Sodium calcium silicate glass. Carefully! Harmful utensils. Cold-decorated glassware

There are universal Construction Materials, which are used in the construction of any objects, regardless of their technological purpose. Silicate glass refers to just such elements. This is one of the oldest materials that mankind has learned to produce since time immemorial. Moreover, the composition of the current substance is not much different from the ancient one. Only the manufacturing technology has changed and there are much fewer useless impurities in the composition.

Material manufacturing

To date, there is one generally accepted method of manufacturing. The silicate glass industry requires the initial preparation of raw materials, after which the actual smelting process begins.

Step by step it looks like this:

1. The main components for production are quartz sand, limestone and soda. From them, with the help of special equipment, a homogeneous mass is prepared - a mixture, in which all these elements are included in a crushed form.
2. Next, the prepared composition enters the furnace, where, under the influence of a temperature of 300 to 2500 degrees, it melts to a homogeneous liquid mass. This wide range is due to the presence of a large number of glass grades and depends on the additives used. Often these are carbide metals.
3. Next, the resulting substance enters the forms that will correspond to the type of finished product. There, the glass solidifies at a temperature sufficient to prevent the crystallization of the constituent components.
4. The resulting material will not necessarily be transparent. This parameter also depends on the use of additional elements during smelting.

Professional chemists call the material soda-lime-silicate glass. This is due to the fact that the substance is an alloy of three oxides - monovalent sodium, divalent calcium and tetravalent silicon. Moreover, one structural unit contains one share of metal oxides and six shares of silicon oxide at once. This is the reason for all the properties that glass possesses.

The composition of silicate glass can also include other metals and their compounds. They are added to change specifications and give the material new parameters that could help it perform its immediate functions. In this case, non-metallic elements are used much less frequently and are mainly fluorides.

The fact is that glass has a lot of different uses, so it has many brands. These products differ in their transparency, strength, hardness, color. A specific chemical element is responsible for each individual indicator. Therefore, any non-standard model will cost more than ordinary glass made from limestone, sand and soda.

In addition to the familiar and familiar solid material, which is installed in all houses in window frames, there is also liquid silicate glass. This is an aqueous alkaline solution of a standard substance, which does not include calcium oxide. It is obtained by treating silica-containing raw materials with concentrated sodium hydroxide or by fusing quartz sand with ordinary soda.

This composition is also widely used in the construction industry. In particular, it is used for the manufacture of refractory materials. After liquid treatment of concrete, wood, paint, I cease to be afraid of open fire. The substance also well strengthens weak soils, prone to weathering of useful trace elements. It is used as the main component in the manufacture of heat-resistant ceramics for the smelting of metal molds.

One of the main characteristics of the material is the silicate module of liquid glass. This indicator characterizes the percentage of silicon oxide to sodium oxide in the composition. The value only indicates the yield of the product from silica, but does not determine the quality of the solution itself. For calculations, chemical research methods are used, which are carried out using special equipment.

Material characteristics

The applicability of any material is determined by its technical parameters. Properties of impurity-free silicate glass under normal conditions:

. physical density is in the range of 2500-2600 kilograms per cubic meter and does not depend on the temperature conditions of the atmosphere;
. modulus of elasticity (Young's modulus) - 70 gigapascals;
. shear modulus, which characterizes the ability to resist shear deformation, is at around 26.2 gigapascals;
. the value of the ratio of relative transverse compression to relative longitudinal tension or Poisson's ratio - 0.25;
. tensile strength - 1000 megapascals, but when hardening, it is possible to increase the base rate by 3-4 times. Every house has silicate glassware, so many people know that if you drop a glass on the floor, it does not always break, since a tempered brand is used to make it;
. hardness index on the Mohs scale - 7 units;
. in terms of brittleness, glass belongs to the category of ideally brittle materials, which means that it can be broken without visible deformation;
. thermal conductivity is extremely low - 0.0023 cal / (cm * s * hail);
. melting temperature is in the range of 400-600 degrees Celsius.

The price of such glass per square meter depends on the brand.

Glass

(Glass) - An inorganic melt product cooled to a solid state without crystallization.

In composition:

Soda lime silicate glass

(Soda-lime glass) - Glass, the main components of which are silicon dioxide, sodium and calcium oxides.

Borosilicate glass

(Borosilicate glass) - Silicate glass containing boron as a characterizing component. Borosilicate glasses are usually heat resistant.

According to the manufacturing method:

Sheet glass

(sheet glass) - Glass made in the form of flat sheets.

drawn

(Drown glass) - Glass, usually in the form of a sheet, produced by continuous mechanical drawing.

rolling

(Rolled glass) - Sheet glass made from glass mass by rolling it continuously between two rolls or by periodically rolling on a table using one roll.

polished flat

(Polished plate) Clear glass, both surfaces of which are ground and polished to be flat and parallel in order to provide a clear, undistorted image when viewed through it or when reflected.

Thermopolished

(Float glass) - Sheet glass, produced by molding a glass melt on a metal melt at a controlled temperature in a protective atmosphere.

multilayer

(Laminated) - Sheet glass consisting of two or more sheets of glass glued to each other over the entire surface with a polymer film

hard coated glass

(hard coat glass) - Glass with a coating that is resistant to climatic influences, applied by the pyrolytic method.

Soft coated glass

(soft coated glass) - Glass with a coating that is not resistant to climatic influences, applied by spraying in a vacuum.

Strained glass

(Toughed glass) - Glass, the surface of which is rapidly cooled from a temperature close to the softening point so that residual compressive stresses remain on the surface after complete cooling. This increases the thermal and mechanical strength of the glass and causes it to shatter into smaller fragments without sharp corners than normal glass when subjected to breaking stresses. Used where safety glass is required.

