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According to data from the National Bureau of Statistics, in November 2024, the plastic products industry in China achieved a total output of 7.225 million tons, a year-on-year increase of 6.5%. From January to November 2024, the cumulative production of enterprises was 69.866 million tons, a year-on-year increase of 3.3%. The top ten provinces in terms of plastic product output in China in November were, in order, Guangdong, Zhejiang, Hubei, Jiangsu, Shandong, Fujian, Anhui, Hunan, Hebei and Sichuan.   According to regional statistics, in November 2024, the output of plastic products in the eastern region was 4.58 million tons, accounting for 63.4%. The output of plastic products in the central region was 1.704 million tons, accounting for 23.6%. The output of plastic products in the western region was 804,000 tons, accounting for 11.1%. The output of plastic products in Northeast China was 118,000 tons, accounting for 1.6%. According to data from the General Administration of Customs, in November 2024, the export value of plastic products reached 9.21 billion US dollars, up 3.8% year-on-year. The import value was 1.43 billion US dollars, up 0.2% year-on-year. From January to November, the total export value of plastic products was 95.8 billion US dollars, increasing by 5.6% year-on-year. The total import volume was 16.21 billion US dollars, increasing by 3.4% year-on-year, and the trade surplus was 79.59 billion US dollars.                                       (Source: Zhejiang Jinjia Plastic Machinery Co., Ltd.）

    With the rapid development of the global economy, plastics, as an indispensable part of modern industry, play a significant role in multiple fields such as packaging, construction, automobiles, and electronics. It is highly popular in the market for its features such as lightness, durability and high cost-effectiveness. However, along with the widespread use of plastic products, a series of problems such as environmental pollution have also emerged. In particular, "white pollution" has become one of the key issues of global concern.     In recent years, with the gradual enhancement of environmental awareness and the increasingly strict environmental protection laws and regulations imposed by governments around the world, the plastic industry is facing unprecedented transformation pressure. On the one hand, traditional plastic materials are limited because they are difficult to degrade. On the other hand, the research and application of new bio-based degradable plastics have become a new development trend. In addition, the circular economy model has also been promoted within the industry, reducing resource waste through recycling and reuse to achieve sustainable development goals.     Facing challenges, plastic enterprises have been increasing their investment in research and development, dedicated to developing more environmentally friendly and efficient products and technologies. For example, using natural plant fibers or microbial fermentation products as raw materials to produce green plastics; Improve the production process flow to reduce energy consumption and emissions; Develop intelligent packaging solutions, etc. These innovations not only help solve environmental problems, but also bring new growth points to the industry.     To promote the healthy development of the plastic industry, many countries and regions have introduced relevant policies to provide support. For example, provide financial subsidies to encourage enterprises to carry out technological transformation and upgrading; Establish a specialized agency to be responsible for supervising the implementation of relevant standards; Strengthen exchanges and cooperation with other countries to jointly address cross-border pollution issues. Through these measures, the entire industrial chain can be effectively promoted to develop in a higher-quality direction.     When discussing the future development of the plastic industry, a key piece of equipment - the screw - cannot be overlooked. Whether in injection molding or extrusion molding processes, the screw is one of the key factors determining the quality of the product. It can not only evenly mix raw materials and heat them to an appropriate temperature, but also regulate the flow state of the melt by controlling the rotational speed, thereby ensuring the performance stability and consistency of the final product. Therefore, while pursuing higher efficiency and better quality, choosing the appropriate screw design is crucial for enhancing the overall production line level.     In conclusion, although the plastic industry is currently confronted with numerous challenges, it is entirely possible to transform these challenges into development opportunities through continuous technological innovation, proactive response to environmental protection requirements, and strengthened international cooperation. In this process, high-quality production equipment such as high-performance screws is an indispensable basic guarantee. Only by constantly optimizing the technological process and improving manufacturing accuracy can the sustainable development of the plastic industry be truly achieved.   Our company specializes in manufacturing alloy barrels and screws with high wear resistance and corrosion resistance, including bimetallic barrel for injection moulding machine, bimetallic screw for injection moulding machine,bimetallic barrel for extrusion machine,bimetallic screw and barrel for rubber machine,supercritical carbon dioxide foaming screw, bimetallic twin barrel screw.,ect.Welcome to visit our website https://jinjiahj.en.alibaba.com.  If you are interested in our products, feel free to contact me.

