We usually use three exclusion methods to choose the suitable resin for artificial stone:
1. Stirring and vacuuming method: the negative pressure of stirring is used to keep the artificial stone basically boiling, which is conducive to the chemical reaction and the easy removal of bubbles generated during the stirring process.
2. Chemical defoaming method: using a polymerization inhibitor (commonly known as defoaming agent) that has a blocking effect on the crosslinking and curing of the resin can prevent the resin from polymerizing for a certain period of time. After a period of time, the resin can polymerize at a normal speed, which is a bubble Effectively expel winning time. The use of this method has little effect on the heat release caused by resin curing. If the amount of initiator and accelerator is reduced, although it can also delay the polymerization of the resin, it will be deformed due to the heating curve of the resin and affect the quality of the artificial stone.
3. Vibration defoaming method: the use of this method should pay attention to the amplitude, frequency and vibration time of the platform. If the amplitude is too large, the filler will be deposited on the surface of the template, resulting in a lean resin, slow curing, small shrinkage, and low exothermic temperature; and On the other side, due to the rich resin, the cured block, the shrinkage is slow, and the heat release temperature is high, which is prone to warping.
The above three methods, especially the first and third methods, are more practical, reliable, and have the effect of long-term investment. The second method, although simple, is too expensive for large-scale production.
In addition to the exclusion method, we should also pay attention to the curability and chemical structure of the artificial stone resin in the selection of resin:
1. Resin curing performance: It is required that the resin should have a moderate low shrinkage rate and a high pre-curing strength or green strength during curing.
2. The chemical structure of the resin generally adopts isophthalic acid-propylene glycol type resin. It can meet the requirements of the American Artificial Marble Association (CMI) for 500 cycles of thermal shock. It is boiled with distilled water for 48 hours, the color remains basically unchanged, the white flower resistance and anti-foaming performance are both good, but the price is relatively expensive. Ordinary resin cannot be used for artificial stone manufacturing.
Artificial stone resin is an unsaturated polyester resin synthesized with phthalic anhydride and standard diol as the main raw materials, and has been dissolved in styrene. Orthophthalic resin, low shrinkage, light appearance, low curing exotherm peak, anti-aging, strong water resistance, high product strength, suitable for room temperature curing high performance artificial quartz stone products.