How to distinguish between good and bad glassware

Generally speaking, the higher the transparency, the higher the clarity, the better the uniformity, and the thinner the wall of the vessel, the better; in addition, whether the shape of the vessel and the mold fit and whether the seal is smooth are also indicators for evaluating the vessel.

The difference between soda lime glass and lead crystal glass is that lead crystal glass has good optical properties, good light transmittance, metallic feeling on impact, heavier hand feeling, and most of the surfaces have no patterns, and the walls of the utensils are thin and very transparent. Generally used For more high-end utensils. The soda-lime glass has poor permeability, thick wall, and most of the surface has patterns to cover up the bubbles caused during production. Poor quality glassware will appear blue or green when looking at the cup due to impurities. In addition, the content can be analyzed through laboratory tests to finally determine its actual composition.

In terms of price, the cost of lead crystal glass and high boron glass has increased due to the addition of lead oxide and boron oxide. Therefore, the order of the same specifications of glassware from high to low is lead crystal glass and high boron glass. , Soda-lime glassware; the price of glassware manufactured by the press-blowing method is higher than that of the pressing method; the price of glassware with a complicated process is higher than that with a simple process. Generally, glassware with feet (such as goblet) is more expensive For high feet, such as a goblet, the cup shape must be blown out by the pressure-blowing method, and then the cup feet must be manufactured. Finally, the two are combined to make a finished product. The process is complicated and the price is naturally higher. On the contrary, the process is simple and the production efficiency is fast. (Such as the production of ashtrays, which can be pressed 100 per minute), the price is naturally relatively cheaper; glassware with surface decoration has one more process than glassware directly molded and packaged, and the price increases accordingly.

For glassware of the same quality, white is the cheapest, static color is more expensive than white, and variegated color is more expensive; the price of different quality is different, the higher the quality, the more expensive the price (such as the superior grade is more expensive than the uniform grade); well-known brand It is more expensive than ordinary brands; due to the difference in production technology, the price of the same quality glassware produced in different countries is different.

It is understood that in the glass composition of the same system, the higher the SiO2 content, the higher the transparency, the better the thermal and chemical stability, the higher the refractive index of K2O than NA2O, the gloss, and the better transparency and whiteness. However, due to the high price of potassium raw materials, they are generally not used in reality. At present, the common raw materials used in the production of glassware are lime-soda glass, high boron glass, high white material and lead crystal glass (high lead crystal glass contains PbO: 30～ 35%, medium lead crystal glass contains PbO: 24-30%, lead crystal glass (also known as crystal glass) contains PbO: 24%, low lead crystal glass contains PbO: 24% or less). Among them, soda lime glass has the lowest cost and is mostly used to produce ordinary glasses; high boron glass is better than lime soda glass in heat resistance, and its material cost is higher than the former; high white material has a good ability to withstand rapid temperature changes. It is mostly used to make glassware for microwave ovens, and its material cost is higher. Lead crystal glass has high permeability, and currently only a few developed countries have the production technology. It is usually used to produce high-end glassware, and its material cost is the highest. In addition, glassware made of lead crystal glass has a high degree of manual processing, so the processing cost and added value are high.