    The history of plastic can be traced back to the middle of the 19th century. In 1862, the British chemist Alexander Parks demonstrated the earliest synthetic material nitrocellucellulose and named it "Parkesine". In 1869, American chemist John Wesleary Arter used camphor as a plasticizer to nitrify natural cellulose, creating the world's first plastic variety - celluloid, marking the beginning of human use of plastics. In 1907, Leo Beklan, a chemist born in Belgium, discovered phenolic plastics, which were widely used in the emerging telecommunications industry at that time. Since then, with the continuous advancement of technology, various plastic materials such as polyethylene, polyvinyl chloride and polystyrene have emerged one after another, and the plastic family has been growing increasingly larger.     In the early days, plastics quickly emerged in various fields due to their advantages such as light weight, corrosion resistance and low cost. It has gradually replaced many traditional materials, such as metal, wood and glass, etc. During World War II, plastic played a significant role and was widely used in the manufacturing of military equipment and materials, meeting the special demands for materials during the war. After the war, the application of plastic in civilian fields was further expanded and it entered ordinary households. From daily tableware and toys to clothing and furniture, plastic products were everywhere, greatly changing people's lifestyles.     1.The characteristics of plastics: Diverse properties lead to wide applications       Plastic is a high-molecular organic material mainly composed of polymers. After adding appropriate additives, it is shaped under certain temperature and pressure and can maintain its predetermined shape at room temperature. Its main raw materials come from petroleum or natural gas. Plastic possesses numerous excellent properties, which is also the key for it to stand out among many materials. First of all, plastic is characterized by its light weight, which gives it a significant advantage in fields with strict weight requirements such as transportation and aerospace. For instance, a large number of plastic components are used in aircraft and automobiles, which not only reduce their own weight but also lower energy consumption and enhance operational efficiency. Secondly, plastic has excellent corrosion resistance and can remain stable in various harsh chemical environments, being less prone to corrosion and damage. Therefore, in industries such as chemical engineering and construction, plastics are widely used in the manufacture of pipes, storage tanks and other equipment, which greatly extends the service life of the equipment and reduces maintenance costs. In addition, plastic also has excellent insulating properties and is an indispensable material in the electrical industry. It is often used as the insulation layer of wires and cables, the casing of electrical appliances, etc. Its impact resistance, tensile strength and bending resistance are also quite excellent, which can meet the requirements for material strength and toughness in different scenarios. Meanwhile, plastic also has the characteristics of heat preservation and energy conservation, and has been widely used in the field of building insulation materials. Plastics can be classified into general-purpose plastics, engineering plastics and functional plastics according to their different uses and properties. General-purpose plastics, such as polyethylene, polypropylene and polyvinyl chloride, have large production volumes, wide applications and low prices, and are widely used in packaging, daily necessities and other fields. Engineering plastics have excellent mechanical properties and can be used as engineering structural materials, such as polyamide (nylon), polycarbonate, etc. They are often used to manufacture mechanical parts, electronic device casings, etc. Functional plastics have special properties. For instance, medical plastics are used in the manufacture of medical devices, and photosensitive plastics are employed in the field of optoelectronics, etc.       2.The wide application of plastics: Penetrating all areas of life.       In daily life, the application of plastics is everywhere. The food packaging bags, beverage bottles, cling film and other products we use are mostly made of plastic. These plastic products not only facilitate the storage and transportation of food, but also effectively extend the shelf life of food. Disposable tableware, plastic bags and other plastic products have brought great convenience to people's lives and met the demands of a fast-paced life. In the field of construction, plastic pipes, doors and Windows, insulation materials, etc. have been widely applied. Plastic pipes have the advantages of corrosion resistance and convenient installation, and are gradually replacing traditional metal pipes. Plastic doors and Windows have excellent heat insulation and sound insulation performance, which can enhance the energy-saving effect and living comfort of buildings. Insulation materials such as polystyrene foam plastic play a significant role in building insulation. In the field of electronics and electrical appliances, plastics are equally indispensable. Many electrical appliance casings, insulation layers of wires and cables, circuit boards, etc. are made of plastic. The insulating and molding processing properties of plastics make the design of electronic and electrical products more flexible and diverse, and also reduce production costs. In the automotive industry, the application proportion of plastics is constantly increasing. Plastic materials are used for automotive interior parts such as seats, instrument panels, and door interior panels, as well as some exterior and structural components. This not only reduces the weight of the car, improves fuel economy, but also lowers the noise inside the vehicle and enhances the ride comfort. In addition, plastics also have extensive and significant applications in fields such as aerospace, medical and health care, and agriculture. For instance, high-performance plastic components used in the aerospace field can meet the requirements of aircraft for lightweight materials and high strength. Disposable syringes, infusion sets, medical plastic packaging, etc. in the medical and health field ensure the safety and hygiene of the medical process. Plastic greenhouses and plastic film in the agricultural field have created favorable environmental conditions for the growth of crops, increasing their yield and quality.     3.Screw: The core driving force in plastic production       In the vast industrial system of plastic production, although the screw may seem like an insignificant component, it plays an irreplaceable core role and can be regarded as the "heart" of plastic molding. From plastic pellets to various plastic products, screws run through the key links of plastic production. Their performance directly affects the quality, production efficiency and production cost of plastic products. The most fundamental and important function of a screw is the transportation of plastic. In plastic processing equipment, the screw, through its own rotational movement, acts like a "conveyor belt", continuously transporting plastic raw materials from the hopper to the processing area. Whether it is an injection molding machine, an extruder or a blow molding machine, the stable conveying of the screw is a prerequisite for the smooth progress of production. Take the extrusion production of plastic pipes as an example. The screw needs to push the plastic particles to the mold at a constant speed and stably. If there are fluctuations during the conveying process, such as the feeding speed fluctuating, it will lead to uneven wall thickness of the pipe, seriously affecting the product quality and performance.     The screw also has a powerful mixing function. In plastic production, to improve the performance of plastics, various additives are often added, such as plasticizers, stabilizers, fillers, etc. During the rotation of the screw, through its unique structural design, such as the shape of the thread, the variation of the pitch, and the mixing elements, it can thoroughly mix the plastic raw materials and additives, ensuring that various components are evenly dispersed in the plastic melt. This uniform mixing is crucial for the consistency of the performance of plastic products. Take the production of engineering plastic components as an example. Only by thoroughly mixing reinforcing fibers, flame retardants and other additives with the plastic matrix can the components have good mechanical properties and flame retardant performance, meeting the usage r equirements of different fields.       With the continuous development of the plastic industry and the increasing quality requirements for plastic products, the design and manufacture of screws are also constantly innovating and optimizing. The researchers and engineers of Zhejiang Jinjia Plastic Machinery CO.,LTD have developed various high-performance screws by improving the structure, materials and processing techniques of the screws to meet the demands of different plastic varieties and molding processes. Our company specializes in manufacturing alloy barrels and screws with high wear resistance and corrosion resistance, including bimetallic barrel for injection moulding machine, bimetallic screw for injection moulding machine,bimetallic barrel for extrusion machine, bimetallic screw and barrel for rubber machine,supercritical carbon dioxide foaming screw, bimetallic twin barrel screw.,ect.    If you want to make good plastic products, we are your best choice.

