ZHEJIANG YUJIN PLASTIC MACHINERY CO., LTD.

Introduction

Zhejiang Yujin Plastic Machinery Co., Ltd. (浙江宇劲塑料机械有限公司) is a Chinese plastics-machinery manufacturer based in Jintang Town, Dinghai District, Zhoushan, Zhejiang Province. Established in 2013, the company develops and manufactures precision screw-and-barrel assemblies and related plasticizing components for demanding injection-molding applications. Its stated technical focus includes optical-grade transparent products, fluoropolymer molding, metal injection molding, and processing of highly abrasive or flame-retardant compounds.

Yujin operates within Zhoushan’s specialized plastics-machinery cluster, an important Chinese manufacturing base for screws, barrels, and other components used in injection molding and extrusion. Rather than supplying complete injection-molding machines, the company’s principal role is as a component and process-technology supplier whose products influence plasticization, melt homogeneity, corrosion resistance, wear life, throughput, and molded-part quality.

The company’s development reflects broader trends in plastics processing: the growing use of glass-fiber-reinforced engineering polymers, halogen-free flame-retardant materials, fluoroplastics, metal-filled feedstocks, and optical polymers. These materials can impose substantially greater thermal, mechanical, or chemical demands on plasticizing equipment than conventional commodity thermoplastics.

History and Development

Yujin was founded in 2013 in Zhoushan, Zhejiang Province. Its development has followed the expansion of specialized injection-molding applications requiring more durable and application-specific screw-and-barrel designs.

Key development milestones include:

• 2013: Establishment of Zhejiang Yujin Plastic Machinery Co., Ltd. in Zhoushan.
• Subsequent development: Expansion from conventional plasticizing components toward assemblies designed for high-glass-fiber, metal-injection-molding, optical, and fluoropolymer applications.
• Recent technical emphasis: Development of high-precision and intelligent-manufacturing capabilities intended to improve component consistency and process performance in demanding molding environments.

The company describes itself as a high-technology enterprise integrating research and development, manufacturing, and sales. Its public company profile places particular emphasis on injection molding under extreme operating conditions rather than on the broad production of general-purpose plastics machinery.

Business Operations and Segments

Yujin’s activities center on the design, manufacture, and supply of screw-and-barrel systems for injection molding. These assemblies typically comprise a reciprocating screw, barrel, non-return valve, nozzle-related components, and associated wear- or corrosion-resistant surfaces, depending on the machine and polymer being processed.

Its principal operating areas can be grouped as follows:

The company’s position in the supply chain is comparable to that of other specialist component manufacturers serving injection-molding machine builders, molders, and processors. Its commercial value is therefore connected less to machine capacity alone than to the relationship between screw geometry, metallurgical treatment, polymer formulation, processing temperature, residence time, and required service life.

Products and Technologies

Plasticizing Screw and Barrel Assemblies

The company’s main product category is the plasticizing screw and barrel assembly. In an injection-molding machine, the screw performs several functions:

1. It conveys polymer pellets from the feed zone.
2. It melts and homogenizes the material through controlled shear and barrel heating.
3. It meters a consistent melt volume.
4. It injects the melt into the mold during the injection cycle.

Screw geometry can be adapted through changes in flight depth, compression ratio, mixing sections, barrier features, tip configuration, and non-return-valve design. The appropriate configuration depends on polymer viscosity, filler loading, thermal sensitivity, required throughput, and product-quality requirements.

High-Glass-Fiber Applications

Yujin identifies screw-and-barrel assemblies for compounds containing more than 50 percent glass fiber among its specialized products. Such compounds are used where high stiffness, dimensional stability, and strength are required, but they are also highly abrasive. Abrasion can reduce screw-flight dimensions, enlarge clearances, alter metering behavior, and eventually reduce molding consistency.

The company states that its assemblies for high-glass-fiber applications, including V0 and halogen-free flame-retardant materials, are designed for service lives exceeding one year under specified operating conditions. Actual life depends on factors such as fiber length, filler concentration, processing temperature, screw speed, back pressure, contamination, and maintenance practices.

Optical-Grade Transparent Products

Yujin also identifies optical transparent-product injection molding as a core specialty. Optical polymers require careful control of contamination, residence time, melt temperature, shear history, and surface condition. Small imperfections, color changes, bubbles, black specks, or flow irregularities can affect the performance or appearance of lenses, light guides, transparent covers, and other optical components.

