Views: 45 Author: Site Editor Publish Time: 2022-09-19 Origin: Site
From the perspective of equipment structure, cold-feed extruder generally has a longer body compared with hot-feed extruder, the length-diameter ratio (L/D) is 8-20, and the thread groove is shallower. Due to the long body, multiple functions and low feeding temperature, its power is much larger than that of the hot-feed extruder, which is about 2-4 times that of the hot-feed extruder of the same specification. The power of the cold feed extruder with a diameter of 250ram is 500kw, while the hot feed extruder of the same specification is only 105kw, but the production capacity is lower than that of the hot feed extruder. The appearance of the cold-feed extruder simplifies the production process, and the fed rubber no longer needs to be heated, and the rubber material is fed into the extruder at room temperature to obtain various shapes of rubber embryos. It can completely replace the hot feed extruder, and can save the rubber material hot refining process, simplify the production process, and enable the machine head to establish a higher pressure, which has a certain effect on improving the quality of extruded products, so in some It has been widely used in the production of products.
However, the screw with the main and auxiliary screw thread structure designed to obtain a better plasticizing effect of the rubber compound affects the extrusion output, and requires a large driving power, which limits its use in some production processes. 1.1.4 Main and auxiliary thread cold feeding extruder The main and auxiliary thread cold feeding extruder appeared in 1970. Its main thread is the same as that of the ordinary screw. The secondary thread with the height difference, and the secondary thread changes in the pitch and the height of the thread, and only allows the rubber material to be transported forward through the narrow slit, thus effectively eliminating the "dead zone" of the rubber material in the ordinary screw groove, It strengthens the effect of plasticization and mixing, but the mixing quality of the rubber compound is uneven, and the energy consumption is large.
The follow is the list：
cold feed type
pin type
The emergence of the cold-feed vented extruder originated from the design of the vacuum extruder screw proposed by Bernhatdt in 1956. The screw used in it can be divided into ordinary type cold discharge screw and strong shear type cold discharge screw according to the flow state in the groove of the narrow compression section of the rubber material. The screw of the cold feed exhaust extruder is divided into a feeding section, a compression section, a throttling section, an exhaust section and an extrusion section. The throttling section adopts shallow grooves and equal-distance and equal-depth threads, which can make the rubber material obtain higher shearing and stable conveying process, and also improve the exhaust effect. In a cold-fed screw extruder, room temperature bead is fed to the extruder. Rubber Extruders are also often classified by whether they are used for venting.
In the continuous exploration of extrusion technology, that is, in the late 1960s and early 1990s, the research on pin technology began. The pin is inserted radially into the screw thread groove from the circumferential direction of the barrel to shear the flowing rubber compound. and stir. The rubber material becomes a melt and flows in the screw thread at a low shear rate, gradually forming a continuous viscous fluid, which destroys the laminar flow and agglomeration of the rubber material during the extrusion process, breaks the rubber block, and achieves the The effect of good plasticization, low glue temperature and energy saving simplifies the production process.
The technology was patented in the United States in 1979. The appearance of the pin-type cold-feed extruder has greatly developed and improved the technology of the cold-feed extruder. This kind of extruder not only has a great improvement in the screw structure, but also has a great effect on the plasticizing performance of the rubber compound, the compactness of the extruded product, and the extrusion amount due to the addition of pins on the barrel. It can meet the extrusion requirements of various production processes. At the same time, due to the improved screw structure, the driving power is reduced, and the unit energy consumption is significantly reduced. Because of its good plasticizing performance, low debinding temperature and large extrusion volume, it has been more and more widely used in rubber industrial production.
Seahawk Machinery Rubber machines include rubber extruder, rubber co-extrusion lines, rubber salt bath(LCM) line, rubber and plastic air conditioning insulation tube vulcanization production line, silicone vulcanization production line, rubber hose production line and etc.
