With the continuous expansion of extrusion machine application field and continuous technological advancement, the extrusion machine market still maintains a certain upward momentum. However, a sharp drop in the price of domestically produced extrusion machines has become a reality. The shoddy manufacturing and vicious price wars of some manufacturers have affected the overall image and market competitiveness of domestic presses, and also hindered the development of the plastics processing industry.

Experts believe that the future market for the main machine and production line of the extruder will develop towards high-tech content and lower prices. From the perspective of molding equipment, domestic mainframes are basically conical twin-screw extruders and single-screw extruders. The technology is relatively mature and the market has the largest sales. However, the general specifications of these products have exceeded demand and can only be maintained in the market. About 50%~60% of the peak period. The future focus of the domestic host market should be the development of parallel counter-rotating twin-screw extruders to meet the molding needs of large extrusions. Parallel and co-rotating twin-screw extruders should develop in the direction of the sixth and seventh generations of high speed and large aspect ratio. The single-screw extruder is developing in the direction of super-large, super-micro, large aspect ratio, high output, and good exhaust performance. The screw and barrel structure that meets the needs of special processing has become the focus of everyone's research and development. . In fact, the single-screw extruder is a low-energy, low-cost model. As long as the technology is appropriate and the structure design is reasonable, the efficiency of a twin-screw extruder can also be achieved. According to reports, the plastic extrusion machines currently used in the United States are dominated by single screws. High-tech single-screw extruders are gradually replacing twin-screw extruders in some fields.

Special single screw extruder

With the needs of market development in recent years, different domestic and foreign manufacturers have launched various special structure single screw extruders to meet the special market needs. The following is a special introduction to the domestic research and development progress of several special extruders.

Successfully developed portable extruder

Beijing University of Chemical Technology successfully developed an ultra-high-speed miniature portable single-screw extruder.

The diameter of the screw of the machine is only 12mm, and the total weight of the machine is less than 2.5kg; the working speed of the screw is 800~1200rpm, which can realize continuous or intermittent operation. In addition, because the processed material has the characteristics of high wall slippage and easy bridging, it is equipped with a specially designed forced feeding device; because the extruder is portable operation, a special multi-channel exhaust device is designed to fully ensure the gas的出。 The discharge. In addition, the machine also has the characteristics of deep groove and large pitch, two driving modes (electric and pneumatic), and the whole machine is easy to clean, maintain, and repair.

The machine was originally designed for processing a special low-density and low-viscosity material, and can be used for extrusion processing of various low-viscosity materials, such as hot melt adhesives, low molecular weight resins, various paraffins, fuels, pigments, cosmetics, etc. The processing and shaping.

The research and development of ultra-micro extruder has many unimaginable difficulties in the design and processing of general equipment. According to reports, the key to the development of this equipment is to solve the problems of feeding and exhausting the micro-extruder, and achieving low-temperature extrusion and transportation. .

Commercialization of millstone extruder

Many domestic manufacturers have completed the development of millstone extrusion machines and realized the commercial production of millstone extrusion machines.

It is difficult to process high-filled materials using 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%, processing becomes quite difficult. When processing magnetic materials, the amount of magnetic powder added 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 an ordinary extruder.

Some domestic manufacturers and research institutes have carefully developed independently designed grinding disc extrusion machines according to the needs of domestic magnetic materials and other high-filling materials. Typical examples are Beijing Fengji and Beijing University of Chemical Technology.

The grinding disc extruder can adjust the grinding disc combination to adapt to different high filling materials, such as glass fiber reinforced, magnetic plastic, conductive material, new ceramics and other materials.

In order to meet the needs of extrusion processing of high-filled materials, Beijing University of Chemical Technology is also conducting experimental research on direct extrusion molding with a grinding disc extruder, and the extrusion molding processing test of a variety of composite materials has been successfully applied.

Serialization of reciprocating screw extruder

The reciprocating screw extruder has been booming in the domestic market in the past few years, and it has also become a symbolic product showing the technical strength of different manufacturers. In particular, various twin-screw extruder manufacturers have launched reciprocating screw extruders. As the twin-screw market is extremely hot, the market for reciprocating screw extruders is relatively flat, and the extrusion manufacturers still focus on twin-screw extruders. Recently, Baoying Jinxin Special Plastic Machinery Factory cooperated with Beijing University of Chemical Technology to develop reciprocating single-screw extruders of various specifications, which initially realized the serialization of reciprocating extruders.

It is reported that Baoying Jinxin’s series of products include four specifications, 45, 78, 110 and 140, of which two specifications of 45 and 78 have been successfully developed, and two models of 110 and 140 will be launched soon.

The biggest feature of the reciprocating single screw extruder is to realize high filling processing of different materials. When used in the processing of glass fiber reinforced materials, the added amount of glass fiber can reach more than 50%, which is especially suitable for the processing of high filling materials and has a very broad market prospect. Because of its unique reciprocating structure, it cannot meet the requirements of pressure building well, so it is generally not suitable for direct extrusion molding of products. Usually used for forming processing, also need to be equipped with a dedicated forming extruder.

The several single screw extruders introduced above can be said to be representative products in the current Chinese market. However, despite the rapid development of China's extrusion machine market and many new models have been launched, we cannot ignore that China's extrusion machine technology still has a large gap compared with foreign developed countries. For example, it still lags behind the international advanced level in the field of super large and micro equipment. Only by stepping up their efforts can domestic enterprises win opportunities in the fierce market competition and truly develop from a big country of plastic machinery to a powerful country of plastic machinery.