Roller Coat

Product Description

GMI exploited Erode-Resistant Protective Coating for ceramic roller since 2002. The Erode-Resistant Protective Coatings are composed of Base Coating and Cover Coating. The Base Coating is heat-endurance which will not make chemical reactivity with exterior of ceramic rollers and Cover Coating in high temperature (1000~1250 centigrade). The Cover Coating can be sintered quickly and stiffen to form a rigid protective layer, which attach to the Base Coating, while the Base Coating will stick onto the surface of the ceramic roller in some extent. Both Base Coating and Cover Coating form the protective layer to protect the surface of the ceramic roller away from the erode by caustic gas and pollution by impurity in kiln, such as drops of the glaze or frits. When the coating becomes dirty and being replaced, the coating will be stripped easily as the shell of cooked eggs. Then wash the surface of the rollers, spread the new batch of protective coating onto the rollers again. After the coating is dry, the rollers can be recycled.

2. Preparation of Coating Slurry

2.1. Base Coating slurry

To prepare the Base Coating slurry, the dry power is first mixed with water at a weight ratio of 1: 1.3. The mixture is then grinded in a mill in order to thoroughly mix the power and water (an alternative is to stir the mixture in a high speed stirring machine for one or two hours). Finally, the slurry is sieved with a 60-mesh sieve and stored for future use with the density controlled at a value between 1.35 and 1.45g/m³.

2.2. Cover Coating slurry

The Cover Coating slurry is prepared using the same procedure with the Base Coating as mentioned at item 2.1, except that the ratio between the power and water is 1: 1.1 instead. Additionally, the density of the final product should be controlled at a value between 1.50 and 1.60g/m³.

2.3. Both Dry powder and the Slurry are available for customers

3. Application of Coating

3.1. Before application, the slurry for each coating shall be stirred thoroughly. The surface the ceramic roller should be cleaned to obtain a smooth surface.

3.2. The coating slurry can be poured or brushed onto the roller surface. The Base Coating shall be applied first with the thickness between 0.2 and 0.3mm, let the Base Coating dry in the air for at least 30 minutes. Then apply the Cover Coating slurry onto the dried Base Coating layer with thickness between 0.4 and 0.6mm. To obtain desired thickness, both Coatings can be applied more than one time and the number of application times can be adjusted accordingly.

3.3. The ceramic rollers with coating applied shall be placed close a kiln so that the Coating can be dried enough after application.

3.4. Before the rollers are inserted into the kiln, the coating should be double checked to make sure it is dry. The coated rollers shall be installed onto the firing zone directly. By this way, the separation of the coating from the roller can be avoided, which usually happens when the roller is installed into the preheated zone.