By appearance:

clear glass

(Clear glass) - Transparent colorless glass

Super clear glass

(Extra-clear glass) - Colorless glass with a reduced iron content, due to which its increased transparency is achieved

Mass-tinted glass

(Tinted glass) - Glass, colored in the mass, with a reduced transmittance of light and solar energy. (Domestic manufacturer - Saratov Institute of Glass)

Patterned rolling glass

(Figured rolled glass) - Semi-transparent rolled glass with a pattern on one of the surfaces.

reflective glass

(Reflective glass) - Glass with a metallized reflective coating on one side.

Mirror

(Mirror) - Sheet glass having a highly reflective coating (more than 80%) on one surface.

Stained glass

(Stained glass) - in fact, the stained-glass window itself is a composition of glasses separated by a metal stretch.

Reinforced glass

(wired glass) - Flat glass with a built-in metal mesh with square or hexagonal cells. Glass may have one green cast surface (reinforced cast glass); it can be polished (polished wired glass) or translucent with a hexagonal mesh (patterned rolled wired glass). It is applied as safe and fire-resistant.

Curved glass (bending)

(Curved glass) - Glass curved along the radius by heating it in a special furnace.

For additional features:

fire resistant glass

(Flameproof glass) - Glass that does not break easily when heated, or in contact with a flame.

Heat resistant glass

(Heat-resisting glass) - Glass capable of withstanding severe thermal shock, usually due to a low coefficient of thermal expansion.

neutral glass

(Neutral glass) - Glass with high chemical resistance

Sunscreen

(Solar control glass) - Glass that reduces the transmission of solar radiation in the entire spectrum of wavelengths or in part of it (usually tinted or reflective).

enameled hardened

(Enamel toughened) - Sheet glass coated with enamel paint and tempered. Usually used for finishing facades.

Safety glass

(Safety glass) - Glass that, when broken, forms fragments that are much less likely to cause serious cuts than ordinary glass fragments. Usually it is tempered glass.

Impact resistant ("bulletproof")– High-strength glass that can withstand heavy impact. It is divided into several protection classes. Depending on the class, this is usually tempered or laminated glass.

Glass with low emissivity coating

(Low E glass) - Glass with a coating that provides increased thermal insulation. The cover is either hard or soft.

double glazing

(Insulating unit) - A product consisting of two or more sheets of glass, connected along the edges so that between them hermetic cavities filled with dried gas are formed.

Glass-tinted coating

This is ordinary colorless glass, on which a layer of metal oxide is deposited in a vacuum chamber. Such a coating is called soft ("off-line" - in contrast to the hard coating, which is applied directly to the line at the factory - "on-line"). It is subject to physical and atmospheric influences. Tinted sprayed glass has light and heat reflective properties.

Triplex

The bonding of two or more layers of clear, colored or reflective glass.

Tempered glass (stalinite)

This is tempered glass. As a result, it acquires such properties as increased heat resistance (up to 300 degrees), increased strength (5-6 times stronger than ordinary glass) and safety of use (when broken, it shatters into small safe fragments).

Energy saving glass

High-quality glass with one-sided multi-layer low-emissivity coating applied by the magnetron method. The purpose of glass is to preserve the thermal radiation emitted from heating systems and lighting fixtures and thereby reduce heat loss through window structures.

Glass brand

Higher quality glass is M1, the lowest quality is M6. Brand M7 is glass of brand M4, only large (3210 x 2250 mm) size. When packing finished glass into boxes at the factory, each sheet is checked for the presence and number of defects per unit area.

Leaching

Staining due to alkali attack caused by the presence of water.

Iridization

The appearance of specific "fatty" or oil-skin-like spots.

Grinding

The first stage of edge processing. This is a rather rough processing, after which the edge is matte, rough.

Polishing

The edge of the glass is polished, that is, the edge is brought to a transparency similar to the glass itself.

curved glass(bending) (Curved glass)

Glass curved along the radius by heating it in a special furnace.

bending

The process of forming glass by reheating it until it assumes the shape of a glass mold without changing the profile of the glass.

Engraving

The notching of a glass surface with an abrasive tool, usually for the purpose of decoration.

Sandblasting

Obtaining a matte glass surface by blasting fine abrasive particles at high speed.

Bubble

A cavity in glass filled with gas.

Etching

Surface treatment of glass with hydrofluoric acid or other chemicals, mainly for marking or decoration.

float process

A modern way of making quality flat glass, in which a ribbon of hot glass is poured onto the surface of molten tin, which is denser than glass.

German company engaged in the production of machine tools and tools for glass processing, founded in 1923. Owner trademarks Silberscnitt, Diamantor and Veribor.

suckers

Universal lifting suction devices for working with all types of cargo. Suitable for all materials with a smooth, flat, sealed surface.

Reismus

Fast Parallel Cutting Device large sheets glass.

lead tape

Self-adhesive lead tape with 99% pure lead.

beveli

Glass elements made of 5 mm glass with a 1.5 mm curly facet edge, glued to the glass.

UV glue

Adhesive for bonding glass to other materials. Such an adhesive reaches its tensile strength due to the action of UV radiation (spectrum length 315-400 nm). The final seam is crystal clear.

glass block

In appearance, the glass block is a glass brick. Inside the glass block there is ordinary air, which gives this material excellent heat-saving and sound-proof properties. Glass blocks are colorless, colored.

fusing

A term that has taken root in Russian to refer to a number of technologies for processing warm glass.

hot glass

Glass that is formed at temperatures above 1000 C.

warm glass

Glass that is formed at temperatures between 600 and 900 C.

glass sintering

Thermal connection of several glass elements into one.

facet from 5-50mm - Facet, beveled edge of mirror glass, also the plane of the edge of precious stones (polished chamfer).

Tableware is made from sodium - calcium - silicate glass, crystal various kinds, as well as from muffled borosilicate glass; household utensils - from sodium - calcium - silicate glass with additives that increase chemical and thermal stability; kitchen - from special household glass and glass-ceramics.

By color Distinguish between glassware made of colorless, colored (colored in mass) and overhead (two- and multi-layered). The names of colored glasses are given by color tone (yellow, green, pink, etc.), by the nature of the dye (cobalt, manganese), by analogy with precious stones: rubies (red), topazes (yellowish brown), sapphires (light -blue), emeralds (light green).

