Introduction
Nanjing Kejin Tech Co., Ltd. (Chinese: 南京科晋橡塑科技有限公司) is a Chinese manufacturer of plastics- and rubber-processing machinery headquartered in the Dachang area of Nanjing, Jiangsu Province. The company focuses on extrusion, compounding, mixing, modification, and pelletizing equipment for polymer processors and materials producers.
Its principal product portfolio includes co-rotating and counter-rotating parallel twin-screw extruders, parallel and triangular three-screw extruders, and reciprocating single-screw extruders. These machines support the production of modified plastics, blends, reinforced compounds, color masterbatches, elastomers, grafted materials, cross-linked compounds, wood–plastic composites, and devulcanized or mixed rubber.
Kejin occupies a specialized position within the plastics machinery sector. Rather than producing polymer resins, it supplies the processing systems used to convert polymers, additives, fillers, fibers, pigments, and recycled materials into engineered compounds and pellets. Its activities therefore connect raw-material suppliers with downstream sectors such as automotive components, electrical and electronic products, packaging, construction materials, consumer goods, and rubber products.
History and Development
Public company materials describe Nanjing Kejin as a production-oriented enterprise combining equipment research and development, design, manufacturing, sales, and after-sales service. Its development can be outlined through several identifiable milestones:
- Establishment of a dedicated plastics and rubber machinery business: The company developed around equipment for polymer compounding and rubber processing rather than general-purpose mechanical manufacturing.
- Expansion of screw-extrusion configurations: Its portfolio grew to include co-rotating and counter-rotating twin-screw systems, several three-screw configurations, and reciprocating single-screw machines.
- Broadening of downstream pelletizing technology: Kejin added multiple strand-cutting, hot-cutting, water-ring, water-underwater, and related pelletizing arrangements to accommodate differing material rheology and product specifications.
This progression reflects the wider development of the Chinese compounding-machinery industry, in which equipment manufacturers have increasingly combined screw design, process engineering, auxiliary systems, and customer-specific production lines.
Business Operations and Segments
Kejin’s activities are centered on the design and manufacture of polymer-processing equipment. Its operating scope includes:
- Extruder engineering and equipment manufacture
- Plastics compounding and modification systems
- Rubber mixing and devulcanization equipment
- Pelletizing and granulation auxiliaries
- Process-line design and integration
- Technical support and after-sales service
The company’s business model is primarily equipment-based. Its customers purchase machinery configured for particular formulations, production capacities, residence-time requirements, temperature profiles, and pellet specifications. Such projects commonly require the coordinated selection of screw elements, barrels, feeding systems, venting arrangements, heating and cooling units, die heads, pelletizers, and controls.
Products and Technologies
Twin-Screw Extruders
Twin-screw extruders form a central part of Kejin’s product range. Co-rotating parallel twin-screw machines are widely used for continuous compounding because their intermeshing screws can provide distributive and dispersive mixing, controlled residence time, and flexible modular screw configuration.
Typical process duties include:
- Polymer blending and alloying
- Mineral and glass-fiber reinforcement
- Flame-retardant compounding
- Color masterbatch production
- Filler incorporation
- Elastomer modification
- Grafting and reactive processing
- Wood–plastic composite compounding
Counter-rotating parallel twin-screw extruders are suited to applications requiring a different conveying and shear profile from co-rotating systems. Their use can be considered where formulation behavior, heat sensitivity, feeding characteristics, or mixing requirements favor counter-rotating screw movement.
Three-Screw Extruders
Kejin lists both parallel three-screw and triangular, or “品字型,” three-screw extruders. Additional screw channels can alter conveying capacity, mixing intensity, and material residence behavior. These systems may be selected for formulations requiring high throughput, enhanced blending, or particular process-stability characteristics.
Their suitability depends on the polymer system, filler loading, moisture level, thermal sensitivity, and desired degree of dispersive mixing. In practical installations, three-screw configurations are normally engineered together with feeding, venting, die, and pelletizing equipment rather than treated as isolated machines.
