatic Grounding
In plastic pellet screening, fine powder wedging, static adsorption, and dust escape are common factors affecting classification and impurity removal performance. Screen cleaning, enclosure, and grounding need to work together.
Screen cleaning method. The equipment can be equipped with a bouncing-ball screen cleaning device. Bouncing balls are located below the screen and continuously bounce under vibration, striking the underside of the screen to dislodge wedged or adhering pellets and fines. For working conditions with more severe fine powder adhesion or stronger static electricity, the suitability of an ultrasonic screen cleaning system can be evaluated. The choice of screen cleaning method should be determined based on pellet shape, fine content, static tendency, and actual blinding conditions.
Enclosed structure. The rotary vibrating sieve can use a fully enclosed structure, with sealed connections at the feed inlet, discharge outlet, reject outlet, and inspection ports to reduce the dispersion of fines and cutting debris into the workshop and also reduce external impurity ingress into the screening chamber. A dust collection interface can be set on the upper cover to connect to the on-site dust collection system.
Electrostatic grounding. Plastic pellets easily generate static electricity during conveying and screening. Fine powder adheres to the screen, screen frame, and areas near the discharge outlet. The equipment should implement reliable electrostatic grounding, and metal components and pipe flange connections of the system should maintain continuity. Grounding connections should be included in regular inspection, as vibration and disassembly may loosen connection points.
5. Operation, Maintenance, and Selection Communication
When a plastic pellet rotary vibrating sieve operates with multiple material changeovers, maintenance priorities include screens, screen cleaning devices, seals, and grounding condition. If the screen is damaged, loose, or blinded, it should be handled promptly. After bouncing balls wear, they should be replenished or replaced in time. Aging seals should be replaced. Vibration motor fasteners and lubrication status should be checked as required, and operating current and vibration conditions should be recorded. It is recommended to establish inspection records and convert unexpected downtime into planned maintenance through trend observation.
During selection communication, it is recommended to provide the equipment supplier with: plastic pellet categories and material characteristics (pellet shape, particle size distribution, bulk density, flowability, static tendency, fine and linked pellet content, hygroscopicity), single-shift or continuous processing volume, finished pellet size standards and impurity removal requirements, screen mesh, material hygiene requirements, workshop space and floor height, dust explosion hazardous area classification, and upstream and downstream equipment interface conditions. For multi-material rotation production, the changeover frequency and cleaning method should also be explained. For materials such as plastic pellets, it is advisable to conduct on-machine testing with actual materials before selection to observe screening performance under different screen meshes, layer configurations, screen cleaning methods, and vibration parameters, impurity removal performance, finished pellet size distribution, and fine content. Equipment parameters are reference values. Actual selection should be confirmed based on material testing results and site conditions.
6. Conclusion
The core of a plastic pellet rotary vibrating sieve adapting to multiple rubber and plastic materials is not to cover all materials with one fixed set of parameters, but to adjust screen configuration, vibration parameters, screen cleaning method, and material selection according to pellet shape, particle size distribution, fine content, static tendency, and hygiene requirements. Multi-layer screens separate interception, classification, and fines collection. Screen cleaning and grounding work together to reduce fine powder adhesion and blinding. The enclosed structure reduces dust escape, and the quick-release structure facilitates multi-product changeovers. For rubber and plastics processing enterprises facing problems such as many material types, multiple particle size specifications, and frequent changeovers, targeted configuration based on material characteristics and production line conditions is more practically meaningful than simply comparing equipment parameters.
Chemical Industry Client Testimonials
Wanhua Chemical, Yuntianhua Group, Kingfa Science & Technology, Formosa Plastics Group, China Pingmei Shenma Group, Kemai Co., Ltd., Luxi Chemical, Liby Group, Oriental Yuhong, Davco, Chenming Group, Guanhao High-Tech
Kaifei Chemical, Sunsine Chemical, Weilin Co., Ltd., Xuyang Group, 3Trees, Maydos, Loyal Group (Kingpor Group), AkzoNobel, CSSC Hanguang, Haike Group, Nice Group, Taishan Fiberglass, Wanhua, Red Eagle, China XLX Fertiliser (Xinlianxin), CCtech Catalysis, China National Bluestar, Sakura Paint, ITANOS, Yanggu Huatai, Sennics, Longxing Chemical Group, Tunhe Co., Ltd., GHW International, Jianye Chemical, Finehope
Fortune 500 Client Testimonials
CNPC、CSCEC、Sinochem Holdings、CRCC、China Minmetals Corporation、CNOOC、CR、Sinopharm、CHN Energy、COFCO Corporation、Huawei Technologies、PowerChina、CITIC Group、Wuchan Zhongda Group、NORINCO、Chalco、CNBM、 Shaanxi Coal and Chemical Industry Group、Ansteel Group、CETC、CSSC、CASC、CEC、Jinchuan Group、CASIC、Conch Cement、CNNC、SPH、Shanxi Coking Coal Group、 Zhongtai Chemical、GPHL、DEC、Sinosteel Corporation、MCC、China National Salt Industry Chemical、China Baowu Steel Group、China Animal Husbandry Industry Co., Ltd.、CECEP
About Gaofu
Originated in the 1980s, Xinxiang Gaofu Machinery Co., Ltd. has developed into a leading enterprise after more than 40 years of steady development. The company holds authoritative national qualifications including National-level Specialized, Refined, Unique and Innovative Little Giant Enterprise, National Green Factory, National High-tech Enterprise, and National Intellectual Property Advantage Enterprise, and acts as the President Unit of the Vibration Industry Association.
It has established three provincial and municipal R&D platforms: Henan Provincial Industrial Design Center, Henan Provincial Engineering Technology Research Center for Intelligent On-line Screening System, and Xinxiang Municipal Fine Screening Engineering Technology Research Center. Up to now, Gaofu has obtained more than 500 patents covering invention, utility model and design. It has been awarded the Science and Technology Achievement Prize by the Ministry of Industry and Information Technology of China and has participated in drafting and formulating 4 national standards.
Gaofu’s product portfolio covers multiple series and hundreds of specifications, mainly including vibrating screening equipment, conveying equipment and intelligent automatic material handling systems. We provide one-stop overall solutions such as automatic feeding systems, powder supply systems, pneumatic conveying systems, metering and weighing systems, batching systems, micro-ingredient batching systems, water supply systems, oil supply systems, fluid conveying systems, central kitchen powder supply systems, powder conveying systems and feeding systems.
In terms of food production lines, our mature supporting systems cover two major categories: baking production lines and pasta production lines. The baking series includes production lines for bread, cake, crisp cake, croissant, toast, pizza, biscuit and hamburger. The pasta series includes intelligent production lines for steamed buns, stuffed buns, twisted rolls, sesame paste cakes, steamed dumplings, boiled dumplings, fried dough sticks and pies.
Gaofu products sell well across Greater China and are exported to more than 100 countries and regions worldwide, including Russia, Canada, the United States, New Zealand, Japan, Brazil and South Africa. Widely applied in food, pharmaceutical, chemical, metallurgical, building materials, mining, thermal power, environmental protection and other industries, our products have won the trust and recognition of over 10,000 global customers.
Adhering to the corporate mission of improving material quality and efficiency to meet customer needs, Gaofu has long-term stable cooperative relationships with global clients to achieve harmonious and win-win development. At present, Gaofu has become an official qualified supplier of many Fortune Global 500 enterprises, including CNPC, Sinopec, Sinochem Group, China Resources Group, Sinopharm Group, COFCO, China National Building Material, China Aerospace and Jinchuan Group.
