glassware product assortment

The quality of glass products is influenced by many factors: structural and dimensional features, mechanical strength, thermal stability, hygienic, aesthetic properties, etc. In terms of structural and dimensional features, household glassware must comply with approved samples. Products on a flat horizontal surface should not swing.

Glass products must have good mechanical strength. The thermal stability of products is considered satisfactory if 99% of the tested products pass the tests prescribed by GOST.

It is necessary that glass products have transparency and no color shades (especially crystal). Products made of colored glass and glass with a color must be evenly colored.

It is important that the surface of the product has a clean, smooth surface without burrs and scratches and a clearly defined pattern. The edge of the product should not be cutting, for this it is melted, ground and polished.

In accordance with the current GOST, glass tableware and decorative items are produced in one grade. Crystal products are divided into grades 1 and 2. When determining the grade of a product, the type of defect, its size, quantity and location are taken into account. On glass products there are defects in glass mass, working out and processing. These defects occur during the process of cooking, molding the product and its processing, they significantly reduce the quality of finished products.

Glass defects include the following. Gas inclusions appear due to insufficient clarification of the glass mass.

These include midge and bladder defects. Turbid and squeezing bubbles in the product are not allowed.

Swiel, schlier are transparent inclusions that differ from the main mass of glass in chemical composition or physical properties. The striae are filiform, hairy, in the form of knots and bundles.

Crystalline inclusions have a crystalline structure (white) glass particles.

Workout defects are formed during the molding of glass products.

Variation in thickness in the walls and bottom of the product is the result of uneven distribution of glass mass during the production of the product.

Chips, chips - damage with a conchoidal structure, formed as a result of breaking off a piece of glass during mechanical action.

Scree - small chips.

Forged - unevenness, manifested as a fine waviness of the surface.

Wrinkles are irregularities that appear as ripples on the surface.

A crease is an irregularity in the surface of a pocket-like shape.

Curvature, folds and wrinkles on products are not allowed.

Defects in the processing and decoration of products are remelting of the edge, asymmetry of patterns, under-finishing and translations on products (allowed), breaks, blockage of the diamond edge, blots, fading of paints and films, swelling, cracking, streaks on products are not allowed, as they sharply reduce the aesthetic and hygienic properties of products. The total number of permissible defects in terms of appearance in one product should be no more than 2 - for small, 3 - for medium and 4 - for large. For especially large products, the total number of permissible defects that do not spoil the presentation is not regulated.

For crystal products, the total number of permissible defects in terms of appearance should not exceed for grade 1 for small items - 2, for medium - 3 and for large - 4, and for grade 2, respectively: 3, 4 and 5.

Tableware is sorted on the basis of the defects found on it in the glass mass, production and processing. At the same time, they take into account: the type (name) of the defect, its size and location (on the body, leg, bottom), the number of defects of the same name on the product, the total number of names of defects, the size of the product itself (on large products, defects are allowed in a larger number or larger sizes) , the method of manufacturing dishes (blown or pressed), the nature of the decoration of the product (for products with expensive cuts, more stringent requirements are imposed on the quality of their processing).

Glassware defects include: various shades of glass mass (greenish, bluish, etc.); stone - non-melted particles of the charge, refractory materials of the furnace or pots or areas of the beginning of crystallization of the glass mass; schlier - glass clots of a slightly different composition than the main glass mass, and not completely dissolved in it; usually has the shape of a drop; svil - transparent wavy threads in glass or on the surface of the product; bubble - gaseous inclusions in glass; midge - small bubbles (with a diameter of not more than 0.8 mm); incorrect distribution of the glass mass - uneven thickness of the walls and bottom of the products; incorrect shape of the product; improper attachment of the handle or leg; defects in the processing of the edge and bottom of products - crevices, scree of the edge (minor damage to the edge), sharp edge, traces of ponti, etc .; decoration defects - incorrect arrangement of patterns, etching of smooth places, irregular edges, etc.

Good-quality dishes should be of the correct shape, stable, not sway when placed on a flat surface. The lids of sugar bowls, butter bowls, vases, jugs in color, style, size must match the body of the product. Corks for decanters should be correctly matched in style and color and tightly ground to the throat. The edge of blown and pressed products must be well melted or ground and polished.

The following are not allowed in the dishes: crevices with sharp edges (not melted); blisters cloudy and sagging and blisters transparent with a diameter of more than 3 mm; midge, densely located; stones; scale - iron particles from blow tubes; scree edges; cuts - barely noticeable cracks; roc (crystallized opaque glass particles); blown walls - too thin walls in some places of the products. In tea glasses, in addition, schlieren and chips are not allowed.

