What Is a Rubber Roller?
A rubber roller is a bar material made of metal, plastic, or other material with a core coated with rubber or other elastic material and polished.
Taking advantage of the unique characteristics of rubber coated on the surface, rubber rolls are used to convey a wide variety of materials. Steel is generally used for the roller core, but aluminum, stainless steel, and plastic are also used depending on the conditions of use.
In recent years, roller cores made of carbon fiber reinforced plastic have also been distributed to reduce weight. The characteristics of the rubber surface are also important, and it is important to select the right material and surface performance for the application.
Uses of Rubber Rollers
Rubber rollers are used in a wide range of fields from printing machinery to paper manufacturing, steel making, and converting industries. Depending on the application, rubber roll manufacturers select the core, rubber material, and surface profile such as unevenness.
Typical applications are as follows:
1. Printing
Rubber rollers have been used for a long time for printed materials such as newspapers because they need to be transported at high speed. There are many types of rubber rolls, ranging from rotary printing to gravure printing, corrugated cardboard printing, and others.
2. Paper Making
Along with printing, paper manufacturing is another application where rubber rollers have been used for a long time. In paper transport lines, static electricity tends to be generated between the rubber rollers and the material. Static electricity not only causes dust adhesion, but also deteriorates the rubber itself by generating ozone. Rolls with functions that prevent such defects from occurring are used.
3. Steel Making
We are surrounded by many products made of steel, such as houses, automobiles, and railroads. Rubber rollers are also used in the manufacture of steel.
The requirements for rubber rolls used in the field of iron manufacturing are high. First of all, they must be able to withstand high temperatures and large loads. In addition, in cooling equipment lines, coils must be cleaned continuously with acid, and rubber rolls for conveyance must also be resistant to chemicals.
Structure of Rubber Rollers
Rubber rollers are composed of a core and surface rubber. The features of each component are described below:
1. Roller Core
Since rubber rollers are often used in harsh environments, such as under high loads, it is necessary to select a core material that can withstand such conditions. Steel pipes have been commonly used as the material. However, stainless steel, aluminum, and resin materials are also used for special applications. In recent years, as conveyor speeds have increased, specially processed core materials that can withstand increased centrifugal force have also been developed.
2. Rubber
There are many performance requirements for rubber that is in direct contact with the material to be conveyed. The first typical requirement is a high coefficient of friction. If the coefficient of friction is low, it will not be able to grip products being conveyed at high speeds.
Next is durability against deformation. Since strong tension is applied to the material during conveyance, wrinkles may occur. If these wrinkles are transferred to the rubber surface and remain, product defects will occur continuously. Therefore, the ability to recover from deformation is important.
Next in importance is chemical resistance. Rolls are often exposed to acids and chemicals in the papermaking and steelmaking processes, and resistance to these chemicals is required.
Other Information on Rubber Rollers
Manufacturing Process of Rubber Rollers
The manufacturing process of rubber rollers varies. However, the first step common to all is the blending and refining of raw materials. After that, rubber and roller core are bonded by one of the following four methods, and then the rubber is vulcanized to cause a cross-linking reaction, giving it elasticity. The product is then subjected to special surface treatment and polishing.
1. Lamination Method
Refined rubber is formed into a sheet using a calender roll, and the rubber sheet is rolled up and bonded to a roller core. Basically, adhesive is applied to the roller core.
2. Extrusion Method
This is a simple method in which refined rubber is formed into a rubber roller using an extruder. Along with the lamination method, this is the most commonly used molding method.
3. Mold Molding Method
In this method, a die is used to manufacture the product. The die is filled with refined rubber and then heated and pressurized in a press to form the product. By increasing the size of the mold, a large number of rubber rolls can be produced at one time.
4. Injection Molding Method
Refined rubber is poured into a resin mold and heated in an oven for molding. This method is not suitable for mass production and is used for small-lot production or prototypes.