By molding method Distinguish between hand-blown, free-blown, machine blown, pressed, press-blown, multi-stage molding, lightning, centrifugal production.

According to the method of heat treatment Distinguish between dishes not hardened, i.e., annealed, and hardened by hardening.

The vast majority of high-quality glass products and all crystal products are produced annealed.

Hardening consists in heating the products to 700 ° C and subsequent rapid and uniform cooling by air blowing. In this case, high, evenly distributed residual stresses appear in the glass, which increase the impact strength by 5–8 times, and the heat resistance by 2–3 times. Harden some types of pressed tableware and heat-resistant borosilicate glass cookware by tempering.

By size dishes are divided into small, medium, large, extra large. The size of products is characterized by diameter, length or height, and the size of hollow products is characterized by capacity.

By way of decoration Distinguish between smooth and decorated dishes. Decorated dishes, depending on the nature, complexity and artistic merit of the cuts, are divided into group and non-group. Sections of group blown glassware made of sorted colorless glass are subdivided into groups 1-7, colored glass - into groups 3-8, from overlay glass - into groups 4-8. Cuts of crystal products are referred to the 4th-10th difficulty groups.

The group combines drawings of the same complexity, but with a different plot. They are designated by three-digit numbers, in which the hundreds digit indicates the group number.

Out of group products are characterized by original forms, complex, often combined patterns of high artistic value. They are individual for the products of each plant.

Many products with the “H” index and sold at contractual prices are classified as out-of-group.

The cutting of pressed products is not divided into complexity groups.

Modern tendencies in the decor of glassware - an expansion of the range of colored glasses, a combination of colored and slightly muted glass in the overlay, contrasting combinations in the pattern of elements of a diamond edge, matte engraving, a chandelier, the widespread use of decal patterns and silk-screen printing of various subjects, picturesque cuts with paints and gold, often in combination with matting. Harvest cuts and products are still popular.

By completeness distinguish between piece products, sets (include products of the same type - a set of glasses, etc.), devices (contain products different types one purpose) - for water, jam, flask, toilet, etc. The products of the sets are characterized by the unity of the artistic and constructive solution.

Modern industry, both domestic and foreign, produces a wide variety of glassware. The range of large manufacturers of tableware can include hundreds of items of various products. Modern merchandising classifies such glass goods according to several criteria at once:

By type of glass (products made of ordinary, painted, heat-resistant, crystal glass);

According to the production method (pressed, blown, press-blown products);

By purpose (household, household, kitchen utensils, art products);

By type (mugs, plates, glasses, wine glasses, glasses, glasses, vases and much more);

By styles, which are determined by the shape of the case;

According to the design features (with a handle, on a leg, and others);

In shape (hollow and flat).

By size (table No. 1.2.);

Table No. 1.2. Parameters of glass products

By capacity in cubic centimeters, height and diameter (for vases);

By the nature and complexity of the decoration (decorations applied during the production process and decorations applied to finished goods).

By completeness (pair, set, device, service, set).

The range of household utensils can be reflected as follows:

a) dining room

b) tea and coffee;

c) kitchen;

d) business.

Tableware includes: dishes, vases, salad bowls, butter dishes, herring bowls, glasses for wine, water, mineral water, drinks, juices, carafes for wine and water, jugs, wine glasses, mugs, sets, etc. Colored glass tableware (during its manufacture, dyes are added to the glass mass - lustrin, cobalt, etc.). Outwardly spectacular, with high aesthetic qualities, this dish can become an organic part of interior design. Glass manufacturing technology is much simpler than crystal; glassware is cheaper and therefore recommended for everyday home use.

Kitchen utensils are made of heat-resistant glass and ceramic glass, represented by pots of various capacities, baking dishes, braziers, frying pans.

1.1.9 Composition and properties of glass products

The main types of ordinary glasses, depending on the name of the main glass-forming oxide, are sodium-lime, potassium-lime, and potassium-lime-sodium.

Phosphate and borate glasses are used mainly for technical and special purposes. Mixed glasses, such as borosilicate glasses, are used to produce thermally stable products (cookware), in optics, and for other purposes.

One of the varieties of special glasses is the glass-ceramic class of materials obtained by directional crystallization of glasses of special compositions and possessing a number of specific properties.

Silicate glasses include varieties such as:

- lime-sodium Na 2 O CaO 6SiO 2 (for window glass, glass containers, partially dishes);

- lime-potassium K 2 O CaO 6SiO 2 (for the production of household and chemical dishes);

- crystal glasses PbO CaO 6SiO 2 (lead and lead-free - barium crystal) colored glasses contain various metal oxides that color the glass in various colors and shades (according to the table). For example, CoO gives an intense blue color (cobalt), sapphire - blue of low intensity CuO 1-2%; Gold ruby - AICl 3 particles 5-10 microns; Copper ruby - AuCl 3 particles 10-13 microns; Topaz - golden yellow with shades (selenium oxide); Yellow - pure yellow tone - (cerium oxide); Green - pure green tone, uranium oxide, 4.5

copper oxide; etc.

- Quartz glass obtained from pure sand. This is a very heat-resistant glass and is made from laboratory glassware, as well as medical lamps that transmit ultraviolet rays.

- Borosilicate glass. They include boron compounds (12.5℅). They are used to make kitchen utensils (pots, pans) that can withstand high temperatures. These are heat resistant glasses.

- Sitally obtained by controlled crystallization. Glass can be transparent or opaque. Glass-ceramic glassware is used to make dishes, trays for microwave ovens.

Ordinary glass - soda-lime, potash-lime, soda-lime-potassium.

Glasses of this group are characterized by transparency, strength, low cost.

The cheapest representative of this group of glasses is soda-lime (soda), or sodium-calcium-silicate, which has different color shades (greenish, yellowish, grayish, etc.) in varying degrees of severity. This glass is used to produce household dishes (jars, bottles) and cheap, usually colorless, everyday tableware.

