Laboratory small internal mixer small open mill

Introduction to Common Rubber Machinery and Equipment -- Rubber Production Equipment
It is a machine for preparing rubber or semi-finished products, including raw material processing machinery, rubber mixing machine, extruder, calender, curtain canvas pretreatment device and cutting machine.
Rubber mixing machine:
Rubber mixing machine is divided into open type and closed type.
Open rubber mixer (open mill):
Double roller open rubber mixing machine was used in production since 1826. Its structure is relatively simple, and it is still widely used in modern times.  
It is mainly used for hot refining, pressing, breaking, plasticizing and mixing of rubber. It is composed of roller, roller bearing, roller pitch adjustment device, emergency brake device, frame, base, transmission device, heating and cooling system, etc.
The working principle of the open type rubber mixing machine is: raw rubber or rubber material is pulled into the roll gap between two opposite rotating rollers at different speeds by friction, and the plasticity is increased by strong shearing and extrusion.
Closed rubber mixer: (internal mixer)
In 1916, the elliptical rotor closed rubber mixing machine was invented
It is mainly used for plasticizing and mixing of rubber. It has an internal mixing room more than the open rubber mixing machine. After the raw rubber and mixing agent are loaded into the internal mixing chamber from the feeding hopper, the material gate is closed, the upper top bolt of the pressing device is pressed, and the two rotors in the internal mixing chamber rotate at different or the same speed. The rubber loaded between the rotors and between the rotor and the internal mixing chamber is subject to continuous stirring, rolling and strong kneading, resulting in oxidation and chain breaking, which increases the plasticity.
At the same time, the rubber is dispersed and uniformly mixed due to shearing, so as to achieve the purpose of rubber mixing. For one hundred years, the closed rubber mixing machine has developed rapidly in the rubber industry. Later, there were other forms of closed rubber mixing machines with rotors. The mixing cycle of the modern airtight rubber mixing machine is 2.5~3 minutes, and the capacity of the internal mixing room is 650 liters.
Extruder:
Rubber machinery is used for extruding tread, inner tube, rubber tube and various rubber strips, and also for covering cable and wire products. Screw extruders are common. Its working principle is: the rubber material is stirred, mixed, plasticized and compressed in the barrel by virtue of the rotation of the extrusion screw, and then moves towards the die, finally extruding a certain shape of product from the die. According to the needs of the product, multiple machines can be used for compound extrusion of various rubber materials. Screw extruder is divided into hot feed and cold feed. The hot feed extruder usually feeds the strips preheated by the open rubber mixer. The rubber fed by the cold feed extruder is not subject to hot refining, so the hot refining equipment can be omitted.
Calendering:
It is mainly used for gluing or rubbing of curtain canvas, pressing, laminating and embossing of rubber materials. The main working part of the calender is the roller, and the number of rollers is usually 3 or more. When the rubber with a certain temperature and plasticity is fed into the gap of the opposite rotating roller, it is strongly squeezed and extended under the action of friction, forming the required product. The yi calender was made in 1857 and used in production, and has been continuously improved since then. Especially since the 1950s, the development of plastic industry has effectively promoted the improvement of high-precision and high-speed calenders. In order to obtain calendered products with uniform thickness, new calenders are generally equipped with roller deflection compensation devices. The thickness of rolled semi-finished products is measured with special equipment. Some calenders are also equipped with automatic thickness adjustment systems controlled by electronic computers.
Characteristics of internal mixer mixing
Put the plastic rubber and various ingredients into the high temperature and high pressure internal refining chamber. After a short time of kneading, dispersion and mixing, the rubber mix required by the process can be obtained.
The mixing process is as follows: lifting the top bolt → feeding → falling the top bolt → pressurized mixing → end of mixing → turning → discharging → turning back.