Sodium calcium silicate glass. Caution! Harmful dishes. Cold decorated glass products

There are universal construction Materials, which are used in the construction of any objects, regardless of their technological purpose. Silicate glass is one of such elements. This is one of the oldest materials that humanity 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 less useless impurities in the composition.

Manufacturing material

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

In stages it looks like this:

1. The main components for the production are quartz sand, limestone and soda. With the help of special equipment, a homogeneous mass is prepared from them - a charge, into which all these elements are included in a crushed form.
2. Further, 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 large number of glass grades and the additives used. Often these are carbide metals.
3. Further, the resulting substance enters the forms that will correspond to the type of the finished product. There, the glass solidifies at a temperature sufficient to prevent crystallization of the constituent components.
4. The resulting material does not have to be transparent. This parameter also depends on the use of additional elements during smelting.

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

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

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

In addition to the familiar and familiar to all 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 processing silica-containing raw materials with concentrated sodium hydroxide or by fusing silica 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 treatment with liquid, concrete, wood, paint cease to be afraid of open fire. The substance also strengthens well weak soils, prone to weathering of beneficial trace elements. It is used as the main component in the manufacture of heat-resistant ceramics for smelting metal molds.

One of the main characteristics of the material is the silicate module of water glass. This indicator characterizes the percentage of silicon oxide to sodium oxide in the composition. The value only shows the product yield from silica, but does not in any way 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 silicate glass free of impurities 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;
... elastic modulus (Young's modulus) - 70 gigapascal;
... shear modulus, which characterizes the ability to resist shear deformation, is at around 26.2 gigapascals;
... the value of the ratio of the relative transverse compression to the relative longitudinal tension or Poisson's ratio - 0.25;
... tensile strength - 1000 megapascals, but with hardening it is possible to increase the base figure by 3-4 times. There are dishes made of silicate glass in every home, so many people know that if you drop a glass on the floor, it does not always break, since a tempered brand is used for its manufacture;
... hardness indicator on the Mohs scale - 7 units;
... in terms of brittleness, glass belongs to the category of ideally brittle materials, which means its breakage without visible deformation;
... thermal conductivity is extremely low - 0.0023 cal / (cm * s * deg);
... the melting point 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 without crystallization.

By composition:

Sodium-calcium-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.

By 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, made by continuous mechanical drawing.

Rolling

(Rolled glass) - Sheet glass produced from molten glass by continuous rolling between two rolls or by periodic rolling on a table with one roll.

Polished flat

(Polished plate) - Transparent glass, both surfaces of which are ground and polished to give them flatness and parallelism, in order to provide a clear, undistorted image when viewed through it or when reflected.

Heat-polished

(Float glass) - Sheet glass produced by molding a strip of molten glass on a molten metal 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, resistant to climatic influences, applied by the pyrolytic method.

Soft coated glass

(soft coated glass) - Glass coated, 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 leads to the fact that it breaks into smaller fragments without sharp corners than ordinary glass, under the influence of destructive stresses. Used where safety glass is required.

In appearance:

Clear glass

(Clear glass) - Transparent colorless glass

Super clean glass

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

Tinted glass

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

Patterned rolled 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 with a highly reflective coating on one surface (more than 80%).

Stained glass

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

Reinforced glass

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

Curved glass (bending)

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

By additional properties:

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 its part (usually tinted or reflective).

Enamelled tempered

(Enamel toughened) - Enamelled and tempered sheet glass. Usually used for facades.

Safety glass

(Safety glass) - Glass that, when broken, forms fragments, the likelihood of serious cuts by which is much less than ordinary glass fragments. This is usually tempered glass.

Shockproof ("bulletproof") - Heavy-duty glass that can withstand heavy impact. It is divided into several classes of protection. Depending on the class, this is usually tempered or laminated glass.

Low emissivity coated glass

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

Glass unit

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

Glass-tinted spraying

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

Triplex

The connection of two or more layers of colorless, colored or reflective glass.

Tempered glass (stalinite)

This is glass that has passed the tempering procedure. 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 crumbles into small safe fragments).

Energy saving glass

High quality glass with one-sided multilayer low-emission magnetron coating. The purpose of glass is to preserve the thermal radiation emitted from heating systems and lighting devices and thereby reduce heat losses through window structures.

Glass brand

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

Leaching

Staining due to alkaline action caused by the presence of water.