Lime-potassium (potash) or potassium-calcium-magnesium-silicate glass has higher heat resistance, increased brilliance and transparency; used to make high quality tableware. Potassium-calcium-silicate glass, due to the introduced potassium oxide, has a greater colorlessness, which makes it possible to improve products in terms of aesthetic properties, both colorless and colored (greater purity of color is achieved). This glass is somewhat more expensive, it is used mainly for the production of tableware.

Lime-sodium-potassium (soda-potash), or sodium-potassium-calcium-magnesium-silicate, glass has an increased chemical resistance due to the mixing of sodium and potassium oxides; most common in the manufacture of tableware.

All properties of glass are divided into two groups: physical and chemical properties and chemical.

The main indicators of the physicochemical properties of glasses are their density, strength, brittleness, hardness, thermal conductivity, thermal expansion, thermal stability, and transparency.

The range of glass goods is quite dynamic and changes due to constant development science, the state of production technology, the nature of consumer demand, the change in style directions.

The range of household products is classified according to the purpose and operating conditions, the composition and color of glass, the method of molding and the nature of heat treatment, types (names), sizes, styles of products, methods and complexity of decoration, completeness.

By purpose, household goods are divided into dishes and decorative items for table setting and interior decoration, household utensils for storage food products and home canning, cooking utensils, lamp products (table lamps, lamp tanks, lamp glasses) and mirrors.

According to the composition of glass, dishes from sodium - calcium - silicate, special household and crystal glass are distinguished.

Tableware is made from sodium - calcium - silicate glass, crystal of various types, as well as from opaque borosilicate glass; household utensils - from sodium - calcium - silicate glass with additives that increase chemical and thermal stability; kitchen - from special household glass and glass-ceramics.

According to the color, dishes made of colorless glass, colored glass (colored in mass) and laid on glass (two multilayered) are distinguished. The names of colored glasses are given by color tone (yellow, green, pink, etc.), by the nature of the dye (cobalt, manganese), by analogy with precious stones: rubies (red), topazes (yellowish brown), sapphires (light -blue), emeralds (light green).

According to the method of molding, hand-blown, free-blown, machine-blown, pressed, press-blown, multi-stage molding, molded, centrifugal ware are distinguished.

According to the method of heat treatment, dishes are distinguished not hardened, that is, annealed, and hardened by hardening.

The vast majority of high-quality glass products and all crystal products are produced annealed.

Types of glassware

There are about thirty items of tableware; these are glasses, goblets, glasses, goblets, wine glasses, jugs, decanters, sugar bowls, oilers, vases for table setting (for fruit, jam, cookies, cream, sweets, salad bowls), bowls, etc.

Decorative items- These are glass sculpture, flower vases, toilet utensils, horn-shaped glasses, dishes, etc.

Each type of product is produced in several varieties (articles), differing in size and style.

By size, the dishes are divided into small, medium, large, extra large. The size of products is characterized by diameter, length or height, and the size of hollow products is characterized by capacity.

According to the style, the products are subdivided taking into account the shape of the body (ball, oval, cone, etc.), the presence of sticky (handle, leg, lid holder) and removable (cork, lid) parts, the nature of the edge (smooth, cut) and the bottom of the products. The dishes are produced with a bottom of normal thickness, thickened, as well as on a pallet (a ledge or ledge at the bottom of the product).

The leg of products can be of different heights, shapes (straight or figured) and processing (faceted and even). Blown vases for flowers, depending on the complexity of the form, are divided into three groups.
The style, along with the aesthetic features of glass mass and cutting, largely determines the artistic expressiveness of products. It is subject to change in accordance with the requirements of the style. At present, tableware of a festive and gift character is distinguished by a complex silhouette, careful processing and complex shape of details. Everyday utensils have simpler and more solid forms.

According to the method of decoration, smooth and decorated dishes are distinguished. Decorated dishes, depending on the nature, complexity and artistic merit of the cuts, are divided into group and non-group. Sections of group blown glassware made of sorted colorless glass are subdivided into groups 1-7, colored glass - into groups 3-8, from overlay glass - into groups 4-8. Cuts of crystal products are referred to the 4th-10th difficulty groups.

The group combines drawings of the same complexity, but with a different plot. They are designated by three-digit numbers, in which the hundreds digit indicates the group number.

Non-group products are characterized by originality of forms, complex, often combined drawings of high artistic value. They are individual for the products of each plant. Many products with the “H” index and sold at contractual prices are classified as non-group products.

The cutting of pressed products is not divided into complexity groups.

Modern trends in the decor of glassware - expanding the range of colored glasses, a combination of colored and slightly muted glass in the overlay, contrasting combinations of diamond-cut elements in the pattern, matte engraving, a chandelier, the widespread use of decal and silk-screen printing patterns of various subjects, picturesque cuts with paints and gold, often in combination with matting. Harvest cuts and products are still popular.

By completeness, they distinguish piece products, sets (they include products of the same type - a set of glasses, etc.), devices (contain products of different types for the same purpose) - for water, jam, flask, toilet, etc. Products of kits are characterized by the unity of artistic and constructive solutions.

The range of dishes for table setting is extremely diverse and is grouped taking into account all the features mentioned earlier. Main types of products: glasses, mugs, cups, goblets, wine glasses, wine glasses, goblets, decanters, jugs, milk jars, vases for table setting (for fruits, cookies, sweets, jam, cream, salad, bowls), butter dishes, sugar bowls, croutons and etc.

Decorative items are represented by sculpture, flower vases, toilet utensils, horn-shaped glasses, etc.

Household utensils are produced manually or mechanically from colorless and semi-white glass. The assortment includes thermoses and other products for storing food - jars, jars for pickles and jams, kegs, bottles for storing liquids. Thermoses are divided according to their purpose into thermoses for liquids and food (with a wide mouth), according to the capacity of the flask, the design and material of the shell (metal, plastic, combined).

