Rubber Extruder Development HistoryPlunger Extruder
Screw-type Hot Feed Extruder
Ordinary cold feed extruder
Rubber Extruder
Ordinary cold feed extruder
Cold Feed Extruder
Cold Feed Extruder
Cold Feed Extruder
Cold Feed Exhaust Extruder
Pin Cold Feed Extruder
Compound Extruder
MC T D 90, MC T D 1500, MC T D 2000 consisting of a triple-compound extruder, which is characterized by a small size, energy savings of 20%, and is used in North America for tire retreading operations. Although MCT and MCTD extrusion technologies have many advantages that developers have publicized, not all MCT extruders have been successful. In China, an MCT 95/50/50 triple-compound machine was introduced for extruding the tread of a flat tire, but it failed due to uneven plastification and other problems. According to the opinion of German Troesteel Company, this design is not successful.
The use of domestic rubber extruder status quo
With the emergence of cold-feed extruder and widely used, hot-feed extruder is gradually narrowing the scope of application. Rubber extruder from hot feed to cold feed development, cold feed pin extruder has become the mainstream of development. At present, pin-type extruder has been more widely used in China's rubber industry, involving tire tread, radial tire sidewalls, bead rubber, all kinds of hose and liner film, and so on. Both imported and domestic machines are used, with screw diameters ranging from 85 to 250 m m and L/D ratios from 12 to 16. The pin-type cold-feed extruder has many advantages over hot-feed extruders and ordinary cold-feed extruders. Over the past decade, it has been widely used in China's rubber industry, and its applications are expanding. The pin-type cold-feed extruders introduced in China in the early days were mainly used for the extrusion of radial tire tread rubber and the production of rubber core and cover rubber in the production of hose. Nowadays, the majority of semi-steel and all-steel radial tire treads are produced with pin-type cold feed extruders. In the production of bias tires, as well as in the production of other rubber products, many manufacturers use pinned cold feed extruders. In the rubber industry, the traditional production process is the extruder as a molding extrusion process equipment, pin type cold feed extruder due to the large extrusion volume, good plasticizing effect and has been widely used in steel wire, fiber cord calender and airtight layer of film calender rubber supply. In recent years, pin type cold feed extruders have also been popularized for glue filtration and have been well received by users. Pin type cold feed extruder has also been widely used in the production of radial tires, radial tire production has become the key equipment, although some enterprises in the production of composite extrusion process is still used outside the machine, but with the new technology, new technology improvements and updates, as well as the development of the market economy, the old production process and equipment will be eliminated, composite extruder is the inevitable direction of the composite production process. However, at present in China's rubber industry production enterprises, hot feed extruder still occupies a large proportion. According to incomplete statistics on the use of open refiners for rubber hot feed extrusion production process in the country accounted for 70% or so, many of China's old rubber production enterprises using the 2O century 5 O years of extrusion equipment, technology and equipment backward. Some enterprises believe that the old extrusion equipment has its certain advantages, such as refining machine refining dispersion is good, maneuverability is good, skilled operators, etc., but the advantages of the pin type cold feed extruder than the hot feed extruder. Pin type cold feed extruder represents the development direction of rubber extruder, has great potential for development. It can be seen, China's rubber production enterprises in the technical transformation of the extrusion process, and further promote the use of pin type cold feed extruder there is a lot of space.
[edit]Rubber extruder development trend
Screw to the direction of the development of multi-screw
Screw extruder threaded elements of the engagement zone has a large speed gradient, therefore, the engagement zone is conducive to the full mixing of materials. Twin-screw, "a" three-screw, triangular three-screw and four-screw extruder the number of engaging areas were 1, 2, 3, 4, due to the increase in the number of engaging areas, the ability to mix the material is also gradually enhanced. Triangular three-screw and four-screw extruders have a special structure - the center zone. The material in the center area forms a circular flow, and the existence of the circular flow promotes the mixing of the material in the center area and increases the mixing time of the material in the center area. After analysis, the material will not be retained in the center zone. The flow rate, return flow rate, return coefficient, and average shear rate of twin-screw, three-screw, three-screw, and four-screw extruders are gradually increased, which theoretically proves that the multi-screw extruder has a better production capacity in the aspects of material transportation and mixing, and that the multi-screw extruder is more suitable for the polymer processing. It is verified theoretically that the multi-screw extruder has better production capacity in terms of material transportation capacity and material mixing capacity.
