PAST AND FUTURE OF EXTRUDER

I. The Definition of Extruder

    Extruder is also known as plastic film molding processing equipment. It is a kind of plastic processing machinery. Its main function is to mix and process plastic fragments or granules of different compositions in a certain proportion, and after a series of processes, finally form plastic sheet or film form products, in order to be reprocessed into a variety of stereotyped plastic products. Plastic extruders can be divided into single-screw, twin-screw and multi-screw extruders according to the number of screws.

Ⅱ. The Basic Introduction of The Extruder

    In the plastic machinery, plastic extruder is usually referred to as extruder. Plastic extruder can be basically categorized as twin-screw extruder, single-screw extruder, multi-screw extruder and screwless extruder. Screw extruder is relying on the pressure and shear force generated by the screw rotation, can make the material can be fully plasticized as well as uniform mixing, through the mouth molding. Screw is the heart of the extruder, is the key component of the extruder, screw performance is good or bad, determines an extruder's productivity, plasticization, filler dispersion, melt temperature, power consumption, etc., which can directly affect the scope of application of the extruder and production efficiency. Through the rotation of the screw on the plastic to produce the role of plastic in the machine can occur in the brief movement, pressurization and from which to obtain part of the heat, plastic in the barrel in the process of moving mixed and plasticized, viscous flow state of the melt in the flow through the mouth of the die, the desired shape and molding. At present, China's single-screw extruder is the most widely used, suitable for general material extrusion processing.

Ⅲ. The Characteristics of Extruder Products

    The energy saving of the extruder can be divided into two parts: one is the power part and the other is the heating part.

    Power part of the energy saving: most of the use of frequency converter, energy saving is through the saving of the motor's residual energy consumption, for example, the actual power of the motor is 50Hz, and you actually only need 30Hz in production is enough to produce, those excess energy consumption will be wasted, the frequency converter is to change the power output of the motor to achieve the effect of energy saving.

    Heating part of the energy-saving: heating part of the energy-saving mostly electromagnetic heaters are used to save energy, the energy saving rate is about 30% to 70% of the old resistance circle.

Working Process

    Plastic material enters into the extruder from the hopper, and is transported forward by the rotation of the screw. During the forward movement, the material is heated by the barrel, and the shear and compression brought by the screw makes the material melt, thus realizing the change among the three states of glassy state, high elasticity state, and viscous flow state.

    Under pressure, the material in the viscous flow state passes through the mouth mold with a certain shape, and then becomes a continuous body with a cross-section similar to the shape of the mouth according to the mouth mold. Then, it is cooled and shaped to form a glassy state, and the desired processed part is obtained.

Ⅳ. China Extruder Industry Technology

Number of Industry Patent Applications

    Statistics show that in April 2024, from the State Intellectual Property Office patent search and system search keyword "extruder", resulting in the number of China's extruder-related patent applications in April 2018-2024 is shown in the chart below. Among them, the number of patent applications related to extruders in China in 2023 was 1512.

Chart: Number of patent applications related to extruders in China from April 2018 to 2024 April

Number of Industry Patent Disclosures

    Statistics show that in April 2024, from the State Intellectual Property Office patent search and system search keyword "extruder", resulting in the number of China's extruder-related patent disclosure from 2018 to April 2024 is shown in the chart below. Among them, in 2023, China's extruder-related patent disclosure number is 2141, as of April 2024 China's extruder-related patent disclosure number is 20820 total.

Chart: Number of Patent Publications Related to Extruders in China, 2018-2024 April 

Industry Status

    According to the "Extruder Industry Market Depth Research and Investment Forecast Report 2023-2028", extruders are widely used in multiple scenarios such as thermoplastics, profiles, modified pelletizing, pipe and sheet manufacturing, covering electronics, construction, automotive, and furniture, with their advantages of continuous production capacity, good versatility, lower cost, mature production process, and high production efficiency, and covering They are widely used in many scenarios, including electronics, construction, automotive, and furniture manufacturing, covering many end-use applications. With the rapid growth of the domestic construction and automotive industries, the market demand for extruders is growing, showing a broad prospect.

    Currently, in the background of many enterprises' efforts, the domestic production of extruders has ranked among the world's full list, and China has become one of the world's major producers of extruders, and many enterprises, such as Jinwei Machinery, Tongjia Machinery, Jinhu Extruder, are deeply cultivating their business in this field. According to the data, from January to September 2022, the export quantity and value of domestic extruders far exceeded imports, showing China's export competitiveness in the global extruder market.

    However, due to the late start of the industry and relatively weak technical research and development capabilities, China's extruder products are mainly concentrated in the low-end market, with low profit margins. The high-end market is still dependent on imports, mainly occupied by international leading enterprises such as Germany Kobelco, Germany KraussMaffei, Japan Nippon Steel Plastics and so on. This shows that, despite the huge market potential, the degree of localization still needs to be improved.

Ⅴ.  Future Trends

◆ Labor and material consumption, mainly in terms of minimizing the time to change products, as far as possible during the production process as well as automatically;

◆ Increased productivity through the plasticizing capacity of the equipment, increased gear torque, and further screw L/D ratios;

◆ In extrusion molding, cooling has been limiting productivity improvements and cooling limitations must be broken;

◆ Continuous application of inductive measurement technology and artificial intelligence technology in the control system of the extrusion line, so that the stability of plate and sheet production and the products are further improved.