Rubber barrel: rubber processing efficient "engine" in the field of rubber products production, rubber barrel as a hero behind the scenes, with its excellent performance and broad applicability, for rubber processing provides a solid and reliable support, power towards the development of high quality rubber products enterprises new journey.   First, the characteristics of the Bimetallic screw and barrel for rubber machine   (1) Accurate temperature control Rubber cylinders are usually equipped with advanced heating and cooling systems, which can achieve accurate temperature control according to different rubber materials and process requirements. The heating method mainly adopts resistance heating, and the thermocouple is used to achieve the effect of segmented temperature control to ensure that the temperature distribution in the barrel is uniform. This precise temperature control enables the rubber to always maintain an ideal flow and plasticized state during processing, thus ensuring the quality and performance of rubber products. (2) Excellent wear resistance The inner wall of the rubber cylinder is specially treated and has excellent wear resistance. Whether in the face of high hardness rubber materials, or in the continuous production process for a long time, the inner wall of the barrel can remain smooth and intact, reducing wear and scratches. This wear resistance not only extends the service life of the barrel, but also reduces the production failure and maintenance costs caused by wear, and improves the production efficiency. (3) Flexible structural design Rubber barrel has a variety of structural forms to choose from, such as integral barrel, segmented barrel, bushing barrel and casting wear-resistant alloy barrel. The integral cylinder is suitable for small extruder, the heating and cooling device is convenient, and the temperature control is easy to ensure; The segmented barrel is suitable for larger size extruders and exhaust extruders, which is convenient for machining and maintenance; Adding a liner cartridge or casting a wear-resistant alloy cartridge is widely used in large extruders, which can save valuable alloy steel and reduce equipment manufacturing costs. This flexible structural design enables the rubber barrel to meet the needs of different sizes and types of rubber processing. (4) Efficient production efficiency The combination of rubber barrel and screw can achieve efficient transportation and processing of rubber materials. Under the rotation of the screw, the rubber material moves forward in the barrel, and is affected by various forces such as extrusion, flipping and shearing to complete uniform mixing plasticizing and melting molding. This efficient production method greatly improves the production efficiency of rubber products, reduces the production cost, and brings significant economic benefits to enterprises.   Second, the scope of application of rubber barrel   (1) Rubber products processing Rubber products are widely used in the processing and production of all kinds of rubber products, such as tires, shoe materials, wire and cable, pipes, seals and so on. In the tire production, the rubber barrel can ensure the uniform mixing and plasticizing of the rubber material, improve the performance and quality of the tire; In wire and cable manufacturing, rubber barrel can process rubber material into various specifications of insulation layer and sheath to ensure the electrical and mechanical properties of wire and cable; In the production of seals, the rubber barrel can precisely control the flow and formation of the rubber material to produce high-quality sealing products. (2) Different rubber materials processing rubber barrel can adapt to the processing of a variety of rubber materials, including natural rubber, styrene butadiene rubber, nitrile rubber, neoprene rubber, silicone rubber, fluorine rubber and so on. Different materials of rubber have different performance and processing requirements, rubber barrel by adjusting the temperature, pressure and screw speed and other parameters, can meet the processing needs of various rubber materials, to achieve efficient and stable production. (3) A variety of processing technology Rubber cylinder is not only suitable for traditional extrusion molding process, but also for injection molding, hot pressing and other rubber processing technology. In injection molding, the rubber barrel can heat and melt the rubber material, and inject it into the mold through the push of the screw to rapidly shape a variety of complex rubber products; In hot pressing, the rubber cylinder can process the rubber material into semi-finished products, and then the final molding is carried out by hot pressing equipment. This wide range of process applicability makes the rubber barrel has an irreplaceable important position in the production of rubber products. With its precise temperature control, excellent wear resistance, flexible structural design and efficient production efficiency, rubber barrel has become the core equipment of the rubber processing industry. It can not only meet the production needs of all kinds of rubber products, but also adapt to a variety of rubber materials and processing processes, and provide strong technical support and production guarantee for rubber products enterprises. Choosing rubber barrel is to choose efficient, stable and reliable rubber processing solutions to help enterprises stand out in the fierce market competition and achieve sustainable development.   Our company focuses on the production of ultra-high wear-resistant tungsten carbide alloy barrel screws, including Bimetallic barrel for injection moulding machine , Bimetallic screw for injection moulding machine,Bimetallic barrel for extrusion machine, Bimetallic twin screw and barrel for rubber machine,supercritical carbon dioxide foaming screw, Conical twin screw barrel and Parallel twin screw barrel We are willing to work together with general customers to create the most wear-resistant bimetallic barrel screw in China.

