Glass is a versatile material with qualities beyond its transparency and brightness. It also possesses high strength and hardness, making it indispensable in various aspects of daily production and life. In addition to commonly known types like float glass and toughened glass, there are specialized varieties of glass with unique properties such as hot melt glass, laminated glass, and ground glass. To understand the quality requirements and manufacturing process of glass containers, please continue reading.
Ⅰ. Quality Requirements of Glass Bottles and Jars
Glass bottles should meet specific performance standards and quality requirements:
① Glass quality: The glass should be pure and uniform, free from sand, stripes, bubbles, and other defects. Colorless glass should have high transparency, while colored glass should exhibit uniform and stable colors and be capable of absorbing specific wavelengths of light energy.
② Physical and chemical properties: Glass containers should possess chemical stability and should not interact with the contents. They should have sufficient shock resistance and mechanical strength to withstand processes such as washing, sterilization, heating, cooling, filling, storage, and transportation without damage under normal internal and external stresses, vibrations, and impacts.
③ Molding quality: Glass bottles should maintain consistent capacity, weight, and shape. The wall thickness should be uniform, and the bottle mouth should be smooth and even to facilitate convenient filling and effective sealing. The bottles should be free from distortion, surface irregularities, unevenness, cracks, and other defects.
II. Glass Packaging Container Manufacturing Process
The production of glass packaging containers involves the following steps:
- Mold Design and Manufacturing: The mold for the desired container shape is designed, determined, and manufactured.
- Glass Raw Material Preparation: Quartz sand, along with other auxiliary materials, is melted at high temperatures to form a liquid.
- Injection and Forming: The liquid glass is injected into the mold and then cooled, cut, and tempered to obtain the desired container shape. Colored glass bottles often have distinct patterns formed by the mold.
- Molding Techniques: Glass packaging containers can be produced using manual blowing, mechanical blowing, or extrusion molding methods, depending on the chosen production technique.
- Glass Composition: Glass containers can be classified based on their composition into sodium glass, lead glass, and borosilicate glass types.
Glass packaging containers are made from natural ores, quartz stone, caustic soda, limestone, and other raw materials. They offer high transparency, resistance to corrosion, and minimal alteration when in contact with most chemicals. Glass containers are simple to manufacture, allowing for versatile shapes, hardness, heat resistance, cleanliness, ease of cleaning, and reusability. They find extensive use as packaging materials in various industries, including food, oil, wine, beverages, condiments, cosmetics, and liquid chemicals. However, glass containers also have drawbacks, such as their weight, high transportation and storage costs, and susceptibility to impact damage.
Glass
Glass is an amorphous inorganic non-metallic material typically composed of various inorganic minerals (such as quartz sand, borax, boric acid, barite, barium carbonate, limestone, feldspar, soda soda) as primary raw materials, along with small amounts of auxiliary materials. Its main components are silica and other oxides. The chemical composition of ordinary glass includes Na2SiO3, CaSiO3, SiO2, or Na2O·CaO·6SiO2, with silicate double salts being the primary component. Glass is an irregular structured amorphous solid and is widely used in buildings for its ability to allow wind and light to pass through. Colored glass incorporates metal oxides or salts to achieve specific colors, while processes like tempering can enhance glass strength through physical or chemical means.