#driveroller

Rubber roller (also called rubber cylinder, rubber roll), is a product made of roller core and the rubber layer that covers on the core. Rubber coated rollers are widely used in printing, paper making, textile, converting, plastic film, grain processing, metallurgy, logistics and other industries. The inspection standards of rubber rollers mainly include rubber hardness, roller precision, roller surface roughness, wear resistance, aging resistance, high temperature resistance, low temperature resistance, impact performance, tensile performance, thermal conductivity, corrosion resistance, electrical properties, resilience, etc. In this article, FUTIAN ROLLER will briefly introduce the inspection of rubber hardness, roller precision, aging resistance and elasticity of rubber roller.

1、Rubber hardness

The rubber hardness of the roller refers to the performance of rubber roller’s resistance to the measuring instrument probe under given conditions. The hardness of rubber roller, which is usually expressed by Shore hardness, will affect its functions such as shock resistance and adhesion. However, it should be noted that higher hardness of rubber roller does not mean better quality. In some industries, rubber roller of low rubber hardness is more favorable.

The picture following is customized wide format EPDM rubber coated rollers for printing machine made by FUTIAN ROLLER.

2、Precision of rubber roller

1) Diameter of rubber roller: the diameter is usually measured with micrometer, vernier caliper, etc.

2) Roller cylindricity: the cylindricity of small rubber rollers can be measured on equipment such as three coordinates. While currently there is no rather good way to measure the cylindricity of larger rollers directly. Generally, we use the maximum difference between the change of roller diameter and runout as the roller cylindricity data. Now the cylindricity of rubber coated roller manufactured by Futian Roller is not more than 0.05mm.

3) Runout of roller: in the inspection standards of rubber rollers, the circular run-out represents the shaking degree of rubber coated roller during operation, which is usually measured with a dial indicator.

3、Aging resistance of rubber roller

To test this performance, it mainly needs to prolong the ultraviolet light treatment time, and generate high temperature to aggravate the oxidative cracking of the rubber roller. Then the aging resistance can be obtained by recording the aging time and degree of the rubber roller.

4、Elasticity of rubber roller

Pressurize the rubber roller in the static state until indentation occurs, and record the time when the indentation disappears. The shorter the time, the better the elasticity is.

It should be noticed that affected by changes of environmental factors such as temperature and humidity, the performance of rubber coated roller will change accordingly. Therefore, the rubber cylinder’s performance must be measured and compared in the same conditions.

In general, rubber roller coating process refers to that the rubber roller factory cover the roller core with rubber and then vulcanized, polished, etc. According to the customer's requirements, the rubber roller is machined to the required size, hardness, color, etc. The rubber roller coating process involves the following processes:

1. Cleaning rubber roller core: If the rubber roll core is a new one, the oil stain on the rubber roller core surface should be cleaned with cleaning agent; If it is an old rubber roll core, the outside layer of the old rubber roller should be removed before cleaning the remaining rubber on the core surface with cleaning agent.

2. Roughening surface treatment on the rubber roller core: The purpose of making roughening surface treatment is to increase the bonding area between the surface of the rubber roll core and the coated rubber, which can make sure that the rubber coating is stably covered on the roller core.

3. Sand blasting processing: After roughening surface treatment on the rubber roller core, rubber roller factory will select different kinds of sand to do sandblasting according to the different material of the roller core. The sandblasting processing is to make the surface of rubber roller rougher, and the bonding between the rubber and the roller core will be better.

4. Rubber coating: The rubber will be extruded on to the roller core after the above treatment. Different coating rubber can meet different requirements. For example, natural rubber coated roller has good ink resistance, polyurethane rubber roller has good wear resistance and pressure resistance, and rubber roller with silicone coating appears to have good high temperature resistance.  

5. Roller vulcanizing: It generally takes 10-15 hours for the rubber roller to be vulcanized. After vulcanization, the covered rubber and the core of the rubber roller will be bonded closely.

6. Rubber roller polishing: The rubber rolls need to be polished according to the size required by the customer.

After the above processes, the rubber roller coating process is completed. Then the rubber rollers will be further machined, such as cnc turning, grooved, grinding, according to the customer’s requirements.