Multi-fluid transfer screw (MCT) extruder
The MCT extruder is divided axially along the screw into a feed section, a transfer mixing section and a discharge section. In the transfer mixing section, the screw and barrel wall have threads with opposite helix, the number of flow channels in the screw increases and the depth of the threads decreases, reaching the extreme value in the middle of the mixing and transferring area and then gradually recovering to the original state, in the process of increasing the number of flow channels in the screw, the number of flow channels in the barrel wall is opposite to the number of upward flow channels in the screw, and the depth of the flow channels is opposite to that of the screw. MC T extruder and ordinary cold feed screw extruder in the essence of the big difference, ordinary screw extruder is the use of friction for plasticization, while the MC T extruder plasticization of rubber is dependent on mechanical action, friction is very small, so the MC T extruder screw length is much shorter than the ordinary extruder screw length, only about 7 times the diameter of the screw. The MC T extruder can be used not only for the production of easy-to-extrude compounds and semi-products such as tread rubber for heavy-duty tires, but also for the production of highly synthetic rubber components that are more difficult to extrude and have a good surface quality and shape of the outer contour edges. Compound", *** extrusion. For example, a 95 mm main MC T extruder and two 50 m m secondary MC T extruder can be composed of "triple-compound" extruder. Because the plasticizing mixing zone of MCT extruder is very short (about 2.5 D), there is no obstacle interference elements in the flow channel, the screw fins and the flow channel have a propulsive effect on the material, the temperature rise of the material in the machine is low, so that the screw rotational speed is high, the production capacity is large, generally MCT extruder in the screw, the head, the bearings and the charging area set up a thermostat port, the temperature rise is the same conditions, the production capacity of MCT extruders is greater than that of pin barrel extruder, and even greater than that of the smooth barrel extruder. Extruder, and even larger than the smooth barrel extruder. By the end of the 1990s, hundreds of MT extruders were in operation around the world, with more than 100 in North America alone for hot and cold retreading of tires, and in conjunction with the CTC-SB I and CTC-SB II extruders/formers, the MT is extruded directly into the carcass, which improves quality, and saves manpower and material resources. Industrial trials have been carried out with the 254 mmm MCT, and the German Institute of Rubber Technology was exploring the use of ultrasound to reduce the viscosity of elastomers at the end of the 1990s in an attempt to address the shortcomings of the MCT extruder with respect to quality, throughput, and energy savings for general industrial rubber. The major rubber extruder manufacturers in Europe and the USA have taken the development of the MCT extruder as a new direction. In recent years, the focus has been on the development of improved MCT extruders. The third generation of MC T extruder MC T D and pin MC T extruder may be the future direction of development, especially the pin MC T extruder both pin screw extruder and MC T extruder advantages, has a broad market prospects and development space.
Multi-compound head development
The extruder head is a key component in determining the final quality of the extruded product. The traditional single-screw extruder head can only be used to extrude a single species of rubber products, the head structure is relatively simple, the head pressure is relatively low, so the technical problems are easy to deal with. With the development of extrusion technology and production needs, the structure and technology of the extruder head with more than a decade ago, compared to a great development, especially in tire production requires the use of different properties of the rubber in the head of the composite extrusion of tread, sidewalls and triangular rubber and other components, for this reason, from the 6 O's by the German T r o e s t e r company and B e r s t o r f f first developed for the extrusion of two kinds of rubber double Composite extruder head, to the 80's and 90's has developed a three-composite and four-composite extruder head, is currently developing a five-composite extruder head, will soon have the product out.
