Glass is one of the most popular, demanded materials for different spheres of life. It is used in construction and decoration, it makes works of applied and high art, it is used in the space industry. This is one of the available, simple in composition materials. The most common type that we most often encounter and use products from it is silicate glass.
What it is?
The oldest glassware is considered to be the beads found during excavations in Egypt, scientists believe that the find is more than five thousand years old. Since then, the composition of glass has changed little. The main element of the material is quartz sand (Si0 2 ) - silicate. Soda, potash, limestone and a few more elements are added to it.
In industry, to obtain a glass mass, oxides of basic substances are mixed and melted in an oven. The melting point depends on additives that change the properties of glass. The resulting mass is molded in several ways: by making flat glass, giving it a different shape (utensils, shades for chandeliers, glass for watches, etc.), making blanks for subsequent piece processing by glass blowers, and much more.
Lomonosov M.V., Kitaigorodsky N.I. made a significant contribution to the development of glassmaking, and Mendeleev D.I. et al. Took an interest in the practical side of the issue. It is easy to define silicate glass. What is this A material having an amorphous-crystalline structure obtained by a melt of mixed oxides followed by cooling.
Glass making
The main element for the production of glass is quartz sand, to which at least five ingredients are added in proportions. To the main recipe, depending on the further purposes of using the obtained material, additives are made: oxidizing agents, mufflers, bleaches, dyes, accelerators and so on. Oxides of metals are used as dyes. For example, copper will stain the mass of glass red, iron will give a blue or yellow hue, cobalt oxides will give a blue color, and colloidal silver a yellow.
The prepared dry mixture is loaded into a glass melting furnace, where the raw material melts at a temperature of 1200-1600 ° C, the process takes from 12 to 96 hours in time. Glass manufacturing is completed by a quick cooling process, only under this condition the glass melt will receive all the required qualities: transparency, mechanical resistance and additional properties laid down in the process of mixing oxides.
Types of silicate glass
The release of material refers to energy-consuming processes, and the silicate industry is engaged in it . Glass production in the industry takes place in tunnel-type furnaces with continuous support of the set temperature. A dry mixture is loaded from one end of the furnace, and finished material is unloaded at the outlet.
Due to its widespread use in various industries, silicate glass can be divided into types:
- Quartz without impurities of sodium oxides, potassium - this is alkaline-free glass. It has high resistance to heat and excellent electrical properties. Of the shortcomings - it is difficult to process.
- Sodium, potassium, sodium-potassium - alkaline glass. The most common type of material, suitable for widespread use. It makes glass for an aquarium, window, dishes and more.
- Alkaline with a high content of heavy metal oxides. For example, the addition of lead is necessary to obtain crystal, optical glass.
Multi-use
Silicate glass has a number of properties that allow it to be used in a wide range. Each of its qualities can be strengthened, in connection with which additional opportunities open up. For example, glass coated with an amalgam serves as a mirror and can also be used as a solar battery under certain conditions.
Hygienic and practical properties of glassware are undeniable. The material does not have porosity, which means that pathogenic bacteria do not multiply in it, it is easy to clean, and is resistant to any food products. Heat-resistant dishes from it are multitasking: you can bake at high temperature in the oven or put in the freezer without any damage.
Layering and thickness
The material has a different thickness, which determines its capabilities. Sheet, 2 mm thick, suitable for windows. Glass for an aquarium is used at least 5 mm, depending on the volume of water poured into the tank. However, aquarists are increasingly coming to the conclusion that the use of an acrylic analog is much more convenient, especially if a capacity of 500 liters or more is required.
The use of laminated material (triplex) expands the possibilities: the fabric glued with a polymer film is practically indestructible, it is safe because it does not crumble. It is almost impossible to break two 10 mm thick silicate glasses with a film layer with a hammer. Transparent bridges, cladding of building facades, pool fences, etc. are made of triplex.
The properties
The use of silicate-based materials finds its place in construction. They are used not only for the manufacture of windows, but also as additional protection and a binder. So, foundation blocks are treated with liquid glass , which makes them resistant to moisture, fungus, temperature fluctuations, etc.
Curved translucent or matte material is used in everyday life, furniture doors, showers, building facades and so on are made from it.
Silicate glass properties have the following:
- Transparency.
- Light reflection.
- Environmental friendliness.
- Heat resistance.
- Resistance to aggressive chemical environment.
- Resistance to natural aggressive environment.
- Durability.
- Low thermal conductivity.
Additional qualities, such as resistance to stress and mechanical damage, give the material a hardening method. The essence of the process is rapid heating and the same rapid cooling in a short period of time. Strength is increased by 4-5 times. It makes glass for watches, door leafs, furniture, interior partitions.
Product Manufacturing
Silicate glass dishes and household products are produced in several main ways:
- Pressing. A viscous mass is poured into a fixed mold, after which certain parameters are set using the movable part of the mold (punch). The mold on the inner surface may have a pattern that is transferred to the outer part of the product during stamping.
- Blowing. It differs in mechanical and manual. The wall thickness of the product varies from 1 mm to 10 mm. In this way vases, bottles, wine glasses, glasses are made. Hand blowing is an art. Glass-blowing masters create unique works by combining a transparent and colored mass, they include metal, natural raw materials, gold and more in the body of the work. Identical products of manual blasting are not found.
- Casting. It is mainly used for making figures, figurines. In industry, optical glass is manufactured by casting .
- Multi-stage articulation. Parts made using two technologies are used: blowing and pressing. For example, the capacity of a glass is blown out, and the leg is pressed, the finished parts are connected.
Decorative processing
Silicate glass is a fertile material for many types of decoration. Distinguish between hot and cold design.
Hot items include:
- Mass staining with metal oxides.
- Mixing masses of different colors with further shaping (Venetian glass with stains).
- Cracking The mass is molded into a product, it is cooled rapidly, as a result of which surface cracks appear, to fix the product they melt.
- Fusing.
- Hot forming cords, threads, followed by additive on the product.
- The formation of an additional shape of the edge during the blasting process. Achieved by the use of tools.
Cold forms of decor:
- Mechanical: grinding, engraving, diamond cutting, sandblasting.
- Chemical: etching with hydrofluoric acid.
- Overheads: painting, drawing a decal, silk-screen printing, metallization, plasma spraying, painting with luster paints.
Other types of glass
Modern technology has allowed to give silicate glass additional qualities. Of these, the most interesting and demanded are:
Smart glass: a type of material that changes its properties under the influence of external conditions. For example, under the influence of electric current, the product becomes dull, when the circuit is disconnected, it returns to a transparent state.
Fiberglass (fiberglass): obtained by drawing the material into thin (measured in microns) threads. From them create a fairly flexible material. Used for the production of optical fiber, insulating materials, etc.
Lightened glass: ordinary silicate glass has a greenish or grayish tint, clearly visible when looking at a slice. As a result, the canvas is slightly colored. To avoid this effect, brighteners are added during the manufacturing process to neutralize the unwanted color. It differs from ordinary material in increased light transmission, color transfer without color change.