Dry stone grinding, as the name implies, does not add water when grinding stone. Adding water when grinding is called water grinding. What is the difference between the two? When is the dry grinding? When is the water mill?
1. What is the difference between dry grinding and water grinding?
1, the polishing pad is different
The mainstream polishing pads currently on the market are mostly made of synthetic diamond particles and resin binders. Diamond is the diamond we usually say, and resin, in a broad sense, is a general term for a variety of high molecular polymers that can be used as plastic raw materials.
When the stone is grinded, the grinding piece and the surface of the stone are rubbed, and the high temperature is instantaneously generated under the speed and pressure of the machine rotation. This temperature can melt the general resin, and the inferior polishing pad is easily deformed and distorted when it is ground for this reason. Adding water to the stone water mill can accelerate the heat dissipation, and the requirements for the polishing pad composition are slightly lower, while the dry grinding does not add water, and the heat is emitted slowly. Therefore, the resin used for the dry polishing pad must select a high-quality resin with high temperature resistance.
Dry polishing pad with high temperature resistant resin
Simply speaking, due to the composition, the dry polishing pad can be water-grinded, but the ordinary polishing pad can not be dry-grinded for a long time. The grinding plate made of high-quality resin can be dry-grinded or water-grinded.
2, water mill damage to the stone is less
The high temperature generated during the grinding of the stone can cause certain damage to the structural crystal of the stone. Stones are burnt at high temperatures, which are prone to a series of problems such as loss of light, chipping, and chalking.
The reason is the composition of the stone. The main component of the marble is calcium carbonate. Calcium carbonate is converted into calcium oxide after being calcined at a high temperature, which is the so-called firing process of lime.
Chemical reaction type: CaCO3 (heating) = CaO + CO2 (gas) When adding water to the stone, it can accelerate the heat dissipation and reduce the damage to the stone.
3, the gloss of the water mill is more soft and beautiful
During the grinding and polishing process of the stone, all the light emitted by the high temperature is different from the light thrown out at the natural temperature.
The luster that is thrown out at natural temperature looks bright and bright, and under high temperature conditions, the heat generated by the friction moment has a certain destructive effect on the crystal structure of the stone, so the gloss produced by the dry grinding has glare and burning. Eclipse, dry, not transparent.
Generally, when black stone is ground, it tends to be white, and water mill is better than dry mill. The beige stone is dry-grinded all the way, and the color is not transparent, the bright is bright, but the gloss is dry and faint, which is due to the high temperature ablation during grinding.
The heat generated by dry grinding is harmful to any stone. It is not obvious on white or beige light stone, but it is especially noticeable on black stone. Therefore, dark stone, relatively transparent jade, etc., it is best to grind.
4, the pollution caused by dry grinding is difficult to handle
Dry grinding produces dust, which is mostly flying in the air, and a small amount is dissolved or absorbed into the holes of the stone. These extremely fine stone powders enter the interior of the stone to absorb moisture and absorb moisture, which will pollute the stone for a long time.
Flying dust in the air is very detrimental to the health of stone caregivers. Moreover, the dust generated during dry grinding is difficult to handle. The dust generated during the grinding process of the stone is very delicate and can produce a floating effect. As the mesh size increases, the fineness of the dust increases exponentially, and the dust volume becomes larger and larger. It is very difficult for you to deal with these dusts in the city.
Second, when does the stone dry grinding?
1, no protective stone
Stones that have been glazed, mirrored, or heavily aged on the surface need to be opened before the protective agent is applied. The specific method is to grind the crystallization, sealing layer or aging layer of the surface to facilitate the grinding. Absorbent absorption.
Stone coating protective agent, in order to achieve good results, requires the stone to be clean and dry, the stone that has not been protected is easy to absorb water. If the surface of the stone is opened by water grinding, the water absorption will extend the construction period.
Therefore, if there is no protective stone, the surface can be opened by dry grinding before applying the protective coating.
2, grinding and polishing
The stone grinding leveling and grinding optimization step uses water grinding, and in the grinding and polishing process, the light is accelerated by the dry grinding. The specific method is to grind to 1000 mesh by water grinding. The stone can be added with little or no water to semi-dry or completely dry. In practical applications, it is found to be a practical technique to help the stone.
The reason is that during the low-stage water mill, the stone has absorbed water and the ground is moist. Therefore, it can be dry-grinded after 1000 mesh, and the heat of dry grinding can also accelerate the evaporation of water, and the stone is dried in advance, which is the crystal seal of the latter. Glaze operation saves waiting time.
3, wall, corner, countertop
The wall must be dry-ground because the wall does not have water-grinding conditions. The finishing work after the stone is finished, such as the wall and the corner where the large machine is out of reach, can be carried out by dry grinding. As well as lines, small areas of enamel, repairing countertops, etc., dry grinding is more convenient.
Dry grinding is not absolutely without adding water. If the dark stone is dry and whitish during the grinding process, you can add a little water during the grinding, which will be better.