New drive technology and the use of high-power hydraulic motors
With the extrusion process on the performance requirements of the extruder and the advancement of drive technology, the extruder drive system has undergone many changes, the traditional AC motor fixed-speed drive, rectifier motor variable-speed drive and AC motor gearbox step-speed drive at home and abroad in the modern extruder has been eliminated, and replaced by DC motor stepless speed drive. Instead, DC motors are replaced by stepless variable speed drives. DC motors have good torque properties at low speeds and a wide speed range. Domestic DC motors, supported by Siemens technology, have reached the international first-class level and are widely used in various cold-feed extruders. The Swedish company Ha g g l u n d s D r i v e r s A B started to produce high-power hydraulic motors more than 30 years ago, which have been used in the drive systems of high-power equipment such as openers, densifiers, twin-screw extruding and rolling machines and calenders, and have also been used in the drive systems of rubber screw extruders. Due to the relative lag in the development of China's hydraulic technology, there is no high-torque hydraulic motors, imported supporting the price is expensive, so the domestic screw extruder has not been used in this drive technology.
Intelligent control system and networked
Extruders in developed countries have generally used modern electronic and computer control technology, the entire extrusion process parameters such as melt pressure and temperature, the temperature of each section of the body, the main screw and feed screw speed, feeding volume, the ratio of various raw materials, the current and voltage of the motor parameters such as on-line detection, and the use of microcomputer closed-loop control. Some companies have adopted online remote monitoring, diagnosis and control of the extrusion molding line network control. This is to ensure the stability of the process conditions, improve product accuracy are extremely favorable. With the composite extruder, its mechanical properties will inevitably be more complex, with the matching control system is also complex, the control precision is also higher. Therefore, how to design a suitable control system to ensure its economic, safe and reliable operation, and not become obsolete or transitional products in a short period of time, is a problem that we must consider the engineering designers. In the multi-compound extruder control, bus technology, network structure is simple, stable technical performance, not only greatly reduces the amount of wiring, easy to install and maintenance, and greatly enhance the flexibility and reliability of the system, in order to ensure that the system is advanced at the same time, but also achieved good socio-economic benefits.
Small shrinkage and deformation, high dimensional accuracy, fast extrusion speed of precision
Dense extruder The development of new screw extruder, composite **** extrusion technology continues to mature, the last few years, the rubber industry, driving the rapid development of China's rubber extrusion technology to rapidly improve. Meridian tire composite *** extrusion technology can be called a typical representative of the level of rubber extrusion technology.
Precision extrusion technology to be developed
Extrusion molding is a highly efficient, continuous, low-cost, wide-area processing and molding methods, but people wrongly believe that extrusion molding is a low-precision, low-value-added molding processing methods. With a variety of high-precision products market, such as optical fibers, medical catheters, audio-visual film base, photographic film base, projection film as a representative of a series of high-precision products market demand is increasing day by day, the requirements for precision extrusion molding equipment and technology is also increasing. For some special processing and molding, such as the processing of some dangerous and toxic materials, reaction extrusion process requires strict control of temperature, pressure, material residence time and its distribution and other process parameters, as well as the reaction of the material and the outside world heat transfer, etc., these with ordinary extruders often can not be able to do, precision extrusion molding machine for a variety of complex reaction extrusion process provides the necessary equipment conditions. At present, there is still a big gap between domestic manufacturers and the world's advanced level in terms of high-speed, precision equipment. Experts believe that high-yield extrusion equipment, both in terms of the actual level, and the processing level with the foreign advanced level there is a gap of 15-2O years. In real-time monitoring of process parameters and product parameters, as well as the use of advanced control technology, there is also a big gap. Advanced high-precision online testing instruments are mainly dependent on imports, only a few domestic products, and the gap with foreign products in more than 10 years. Overall, China's precision extrusion molding equipment is still in its infancy, there is much room for development.