Both blown and pressed utensils must be thermally stable. When checking the thermal stability of glasses, they are poured with a gentle stream of hot water having a temperature of at least 95 °, then, when the water cools to 65 ° (in blown glasses) or to 55 ° (in pressed glasses), the glasses are quickly emptied and immersed in water having a temperature of 20°. Other types of dishes are tested by immersion for 5 minutes in water having a temperature of 55 °, and then in water having a temperature of 20 °. During this test, the products shall not crack.

To check the grade of dishes, samples are taken from different places in the amount: from a batch of up to 100 pieces - 10%, from a batch of up to 1000 pieces - 5% and from a batch of more than 1000 pieces - 2%.

The procedure and methods for the examination of glass products

Examination of glass and crystal products is carried out personally by an expert in accordance with the technical conditions of agreements (contracts) or a standard (OST), based on the task set by the customer of the examination.

A batch of goods that is heterogeneous in composition must be sorted by name, article number, size before the examination.

If the customer submits several consignments of goods at the same time, then each consignment is checked separately.

The expert must:

1 Familiarize yourself with the order of warehousing and storage conditions of goods

2 Conduct an external inspection of the condition of the transport package, paying attention to the presence of damage.

3. When opening each shipping item, the control (adhesive) tapes must be cut, and not torn off from the cardboard and not torn.

During the opening process, the expert determines the presence and condition of auxiliary packaging, the order of stacking of each row and the degree of filling of each transport package.

The expert enters the results of checking the quality, quantity, completeness of the goods, the state of packaging in a workbook. The actual number of products is compared with the quantity indicated in the packaging diets, specifications or in the marking on the packaging or paper label.

If a discrepancy between the goods and the data of the shipping documents or damage to the goods (the presence of broken products) is detected, the expert must suspend further opening. Then re-check personally in the presence of the customer the quantity of goods and then conduct an additional external and internal inspection of the goods and packaging means in order to establish the reasons for the shortage or damage to the goods.

If a shortage of goods is detected, if no damage to the packaging is found, it is necessary to weigh the shipping item, comparing it with the data indicated in the marking on the box or in the accompanying documents. The expert warns the customer about the safety of the item in which the shortage is found, until the dispute between the supplier and the recipient is resolved.

If the goods are presented to the expert in a package damaged during transportation or in a defective shipping unit, the expert is obliged to demand from the customer an act of the transport organization (commercial act).

The main consumer properties of glass household products are functional, ergonomic, aesthetic and reliability properties.
The functional properties of glass products (for example, plsuda) provide for the possibility of them performing two main functions: "accept" and store food and drinks in the same quantity and quality, and "give" them in whole or in part as needed. These properties depend on the composition of the glass, the shape, size and purpose of the products, the characteristics of food and drinks.

The ability to "accept" and store food and drinks is determined by the following group indicators: chemical resistance to food and drinks, resistance to weathering, resistance to thermal effects, resistance to mechanical stress. The ability to "give away" food and drinks: the functionality of a three-dimensional solution and versatility.

Ergonomic properties predetermine, first of all, convenience
(comfort) of use and hygiene of glass products. The comfort of household utensils is determined by the convenience of holding, transferring, performing storage, washing functions, as well as ease of transportation and storage.
Hygienic properties are primarily due to the nature and properties of glass and are characterized by such group indicators as harmlessness and contamination.

The aesthetic properties of glass household goods are determined by the integrity of the composition, the rationality of the form and information content.

The integrity of the composition characterizes the arrangement, addition and connection of parts into a single whole in a certain order. The rationality of the form characterizes the correspondence of the shape of the product to the functional purpose and environmental conditions, the compliance of the tonal and color solutions of individual elements with the requirements of ergonomics, the style solution - the interior, the manufacturing technology - the properties of the material.
Informativeness of glassware is determined by the symbolism, originality and compliance with their style and fashion prevailing at the time.

The property of reliability of glass products is determined by their durability and storability. The most important is durability, which is characterized by physical and moral wear and tear.

Indicators of a number of consumer properties of products are indicators of the physical and chemical properties of glass.

According to GOST 4.75-82 “Sized glassware. Nomenclature of indicators" consumer properties and their indicators include the following:
- indicators of purpose - the chemical composition and density of glass, the shape and main dimensions of products, their stability on a flat surface;
- reliability indicators - impact strength, hardness, heat resistance, water resistance, fastening strength of parts, annealing quality indicators;
- indicators of ergonomic properties - the content of harmful substances;
- indicators of aesthetic properties - accuracy of reproduction of the author's sample, indicators of compositional integrity, informational expressiveness, perfection of industrial production of products, as well as refractive indices, average dispersion, light transmission, cutting angle;
- economic indicators - the mass of products (consumption of raw materials), cost.