  Bimetallic screw barrel are a crucial component in injection molding machines, as they play a key role in the overall performance and efficiency of the machine. These barrels are made from two different materials, typically a combination of steel and a high-performance alloy, which are bonded together to create a durable and long-lasting barrel. The use of Bimetallic barrel for injection molding machine and Bimetallic screw for injection moulding machine offer several advantages over traditional barrels made from a single material. The combination of materials allows for better wear resistance, increased thermal conductivity, and improved corrosion resistance. This results in a longer lifespan for the barrel, reduced maintenance costs, and improved overall performance of the injection molding machine. One of the main benefits of bimetallic barrels is their superior wear resistance. The high-performance alloy used in the barrel is much harder than traditional steel, making it more resistant to the abrasive wear caused by the constant movement of the screw and the high temperatures and pressures involved in the injection molding process. This helps to extend the life of the barrel and reduce the need for frequent replacements.In addition, the bimetallic construction of the barrel also provides improved thermal conductivity. The high-performance alloy has better heat transfer properties than steel, allowing for more efficient heating and cooling of the barrel during the injection molding process. This helps to maintain a more consistent temperature throughout the barrel, resulting in better quality parts and reduced cycle times.Furthermore, bimetallic barrels offer improved corrosion resistance compared to traditional barrels. The high-performance alloy used in the barrel is more resistant to the corrosive effects of the plastic resin and other materials used in the injection molding process. This helps to prevent rust and other forms of corrosion from forming on the barrel, further extending its lifespan and reducing maintenance costs.Overall, bimetallic barrels are a superior choice for injection molding machines due to their enhanced wear resistance, improved thermal conductivity, and superior corrosion resistance. These barrels help to improve the performance and efficiency of injection molding machines, resulting in better quality parts, reduced maintenance costs, and increased overall productivity.   Our company focuses on the production of ultra-high wear-resistant tungsten carbide alloy barrel screws, including Bimetallic barrel for injection moulding machine , Bimetallic screw for injection moulding machine,Bimetallic barrel for extrusion machine,  Bimetallic screw for extrusion machne,Bimetallic twin screw and barrel for rubber machine,supercritical carbon dioxide foaming screw, Conical twin screw barrel and Parallel twin screw barrel,etc.  

