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Changing Materials - Glass. Fire & Sand - How Glass Bottles and Jars are Made. Raw Materials of Glass. Glass. Glass has been used for thousands of years. In the past it was very expensive and only the richest people could afford glass for windows and jewellery. Today glass is much less expensive and is used to make many different things, from windows and light bulbs to milk bottles and glass jars. Glass is transparent, hard, is easily moulded into shapes and does not flavour food or drink stored in it. This makes it ideal for making bottles and jars. The main raw material used to make glass is sand. This fine white sand is needed because it is very pure and does not contain other unwanted chemicals. The main sources of the silica sand needed to make clear glass are in Australia and South East Asia in countries like Indonesia, Malaysia and Vietnam. There are different types of glass and each uses a slightly different mix of raw materials.

If you have a recycling bin, you cannot put glass bottles and jars in it. Glass production. Glass bottles (for cucumber slices) on shipping pallets A Soviet mayonnaise jar A modern "French Kilner" jar Glass production involves two main methods – the float glass process, which produces sheet glass, and glassblowing which produces bottles and other containers. Glass container production[edit] Glass container factories[edit] Broadly, modern glass container factories are three-part operations: the batch house, the hot end, and the cold end. Hot end[edit] The following table lists common viscosity fixpoints, applicable to large-scale glass production and experimental glass melting in the laboratory:[1] Batch processing system (batch house)[edit] Batch processing is one of the initial steps of the glass-making process.

Furnace[edit] Batch feed (doghouse) of a glass furnace The hot end of a glassworks is where the molten glass is formed into glass products, beginning when the batch is fed into the furnace at a slow, controlled rate by the batch processing system (batch house). Annealing[edit] Glass. Studio glass by Tyler Hopkins, demonstrating many of the essential properties of glass Glass is an amorphous (non-crystalline) solid material that exhibits a glass transition, which is the reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle state into a molten or rubber-like state. Glasses are typically brittle and can be optically transparent. The most familiar type of glass is soda-lime glass, which is composed of about 75% silicon dioxide (SiO2), sodium oxide (Na2O) from soda ash, lime (CaO), and several minor additives. The term glass is often used to refer only to this specific use.

In science, however, the term glass is defined in a broader sense, encompassing every solid that possesses a non-crystalline (i.e. amorphous) structure and exhibits a glass transition when heated towards the liquid state. Silicate glass[edit] Ingredients[edit] Physical properties[edit] Optical properties[edit] Color[edit] The Story of Glass. Some 2000 years ago, a group of Phoenician merchants used blocks of "natron", an alkali, to support their cooking pots over the fire while preparing dinner. When the fire burned out, they discovered a clear residue. This has been credited with being the first human-made glass. The story has a nice imaginative appeal. However, it would not have been possible for the heat from the fire to fuse natron and sand into a glass-like substance.

This would have required a temperature over 1100 degrees centigrade. What likely happened is that the sand in the region was, in fact, powdered obsidian -- natural glass. It would then have been possible for the heat from the fire, assisted by the fluxing action of the natron on the sandy particles, to produce a glass residue. Glass containers for food, beverages, cosmetics and medicines have been with us a long time. How Container Glass is Made Container glass is made of simple, natural ingredients: silica sand, soda ash and limestone. Glass Colour. How to manufacture a glass bottle - Raw Materials and Batch House, Vitro Packaging.