Quality assessment and quality requirements for glass products.

The quality of glassware and decorative glassware must comply with the requirements of GOST 30407-96 “Cookware and decorative glassware. OTU.". Quality assessment is carried out by organoleptic (appearance assessment) and physico-chemical methods (sizing, thermal stability, etc.). In terms of structural and dimensional features, household glassware must comply with approved samples. The product on a flat horizontal surface should not swing. Products that come into contact with hot food (tea glasses and saucers, hot food plates, etc.) must be thermally stable. Blown products should not be destroyed at temperature drops of 95-70-20C, pressed - at 95-60-20C.

Products are not allowed: chips; cut edges; stuck pieces of glass; cutting and crumbling glass particles when decorating products in bulk; through sections; foreign inclusions with cracks and cuts around them. The end surface of the upper edge and the seams of the products must be smooth. The decorative coating applied to the inner surface of products in contact with food must be acid-resistant. The fastening of product handles and decorative elements must be durable. Permissible migration of harmful substances emitted from glass products in contact with food products is established by the State Sanitary and Epidemiological Supervision authorities in the relevant regulatory documents approved in the prescribed manner,
Defects in glass products are divided into defects in glass mass, production and processing.

To glass defects include:

1. Gas inclusions (“midge” with a diameter of more than 0.8 mm and a “bubble” with a diameter of less than 0.8 mm) are formed as a result of insufficient clarification of the glass mass. Turbid and squeezing bubbles in the product are not allowed.

2. Strands and schlieren are transparent inclusions that differ from the main mass of glass in composition or physical properties. Svili are thread-like inclusions, and schlieren are tubercles, nodules, glass clots.

3. Solid inclusions (stones, crystals). Occur as a result of crystallization of glass mass.

4. Insufficient discoloration - the result of the presence of metal oxides in the glass.

Production defects:

1. The difference in thickness in the glasses and the bottom of the product is the result of an uneven distribution of glass mass.

2. Chips and crevices;

3. Scree-small chips;

4. Forged-unevenness in the form of fine waviness of the surface;

5. Wrinkles - unevenness in the form of ripples on the surface;

6. Folds - uneven pocket shape.

Curvature, folds and wrinkles on products are not allowed.

Consumer properties and quality indicators of glass goods

Classification and characteristics of the range of glass products.

glass classification.

Glasses are classified according to composition. Their name depends on the content of certain oxides. The following oxide glasses are distinguished:

silicate - SiO 2;

aluminosilicate - Al 2 O 3, SiO 2;

borosilicate - B 2 O 3, SiO 2;

boron aluminosilicate - B 2 O 3, Al 2 O 3, SiO 2 and others.

Each type of glass has certain properties.

Silicate glasses are divided into ordinary, crystal, heat-resistant. Common ones include soda-lime, soda-lime, potassium-lime, soda-potassium lime glasses.

Crystal glasses are characterized by increased brilliance and strong refraction. Distinguish between lead and lead-free crystal. Lead crystal has an increased mass and is well decorated. Given the dependence on the amount of lead oxide, lead crystal is divided into

1. Crystal glass containing at least 10% lead, boron or zinc oxide.

2. Low lead crystal containing 18-24% lead oxide.

3. Lead crystal containing 24-30% lead oxide.

4. High lead crystal containing 30% or more lead oxide.

Lead-free crystal contains mainly barium oxide (at least 18%), which improves refraction, increases the hardness and brilliance of glass, but reduces transparency.

Heat-resistant glasses withstand sudden changes in temperature.
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They include boron compounds (12-13%). The thermal stability of such glass increases after tempering. Chemical properties of glass.

The chemical resistance of glass determines the purpose and reliability of products. It is very high, especially in relation to water, organic and mineral acids (except hydrofluoric). Alkalis and alkali carbonates act more aggressively. Hydrofluoric acid dissolves glass and, therefore, is used for applying patterns to glass, matting and chemical polishing of products.

The formation of consumer properties of glass products occurs in the process of their production.

Production of glass goods consists of a number of stages: preparation of raw materials, blending, melting of glass melt, production of glass products, processing and decoration of products, sorting, marking and packaging of products.

1. The preparation of raw materials is reduced to the purification of quartz sand and other components from unwanted impurities, fine grinding and screening of materials.

2. The preparation of the charge, i.e., a dry mixture of materials, consists in weighing the components according to the recipe and thoroughly mixing them until completely homogeneous. A more advanced method is the production of briquettes and granules from the charge; at the same time, the homogeneity of the charge is maintained, and cooking is accelerated. In addition, to speed up the melting of glass, 25-30% of glass cullet is added to the mixture. Cullet is washed, crushed and passed through a magnet.