Bimetallic screw and barrel double-metal process is more frequently used in recent years, a corrosion resistance, excellent abrasion resistance and process combination product with High-Speed ​​HVOF spraying device for spraying spraying on the surface of the screw, to obtain a dense structure of the double metalscrew; bimetallic barrel using a cast, high tungsten carbide composition of the alloy cylinder cast one, use the special technology, precision molding.

 Double screw extruder routine maintenance:     500 hours, reduction gear box will wear down the iron filings or other impurities, therefore, should be cleaned gear at the same time to replace the gearbox oil.     Second, after some time the extruder to conduct a comprehensive inspection, check the tightness of all screws.     Third, if the production of a sudden power failure, the main drive and heating is stopped, when power is restored, the barrel must paragraphs re-heated to a specified temperature and incubated for a period of time in order to start the extruder.     Four, Such as the discovery of instrument pointer turned to full-scale, should check the edges of the thermocouple contacts are good.

Rubber extruder screw barrel technical parameters Quenched hardness: HB260-290 Hardness of nitration: HV800-1050 Nitriding depth :0.4-0 .7 mm Nitride crispness: ≤ a Surface roughness: Ra0.4 Screw straightness: 0.015mm Nitride surface chrome layer hardness: ≥ 900HV Chrome thickness :0.05-0 .10 mm Dual alloy hardness: HRC56-65 Alloy depth :0.8-2 .0 mm

Production purposes: injection molding machine / extrusion machinery / bakelite processing machines Processing range: diameter ф20mm-ф250mm Effective length: 8000mm Alloy composition: 88wc/12c0.Crc/25Nicr. XaloY108 Nitride hardness: HRC59 ° -65 °

 Renovation of the barrel process       Barrel inner surface hardness higher than the screw, it's late damage than the screw. The scrap is the diameter of the cylinder diameter increases due to the wear and tear of time. The repair method is as follows:   1, increase the diameter of the barrel due to wear, if there is nitrided layer, the cylinder bore directly boring, grinding to a new diameter, then press the diameter of the preparation of a new screw.   2, a cylinder inner diameter of trimmed by machining to re-cast alloy, of a thickness of 1 ~ 2mm, and then finished to size.   3, under normal circumstances the barrel of paragraph wear faster, the paragraph (take 5 to 7D long) boring dressing, adding a nitriding steel bushings, inner hole diameter with reference to the diameter of the screw, to stay in normal with the clearance, processing or preparation.       After the repair, machine plasticizing parameter does not need to make any changes to its service life is much higher than conventional material parts of your purchases, creates greater wealth for the rubber and plastics industry.

Injection molding machine screw barrel process settings     The end of the barrel is too cold is one of the main cause screw slippage. The cylinder of the injection molding machine is divided into three sections, in the end, i.e. the feed zone, the pellets in the heating and compression process, will form a layer of the melt film to stick to the screw. Without this film, the pellet is not easily transported to the distal end.     The feed zone of the material must be heated to the critical temperature to form a critical layer of the melt film. However, typically the material is very short residence time in the feed zone can not reach the required temperature. This situation is typical in the small injection machine. Duration too short to cause the polymer melting and mixing process is not complete, resulting in screw slippage or STALL.     There are two kinds of simple ways to determine whether the screw slipping. One method is to add a small amount of the material to the end of the barrel in order to detect the temperature of the melt. If the duration is too short, the melt temperature will be less than the cylinder temperature set point. The second method is to check the products: If the products on the pattern of light and dark stripes, which means that the material in the barrel without mixing.     Upon the occurrence of screw slippage, one solution is to raise the temperature of the feed zone of the barrel, no obstacle until the rotation of the screw and retraction. To achieve this goal, barrel temperature may need to be increased to exceed the recommended set point.     High back pressure can also lead to stagnant or slipping of the screw. Raise the back pressure setting will raise the energy applied to the material. If the back pressure is set too high, the screw will not have enough pressure to overcome the back pressure, thus unable to transport materials to the front. This case, when the screw rotation in a certain position without retraction, it will be interested in the material do more work, and thus significantly improve the melt temperature, resulting in a decline in the quality of products and the prolongation of the molding cycle. The back pressure of the melt can be controlled by adjusting the valve of the injection cylinder.

