The sand holes, dimples, cracks and other defects on the stone surface will affect the decorative effect of the stone, and make the stone material beautiful and value discounted. Salvage is usually done with an adhesive mixture. A common example, with epoxy resin as the main component, adding penetrant (usually poly ethylene oxide or alkyl phenol ether surfactant), adding curing agent (usually ethylenediamine or DMPA) and a filler (usually lithopone, talcum powder, micro silicon powder, toner or powder) prepared by stone repair materials. However, there are still many problems with the use of epoxy stone repair materials.
For example, the city hall porch in Massachusetts crack several marble columns and architrave, base on the use of pressure injection epoxy repair repair. They used fine sand with low viscosity epoxy resin repair agent. The bonding results showed that the initial adhesive strength was better, but the micro cracks were found on the bonding surface of marble and epoxy resin. This is related to the creep of the epoxy resin on the surface of the glued stone. Most traditional stone patching agents have solvent evaporation and long curing time. They are not easy to be used in the rapid industrialization process.
The development of new stone repair agent is the rest of the world, such as the United States – meter company developed a new method for resin UV curing agent to repair stone. UV curable resins can absorb ultraviolet energy to cross link or polymerization, so that the material quickly changed from liquid to dense solid. UV irradiation curing reaction can be completed in a few seconds, there is no solvent pollution problems, it is very conducive to large-scale processing of automated machinery. UV curable resins can be made of resins such as polyesters, polyurethane, acrylic acid, or silicones, but some special active groups are required to initiate crosslinking. Italy has automated machinery for the decoration and repair of stone panels, but the light cured resins are also provided. The adhesion and repair of stone is one of the indispensable technologies in the stone industry, and it has a very important impact on improving the economic benefits of the stone industry. In addition, the stone bond and repair is the main technology of stone cultural relics restoration. To do research and technical development work in this area is very beneficial to the protection of cultural relics and the development of tourism.