The company reports an optical-grade transparent-product yield above 97 percent for relevant applications. Such a figure is application-specific rather than a universal measure of all production, and yield depends on the complete molding system, including resin quality, mold design, drying, machine control, and inspection.

Fluoropolymer Molding

Fluoropolymers such as PFA and PVDF are used where chemical resistance, thermal performance, electrical insulation, or low-friction characteristics are required. Their processing can expose plasticizing components to aggressive chemical conditions and elevated temperatures.

Yujin describes super-corrosion-resistant screw-and-barrel assemblies for PFA and PVDF injection molding, with a stated service life of more than three years under defined conditions. Suitable equipment design may involve corrosion-resistant alloys, specialized surface treatments, controlled clearances, and geometries intended to minimize stagnant material and degradation.

Metal Injection Molding

The company lists metal injection molding (MIM) among its specialties. MIM uses a polymer-bound feedstock containing a high concentration of fine metal powder. The feedstock is injection molded, followed by debinding and sintering to produce a metallic component.

MIM feedstocks can impose demanding conditions on screws and barrels because metal powders increase abrasion, while binders may be sensitive to temperature and residence time. Equipment design must therefore balance dispersion and feeding performance with the need to limit wear, contamination, and thermal degradation.

Wear- and Corrosion-Resistant Construction

Yujin’s product strategy emphasizes resistance to two principal failure mechanisms:

• Wear, caused by glass fibers, mineral fillers, metal powders, and other abrasive constituents.
• Corrosion, caused by aggressive polymers, additives, decomposition products, or processing environments.

These requirements may be addressed through material selection, heat treatment, bimetallic barrel construction, surface engineering, optimized screw geometry, and manufacturing controls. The appropriate solution depends on the polymer system and the operating profile rather than on a single universal material.

Applications and End Markets

Yujin’s component technologies serve processors manufacturing technically demanding molded parts. Relevant application areas include:

• Automotive components made from reinforced engineering plastics.
• Electrical and electronic parts requiring flame retardancy or dimensional stability.
• Optical and lighting components made from transparent polymers.
• Chemical-processing, semiconductor, and fluid-handling components made from fluoropolymers.
• Precision metal components produced through metal injection molding.
• Industrial components requiring resistance to abrasion, heat, or corrosive media.

These applications connect the company to several structural trends in the plastics industry. Vehicle lightweighting increases the use of reinforced polymers; electrical and electronic systems require flame-retardant and insulating materials; and chemical and semiconductor equipment relies on polymers capable of operating in aggressive environments.

Global Presence and Market Position

Yujin is headquartered at No. 1 Kangtai Road, Jintang Town, Dinghai District, Zhoushan, Zhejiang Province, China. The company’s public profile identifies a workforce of approximately 51–200 employees and presents the business as a specialist manufacturer serving plastics-processing applications rather than as a diversified machinery conglomerate.

Its market position is based on specialization in screw-and-barrel systems for difficult-to-process materials. This places Yujin in a segment that competes through:

• Metallurgical and surface-treatment capability.
• Application-specific screw design.
• Dimensional precision and manufacturing consistency.
• Ability to address wear, corrosion, and contamination risks.
• Technical support for processors and machine manufacturers.

The company’s activities are linked to the broader Chinese plastics-machinery supply chain, which includes injection-molding machine manufacturers, mold makers, automation suppliers, material producers, and component specialists. Its international relevance depends on the ability to meet the technical, quality, delivery, and service requirements of customers operating beyond China.

Research and Development

Yujin describes research and development as one of its central functions. Its development priorities are concentrated on plasticizing systems for extreme operating conditions, including:

• High-glass-fiber engineering compounds.
• Halogen-free flame-retardant formulations.
• Fluoropolymers such as PFA and PVDF.
• Metal injection-molding feedstocks.
• Optical-grade transparent materials.
• High-precision screw-and-barrel assemblies.

Research in these areas generally involves coordinating screw geometry with material formulation and machine operating conditions. Relevant engineering variables include melt temperature, screw rotational speed, injection rate, back pressure, residence time, compression behavior, and clearance control.

