China's conventional extruders and production lines are gradually becoming popular in the international market with excellent cost performance. At the same time, China has continuously innovated in the field of advanced extrusion technology and has developed a variety of new extrusion products. Precision extrusion technology meets the needs of high precision machining

Melt gear pump

Precision extrusion molding can eliminate the need for subsequent processing methods, better meet the needs of product applications, and at the same time achieve the purpose of reducing material costs and improving product quality. Nowadays, in order to meet the needs of precision direct extrusion of plastic products, a variety of mature technologies have been introduced to the market, and polymer melt gear pumps are one of the important means. This technology has been widely used in chemical fiber, film, profile, pipe, sheet, cable, composite extrusion, granulation and other production lines.

After many years of research on the system of melt gear pumps, Beijing University of Chemical Technology, Rubber and Plastic Machinery Research Institute has successfully completed the development and development of plastic melt gear pumps. Now it is able to design and manufacture plastic melt gear pump products such as 28/28 (center Distance/tooth width), 56/56, 70/70, 90/90, etc., the maximum inlet and outlet pressure difference can reach 30MPa, which can meet the requirements of different production, and has been applied in practice and achieved good results. The Rubber and Plastic Machinery Research Institute of Beijing University of Chemical Technology designed and developed the 115-integrated gear pump extruder through in-depth research on the integrated gear pump extruder.

Gear pumps are also beneficial for precision molding in the rubber industry. In order to meet the domestic demand for rubber melt gear pumps, Beijing University of Chemical Technology has cooperated with Beijing Aviation Manufacturing Engineering Research Institute and Hangzhou Chaoyang Rubber Co., Ltd. to jointly develop XCP150/100 and XCP120/90 rubber melt gear pumps. Out of the unit. This unit has ideal working characteristics, ensuring a linear relationship between the amount of extrusion and the speed of the gear pump, which can achieve precise control of production and improve the dimensional accuracy of the product.

Multi-layer coextrusion technology matures

The multi-layer composite technology utilizes materials with medium and high barrier properties to be combined with other packaging materials to combine the high barrier properties of barrier materials with the low cost or special mechanical and thermal properties of other materials to achieve specific functional requirements.

The structural design of the co-extruded composite film is gradually required to systematically achieve the ideal state of integrating functions, technology, cost, environmental protection, safety and secondary processing, so that the possibility of maximizing the number of composite layers becomes the technology pursued by suppliers. one. The six-layer composite film co-extrusion blow molding technology of Guangdong Jinming Plastic Equipment Co., Ltd. can be described as a typical example of China's development in this field.

The key technologies used in the seven-layer composite film co-extrusion blow molding unit include: two short-length and long-pitch screw plasticizing extrusion systems, engineering analysis software for vibration-induced plasticizing device optimization design, flat valve plus forming die And inclined valve plus molding die, internal cooling technology and double air pressure negative pressure cooling technology, multi-component weight loss metering feeding, online film thickness precision control system, computer centralized automatic control system and bus control (CANOPEN) technology.

At the same time as the number of layers increases, the film production technology that adapts to special functions is also one of the hot spots in the development of the market. Guangdong Shicheng Company designed and manufactured a PP environmentally friendly wood grain film casting production line with a width of 3150mm. The production capacity of the line exceeds 800kg/h. The screw is designed for high-speed shearing and mixing, and high-efficiency plasticizing screw. Customers can directly use high-filled calcium carbonate powder and inorganic pigment toner, thus saving expensive raw material costs. In addition to the production of PP environmentally friendly wood grain film, the whole line can also flexibly convert and produce other products and broaden the types of customers' products. In the trial production process of Shicheng Company, not only the beautiful PP wood grain film was produced, but also the CPP film, PP stationery film and PP stationery sheet.

Innovative three-screw compounding technology

The parallel co-rotating twin-screw extruder is used in the compounding and granulating production line. After more than 20 years of rapid development, the technology is quite mature. On the other hand, the traditional meshing disc type and reciprocating screw extruder are adapted to the requirements of high filling and compounding, and the degree of industrialization is continuously improved.

Chaotic mixing of high performance polymer packaging materials

The project “Key equipment and technology research and development of high-performance polymer packaging materials based on chaotic mixing” jointly developed by Huilong and South China University of Technology passed the scientific and technological achievements appraisal of Guangdong Science and Technology Department and won the national “2007 Science and Technology Progress II”. "No." [Certificate No.: 2007-257], the nominal power of the project "Chaotic mixing type low-energy extruder with multi-sided screw convection screw" is 0.17 kW / (kg / h), only 0.32 kW national standard Half of /(kg/h), energy saving is remarkable, it is the first in the world, and the overall technology and products have reached the international advanced level.

Using rheological modeling method and microscopic rheological model to control the morphological evolution of polymer materials, the flow field in the extrusion process of polymer materials and the morphological evolution of blends and nanocomposites were modeled. , simulations and analysis, especially theoretical studies of melting, mixing and melt flow in extruders, reveal how to improve melting and mixing performance and reduce energy consumption.

Based on the above theoretical research, the chaotic mixing type low-energy extruder developed in principle is obviously different from the extruder widely used at home and abroad: the latter occurs the classic Maddock melting process and shear mixing, its melting and The mixing effect is poor; the former produces dispersive melting and chaotic mixing, and the shear heat generated by the material is less than the heat energy required for melting, which prevents the material from being overheated during the melting and mixing process and wastes energy, and the energy saving effect is obvious. . According to the on-site inspection of the Guangdong Provincial Technical Supervision Machinery Product Quality Supervision and Inspection Station, the nominal specific power (ie, unit consumption) of the extruder is 0.17 kW/(kg/h), which is higher than the national machinery industry standard JB/T 8061-96. The specified value [0.32 kW/(kg/h)] is 0.15 kW/(kg/h) lower.

The comparison with the extruders representing two foreign companies (Davis Standard and Sumitomo Heavy Industries Modern), which represent the highest level of extrusion compounding in the world, shows that the extruder has the highest extrusion output and is equipped with The motor power is the lowest. The extruder also has the advantages of low extrusion melt temperature (lower 10-20 ° C) and strong material adaptability.

On the basis of the above-mentioned macroscopic flow field simulation and microscopic morphology evolution theory research, combined with the development of chaotic mixing type low energy extruder, the polymer blend (especially the viscosity ratio is much larger than 1) and the nanocomposite (especially The morphological evolution, dispersion state and macroscopic properties of non-polar materials such as polyolefins were systematically studied. It was confirmed that the chaotic mixing extruder can improve the processing performance and reduce the processing energy consumption, especially the provided The stretching and folding effect is beneficial to the formation of highly dispersed, flaky, intercalated or exfoliated forms, which solves the problem of easy agglomeration of nanoparticles in the processing of polymer materials to a certain extent, and greatly improves the barrier properties of packaging products. And mechanical properties.

The EVA pre-coating film is produced by extrusion using a chaotic mixing type low-energy extruder, which eliminates the emission of toxic organic solvents and the conventional method of dissolving EVA on the substrate by using a toxic solvent. Environmental pollution and human damage; in addition, the adhesive properties of the extruded film and the composite substrate are greatly improved, and the "green composite process without adhesion promoter" is realized.

Dongguan Pinyang Cable Machinery Co., Ltd. is a professional manufacturer of wire and cable equipment for professional development, design and production. It specializes in: optical fiber extruder, ultra-fine winding machine, earphone wire special machinery and other products, optical fiber extruder, very fine winding Machine, earphone line dedicated mechanical consultation hotline: 13731224526 / Lu Jianjun