Reciprocating Single-Screw Extruders
The company also offers reciprocating single-screw extruders. Reciprocating designs can provide repeated shearing and mixing action and may be applied to demanding compounding, mixing, or thermally sensitive formulations. Their process performance depends on screw geometry, stroke, speed, material formulation, and the relationship between mixing intensity and residence time.
Pelletizing and Granulation Systems
Kejin’s auxiliary equipment range includes several pelletizing methods:
- Water-cooled strand pelletizing
- Air-cooled hot cutting
- Water-ring hot cutting
- Eccentric water-mist pelletizing
- Vertical water-ring pelletizing
- Underwater pelletizing
The choice of pelletizing method affects pellet geometry, cooling efficiency, fines generation, line speed, and suitability for different melt viscosities. Strand pelletizing is commonly used for compounds that can maintain a stable extrudate after die exit, while underwater and water-ring systems can support efficient cooling and continuous pellet formation for selected thermoplastic formulations.
Process Applications
The equipment portfolio is designed for processes involving:
- Plastics modification and blending
- Reinforced plastics
- Coloring and masterbatch manufacture
- Elastomer compounding
- Grafting and reactive extrusion
- Cross-linked materials
- Wood–plastic composites
- Rubber mixing
- Rubber devulcanization
These applications involve different technical priorities. Reinforced compounds require effective filler or fiber dispersion and careful control of fiber damage. Flame-retardant systems require stable additive feeding and adequate mixing. Rubber devulcanization requires control of thermal and mechanical energy so that the material structure is altered without excessive degradation.
Applications and End Markets
Kejin’s machinery serves the intermediate materials segment of the plastics value chain. Its equipment can be used to manufacture pellets and compounds supplied to downstream processors in sectors including:
- Automotive components and interior parts
- Electrical and electronic housings
- Consumer products
- Packaging materials
- Construction products
- Agricultural plastics
- Wire and cable compounds
- Wood–plastic products
- Rubber goods and recycled-rubber applications
The company’s machinery is particularly relevant where processors need to convert standard polymers into materials with improved stiffness, impact resistance, flame retardancy, color consistency, weatherability, dimensional stability, or recycled-content performance.
Global Presence and Market Position
Nanjing Kejin is based in Nanjing, an important industrial and transportation center in eastern China. Its location places the company within the Yangtze River Delta manufacturing region, which contains substantial polymer, machinery, automotive, electronics, chemical, and export-oriented industrial activity.
The company presents itself as serving customers through integrated research, design, manufacturing, sales, and service capabilities. Its participation in the CHINAPLAS eMarketplace places it within an international exhibition and supplier network connecting plastics and rubber machinery manufacturers with processors, compounders, distributors, and materials companies.
Kejin’s competitive position is associated with equipment breadth and process customization rather than a publicly documented global market-share figure. Its ability to supply several extruder architectures and pelletizing methods allows it to address projects ranging from standard compounding lines to more specialized rubber, reactive-processing, and recycled-material applications.
Research and Development
Research and development at Kejin is closely linked to process engineering. The company’s stated capabilities include theoretical and production experience in plastics compounding, modified extrusion pelletizing, wood–plastic blending, masterbatch production, rubber devulcanization, and mixing.
Relevant development priorities for this type of machinery include:
- Screw-element geometry and modular configuration
- Improved dispersion of fillers, pigments, and fibers
- Stable feeding of powders, liquids, and irregular recycled materials
- Control of melt temperature and residence time
- Degassing of volatile components and moisture
- Reduced energy consumption per unit of output
- Lower manual intervention through automation
- Compatibility with recycled and difficult-to-process feedstocks
These priorities correspond to broader industry pressures for more efficient compounding, higher recycled content, lower processing losses, and tighter control of material properties.