Iridization

The appearance of specific "greasy" or oil-film-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)

Radial curved glass by heating it in a special oven.

Bending

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

Engraving

Scoring the surface of glass with an abrasive tool, usually for decoration purposes.

Sandblasting

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

Bubble

A cavity in the glass filled with gas.

Etching

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

Float process

A modern method of making quality flat glass, in which a strip of hot glass is poured onto the surface of molten tin, which has a higher density than glass.

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

Suction cups

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

Gage

A device for fast parallel cutting of large glass sheets.

Lead tape

Self-adhesive lead tape with 99% pure lead.

Beveli

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

UV glue

Adhesive for joining glass to another material. This adhesive reaches its ultimate strength due to exposure to UV radiation (spectrum length 315-400 nm). The end seam is crystal clear.

Glass block

The glass block looks like a glass brick. There is ordinary air inside the glass block, which gives this material excellent heat-saving and sound-insulating properties. Glass blocks are colorless, colored.

Fusing

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

Hot glass

Glass that forms at temperatures above 1000 C.

Warm glass

Glass that forms at temperatures from 600 to 900 C.

Glass sintering

Thermal bonding of several glass elements into one piece.

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

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

By color distinguish between dishes made of colorless glass, colored (colored in the mass) and overhead (two- and multi-layer). Colored glasses are named according to their color tone (yellow, green, pink, etc.), by the nature of the dye (cobalt, manganese), by analogy with precious stones: rubies (red), topaz (yellowish brown), sapphires (light -blue), emeralds (light green).

By molding method distinguish between hand, free, machine blown, extruded, press blown, multi-stage molding, zipped, centrifugal.

By the method of heat treatment distinguish between utensils not hardened, that is, annealed, and hardened by hardening.

The overwhelming mass of high-quality glass products and all crystal products are produced annealed.

Hardening consists in heating products to 700 ° C and subsequent rapid and uniform cooling by blowing air. In this case, high, evenly distributed residual stresses arise in the glass, increasing the impact strength by 5 - 8 times, and heat resistance by 2 - 3 times. Some types of pressed tableware and cookware made of heat-resistant borosilicate glass are hardened by hardening.

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

By way of decoration distinguish between smooth and decorated dishes. Decorated dishes, depending on the nature, complexity and artistic merits of the cut are divided into group and non-group. Cuts of group blown glassware made of high-quality colorless glass are subdivided into groups 1-7, from colored glass - into groups 3-8, from overhead glass - into groups 4-8. Cutting of crystal products belongs to the 4-10th complexity groups.

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

Outside 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 referred to outside the group.

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

Modern tendencies in the decor of glassware - an expansion of the range of colored glasses, a combination of colored and slightly dimmed glass in the overlay, contrasting combinations in the pattern of elements of a diamond facet, matte engraving, a chandelier, the wide use of decal and silkscreen patterns of various subjects, picturesque cuts with paints and gold, often in combination with matting. Sheathed 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 of different types of the same purpose) - for water, jam, crochet, toilet, etc. 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 assortment of large tableware manufacturers can include hundreds of different items. Modern commodity science classifies such glass products according to several criteria:

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

By the way of production (pressed, blown, press-blown products);

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

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

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

By design features (with a handle, on a leg, and others);

Shaped (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 decorations (decorations applied in the production process and decorations applied to finished products).

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

The range of household utensils can be reflected as follows:

a) dining room;

b) tea and coffee;

c) kitchen;

d) economic.

Tableware includes: dishes, vases, salad bowls, oil cans, herring bowls, glasses for wine, water, mineral waters, drinks, juices, decanters for wine and water, jugs, wine glasses, mugs, sets, etc. glass tableware (during its manufacture, coloring agents are added to the glass mass - lustrin, cobalt, etc.). Outwardly spectacular, possessing high aesthetic values, these dishes can become an organic part of interior decoration. Glass making technology is much simpler than crystal; glassware is cheaper and therefore recommended for everyday household use.

Kitchen utensils are made of heat-resistant glass and sitalls, represented by pots of various capacities, baking dishes, braziers, 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 lime-sodium, lime-potassium, lime-sodium - potassium.

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

One of the varieties of special glasses is the sitall class of materials, obtained by directional crystallization of glasses of special compositions and having a number of specific properties.

