Twin screw extruder technology development trend

High speed, high efficiency and energy saving have always been the main theme of the continuous improvement of international plastic machinery in recent years. High speed and high output allow investors to get high returns with low investment. However, the high speed of the screw speed brings a series of extremely difficult problems to be solved: if the residence time of the material in the screw is short, it is easy to cause uneven mixing of the material and plasticization; excessive shear may cause sudden temperature rise and thermal decomposition of the material; Extrusion stability problems; need high-performance auxiliary machines and precision control systems to match; screw and barrel wear problems and design of reduction gearbox design. Therefore, providing solutions to the problems that may arise from high-speedization is one of the important directions for the technological innovation of twin-screw suppliers.

The new twin-screw extruder, the ZEUTX series from Berstorff, Germany, differs in its performance in terms of its excellent screw diameter/productivity ratio. The screw design has a maximum speed of 1200 rpm, a large torque, and an extrusion capacity of between 100 and 3,500 kg/h. The process of mixing, reacting, and venting materials can be performed simultaneously. The barrel and screw adopt modular design, which can meet various special process requirements, and has excellent processing flexibility. It is also equipped with ZSEF type side feeder, which can achieve high solid particle conveying rate. The pelletizer can be used. Match different yields and material processing.

In order to meet the needs of high speed and high production, the extruder has many improvements. Equipped with a barrel heater, the temperature rise of the extruder can be completed in a very short time, the maximum heating temperature can reach 450 ° C; the cooling flow channel design truly achieves reverse flow cooling, optimizes the cooling system; Tightening device", the time to replace the barrel can be faster than the traditional bolted type; the barrel uses a patented induction hardening process, which gives excellent wear resistance, thus eliminating the need for expensive wear-resistant bushings; In addition, it is equipped with the company's advanced process control system.

Multifunctional

In terms of function, the twin-screw extruder is no longer limited to the molding and mixing of polymer materials, and its use has expanded to include food, feed, explosives, building materials, packaging, pulp and ceramics. In addition, the "one-step direct extrusion process" which combines the kneading granulation and the extrusion molding process into one is also very attractive.

WPC (Wood Composites) is used in outdoor applications, such as deck decking and fences, for a long time, especially in the United States. The Cincinnati company has developed the Fiberex series and continues to optimize it for WPC molding. The fourth-generation Fiberex, with an extended, wear-resistant processing unit, can fully meet the different requirements of customers and achieve high output. At last year's NPE show, Cincinnati demonstrated the entire Fiberex pilot line with a Fiberex T58 extrusion machine with a capacity of 200 kg/h (440 lb/h) for forming 75% of the molding process. Wood powder filled PP compound. The production line manufactures a profile for the furniture industry with a wall thickness of 2.5 mm and an extrusion setting speed of 2 m/min.

Large size and precision

Achieving large-scale extrusion molding equipment can reduce production costs, especially for large twin-screw granulators, blown film units, and pipe groups. In China, large-scale equipment has long relied on imports, and research on the localization of large-scale twin-screw granulators is underway. Precision can increase the gold content of the product, such as multi-layer composite co-extruded film. As an important means to achieve precision extrusion, the melt gear pump should be intensively developed and researched.


Post time: Jul-13-2021

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