Kitchen utensils made of heat-resistant glass and ceramic glass are represented by pots of various capacities, baking dishes, braziers, frying pans. Sets of pans and the “Kid” set are produced from sitall. Heat-resistant glassware is tempered and not decorated. White glass-ceramic tableware with a smooth shiny surface is additionally decorated with decal patterns.

The range of glass goods is quite dynamic and changes due to the constant development of science, the state of production technology, the nature of consumer demand, and the change in style trends.

By purpose, household goods are divided into dishes and decorative items for table setting and interior decoration, household utensils for food storage and home canning, kitchen utensils for cooking, lamp products (table lamps, lamp tanks, lamp glasses) and mirrors.

According to the composition of glass, dishes from sodium - calcium - silicate, special household and crystal glass are distinguished.

According to the method of molding, hand-blown, free-blown, machine-blown, pressed, press-blown, multi-stage molding, molded, centrifugal ware are distinguished.

According to the method of heat treatment, dishes are distinguished not hardened, that is, annealed, and hardened by hardening.

The vast majority of high-quality glass products and all crystal products are produced annealed.

Types of glassware

Decorative products are glass sculpture, flower vases, toiletry, horn-shaped goblets, dishes, etc.

Each type of product is produced in several varieties (articles), differing in size and style.

The style, along with the aesthetic features of glass mass and cutting, largely determines the artistic expressiveness of products. It is subject to change in accordance with the requirements of the style. At present, tableware of a festive and gift character is distinguished by a complex silhouette, careful processing and complex shape of details. Everyday utensils have simpler and more solid forms.

The group combines drawings of the same complexity, but with a different plot. They are designated by three-digit numbers, in which the hundreds digit indicates the group number.

The cutting of pressed products is not divided into complexity groups.

Decorative items are represented by sculpture, flower vases, toilet utensils, horn-shaped glasses, etc.

October 27, 2015 Guest (nastya)

www.treeland.ru

What dishes are unhealthy: what you can and cannot cook food in

Can dishes be unhealthy: what should be stored and prepared food

To avoid many diseases, it is important not only to eat right, but also to know which dishes are harmful to health, because the material from which they are made can release hazardous substances.

Is there a safe tableware for health ^

Among the wide range of products for storage and cooking, cast-iron, earthenware, enameled utensils and those made from of stainless steel. In all other cases, harmful dishes can have a negative impact on the human body:

Release toxic substances when heated;
Cause severe allergies or food poisoning;
Oxidize, as a result of which harmful substances are activated.

Of course, when choosing any dish, you should pay attention not only to the material from which it is made, but also to the composition, which is usually indicated on the labels. For example, low-quality stainless steel may contain nickel, which gives food a metallic taste when it is heated.

In what dishes you can and cannot cook food ^

Dishes that are unhealthy: myth or reality

Cast iron cookware: benefits and harms

Cast iron products are best used for frying or cooking, because the food in it does not burn, and the material itself is environmentally friendly and only becomes stronger and safer over time.

Aluminum cookware: harm and benefit

It is such dishes that are considered the most harmful, because when heated, they actively release metal ions. Under the influence of acids contained in milk or any other product, aluminum passes into food.

It is strictly forbidden to fry and boil soups or vegetables in such pots.
Daily use of aluminum utensils often leads to food poisoning.

Copper utensils: benefits and harms

Dishes made of copper are completely harmless to the body, because even if its ions enter it, they are very quickly excreted.

Despite this, it has a significant drawback: when cooking fruits or vegetables, copper destroys most of the vitamins they contain;
If the food contains acids, then it can react with them.

Damage to crystal glassware

Most often, people drink drinks from crystal glassware, and in this case it is considered safe.

If you store liquids in it, then it begins to release lead, which further harms the body.

Silicone utensils: benefits and harms

Despite the fact that silicone contains chromium, cobalt, copper and other components, bakeware made from it can be safely used:

due to the special technologies and requirements that apply to the production of such utensils, the release of harmful substances under the influence of temperatures does not occur.

Enamelware: benefits and harms

Initially, enameled utensils were designed specifically to protect against the ingress of metal ions into food, but here it all depends on the color of the coating:

blue, black, cream, white or blue-gray is considered safe,
red, yellow or brown should be discarded - they contain a lot of dyes and have low protective properties.

Silver utensils: benefits and harms

Since ancient times, dishes made of silver have been considered the best: they not only look good, but also kill all kinds of bacteria, thereby preventing them from entering the human body.

More recently, some media reported that this metal is not able to retain useful elements and remove harmful ones, but there is no direct evidence for this.

What is harmful dishes made of polypropylene

Plastic utensils have three degrees of heat resistance:

high,
middle,
low.

In the first case, we mean food containers that can be placed in the microwave, and in all the others - all kinds of bowls, cups, forks, spoons, etc. regardless of the ability to withstand high temperatures, it is not recommended to reheat dishes in such containers, because at high temperatures the plastic can melt and release harmful elements.

Polypropylene dishes can also not be used to store food.

Stainless steel (stainless steel) utensils: harm and benefit

Steel utensils can be safely used for frying and cooking first courses, but food should not be stored in them, because they can release nickel that penetrates into dishes.

cupronickel utensils

For several centuries, cupronickel products have been very popular, and for good reason: despite the fact that they are made from an alloy of copper and nickel, they are safe for human health - it is enough just to clean them from plaque in time.

Pewter

In general, tin utensils are safe, but if they contain lead impurities, which darken them over time, it is best to refuse to use them.

Glassware

Dishes made of ceramics are harmless only if there are no chips or cracks on them, otherwise salts of heavy metals can enter the body.

In addition, plates made of such material may have patterns painted with paints containing lead inside, so it is not recommended for use for its intended purpose.

Galvanized tableware

Such utensils are not suitable for heat treatment of products, because. when heated, it releases zinc.
Keeping food in it is not worth it for the same reasons.