Silicate glasses include varieties such as:

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

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

- crystal glass PbO · CaO · 6SiO 2 (lead and lead-free - barium crystal) colored glasses contain various metal oxides, which paint the glasses in different 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 \u200b\u200b- AuCl 3 particles 5-10 microns; Copper ruby \u200b\u200b- Au Cl 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. It is very heat-resistant glass and is used for making laboratory glassware, as well as medical lamps that transmit ultraviolet rays.

- Borosilicate glasses... 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.

- Sitalls obtained by controlled crystallization. Glass can be transparent or opaque. Tableware, trays for microwave ovens are made of sitalls.

Common glasses are soda-lime, lime-potassium, lime-sodium-potassium.

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

The cheapest representative of this group of glasses is soda-lime (soda), or sodium-calcium-silicate, which is inherent in varying degrees of severity of color shades (greenish, yellowish, grayish, etc.). Household utensils (jars, bottles) and cheap, usually colorless, everyday tableware are produced from this glass.

Lime-potassium (potash), or potassium-calcium-magnesium-silicate, glass has a higher thermal stability, increased gloss and transparency; used to make high quality cookware. Potassium-calcium-silicate glass, due to the added potassium oxide, has a greater colorlessness, which makes it possible to improve products in terms of aesthetic properties, both colorless and colored (greater color purity 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 increased chemical resistance due to the mixing of sodium and potassium oxides; most common in the manufacture of tableware.

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

The main indicators of the physical and chemical properties of glasses are their density, strength, fragility, hardness, thermal conductivity, thermal expansion, thermal resistance, transparency.

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

The assortment of household products is classified by purpose and operating conditions, composition and color of glass, molding method 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 tableware and decorative items for table setting and interior decoration, household dishes for storing food and home canning, kitchen utensils for cooking, lamp products (table lamps, lamp tanks, lamp glasses) and mirrors.

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

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

By color, dishes are distinguished from colorless glass, colored (dyed in the mass) and overhead (two and multilayer). Colored glasses are named according to their color tone (yellow, green, pink, etc.), by the nature of the dye (cobalt, manganese), by analogy with precious stones: rubies (red), topaz (yellowish brown), sapphires (light -blue), emeralds (light green).

According to the method of molding, dishes are distinguished by hand, free, machine blowing, pressed, press blown, multi-stage molding, bending, centrifugal production.

According to the method of heat treatment, a distinction is made between utensils that are not hardened, that is, annealed and hardened by hardening.

The overwhelming mass of high-quality glass products and all crystal products are produced annealed.

Types of glassware

There are about thirty types of tableware; these are glasses, goblets, wine glasses, wine glasses, wine glasses, jugs, decanters, sugar bowls, oil cans, vases for table setting (for fruits, jam, cookies, cream, sweets, salad bowls), dishes, etc.

Decorative items - these are glass sculptures, flower vases, toiletries, horn-shaped glasses, dishes, etc.

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

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

According to the style, the products are subdivided taking into account the shape of the body (ball, oval, cone, etc.), the presence of adhered (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 in the bottom of the product).

The leg of the products can be of different heights, shapes (straight or curly) and processing (faceted and even). Blown flower vases, depending on the complexity of the form, are divided into three groups.
The style, along with the aesthetic features of molten glass and cutting, largely determines the artistic expressiveness of products. It is subject to change according to style requirements. Currently, festive and giftware dishes are distinguished by a complex silhouette, meticulous workmanship and complex shape of details. Household utensils have simpler and more solid shapes.

According to the method of decoration, they distinguish between smooth and decorated dishes. Decorated dishes, depending on the nature, complexity and artistic merit of the cut are divided into group and non-group. Cuts of group blown glassware made of high-quality colorless glass are subdivided into groups 1-7, from colored glass - into groups 3-8, from overhead glass - into groups 4-8. Cutting of crystal products belongs to the 4-10th complexity groups.

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

Non-group items are characterized by originality of forms, complex, often combined designs 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 items.

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

Modern trends in the decoration of glassware - an expansion of the range of colored glasses, a combination of colored and slightly dimmed glass in an overlay, contrasting combinations of elements of a diamond facet, matte engraving, a chandelier, a wide use of decal and silk-screen prints of various subjects, picturesque cuts with paints and gold, often in combination with matting. Sheathed cuts and products are still popular.

