Metal Extrusion Machine Basic Classification

Metal Extrusion Machine Basic classification

Screw extruder is dependent on the rotation of the screw pressure and shear force, can make the material can be fully plasticized and evenly mixed, through the die molding.

An overview editor

Plastic extruders are also one of the types of plastic machinery. Extruder according to the direction of the head material and the angle of the screw center line, the machine can be divided into right angle head and bevel nose and so on. The head of the shell is usually bolted to the fixed on the fuselage, the head of the mold inside the mold core seat, and then use the nut to be fixed to the nose of the nose port, the core of the core is also equipped with And the center of the mandrel and the mandrel has holes which function to pass through the core. Depending on the type of pressurization, the extrusion process can be divided into two types: continuous extrusion and intermittent extrusion. The former equipment used for the screw extruder, the latter equipment for the plunger extruder. In this screw extruder can be roughly by virtue of the number of screws for the single screw extruder and multi-screw extruder.

The working mechanism of the screw extruder depends on the pressure and shear force generated by the rotation of the screw, which allows the material to be fully plasticized and evenly mixed and molded by die; sometimes it can be done at the same time using an extruder Mixing, plasticizing and forming a series of processes, so as to continuous production. In addition, the working mechanism of the plunger extruder is mainly by the use of plunger pressure, the first plastic material in advance from the die extrusion to achieve the effect of forming. The material in the material cylinder will be returned after the extrusion, until the next round of plastic material is added and the next round of operation is carried out. This production process is discontinuous and the material can not be fully agitated As well as the mixing, in addition to the production of pre-plasticization, so the actual production is usually not often used in this law, can only be applied to the poor mobility or very high viscosity plastic, like nitrocellulose plastic this Plastic products of the molding process.

The plastic extruders can be classified as twin screw extruders, single screw extruders, and rare multi-screw extruders and screwless extruders.

Development History Editor

Extruder originated in the 18th century, Joseph Bramah (England) made in 1795 for the manufacture of seamless lead pipe manual piston press is considered the world's first extruder. Since then, during the first half of the nineteenth century, the extruder was basically only suitable for the production of lead pipes, macaroni and other food processing, brick and ceramic industries. In the development process as a manufacturing method, the first time there is a clear record of R.Brooman in 1845 to apply for the use of extruder production Gotebo Polar wire patent. Gutebo's H. Bewlgy then improved the extruder and used it in 1851 for copper on the first submarine cable between Dover and Calais. In 1879 the British M.Gray made the first patent to use the Archimedes spiral screw extruder. In the next 25 years, the extrusion method was gradually important, and gradually by the electric manipulator extruder quickly replaced the previous manual extruder. In 1935 the German machinery manufacturer Paul Troestar produced an extruder for thermoplastics. In 1939 they developed a plastic extruder into a stage - modern single screw extruder stage.