Rolls can be classified in a variety of ways, and there are many precautions when selecting, the following is a detailed introduction:
Classification of rolls
Classification by use
Open mill roll: mainly used for rubber plasticizing and mixing, through two relatively rotating rolls to extrude, shear and knead the rubber material, so that the rubber material to obtain the required plasticity and uniformity.
Calender roll: used to press the mixed rubber material into film or tape with a certain thickness, width and surface quality, often used in the production of rubber products, such as tires, conveyor belts, etc.
Refining machine roll: It is generally used for further refining and purification of rubber, removing impurities and bubbles in rubber, and improving the quality of rubber.
Classification by material
Metal rolls: including cast iron rolls, cast steel rolls and alloy steel rolls. The metal roll has high strength, good rigidity, can withstand greater pressure and load, and is suitable for rubber processing processes requiring higher hardness and accuracy, such as calendering and forming.
Rubber roll: with rubber as the surface material, has good elasticity, flexibility and wear resistance, can adapt to different shapes and hardness of the rubber material processing, and can reduce the damage to the rubber, often used in rubber mixing, laminating and other processes.
Ceramic roll: has very high hardness, wear resistance and corrosion resistance, high surface finish, can provide good processing accuracy and surface quality, but the cost is high, generally used for special processes that require very high surface quality of rubber products.
Classification by structure
Solid roll: simple structure, strength and rigidity, suitable for general rubber processing technology, can withstand greater pressure and torque.
Hollow roll: Lighter weight, easy to install and operate, and can achieve precise control of roll temperature by passing cooling or heating media into the hollow part, suitable for temperature-sensitive rubber processing processes, such as calendered and formed.
Composite roll: by different materials or different structure of the parts of the combination, for example, the core of the roll using metal materials to provide strength and rigidity, the surface of the rubber or other materials to meet the special requirements of the processing process, this roll can comprehensively use the advantages of various materials to meet the complex rubber processing needs.
Precautions for selecting rolls
Consider processing requirements
Process type: Different rubber processing processes have different requirements for rolls. For example, the mixing process requires the roll to have a strong shearing and stirring capacity in order to fully mix the compound and the compound; The rolling process requires smooth roll surface and high precision to ensure uniform thickness and good surface quality of the rolled film.
Process parameters: including roll speed, linear speed, pressure, temperature and other parameters. These parameters should be selected and adjusted according to the specific rubber processing technology and material characteristics to ensure the stability of the processing process and the consistency of product quality.
Consider rubber material properties
Hardness: The hardness of the rubber material is different, and the hardness requirements of the roll are also different. Generally speaking, rubber materials with higher hardness need to use rollers with higher hardness to ensure sufficient pressure transfer and processing effect; The rubber material with low hardness can choose a roll with relatively low hardness to avoid excessive damage to the rubber material.
Viscosity: The viscous rubber material is easy to adhere to the surface of the roll, affecting the processing quality and efficiency. Therefore, for rubber with large viscosity, rolls with good surface finish and anti-viscosity should be selected, or corresponding measures should be taken, such as coating anti-stick agents on the roll surface.
Pay attention to roll quality and performance
Material quality: The material quality of the roll directly affects its service life and processing effect. Materials with reliable quality and stable performance should be selected, such as high-quality metal materials or rubber materials, and suppliers should be required to provide quality certificates and test reports of materials.
Processing accuracy: High-precision rolls can ensure the dimensional accuracy and surface quality of rubber products. When selecting a roll, it is necessary to pay attention to its processing accuracy indicators, such as the roundness, cylindricity, surface roughness, etc., to ensure that it meets the requirements of rubber processing technology.
Surface treatment: The surface treatment of the roll has an important impact on its performance and service life. Common surface treatment methods include chromium plating, hard chromium plating, nitriding, nickel plating, etc. Different surface treatment methods can improve the hardness, wear resistance, corrosion resistance and surface finish of the roll.
Combine equipment and production conditions
Equipment matching: The selected roll should be matched with the rubber processing equipment used, including the size of the roll, installation method, transmission method, etc. Ensure that the roll is properly installed on the equipment and works in coordination with other parts of the equipment to ensure the smooth running of the entire process.
Production scale: Production scale is also one of the important factors to consider when selecting rolls. For large-scale production, rolls with high production efficiency and good durability should be selected to meet the requirements of continuity and stability of production; For small-scale production or experimental production, some small rolls with simple structure can be selected to reduce equipment investment costs.
Maintenance: When selecting rolls, the difficulty and cost of maintenance should be considered. Choosing a roll with simple structure and easy disassembly and maintenance can reduce the difficulty and cost of maintenance and improve the utilization rate of equipment. At the same time, it is necessary to understand the maintenance requirements of the roll, such as regular lubrication, cleaning, replacement of wearing parts, etc., to extend the service life of the roll.