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

The range of tableware for table setting is extremely diverse and is grouped taking into account all the previously mentioned characteristics. The main types of products: glasses, mugs, cups, wine glasses, wine glasses, wine glasses, wine glasses, decanters, jugs, milk jugs, vases for table setting (for fruits, cookies, sweets, jam, cream, salad, dish), butter dishes, sugar bowls, rusks and etc.

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

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

Cookware made of heat-resistant glass and sitalls is represented by pots of various capacities, baking dishes, braziers, pans. Sitall is used to produce sets of pots and a set "Kid". Cookware made of heat-resistant glass is tempered and not decorated. Sitall cookware in white with a smooth shiny surface is additionally decorated with decal patterns.

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

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

According to the method of molding, dishes are distinguished by hand, free, machine blowing, pressed, press blown, multi-stage molding, bending, centrifugal production.

According to the method of heat treatment, a distinction is made between utensils that are not hardened, that is, annealed and hardened by hardening.

The overwhelming mass of high-quality glass products and all crystal products are produced annealed.

Types of glassware

Decorative items are glass sculptures, flower vases, toiletry, horn-shaped glasses, 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 molten glass and cutting, largely determines the artistic expressiveness of products. It is subject to change according to style requirements. Currently, festive and giftware dishes are distinguished by a complex silhouette, meticulous workmanship and complex shape of details. Household utensils have simpler and more solid shapes.

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

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

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

October 27, 2015 Guest (nastya)

www.treeland.ru

What dishes are harmful to health: what can and cannot be used to cook food

Can utensils be unhealthy: how to store and prepare 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 is capable of releasing hazardous substances.

Are there safe dishes for health ^

Among the wide range of products for storage and cooking, cast iron, earthenware, enamel dishes and those made of stainless steel are considered safe. In all other cases, harmful dishes can have a negative effect on the human body:

Allocate 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 tableware, 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, when heated, gives it a metallic taste.

What utensils can and cannot be used to cook food ^

Unhealthy dishes: myth or reality

Cast iron cookware: benefits and harms

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

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 is converted into food.

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

Copper dishes: benefits and harms

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

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

The harm of crystal dishes

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

If liquids are stored in it, then it begins to release lead, which further causes harm to the body.

Silicone dishes: benefits and harms

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

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

Enameled dishes: benefits and harms

Initially, enameled dishes 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 gray-blue color is considered safe,
it is worth abandoning the red, yellow or brown shade - they contain many dyes and have low protective properties.

Silver dishes: benefits and harms

For a long time, dishes made of silver were 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 of this.

Why are polypropylene dishes harmful?

Plastic dishes have three degrees of heat resistance:

high,
average,
low.

In the first case, it means containers for food 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 food in such a container, because at high temperatures plastic can melt and release harmful elements.

Polypropylene utensils should also not be used to store food.

Stainless steel dishes (stainless steel): harm and benefit

Steel utensils can be safely used for frying and preparing first courses, however, food cannot be stored in it, as it can release nickel that penetrates into the dishes.

Cupronickel dishes

For several centuries, cupronickel products have been very popular, and it is not in vain: despite the fact that they are made of an alloy of copper and nickel, they are safe for human health - you just need to clean them from plaque in time.

Pewter

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

Glass ceramic dishes

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

In addition, the inside of plates made of such material may have drawings applied with paints containing lead, therefore, it is not recommended for its intended use.

Galvanized cookware

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

Teflon coated cookware

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

Melamine tableware

If such dishes are damaged, they begin to emit a dangerous poison - formaldehyde.
In this case, it must be discarded. It is also not suitable for frying or cooking.

Ceramic dishes: harm and benefit

Unlike Teflon, thermolon-coated dishes are more harmless because her negative influence on human health is not confirmed by anything.
In addition, it can be heated to 400 degrees or more.

Glassware: harm or benefit

Like ceramic containers, baking containers, mugs and plates made of glass 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 reheat 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 dishes: harm and benefit

Thanks to modern technology, opal glass dishes are 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 makes it completely safe for storing food.
It tolerates temperature extremes, from high to low. Pots made of frosted glass are great for microwave ovens.
It has low thermal conductivity, which allows long time keep food hot.
It lends itself well to washing, it is easy to keep it perfectly clean.
It is resistant to the use of any detergents, they do not cause any visible harm to it.
Thanks to their increased durability, these cookware can be stored in stacks, which saves space in your kitchen.