  Injection molding machine screw barrel hardware problems     If the screw slippage due to equipment not process settings causes the screw and barrel wear might be the culprit. Resin melt in the transition section, and stick to the barrel wall, like the feed zone. When the screw rotates, it will melt cut down and transported to the front. If the screw and barrel wear, the screw would be difficult to effectively materials delivered to the front end. If you are unsure whether by wear and tear, can measure the width of the gap between the screw and barrel, Once the tolerance of non-compliance, should its implementation replaced or repaired.    Screw design, in particular the compression ratio design in the plasticizing plays an important role. The feed zone is too short, the compression ratio is too small, will result in reduced throughput and screw slippage. The resin suppliers will recommend the best compression ratio of its material.    Cause screw slippage may be due to non-return valve (check valve) is not working properly. When the screw rotation ready for injection, the retaining ring should be located in the front-end (open position), connecting the convex buckle and snap ring frame. If the collar is in the end (i.e., closed position), or in the middle of the frame of the tail and the collar, then the polymer melt it will be difficult to pass through this gap. If you found a problem with the retaining ring, and should be replaced.    In addition, a resin feed hopper may also be one of the factors that cause the screw to slip. Proper design of the hopper is homogeneous charge, but often overlooked. With fast compression section (ie square hopper suddenly tightened at the bottom) is more suitable for processing of the raw meal, but not suitable for processing recycled materials. Since the recycled material of broad particle size distribution, and therefore affect the uniformity of the feed, which means that the screw can not convey melt uniformly at the same pressure will eventually lead to slipping. To solve this problem, the compression section (i.e., circular hopper in the bottom of the tapered gradually shrink), to handle a wide particle size distribution of material to be used with gradient.

 21st century, materials, energy, information is the three cornerstones of modern industrial development, their level of development, on behalf of a country's overall scientific and technological development. In materials science, and double metal technology is a very important tool to increase the service life of mechanical parts, ordinary metal material as the parent composite another layer alloy has a special role in the mechanical parts of the work surface, with In order to improve the anti-wear, anti-corrosion performance of the parts and increase component life. To obtain the best value for money in the most economical material structure, bi-metal technology have become a driving force behind the sought-after in the world materials sector. As an emerging, with unparalleled development potential of the new technology, bi-metal technology in China's industrial development in all areas of showing an increasingly important role.     With the rapid development of the plastics processing industry, a variety of new modified plastic materials continue to emerge. High strength reinforced plastic materials, it is often added, such as carbon, asbestos, glass, boron and other reinforcing fibers; addition, in order to reduce production costs in order to obtain a variety of special properties, or the purpose of a plastic resin, they often need to be added a certain proportion of various fillers, such as chalk, silica, heavy crystal white, clay, cellulose, mica, talc, alumina, and metal powder or the like. These reinforcing agents, fillers and inorganic colorant Add or recycled plastic or recycled sediment impurities are exacerbated by a plastic extruder machine, plastic injection machine cardiac member - melter cylinder and the corrosion of the conveyor screw or wear failure, so that the processing machinery production efficiency, product quality is unstable, the frequency of maintenance of machinery and replacement parts, increased costs, a great impact on the economic efficiency of enterprises of various plastic processing industry. Production situation is increasingly urgent appeal: instead of conventional nitriding treatment with high wear-resistant, corrosion-resistant bimetallic barrel and screw screw and barrel as the heart of the machine parts to extend the life of the machine.    What is a bimetallic barrel? With different types of high wear resistance, high corrosion-resistant alloy composite materials as the working layer of the inner bore surface at a cylinder (or as sol cylinder). Alloy material thickness of 2.0 to 3.0 mm, the Rockwell hardness is generally 60 degrees or more, then after the special mechanical processing from the barrel, is a bimetallic barrel; Bimetallic screw is in its spiral rib lot work surface, or the entire spiral edge face, the thickness of the composite layer is generally 1.0 to 2.0 mm and special alloys (alloy Rockwell hardness is generally more than 58 degrees), from the processing of by special mechanical screw. Bimetallic barrel and bi-metal screw unique advantages than conventional nitriding screw barrel sales price is less than 1 times the theoretical service life for the ordinary nitriding screw barrel 4 times or more, the price is quite significant .