Doing stone conservation abrasives and grinding tools is the key

With the development of economy, the use of stone is becoming more and more extensive. Especially in various public places, stone is loved by people for its elegant and noble attitude. Its use will change with time, aging and being polluted. Such problems can be solved through cleaning methods. However, there are times when renovations have to be carried out through grinding. The following is the introduction of abrasives and grinding tools, so that everyone has a preliminary understanding of this.

First, abrasive and grinding tools

Abrasives are materials used for grinding and processing. The current general classifications are ordinary abrasives and superhard abrasives. Ordinary abrasives mainly include corundum (brown corundum, white corundum, etc.), whose main chemical composition is Al2O3 (aluminum oxide). , silicon carbide (black silicon carbide, green silicon carbide), the main chemical composition of SiC (silicon carbide). Their hardness is brown fused alumina, microhardness 2000-2200 kgf/mm2, white corundum, microhardness 2200-2300kgf/mm2, black silicon carbide, microhardness 3100-3300kgf/mm2 Green silicon carbide, microhardness 3200-3400 kgf/mm2; grain size from 4#--fine powder W0.5 (even finer), the order of hardness we can sort out is granite, green silicon carbide, black carbonization Silicon, the processing of marble is white corundum (soft), black, green silicon carbide (hard); from the cost of the material in order is green silicon carbide, black silicon carbide, white corundum, can be made around these abrasives, inorganic Abrasive tools, including rhomboids, ceramics, etc.; organic abrasive tools, including phenolic resins, unsaturated resins, and epoxies (also including emery cloth sandpaper here), these grinding tools make up ordinary abrasives. tool.

Diamond abrasive is a kind of superhard abrasive. Although its processing history is relatively long, as more use, it is a large number of industrial production in the past 30 years. Its microhardness is 8000-10000 kgf/mm2; the hardness is the highest. The processing of materials is the mechanism of micro-cutting, so it is the preferred cutting tool. In recent years, it has a large-scale increase in production and industrial cost reduction, high processing efficiency (is more than 5 times the ordinary), processing effect is good (can Polishing is required for highly demanding materials and, as a result, its use has become more widespread. Diamond grinding tools are mainly metal, resin, ceramic, etc., which are classified according to the type of bonding agent, and the metal grinding tools mainly include iron-based, copper-based, and cobalt-based. Determine the processing costs of different types of materials, as the use of grinding tools, the particle size from the coarsest (20 #), often to the fine granularity up to 400 # until use; its characteristics are long life, but the cost will be higher. Resin grinding tools, due to the relatively low production cost, have relatively more applications. It is also used for rough grinding to polishing. It is the biggest advantage in fine-grained grinding and polishing; ceramic diamond-like grinding tools are recent. The fastest-growing tool of the year, in terms of its processing performance, takes the length of metal processing and avoids short resin processing, and has a very good technical advantage. However, because of its cost, it has not yet been seen in stone renovation.

Second, the stone renovation process steps

The refurbishment of stone floors generally involves the following steps. One is to use coarse-grained grinding tools to “level” the damaged surface, “cut”, or “flatten” the already uneven parts. Generally, this process must have a certain amount of removal. During the construction, attention should be paid to the overall smoothness. Second, the coarser grained tools should be used to grind the stone to remove rough lines in the processing. Also maintain the flatness of the construction surface. Third, the fine grinding process, the removal of this process is relatively small, through 4-5 grain size, so that the finish of the stone can be polished. Finally, the polishing process. To achieve the stone renovation to meet the requirements.

Third, the choice of grinding tools for stone renovation process

1, diamond grinding stone, from silicon carbide abrasives and magnesium oxide, magnesium chloride polymerization, the use of silicon carbide, green silicon carbide is better, black silicon carbide will be relatively cheaper, grain size generally from 16 # - 1200 The hardness of the grindstone produced is also from hard to soft. It is characterized by low cost, good self-sharpening, and strong processing adaptability. It can process granite, marble, artificial stone, ceramic tile, etc., but the processing efficiency is compared. Low, long production cycle, grinding head work requires more pressure, is a conventional grinding tool, this grinding stone storage cycle more than one year later, a variety of properties will change, such as self-sharpening, soft Hardness and so on.

2, silicon carbide resin grinding stone, from the silicon carbide abrasive mixed with the resin consolidation, useful phenolic resin compression class, mixed with liquid resin, the casting class. Mainly used for fine grinding. The characteristics of pressing are good durability and good wettability during grinding. Especially when processing marble, the grinding light has good luminosity and high efficiency, but the cost is relatively higher, mainly using fine Particle size, phenolic type grinding stone in the light-color stone polishing, easy to color, which is not widely used to promote the main reason. With a very fine silicon carbide powder and other materials mixed with the resin, the grindstone poured out, is the main method used in granite, terrazzo, concrete polishing.