Glass bottles and jars have certain performance and meet certain quality standards

Raw materials and chemical composition Bottle glass batch materials are generally composed of 7 to 12 raw materials. There are mainly quartz sand, soda ash, limestone, dolomite, feldspar, borax, compounds of lead and barium, etc. In addition, there are auxiliary materials such as clarifiers, colorants, decolorizers, and opacifiers (see glass manufacturing). Coarse-grained quartz is difficult to melt completely; if the particles are too fine, scum and dust are likely to be generated during the melting process, which affects melting and easily blocks the regenerator of the melting furnace. The suitable particle size is 0.25-0.5mm. In order to utilize waste glass, broken glass is generally added, and its dosage is usually 20-60%, up to 90%.
The chemical composition of glass bottles and jars varies according to their use requirements, molding methods, molding speed, process characteristics and raw material varieties. The vast majority of bottles and jars are made of soda lime silicate glass. The main components of soda lime silicate glass are SiO2, Na2O and CaO. The introduction of appropriate amounts of Al2O3 and MgO can reduce the crystallization tendency of the glass, enhance the chemical stability and mechanical strength of the glass, and improve the formability of the glass. The chemical composition of sodium-calcium bottle glass in most countries in the world is: SiO2 70-74%, CaO and MgO10-14%, Na2O and K2O13-16%, Al2O31.5-2.5%. When manufacturing colorless glass bottles and jars, the content of Fe2O3 in quartz sand is very low (generally about 0.03%). In ordinary soda lime glass, adding Cr2O3 and Fe2O3, the glass is emerald green, adding sulfur-carbon or MnO2 and Fe2O3, the glass is brown. Bottles and jars containing medicines require high chemical stability and are made of borosilicate glass. High-grade cosmetic bottles are usually made of crystal glass containing lead, barium or zinc, and some are opalescent glass, and fluoride is generally used as an opacifying agent.