Teflon coated cookware

Now Teflon is coated not only with pans, but also with other kitchen utensils, however, if the integrity of the coating is violated, it is best to get rid of such dishes, because it provokes the development of obesity and cancer.

Melamine tableware

If there is damage on such dishes, it begins to emit a dangerous poison - formaldehyde.
In this case, it must be abandoned. Also, it is not suitable for frying or boiling.

Ceramic dishes: harm and benefit

Unlike Teflon, thermolon-coated cookware is more harmless, because her Negative influence on human health has not been confirmed.
In addition, it can be heated up to 400 degrees or more.

Glassware: harm or benefit

Like ceramic containers, baking containers, glass mugs and plates do not bring any harm to health, because they are made without the use of elements that negatively affect the human body.

acrylic tableware

If you do not heat food in such utensils, then it is quite safe.
Unlike harmful disposable tableware, it can be used repeatedly, and in this it obviously wins.

Opal tableware: harm and benefit

Thanks to modern technologies Opal glassware is very light and elegant:

Various patterns can be applied to it, which does not affect its strength in any way.
It has practically no pores, which allows it to be considered completely safe for food storage.
It tolerates temperature extremes, from high to low. Frosted glass pans are great for use in microwave ovens.
It has low thermal conductivity, which allows long time keep food hot.
Washable and easy to keep clean.
Resistant to the use of any detergents, they do not cause visible harm to it.
With increased durability, these cookware can be stored in stacks, saving space in your kitchen.

What dishes are not harmful to health

Nickel-plated dishes are considered the most harmful, because. it contains nickel, however it is the most common. Cooking and storing food is best done in containers made from the following materials:

Clay;
Cast iron;
Stainless steel (do not leave dishes in it for a long time).

Harm of plastic bottles and polyethylene film: what is the danger ^

The composition of plastic containers may contain the chemical substance bisphenol-A, a synthetic analogue of the female sex hormone, which is able to penetrate into water or liquid, and then into the human body.

If you drink water from plastic bottles, thereby increasing the content of bisphenol in the body:

Scientists at Harvard University conducted a study and found that drinking cold plastic liquids for just one week increased the level of bisphenol in the urine by 69%.
Bisphenol release is temperature dependent. The higher the temperature, the more active the contamination of water with bisphenol from plastic. That is, the usual summer heat can increase the concentration of a harmful substance in water tenfold.
If you fill with hot liquid or specially heat plastic bottles, then the release of bisphenol will increase up to 55 times! This fact should be known to parents who warm milk in plastic bottles for their children.
An increased concentration of bisphenol increases the likelihood of prostate cancer in men and has a negative impact on men's health, as hormonal levels are disrupted.
It is generally contraindicated for pregnant women to drink water from plastic bottles, since due to bisphenol poisoning, a child may be born with birth defects.

happy-women.com

Carefully! Harmful utensils

We all cook food for ourselves and our loved ones from time to time. We eat several times a day. Do we know what exactly we cook in and what we eat from? Do we use useful or harmful utensils? Let's figure it out.

In Russia, traditionally, dishes were made of wood. And not every tree was suitable for its manufacture. The medicinal properties of wood were of great importance.

So, it was believed that dishes from linden had anti-inflammatory properties, from mountain ash - protected from beriberi. It is known that birch bark has many medicinal properties- from bactericidal to tonic. They ate with wooden spoons from wooden bowls, used wooden bowls, ladles and jugs. In addition, they wove dishes from birch bark - salt shakers, tueski for storing flour and cereals.

Copper utensils appeared next. Perhaps you also have a copper bowl or saucepan in your kitchen? Indeed, in many families, dishes made of copper and its alloys are passed down from generation to generation. And no wonder: it has always been enjoyed with pleasure! The fact is that due to its high thermal conductivity, copper has a remarkable quality for cooking - heat is evenly distributed over the surface of the dishes. And therefore, delicious jam, fragrant coffee or a wonderful sauce are obtained in copper utensils as if by themselves.

But modern science somewhat overshadows our emotions - she warns: even a very small amount of this metal destroys ascorbic acid in berries and fruits.

And one more thing: food stored in copper utensils loses vitamins, polyunsaturated fatty acids are easily oxidized in it, forming compounds dangerous to the body - free radicals.

With frequent use, poisoning is not excluded.

In addition, copper in a humid environment is easily oxidized and a green or blue-green film appears on the dishes - patina. When heated, it interacts with food acids, forming copper salts that are harmful to the body.

Therefore, after washing, the plate or basin must be thoroughly wiped, preventing the formation of a film. If, nevertheless, a patina has appeared, then it must be carefully removed from the entire surface, otherwise using harmful dishes will be dangerous to health. You can do this this way: wipe with table salt moistened with vinegar, and immediately rinse first with warm, then cold water.

Lead in ceramic dishes

For centuries, lead has been added to the alloys used to make dishes. The sad consequences of this in our time are well known to scientists: lead, gradually accumulating in the human body, led to poisoning.

In the Roman Empire, wine vessels and other kitchen utensils contained large amounts of lead. As a result of the use of such harmful utensils, the life expectancy of the population has almost halved. Some historians even believe that the lead poisoning of the Roman "top" was not the last reason for the decline of a powerful state.

Also in our time, scientists have proven that lead is guilty of destroying the health of the Moscow princes - the water that was supplied to the Kremlin flowed through a lead water pipe ...

In many countries of the world, more than a quarter of a century ago, a ban on the use of lead in the manufacture of dishes was introduced.

But, despite this, even today you can easily become the owner of harmful pots or, for example, cups.

It is worth remembering here known history one American couple.

Once, while vacationing in Italy, the couple bought beautiful ceramic cups. Arriving home, they did not put them in a cupboard behind glass to admire and show to guests, but began to use them actively every day.

Two and a half years later, both of the spouses showed signs of lead poisoning: insomnia, nervous breakdowns, sudden bouts of pain “walking” in different parts of the body. The doctors, to whom the sufferers turned, were at a loss - they could not understand what was the matter.