What dishes are not harmful to health

The most harmful is nickel-plated dishes, because it contains nickel, however it is the most common. Food is best prepared and stored in containers made from the following materials:

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

The harm of plastic bottles and plastic wrap: what is the danger ^

The plastic container may contain the chemical bisphenol-A, a synthetic analogue of the female sex hormone, which can penetrate into water or liquid, and then into the human body.

If you drink water from plastic bottles, you will increase the content of bisphenol in your body:

Scientists at Harvard University conducted research and found out: the use of cold liquids from plastic for just one week increases the level of bisphenol in urine by 69%.
The release of bisphenol is temperature dependent. The higher the temperature, the more active the water is contaminated with BPA from plastic. That is, the usual summer heat is capable of increasing the concentration of harmful substances in water tenfold.
If filled with hot liquid or specially heated plastic bottles, then the release of bisphenol will increase up to 55 times! This fact should be known to parents who heat milk in plastic bottles for their children.
An increased concentration of bisphenol increases the likelihood of prostate cancer in men and has a negative effect on men's health, as hormones are disturbed.
Pregnant women are generally contraindicated to drink water from plastic bottles, since due to bisphenol poisoning, a child may be born with birth defects.

happy-womens.com

Caution! Harmful dishes

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

In Russia, traditionally, the dishes were wooden. Moreover, not every tree was suitable for making it. The medicinal properties of wood were of great importance.

So, it was believed that linden dishes had anti-inflammatory properties, from mountain ash - they protected from vitamin deficiency. 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 birch bark dishes - salt shakers, tueski for storing flour and cereals.

Copper crockery appeared next. Perhaps you also have a copper basin 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 used with pleasure! The fact is that due to its high thermal conductivity, copper has an excellent quality for cooking - heat is evenly distributed over the surface of the dishes. And therefore, delicious jam, aromatic coffee or wonderful sauce are obtained in copper dishes as if by themselves.

But modern science somewhat darkens 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 dishes loses vitamins, polyunsaturated fatty acids are easily oxidized in it, forming compounds dangerous for the body - free radicals.

With its frequent use, poisoning is not excluded.

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

Therefore, after washing, the plate or basin must be thoroughly wiped, avoiding the formation of a film. If, nevertheless, the patina has appeared, then it must be carefully removed from the entire surface, otherwise using harmful dishes will be dangerous to health. This can be done as follows: wipe with table salt dipped in vinegar, and immediately rinse first with warm, then cold water.

Lead in ceramic dishes

For centuries, lead was added to the alloys from which the cookware was made. 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 cooking utensils contained large amounts of lead. As a result of the use of such harmful dishes, the life expectancy of the population has almost halved. Some historians even believe that the lead poisoning of the Roman "elite" was not the last reason for the decline of the 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 supply ...

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

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

It is appropriate to remember here famous story one American married couple.

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

Two and a half years later, both of the spouses showed signs of lead poisoning: insomnia, nervous disorders, 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 absolutely unnecessary operations, and the woman was persistently treated for liver disease.

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

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

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

Therefore, we draw a conclusion for ourselves: if we buy a plate, cup, pot that we like, they are brightly colored, we are not shy and be sure to ask the seller for a certificate. And in this document we are looking for information on the results of testing dishes for the content of toxic substances. But, unfortunately, the reality is that certificates are often forged.

So, it may be better to be careful not to buy ceramics with too 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, besides being not useful in itself, also accelerates the process of lead release. Therefore, for beauty, it is not forbidden to acquire such cups-plates, but for everyday use for their intended purpose - experts categorically do not advise.

Lead in cans

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

There are cases when, during long-term storage, lead accumulated up to 3 mg / kg, 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, as a rule, contain another toxin - tin.

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

Aluminum

Even 10-15 years ago, aluminum cookware could be seen in almost every kitchen. It is easy to clean and does not burn food in it during cooking. It is very good to boil milk in such a saucepan, boil milk porridge, 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 the vegetables being cooked in microscopic doses, aluminum "exfoliates" from the dishes and ends up safely in our stomach. Aluminum does not oxidize in water, but even it "washes away" its microparticles.

So you should not boil water or store it in hazardous aluminum dishes, however, like any other food.

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

Well, if you have been cooking for yourself in dishes made of this metal for years, then the opinion of experts is as follows: 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.

