Brief Description:A parallel twin-screw extruder is an automatic feeding machine that has a wide range of applications and can process various materials. Extrusion molding is a process where, under certain conditions, a plastic material with a certain degree of plasticity is continuously pressed through a die to form a product with a specific cross-sectional shape.
Twin-screw extruderIntroduction:
One of the types of plastic machinery, originating in the 18th century. According to the angle between the material flow direction at the head and the centerline of the screw, the head can be divided into right-angle heads and oblique-angle heads, etc. It relies on the pressure and shear force generated by the rotation of the screw, allowing the material to be fully plasticized and uniformly mixed, and then shaped through a die.
All technological advancements are mainly focused on the transmission and extrusion sections. Only by combining the core hardware technology with the core software technology can a cost-effective and competitive modern co-rotating twin-screw extrusion equipment be created. It is primarily composed of two major parts: the transmission section and the extrusion section.
1. The transmission part provides torque for the screw, and strong torque output is the guarantee of efficient operation; the extrusion part mainly consists of the barrel, screw elements, and core shaft, where the material undergoes plasticization, mixing, and extrusion.
All of its technological advancements are also concentrated in these two parts, serving as the hallmark of updates and iterations.
Compared to other models, one of its major features is the difference in the transmission system. It requires evenly distributing power to two screws within a confined space, which is known as torque distribution technology. Different torque distribution technologies determine the load capacity of the gearbox and even directly affect the lifespan and performance of the entire machine.
The extrusion section is mainly composed of the barrel, screw elements, and core shaft, serving as the functional area for plasticization and mixing. The key performance indicators for evaluating the extrusion section include screw clearance, volumetric efficiency, rotational speed, core shaft strength, and the lifespan of the screw elements.
The development trend is towards smaller screw clearances, larger volumetric ratios, higher rotational speeds, stronger core shafts, and highly wear-resistant screw elements. While achieving high efficiency and large output, the overall service life of the machine can still be further improved, with stable product quality.
After a certain period of operation, if the barrel and screw components are severely worn, issues such as unstable operation, decreased output, and reduced physical properties of the extruded material will occur. Especially when the working clearance between the barrel and the screw exceeds the standard specified range, one must be cautious of phenomena like backflow of the material due to back pressure, fluctuations in the screw's feeding, and prolonged retention of the molten material inside the barrel, as these phenomena will certainly affect the physical properties of the molded plastic.
This equipment adopts a dual-metal technology with an alloy cladding to repair the barrel and screw, which is a cost-effective process we recommend, especially for the barrels and screws of large-scale plastic injection molding machines and twin-screw extruders. Where conditions permit, we should, as much as possible, use the process of adding a dual-metal alloy protective layer to repair the barrel and screw.
Twin-screw extruder
Widely used in the filling, blending, modification, and reinforcement of rubber and plastics as well as engineering resins, devolatilization treatment of chlorinated polypropylene and super absorbent resins, granulation of toner and magnetic powder, preparation of cable insulation and sheathing materials, low-smoke halogen-free flame-retardant PVC cable materials, and various silane cross-linked materials.
A co-rotating twin-screw extruder is an automatic feeding machinery with a wide range of applications, capable of processing various materials. Extrusion molding is a process where plasticized material is continuously pressed out through a die under certain conditions to form a product with a specific cross-sectional shape. Based on the changes in the material during the extrusion process, the working part of the screw is generally divided into three sections according to their functions: the feeding section, the compression section, and the extrusion section. As the material moves forward along the screw, due to mechanical and thermal effects, its viscosity and plasticity undergo certain changes, transforming it into a viscous fluid.
The typical reduction ratio of this equipment should be between 10:1 and 20:1. The first stage can use either gears or pulleys, but the second stage is better off using gears with the screw positioned at the center of a large gear. For some slow-running machines (such as twin-screw machines for UPVC), there may be three reduction stages, with maximum speeds as low as 30 rpm or lower (reduction ratios up to 60:1). On the other hand, some very long twin screws used for mixing can operate at 600 rpm or faster, thus requiring a very low reduction ratio and more intensive cooling.
Extrudable plastics are thermoplastics, which melt when heated and solidify again upon cooling. Therefore, heat is required during the extrusion process to ensure that the plastic reaches its melting temperature. The heat to melt the plastic can come from several sources. Initially, preheating of the feed using a floor scale and heating of the barrel/die heaters may play a role and are particularly important at startup. Additionally, the energy input from the motor, i.e., the frictional heat generated inside the barrel as the motor overcomes the resistance of the viscous melt to turn the screw, is also an important heat source for all plastics, except for small systems, low-speed screws, high-melt-temperature plastics, and extrusion coating applications.
Nanjing Xintuo Intelligent Equipment Co., Ltd. was established on May 29, 2020, with Zhou Xianting as the legal representative. The registered capital is 10 million RMB, and the unified social credit code is 91320113MA21LF2H92. The company is located in the Baima Town Industrial Concentration Zone, Lishui District, Nanjing City. It belongs to the other manufacturing industry. Its business scope includes: Permitted projects: import and export of goods; import and export of technology (projects that require approval by relevant departments can only be carried out after obtaining such approval, specific business items are subject to the approval results). General projects: sales of intelligent material handling equipment; research and development of machinery and equipment; general equipment manufacturing (excluding special equipment manufacturing); specialized equipment manufacturing (excluding licensed specialized equipment manufacturing); sales of metal products; wholesale of electronic components; sales of instruments and meters; sales of artificial intelligence hardware; processing and sales of mechanical parts and components; general component manufacturing; sales of plastic products; production and sales of Class I medical devices; sales of Class II medical devices; sales of health supplies and disposable medical supplies; sales of special labor protective equipment; technical services, technical development, technical consultation, technical exchange, technology transfer, and technology promotion (except for projects that require approval, activities can be conducted independently according to the business license). The current operating status of Nanjing Xintuo Intelligent Equipment Co., Ltd. is active (in operation, open, registered).
