Artificial stone (also known as "artificial marble") is a new type of composite material because it is non-toxic, non-radioactive, flame retardant, non-sticky, non-staining, antibacterial, mildewproof, abrasion resistant, impact resistant, and easy. Maintenance, splicing seamless, arbitrary modeling, etc., is gradually becoming the new favorite in the decoration building materials market. Then, what factors are caused by bubbles and pockmarks on the surface of artificial stone? How to exclude?
1. The moisture content of the filler exceeds the normal target. When the water content of the filler particles is high, a tiny blisters will form around the surface. Since the curing of the resin is an exothermic process, the heat released by it destroys the balance of the outer wrap of the particles, leaving the blisters in the artificial stone matrix and solidifying. Bubbles and pockmarks appear on the surface.
2. The air is brought into the artificial stone matrix during the mixing process.
3. The ratio of resin to curing agent and initiator is improper, and the bubbles remaining in the matrix cannot be discharged in time.
There are usually three ways to exclude:
1. Vibration defoaming method. The use of this method should pay attention to the amplitude, frequency and vibration time of the platform. The amplitude is too large to deposit the filler on the surface of the template, resulting in a resin lean, slow curing, small shrinkage, low exothermic temperature, and the other side is cured by resin. Block, slow shrinkage, high exothermic temperature, prone to warping.
2. Chemical defoaming method. The polymerization inhibitor (known as defoamer) which has a retarding effect on the cross-linking of the resin can prevent the polymerization of the resin in a certain period of time. After a period of time, the resin can be polymerized at a normal speed to obtain time for the effective discharge of the bubbles. The use of this method has little effect on the heat release caused by the curing of the resin. If the amount of the initiator and the accelerator is reduced, although the polymerization of the resin can be delayed, the quality of the artificial stone is affected by the deformation of the heating curve of the resin.
3. Stirring and vacuuming method. The artificial rock is kept substantially boiling by the stirring negative pressure, which is beneficial to the chemical reaction and the bubbles generated during the stirring process are easily eliminated.