Glass is the oldest material. Ordinary glass bottles are made of ordinary silicate glass raw materials (SiO2,Na2O,CaO) by adding glass bottle decoloring agent or coloring agent, etc., after melting at high temperature (about 1 400℃), molding, annealing, surface treatment and inspection. Since the birth of milk bottle in 1884, glass bottle has been used as packaging container for liquid food for more than 100 years.
Although glass bottles have amber, cyan, dark green and other colors, most beverage bottles are colorless and transparent, so you can see through the inside to observe the filling amount, the color of the contents, the size and dispersion of the pulp, and whether the beverage is layered or precipitated. It is convenient for consumers to choose and drink with confidence. The problem that the container is corroded by beverage and dissolved out is directly related to the safety of food, so many countries attach great importance to the chemical stability of packaging materials. When glass bottles are used as packaging containers for fruit and vegetable juices or other beverages, there is almost no dissolution from the container materials. Compared with other containers, glass bottles have good chemical stability and durability, which is superior to other beverage containers. Whether it is a pressurized carbonated beverage or a vacuum seedling-killing beverage, the glass bottle can guarantee complete sealing. Unlike some plastic and paper containers, glass containers are not breathable, so they can prevent the influence of outside air on beverages, such as vitamin C reduction and flavor deterioration. The relationship between the strength of glass bottle and the chemical composition of glass is negligible, but the surface condition of glass bottle is closely related to its tensile properties. Even if the glass surface is scratched or bruised, the strength will be reduced to a great extent, but for carbonated drinks, the pressure of the pressed gas is generally bearable. Glass bottles are widely used and have good adaptability to the contents. Glass bottle is the mainstream packaging material for health and environmental protection.