Classification of rubber extruders
1. Plunger rubber extruder
The plunger rubber extruder originated in the 18th century. The manual piston extruder manufactured by Joseph Bramah of England in 1795 for the manufacture of seamless lead pipes is considered to be the world's first extruder. Since then, in the first 50 years of the 19th century,
Extruders are basically only used in the production of lead pipes, macaroni and other food processing, brick making and ceramics industries.
2, screw type rubber extruder
The rubber extruder that appeared in 1870 was a hot feed extruder. The rubber compound that it feeds must be hot-smelted, and the feed is uniform, stable, and constant, and the material temperature is maintained at 50 to 70 °C. The screw is short, the thread groove is deep, and the homogenization effect is not ideal.
Since the 1970s. At one time, the aspect ratio became smaller. Since the hot feed extruder can be continuously extruded, the operation is simple, the production efficiency is high, and the shape of the extruded product is stable, the hot feed extruder is still used in the production process of many products.
Used in the production of tires for the extrusion of various treads, various types of rubber and for the extrusion of rubber and rubber in the production of hoses, cables and other rubber products.
3. Ordinary rubber extruder
Cold feed extruders appeared in the 1940s, and were popularized and popularized in the 1960s, and became the mainstream of development in the 1980s. Until the early 1990s. In Europe and the United States, the products produced by cold feed extruders have accounted for 95% of the total production. There are separate screw extruders.
A baffle screw extruder, a cavity screw extruder, a transfer type kneading extruder, a pin screw extruder, a multi-channel transfer mixing screw (MCT) extruder, and the like.
4, cold feed type rubber extruder
The emergence of a cold feed venting extruder was derived from the design of the vacuum extruder screw proposed by Bernhatd in 1956. The screw used in the screw can be divided into a common cold discharge screw and a strong shear cold discharge screw according to the flow state in the narrow compression section of the rubber.
The screw of the cold feed venting extruder is divided into a feeding section, a compression section/throttle section, an exhaust section and an extrusion section. The throttling equidistant isobaric thread is used in the throttling section, which enables the rubber to obtain a high shear and stable conveying process, and also improves the exhaust effect.
5, pin type rubber extruder
In the continuous exploration of extrusion technology, the research of pin technology began in the late 1960s and early 1990s. The pin was inserted radially into the screw thread groove from the circumferential direction of the barrel to cut the flowing rubber. And stirring.
The compound turns into a melt and flows in the screw thread at a low shear rate, gradually forming a continuous viscous fluid, which breaks down the laminar flow and agglomeration of the rubber during the extrusion process, breaking the rubber block and reaching The rubber compound has good plasticization, low glue temperature and energy saving effect, which simplifies the production process.
6, composite rubber extruder
In the rubber industry production, the composite extruder is mainly used for the extrusion of tire composite tread, automotive sealant strip, color force tire tread, hose composite and plastic-plastic composite extrusion, and multi-layer coextrusion of rubber sheet. The compound extrusion production process is an advanced technology in the rubber industry production.