Modularity and specialization of extruder design
"Modular" production can be adapted to the special requirements of different users, shorten the research and development cycle of new products, and strive for a larger share of the market; and "specialized" production can be extrusion molding equipment of various systems and modular components
[Edit]Conclusion
Since the introduction of pin type cold feed extrusion technology, domestic and foreign extruder manufacturers are still exploring new extrusion technology. But so far, whether it is MC TD and gear pump extrusion technology, or other extrusion technology, although they all have some advantages, but in terms of increased production, lower rubber and reduce energy consumption is not advantageous, on the contrary, due to the complexity of the structure, maintenance difficulties, difficult to be accepted by the user, and therefore does not have the advantage of scale in practical use. In the future, pin-fed cold feed extrusion will continue to lead the field of extrusion technology. At the same time, China's compound extrusion technology is becoming more and more perfect, can fully meet the various needs of different users.
[Editorial]Literature
[ 1 ] He Min. The latest development of tire component extrusion technology. Modern Rubber Technology [ J ] , 2 0 0 2 , 2 8 ( 4 ) : 4 8- 51. [ 2 ] Zhao Guangxian. Development trend of rubber extrusion equipment and process [ J ]. Rubber Industry , 2 0 0 2 , 4 9 ( 7 ) : 4 3 4-4 3 7 . [ 3 ] Su Heping, et al. Technical Characterization and Research Progress of Multi-Flow Channel Transfer Mixed Screw Rubber Extruder. Journal of Inner Mongolia University for Nationalities (Natural Science Edition) [R], 2005, 20(2): 1 7 6-1 7 9 . [ 4 ] Zhu Xiangzhe, et al. Numerical study on the performance comparison of multi-screw extruders. Proceedings of PPTS 2005 Plastics Processing Technology Summit [C]. 1 8 2-1 8 5 , [ 5 ] Han Fucheng. Overview of the development of extruder in China. Rubber and Plastic Technology and Equipment [ J ] , 2 0 0 4 , 3 0 ( 4 ) : 1 9-2 1 . [ 6 ] Yang Shungen. Review of the development of rubber extrusion technology. World Rubber Industry [ J ] , 2 0 0 5 , 3 2 ( 1 1 ) : 3 6-3 9 . [ 7 ] Yuan Jingpeng, et al. Technical progress and development of rubber extrusion equipment. Rubber and Plastic Technology and Installation [ J ] , 2 0 0 6 , 3 2 ( 2 ) : 1 1-1 5 .
[edit]Rubber machinery
is used to manufacture tires and other rubber products machinery, including general rubber machinery, tire machinery and other rubber products machinery three categories. General rubber machinery is the preparation of rubber or semi-finished machinery, including raw material processing machinery, rubber refining machine, extruder, calender, cord canvas pretreatment device and cutting machine. Rubber refining machine is divided into two categories of open and closed type. Open type rubber refining machine is mainly used for rubber hot refining, pressing, breaking rubber, plasticizing and mixing, open type rubber refining machine in 1826 began to be used for production, its structure is relatively simple, modern still commonly used; closed type rubber refining machine is mainly used for rubber plasticizing and mixing, it is more than the open type refining machine more than a refining chamber. Since the invention of the oval rotor closed refiner in 1916, closed refiner in the rubber industry, the rapid development of closed refiners, and later appeared in other forms of rotor closed refiners. Modern closed refiners have a refining cycle of 2.5 to 3 minutes, and the maximum capacity of the refining chamber is 650 liters. Extruder is a rubber machine used to extrude tread, inner tube, hose and all kinds of rubber profiles, it is also used to cover cables and wire products and so on. Common is the screw extruder, it is working, the rubber material with the help of extrusion screw rotation in the barrel stirring, mixing, plasticizing and compression, and then to the head direction, and finally from the mouth type extrusion of a certain shape of the product. Calendering machine is mainly used for cord canvas gluing or rubbing, adhesive pressing, laminating pressing and embossing. The first calender was made in 1857 and used in production, and has been continuously improved since then. Especially since the 1950s, the development of the plastics industry has strongly contributed to the improvement of high-precision, high-speed calendering machine. Tire