The man even underwent two completely unnecessary operations, and the woman was stubbornly treated for liver disease.

But, following the well-known saying “saving the drowning is the work of the drowning themselves”, the American couple, having “shoveled” a mountain of special medical (and maybe not only) literature, diagnosed itself with lead poisoning! And he was absolutely correct, which was then confirmed by specialists working with poisons.

Let's try to figure out how lead got into the dishes (after all, the cups are ceramic, not metal!). Most likely, they were decorative, and therefore not intended for drinking tea, coffee and other drinks from them.

The fact is that according to sanitary standards, the presence of lead is allowed in the manufacture of decorative dishes. It turns out that it is added to paints to give pottery smoothness and a beautiful shine. But: in the instructions for using such products, it must be written that food cannot be stored in them! And we must understand that this is harmful dishes.

Therefore, we conclude for ourselves: if we buy a vending plate, cup, pot - brightly colored, do not be shy and be sure to ask the seller for a certificate. And in this document we are looking for information about the results of checking dishes for the content of toxic substances. But, unfortunately, the reality is that certificates are often forged.

So maybe it's better to be careful and not buy at all. ceramic products with overly bright red and yellow painting, which almost always indicates the presence of lead and cadmium in the paint.

By the way, the bright green color is possibly “tinted” with copper. And it, in addition to being not useful in itself, also accelerates the process of lead release. Therefore, for beauty, it is not forbidden to purchase such cups and plates, but for everyday use for its intended purpose - experts categorically do not advise.

Lead in cans

In addition to harmful utensils, some tin cans can also become a source of lead poisoning, since their elements are connected to each other with lead-containing solder. These cans are easily identified by the corrugated seam and silver-gray connecting line with irregular outlines. Although the inner surface of the cans is usually coated with a special compound, this does not always help.

There are cases when, during long-term storage of lead, up to 3 mg/kg accumulated, which is much higher than the permissible level. Its content can be especially high in canned acidic foods: tomatoes, fruit juices, etc.

In addition, they usually contain another toxin - tin.

In order not to put yourself in danger, you need to buy canned food in cans with smooth welded seams, which are located between the sticker and the top or bottom end of the jar.

Aluminum

Aluminum cookware 10-15 years ago could be seen in almost every kitchen. It is easy to clean, and food does not burn in it during cooking. It is very good to boil milk in such a saucepan, cook milk porridges, jelly, vegetables for vinaigrette and salad, etc. But, sadly, all this food turns out to be “flavored” with aluminum!

And under the influence of milk, as a representative of alkali, and under the influence of the acidic environment of vegetables being prepared in microscopic doses, aluminum “flakes off” from dishes and safely ends up in our stomach. Aluminum does not oxidize in water, but even it “washes out” its microparticles.

So neither boil water nor store it in harmful aluminum dishes, however, like any other products.

No, if you cooked oatmeal porridge for a child in an aluminum ladle once or twice, nothing bad will happen. But if you do this every day, then do not be surprised that the baby has become terribly excitable.

Well, if you cook for yourself in dishes made of this metal for years, then the opinion of experts is this: sooner or later enough aluminum will accumulate in your body to provoke such formidable diseases as anemia, kidney and liver diseases, various neurological changes, and even Parkinson's disease and Alzheimer's disease.

Relatively recently, beautiful tableware made of melamine made in China and Turkey appeared in our kitchens. In appearance, it resembles porcelain, but is much lighter in weight. Due to its very attractive appearance, purity of colors, it is popular with buyers.

But this is toxic and harmful dishes! One of the sources of danger is the salts of lead (again!), cadmium and other metals that make up the paints with which she signs.

Transfer inks are not coated with any protective layer and are very easy to get into products.

Another danger is that melamine contains toxic formaldehyde. It is isolated by many plastics, but according to the results of special studies, melanin does this especially strongly - tens or even hundreds of times higher than the permissible norm. In experimental animals, such doses of formaldehyde cause mutagenic changes in the body and the formation of cancer cells.

Sanepidnadzor banned the sale of melamine tableware. But walk up to the crockery section of any market and you'll see pretty cups, plates, and all sorts of sets of them.

In addition to melamine, you can also find harmful dishes from other polymeric metals on sale.

Specialists involved in the testing and certification of these products believe that they can be used, but only with strict adherence to the manufacturer's instructions.

For example, if plastic utensils are intended only for bulk products, then liquid cannot be kept in it, otherwise it can absorb toxic substances. If the instructions for use, for example, of plastic containers say that they are for cold food, then do not put hot food in it, etc.

"Stainless steel" and silver

Recently, stainless steel utensils, an alloy of iron, carbon and other elements, have become very popular. Steel with additions of 18% chromium and 8% nickel has been widely used for the manufacture of kitchen utensils. If it is made of high-quality steel (and the production technology is not violated), then it does not change the taste of the products and is safe for health.

Pots and pans made of such steel are preferred with a thick bottom - they provide gradual heating and long cooling. Dishes from "stainless steel" cannot be overheated - after that the food in it will burn. And one more thing: we must remember that nickel is a strong allergen, so people with allergies should be careful with it.

Enamel and glass

Perhaps, good old enamelware meets all safety requirements. She, of course, is in every home. Its main advantage is enamel, which, due to the inertness of its components, does not interact with salts, acids, or alkalis. This makes enameled utensils very popular.

Of course, you can only use such dishes whole. Indeed, in places of damage, cracks and chips, yellowish-red spots appear, which are not removed when washed. This is normal rust. And it, interacting with food acids, forms iron salts harmful to humans. In addition, when washing in places of damage, particles of the cleaning agent may remain, which will also then enter your stomach.

Another type of safe cookware is heat-resistant glass. To give glass these properties, elements are added to its composition that retain strength at high temperatures. So you should not be afraid that a teapot made of such glass on a gas fire or a baking sheet in the oven may crack, crumble, etc., is not worth it.