Sustainability and Environmental Considerations
Kejin describes its equipment as supporting high output, lower energy consumption, reduced labor requirements, and environmentally oriented production. Such claims are relevant to several sustainability challenges in polymer processing, although their practical effect depends on machine configuration, formulation, operating conditions, maintenance, and the electricity source used by the plant.
The company’s technology portfolio can contribute to resource efficiency in several ways:
- Compounding systems can incorporate recycled polymers, mineral fillers, fibers, and industrial by-products into usable materials.
- Rubber devulcanization equipment can support the recovery and reuse of selected rubber waste streams.
- Efficient pelletizing can reduce off-specification material and improve handling.
- Automated feeding and process control can improve formulation accuracy and reduce production variability.
- Higher-throughput equipment can lower energy and labor intensity per unit of output when operated near its intended design conditions.
Environmental performance must nevertheless be assessed across the full production system. Recycling and devulcanization may require drying, filtration, odor control, contaminant management, and quality testing. The resulting material must also meet the performance requirements of its intended application.
Quality Management and Technical Service
The company describes itself as providing manufacturing, sales, and after-sales service capabilities. For extrusion and compounding equipment, service quality is closely connected with commissioning, process trials, screw configuration, spare-parts availability, operator training, and troubleshooting.
Important quality factors for this type of machinery include:
- Dimensional accuracy of screw and barrel components
- Wear resistance in abrasive formulations
- Stable temperature and pressure control
- Reliable feeding and venting
- Consistent pellet dimensions
- Safe operation of heated, rotating, and pressurized assemblies
- Repeatability between production runs
Because compounding lines are highly formulation-dependent, technical support commonly extends beyond machine delivery. Successful installation may require assistance with startup parameters, feed-rate calibration, screw-element arrangement, die selection, pelletizer adjustment, and production optimization.
Innovations and Future Outlook
Kejin’s future development is likely to be shaped by the convergence of several plastics-industry trends:
- Rising demand for recycled-content compounds
- Greater use of lightweight reinforced materials
- Growth in flame-retardant and engineering-plastic applications
- Expansion of wood–plastic and other bio-filled composites
- Increased attention to energy consumption and process emissions
- Demand for flexible production lines serving multiple formulations
- Greater automation of feeding, monitoring, and quality control
Equipment manufacturers are also responding to the increasing complexity of recycled feedstocks. These materials can contain variable moisture, contamination, melt-flow behavior, and additive histories. Extrusion systems must therefore provide robust feeding, filtration, venting, mixing, and process control.
For Kejin, the principal strategic opportunity lies in combining its range of screw configurations and pelletizing systems with application-specific process engineering. Growth will depend not only on equipment capacity but also on demonstrated reliability, energy performance, lifecycle support, international service capability, and the ability to process increasingly diverse recycled and engineered materials.
Summary
Nanjing Kejin Tech Co., Ltd. is a Nanjing-based manufacturer of plastics- and rubber-processing machinery. Its portfolio covers co-rotating and counter-rotating twin-screw extruders, three-screw and reciprocating single-screw systems, and a broad selection of pelletizing auxiliaries.
The company serves the compounding and materials-conversion segment of the plastics industry, supporting applications such as polymer modification, reinforcement, masterbatch production, elastomer processing, wood–plastic compounding, rubber mixing, and devulcanization. Its significance lies in providing the process equipment that enables standard polymers, additives, fillers, fibers, and recovered materials to become engineered compounds for downstream manufacturing.
Kejin’s market outlook is connected to the continuing demand for efficient compounding, material customization, recycling, and lower-resource production. Its long-term competitiveness will depend on process performance, equipment reliability, technical service, and its capacity to adapt extrusion technology to increasingly demanding formulations and environmental requirements.
References
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CPS+ eMarketplace. (n.d.). NANJING KEJIN TECH CO.,LTD.NANJING KEJIN TECH CO.,LTD.. CPS+ eMarketplace. https://www.chinaplasonline.com/eMarketplace/ExhibitorInfo?CompId=1035356Link