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

But these are toxic and harmful dishes! One of the sources of danger is the salts of lead (again!), Cadmium and other metals that are part of the paints with which she signs.

Decal inks are not coated with any protective layer and are very easily incorporated into products.

Another danger is that melamine contains toxic formaldehyde. It is isolated by many plastics, but melanin, according to the results of special studies, 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.

Sanitary and Epidemiological Supervision has banned the sale of melamine tableware. But go to the crockery department in any market and you will see cute cups, plates and all kinds of sets of them.

In addition to melamine, you can find harmful dishes made of other polymer metals on sale.

The specialists involved in testing and certifying this product believe that it can be used, but only with strict adherence to the manufacturer's instructions.

For example, if plastic dishes 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, plastic containers say that they are for cold food, then do not put hot food in it, etc.

"Stainless steel" and silver

Recently, dishes made of stainless steel - an alloy of iron, carbon and other elements - have become very popular. Steel with additions of 18% chromium and 8% nickel is 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 prolonged cooling. Do not overheat dishes made of "stainless steel" - after that the food will burn in it. And one more thing: we must remember that nickel is a strong allergen, therefore people with allergies should be careful with it.

Enamel and glass

Perhaps, good old enameled dishes meet 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, such utensils can only be used whole. Indeed, in places of damage, cracks and chips, yellowish-red spots appear, which cannot be removed by washing. This is common rust. And she, interacting with food acids, forms iron salts harmful to humans. In addition, when washing, particles of the cleaning agent may remain in the damaged areas, which will also then enter your stomach.

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

But we must remember that when using heat-resistant cookware, when it is in a “hot state”, it is necessary to avoid its contact with very cold surfaces - then the saucepan will burst.

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

This begs the question: is there a perfectly safe dish at all? 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 the officers did not suffer from gastrointestinal diseases, as they ate from silver dishes, while the 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 impair vision. And if, again, you use silver dishes all the time, for years, it is possible to "earn" such a serious illness as gastroenteritis and even cirrhosis of the liver!

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

But 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 start on the farm wooden or Teflon special spatulas for turning or mixing the prepared food. And also do not put an empty saucepan or pan on the fire.

By the way, experts advise purchasing pans with a thickened bottom, since 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 porcelain tableware to serve 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 are poured hot.

Enamel dishes are also "tempered", but in a different way. A new saucepan is filled to the brim with a salt solution: 2 tbsp. l. per liter of water and let it boil. Then leave to cool.

But even "hardened" enameled dishes are better protected and not immediately put out of the refrigerator on a hot stove - the enamel may crack from a sharp temperature drop.

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

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

Teflon is a good, but unfortunately very fragile non-stick coating. Therefore, to wash such dishes, you do not need to use not only metal scourers, but also powdered products - even they can scratch Teflon. Wash pans and pans 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, there is no lead impurity in it. And also porcelain - only it should not have metal patterns, including "gold" edges. " Earthenware is also suitable - 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, do not use microwave ovens at all, since 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 capable of removing toxins and toxins without external interference. However, working and living in harmful conditionsLeading the wrong way of life, we accumulate an excess of toxic substances, which our body can withstand with great difficulty. Heavy metals can build up in the plants and animals that we eat. They can get into us with air, water, exhaust gases, tobacco smoke, with household chemicals and from harmful dishes (copper, lead, iron). Heavy metal isotopes are deposited on internal organscausing various diseases.

Eat foods that contain pectin. Pectin has the useful property of collecting heavy metal salts on its surface. It is found in vegetables, fruits, berries. A product like beetroot, for example, also contains flavonoids that convert heavy metals into inert compounds. The starch of potatoes, cooked in their skins, absorbs toxins from the body, removing them naturally. Carrots, pumpkin, eggplant, radish, and tomatoes are also removed heavy metals.

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

Drink tea made from chamomile, calendula, sea buckthorn, rose hips. Tea made from these herbs protects cells from penetration of heavy metals and promotes their elimination. Rosehip and sea buckthorn oil is also useful for heavy metal poisoning. Remove the isotopes of radioactive cesium 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, ginseng before meals.

Drink a tea made from the herb coriander (cilantro), it can flush the mercury out of 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.

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

Use a decoction of oats to remove 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 get rid of heavy metal salts, including cadmium, which is contained in tobacco smoke.

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

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