With Extruder application areas continue to expand and technology With continuous improvement, the market for the extruder market has maintained a certain upward trend, but the sharp drop in the price of domestically produced extruders has become a reality. The crude production and vicious price wars of some manufacturers have affected the overall image and market competitiveness of domestic plastic machines, and also hindered the development of plastics processing industry.
Experts believe that the future market of extrusion machine mainframes and production lines will develop in the direction of high technology content and lower prices. From the point of view of molding equipment, domestically produced main engines are mainly conical twin-screw extruders and single-screw extruders. The technology is relatively mature and the market sales are large. However, the general specifications of such products have been oversupplied and can only be maintained. The peak period of the market is about 50%~60%. The future focus of the domestic mainframe market should be to develop parallel counter-rotating twin-screw extruders to meet the molding needs of large extrusions. Parallel co-rotating twin-screw extruders should be developed in the direction of the sixth and seventh generations of high speed and large aspect ratio. The single-screw extruder is developed in the direction of super large, ultra-miniature, large aspect ratio, high output, good exhaust, etc., and the screw barrel structure adapted to special processing needs has become the focus of everyone's development. . In fact, the single-screw extruder is a low-energy, low-cost model. As long as the technology is right and the structure is reasonable, the performance of the twin-screw extruder can also be achieved. According to reports, the plastic extrusion machine currently used in the United States is dominated by a single screw. High-tech single-screw extruders are gradually replacing twin-screw extruders in certain areas.
Special single-screw extruder
With the development of the market in recent years, different manufacturers at home and abroad Various single-screw extruders with special structures have been introduced to meet special market needs. The following is a special introduction to the development of several special extruders in China.
The successful development of portable extruders
Beijing University of Chemical Technology successfully developed a super-fast micro-portable Single screw extruder.
The machine screw diameter is only 12mm, the total weight of the machine is less than 2.5kg; the screw working speed is 800~1200rpm, which can achieve continuous or intermittent operation. In addition, due to the high wall slip and the extremely easy bridging characteristics of the processed materials, it is equipped with a specially designed forced feeding device. Because the extruder is portable, a special multi-channel exhaust device is designed to fully guarantee the gas. Discharge. In addition, the machine also has a deep groove and large pitch, two drive modes (electric, pneumatic), the machine is easy to clean, maintenance, maintenance and so on.
The machine is initially designed for processing a special low-density, low-viscosity material and can be used for extrusion processing of various low-viscosity materials, such as hot melt adhesives, low Processing of molecular weight resins, various paraffin waxes, fuels, pigments, cosmetics, and the like.
The research and development of ultra-micro-extrusion machines has many difficulties that are unimaginable in the design and processing of general equipment. According to reports, the key to the development of this equipment lies in the micro-extrusion machine. The problems of feeding, exhausting, and achieving low temperature extrusion delivery are solved.
The commercialization of the grinding disc extruder
The development of the grinding disc extrusion machine has been completed by many domestic manufacturers. Realize the commercial production of the grinding disc extruder.
It is difficult to use high-fill materials with ordinary single-screw or twin-screw extruders. When the twin-screw extruder is used for glass fiber reinforced compounding, if the glass fiber content exceeds 45%, the processing becomes quite difficult. When processing magnetic materials, the amount of magnetic powder is usually as high as 60% to 70%, and sometimes even more than 90%. It is almost impossible to process and granulate magnetic materials with a common extruder.
Some domestic manufacturers and research institutes have carefully developed independent design of the disc extrusion machine according to the needs of domestic magnetic materials and other high-fill materials. Typical examples are Beijing Fengji and Beijing University of Chemical Technology.
The disc extrusion machine can adjust the disc combination to adapt to different high-fill materials, such as glass fiber reinforced, magnetic plastic, conductive materials, new ceramics and other materials.
In order to meet the needs of high-filling materials, Beijing University of Chemical Technology is also conducting experimental research on direct extrusion molding of disc extrusion machines, and applied to a variety of composite materials. The extrusion molding process was successful.
Reciprocating screw extruder series
Reciprocating screw extruder in the domestic market in previous years For a while, it has become a symbolic product for different manufacturers to display technical strength. In particular, various twin-screw extruder manufacturers have introduced reciprocating screw extruders. Due to the unusually hot market in the twin-screw market, the market for reciprocating screw extruders is relatively flat, and the manufacturers of extrusion engines are mainly based on twin-screw extruders.
The reciprocating mobile single-screw extruder is characterized by a high filling process for different materials. When used for glass fiber reinforced materials processing, the glass fiber can be added in an amount of more than 50%, which is especially suitable for the processing of high-fill materials, and has a very broad market prospect. Due to its unique reciprocating structure, it can not meet the requirements of pressure building, so it is generally not suitable for direct extrusion molding of products. Usually used for forming processing, it also needs to be equipped with a dedicated forming extruder.
The above-mentioned several single-screw extruders can be said to be representative products in the current Chinese market. However, despite the rapid development of the Chinese extruder market and the launch of many new models, we cannot ignore the large gap between China's extruder technology and developed regions. For example, in the field of ultra-large and micro-devices, it still lags behind the international advanced level. Only by stepping up efforts, domestic enterprises can win opportunities in the fierce market competition, and truly develop from a large plastic machine country to a plastic machine power.