But we must remember that when using heat-resistant dishes, when it is in a "hot state", you need to avoid contact with very cold surfaces - then the saucepan will burst.

Glass is also chemically inert, like enamel, so dishes from it are not dangerous from this point of view. In addition, it is convenient - it washes well and the food in it looks beautiful both when cooking and when serving.

This begs the question: is there such a thing as completely safe cookware? Perhaps it is best to eat from a silver plate with a silver spoon, and drink from a silver cup? After all, everyone knows the healing properties of this metal and the history of the Suvorov army, where officers did not suffer from gastrointestinal diseases, as they ate from silver dishes, while soldiers died in large numbers from these diseases?

Indeed, experts say, silver ions inhibit the development of pathogenic microflora in aqueous solutions.

But it turns out that food enriched with silver ions, with prolonged use, can adversely affect the human nervous system, cause headaches, a feeling of heaviness in the legs, and weaken vision. And if, again, you use silver utensils constantly, for years, it is possible to “earn” such a serious disease as gastroenteritis and even cirrhosis of the liver!

Teflon is the trade name for a polymer used for non-stick coatings on cookware. Indeed, food will not burn in a Teflon pan, even if we grease its surface with only a minimal amount of oil or fat. Agree, it will benefit our health, right? And we don’t need excess fat, and all the more harmful carcinogenic substances that are formed during overcooking of food, all the more so.

But in order for Teflon dishes to serve us "faithfully", it is necessary that they remain intact as long as possible. To do this, first of all, it is necessary to have wooden or Teflon special spatulas on the farm for turning or mixing the cooked food. And do not put an empty pot or pan on the fire.

By the way, experts advise buying dishes with a thick bottom, as experience shows that thin pans, no matter how carefully you take care of them, for some reason do not last long.

And now a few tips about dishes made from various materials. I hope they will be useful to the hostesses.

In order for any china served longer, it must be "hardened". Cups, saucers, plates, etc. are poured with cold water for several hours. And then, taking out one item at a time, they douse it with hot.

Enamel dishes are also “hardened”, but in a different way. A new pan is filled to the brim with a salt solution: 2 tbsp. l. per liter of water and bring to a boil. Then leave to cool.

But even “hardened” enameled dishes are best protected and not immediately placed from the refrigerator on a hot stove - the enamel can crack from a sharp temperature drop.

And further. It turns out that white enamel slows down the absorption of heat, which means that it will take you longer to cook a dish in such dishes than in a pan with dark enamel.

By the way, for making jam, experts consider the best containers made of enamel or stainless steel.

Teflon is a good, but, unfortunately, very fragile non-stick coating. Therefore, to wash such dishes, it is not necessary to use not only metal washcloths, but also powdered products - even they can scratch Teflon. Wash pans and pots with a soft washcloth and liquid detergent, then dry thoroughly with a towel.

Not only heat-resistant glassware is suitable for a microwave oven. You can use other glass, if, of course, it does not contain an admixture of lead. And also porcelain - only it should not have metal patterns, including “golden” borders. Suitable and clay dishes- if it is glazed over the entire surface (including the bottom). But when using plastic, be careful - carefully read the instructions of the company that made the dishes.

Better yet, don't use it at all. microwave ovens because they, with constant use, are also very harmful to health. But since now we are talking about harmful dishes, the danger of microwaves will be discussed in another article.

How to remove heavy metals from the body

The body, in essence, is able to remove toxins and toxins without external intervention. However, working and living in harmful conditions By leading the wrong way of life, we accumulate an excess of toxic substances, which our body can withstand with great difficulty. Heavy metals can accumulate in the plants and animals we eat. They can get into us with air, water, exhaust fumes, tobacco smoke, household chemicals and harmful utensils (copper, lead, iron). Isotopes of heavy metals are deposited on internal organs causing various diseases.

Eat foods containing pectin. Pectin has the useful property of collecting heavy metal salts on its surface. It is found in vegetables, fruits and berries. A product such as beets, for example, also contains flavonoids that convert heavy metals into inert compounds. The starch of a potato cooked in its skin absorbs body toxins, removing them naturally. Carrots, pumpkin, eggplant, radishes, tomatoes also remove heavy metals.

The use of apples, citrus fruits, quince, pears, apricots, grapes helps to eliminate toxic substances. Berries of mountain ash, viburnum, raspberries, blueberries, cranberries bind heavy metals into insoluble complexes, which are subsequently easily excreted by the body. By eating lingonberries, blueberries, blackberries, cloudberries and blackthorns, you cleanse your body of accumulated toxic substances. It is useful to use even marmalade made from these berries.

Drink tea from chamomile, calendula, sea buckthorn, rosehip. Tea from these herbs protects cells from the penetration of heavy metals and promotes their excretion. Rosehip and sea buckthorn oil is also useful for heavy metal poisoning. Remove radioactive cesium isotopes from the body with the help of sorrel, spinach, salads.

Take substances containing lignan, it neutralizes radionuclides. Such substances are found in plants: juniper, sesame and burdock seeds, in the roots of lemongrass and eleutherococcus. Also, with constant exposure to isotopes of radioactive metals, it is recommended to use 40 drops of tincture of Aralia, Leuzea, Rhodiola rosea, and ginseng before meals.

Drink tea made from coriander (cilantro) herb, it can remove mercury from the body within two months. Brew four tablespoons of chopped cilantro with a liter of boiling water in a non-metallic bowl and drink after 20 minutes.

Carry out rice cleansing procedures. They are especially recommended for people employed in hazardous industries. Rice removes toxic metal salts from the body. Soak a spoonful of rice in water in the evening, cook without salt in the morning and eat.

Use a decoction of oats to cleanse heavy metal salts. Pour a glass of oats with two liters of water, boil over low heat for 40 minutes. Drink half a glass four times a day, so you will be cleansed of salts of heavy metals, including cadmium, which is found in tobacco smoke.

Take care of yourself and your loved ones! Be healthy! published by econet.ru

It might be useful to read: