Freshwater pearl processing- preprocessing
Pre-treatment mainly includes sorting, punching, puffing, lighting and other processes. The cleaned pearls will be taken out and continue to be screened according to the size of the pearl and the conventional grade, and the pre-grading will be carried out. The high-grade pearls pass the high-grade method Processing, medium-grade pearls are processed through medium-grade processing, and poor-grade pearls are processed by simple processing. For each Grade, there are corresponding measures, which are pre-classified and organized in advance.
There are two methods of puffing: one is to wrap the pearls in gauze and put them in deionized water for heat treatment, which can reduce the deposition of impurities in the water on the surface of the pearls, and the other is to directly immerse the pearls in the potion. The pearl structure is "loose", resulting in pores, which is conducive to the penetration of bleaching liquid.