The company’s reported development direction also includes intelligent-manufacturing upgrades. In practice, this may encompass improved process monitoring, digital production records, tighter dimensional inspection, and more consistent control of machining and treatment processes. The performance of such systems is ultimately evaluated through repeatability, component life, molded-part quality, and total operating cost.

Sustainability and Environmental Considerations

Yujin’s products contribute indirectly to sustainability objectives by supporting longer component service life, reducing unplanned replacement, and enabling the processing of durable lightweight engineering polymers. More wear-resistant assemblies can help maintain stable production and reduce the frequency with which screws and barrels must be manufactured, transported, and installed.

The environmental balance remains application-dependent. Reinforced and fluorinated polymers can deliver long service life and technical advantages, but their manufacture, processing, and end-of-life management may present additional challenges. Similarly, metal injection molding can produce complex parts with efficient material utilization, while its feedstock and debinding stages require careful process control.

Important sustainability factors for users of Yujin equipment include:

• Extending screw-and-barrel operating life.
• Reducing scrap caused by contamination or unstable plasticization.
• Improving energy efficiency through stable processing.
• Selecting materials and coatings appropriate to the intended service life.
• Managing production waste and end-of-life components responsibly.
• Supporting recycling or recovery strategies where polymer chemistry and product design permit.

These considerations reflect wider industry efforts to combine material performance with lower resource consumption and improved circularity.

Quality Management and Certifications

The company’s public profile emphasizes high-precision manufacturing and high-technology enterprise status. Its products require close control of screw and barrel dimensions, concentricity, surface condition, metallurgy, hardness, and clearances because small deviations can affect plasticization and injection repeatability.

For this type of manufacturer, quality assurance typically includes:

• Incoming inspection of steels, alloys, and treatment materials.
• Computer-controlled machining and dimensional verification.
• Hardness and metallurgical testing.
• Surface and internal-defect inspection.
• Final measurement of critical screw and barrel dimensions.
• Functional validation under representative processing conditions.

Specific certification claims should be distinguished from general quality statements. The company’s public profile supplies information about its technical orientation and product applications, but certification status should be evaluated against the particular product, facility, and customer requirement.

Innovations and Future Outlook

Yujin’s future prospects are tied to the continued adoption of advanced polymer compounds and the increasing technical requirements of injection molding. Several developments are likely to shape its operating environment:

• Greater use of glass-fiber-reinforced and mineral-filled engineering polymers.
• Continued demand for halogen-free flame-retardant materials.
• Expansion of fluoropolymer applications in chemical, electrical, and semiconductor equipment.
• Increasing use of metal injection molding for small, complex precision parts.
• Higher quality requirements for optical and transparent molded products.
• Greater integration of process monitoring, digital manufacturing, and predictive maintenance.

The main strategic challenge is to translate specialized component expertise into repeatable performance across different machine platforms, polymer grades, and customer production conditions. Competition may also intensify as Chinese and international machinery-component suppliers invest in advanced materials, coatings, machining, and application engineering.

Yujin’s specialization gives it a focused position within the plastics-equipment ecosystem. Its ability to sustain that position will depend on technical validation, manufacturing consistency, international service capability, and the extent to which its products reduce total cost of ownership for processors.

Summary

Zhejiang Yujin Plastic Machinery Co., Ltd. is a Zhoushan-based Chinese specialist in precision screw-and-barrel assemblies for injection molding. Founded in 2013, it focuses on technically demanding applications involving optical polymers, high-glass-fiber and flame-retardant compounds, fluoropolymers, metal injection-molding feedstocks, and other abrasive or corrosive materials.

The company occupies a component-focused position within the plastics machinery industry. Its significance lies in addressing the plasticization, wear, corrosion, and consistency challenges associated with advanced polymer processing. Through specialized product design, materials engineering, and manufacturing development, Yujin participates in the broader transition toward higher-performance materials, more demanding molded products, and increasingly controlled plastics-processing operations.

References

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  CPS+ eMarketplace. (n.d.). ZHEJIANG YUJIN PLASTIC MACHINERY CO., LTD.ZHEJIANG YUJIN PLASTIC MACHINERY CO., LTD.. CPS+ eMarketplace. https://www.chinaplasonline.com/eMarketplace/ExhibitorInfo?CompId=1042732Link