machinery, including tire molding machine, tire wire ring machinery, tire curing machine, bladder curing machine, cushion belt curing machine, inner tube jointing machine and inner tube vulcanizing machine, as well as force car tire machinery, tire retreading machinery and recycled rubber production machinery. More than 60% of the world's rubber is used in the manufacture of tires, so tire machinery in the rubber machinery occupies an important position. Tire molding machine is mainly used to hang rubber cord fabric, steel wire bead, tread and other parts of the paste processing into the tire blank. According to the different uses can be divided into ordinary tire molding machine and radial tire molding machine two categories. By a molding machine to complete the whole process of radial tire molding, known as a molding method; carcass with a modified ordinary tire molding machine production, and then in the radial tire molding machine, known as two-stage molding method. Tire sizing curing machine is a machine used to vulcanize the outer tires of pneumatic tires for automobiles, construction vehicles, tractors, and airplanes, etc. This machine appeared in the 1940s. In the shaping vulcanizing machine can be completed tire loading, shaping, vulcanization, tire unloading and post-inflatable cooling and other operations, the temperature of superheated water in the capsule, pressure and steam chamber temperature can be measured, recorded and controlled, the entire production process can be carried out automatically. Other rubber products machinery is the production of adhesive tapes, hoses, rubber shoes, model products, rubber paste and latex products used in machinery. At present, the world's top 32 of Japan's Kobe Steel, the Netherlands VMI, Taiwan's Jingyuan and East Yuk Hydraulic, etc. in mainland China to open joint ventures or wholly owned enterprises. 32 outside of China's three-funded type of rubber machine enterprises also have more than 10, such as Shanghai Sigma Weili, Anhui Granite, Shenzhen Jiaxin Electronics Technology, Qingdao, Xuguang and Yadong, Guilin Galaxy, Longxiang Jian Yang, Guangdong Huada, Shaoxing Jingcheng, etc., the vast majority of which for the small specialized factories. In addition, there are Slovakia's Matador and Qingdao University soft control to implement technical cooperation, joint development of radial tire calendering, extrusion, cutting and molding devices. Canada's RMS and Dalian Bingshan Rubber and Plastic two cooperative production of three composite extrusion line, Japan's Ishikawajima Harima Heavy Industries and Dalian Bingshan Rubber and Plastic *** with the cooperative production of steel cord calender. The United States Ferrer and Qingdao University soft control joint distribution and assembly and maintenance of the refiner. 2006 Qingdao Global Group and India L & amp; T company *** with the establishment of a joint venture funded by Larsen & Toubro (Qingdao) Rubber Machinery Co. In 1995, Japan's Kobe Steel has come to China one after another to settle, carried out a variety of forms of production and technology, capital and marketing cooperation business. Most of these enterprises are developing very quickly, and have achieved results worthy of pride. Such as Shanghai Jingyuan machinery sales have exceeded the headquarters of Taiwan enterprises, crowded into the world's 13th, Yantai Fei Mai (VMI) machinery sales have accounted for more than 1/4 of the total amount of Dutch VMI. Hunan Yishen 80% of the products exported to become Japan's Kobe Steel's main overseas rubber machine enterprises. Ningbo Dongyu put into production, so that the Taiwan Dongyu hydraulic more strengthened the flat trigger vulcanizing machine in Asia's premier position. Slovakia's Matador and Qingdao University after the cooperation of soft control, all-steel tire molding machine sales in China increased dramatically, jumped to become the most active enterprises in Central Europe, in 2006 into the world's rubber machine No. 22. In addition, the world's top 10 rubber machine such as Germany's Krupp, Belstow, VMI, Mitsubishi Heavy Industries and other ministries in China have resident offices, 32 outside of Matsubishi Manufacturing, Nakata Zokei, etc. also followed. Taishige and Microelectronics have also set up corporate companies. China is the world's leading producer of rubber machinery, rubber machinery is the world's fastest growing region, is becoming the center of the world's rubber machinery.