3. Cooking glass melt from the charge is carried out in baths and pot furnaces at a maximum temperature of 1450-1550°C. During the cooking process, complex physical and chemical transformations and interactions of raw materials occur. With the help of clarifiers, the glass mass is freed from gas inclusions, thoroughly mixed until a uniform composition and viscosity is achieved. In case of violations of the modes of processing raw materials, preparation of the mixture and cooking, defects in the glass mass are formed (we will analyze later).

4. The molding of products from viscous glass mass is carried out by various methods. The molding method largely determines the configuration of products, wall thickness, decoration techniques, coloring, and in this regard is an important assortment feature and pricing factor.

Household products are made by blowing, pressing, pressing blowing, bending (bending), casting, etc.

Blowing - the oldest method of molding glass products. Blowing must be mechanized, vacuum-blown, manual in molds and gooten (free).

Manual blowing is carried out using a glass blowing tube. Such blowing can be carried out in molds and without molds. By blowing in molds, products of any configuration and wall thickness with a smooth and shiny surface are obtained. They produce colorless, mass-dyed and overhead products (two- and multi-layered).

Blowing without a mold or free blowing (in the trade - Gooten molding) is also carried out by means of a glass blowing tube, but the products are molded and finally finished mainly in air. Products are characterized by the complexity of forms, smooth transitions of parts, thickened wall.

By mechanized blowing on automatic machines, colorless products of simple outlines, mainly glasses, are produced.

Blown products have the smoothest walls, strong gloss, high transparency, the most diverse shape and wall thickness. Οʜᴎ are decorated in almost every possible way and are considered to be of the highest quality.

Pressing are the most widespread and economical methods of obtaining glass products. Products are formed on automatic and semi-automatic presses in special molds, where a pattern is immediately applied to them. They are characterized by a large wall thickness (more than 3 mm), a large mass, less transparency and heat resistance, a significant bottom thickness, traces of the shape are visible. Pressed utensils have simple shapes with a wide top.

They strive to overcome the non-uniformity of pressed products by creating a light relief pattern on the surface (textured press), pressing without an upper ring, which allows to obtain a freely formed edge different for each product, a combination of pressing and bending (press bending).

Pressblowing characterized by the fact that the molding of products takes place in two stages - first they are molded in a mold, and then in hot air. Products have a narrow neck, thick uneven walls and traces of the shape. Press blowing produces jars, bottles, carafes, vials; Products obtained by this method differ from pressed ones in a more complex shape, and from blown ones, in thick walls, traces of the shape and a rougher pattern.

Casting. The glass mass is poured into a special mold, where it cools and takes on the shape of the mold. This method is used to obtain artistic and decorative products.

centrifugal casting carried out in rotating metal molds under the action of centrifugal forces. Products obtained by this method have a large mass, and large-sized products are finished manually. Aquariums can serve as an example of products made by centrifugal casting.

Other molding methods are less common.

Incorrect molding may cause various defects.

5. Annealing products. During molding, due to the low thermal conductivity of glass, sharp and uneven cooling, residual stresses arise in products that can cause their spontaneous destruction. For this reason, annealing is mandatory - heat treatment, which consists in heating the products to 530-550 ° C, keeping at this temperature and subsequent slow cooling. During annealing, residual stresses are weakened to a safe value and are evenly distributed over the cross section of the products. The thermal stability of glass depends on the quality of annealing.

6. Processing and decoration. Primary processing consists in processing the edge and bottom of the products, grinding the corks to the throat of decanters. Decorative processing is the application of decorations of a different nature to products. Decor determines the aesthetic properties of glass products and is one of the main pricing factors.

Cuttings are classified according to the stage of application (hot and cold), types, complexity.

Hot applied decorations:

1. Colored glass is obtained by adding dyes to glass mass.

2. Colored products are made from 1 layer of glass and coated with 1 or 2 layers of intensely colored glass.

3. Decoration of blown products in a hot state is carried out by applying glass moldings, ribbons, twisted and tangled threads. Variety - decoration with filigree or twisting has the form of 2 or 3-colored spiral threads.

4. Marble or malachite decoration is obtained in the process of melting milk glass with the addition of ground, unmixed colored glass.

5. Cutting ʼʼcrackleʼʼ (ʼʼfrostʼʼ, ʼʼfrosty glassʼʼ) - a network of small surface cracks that form when the product is quickly cooled in water. Next, the semi-finished product is placed in a furnace, where the cracks are melted.

6. Cut-out “under the roller” is used, which creates an optical effect due to the wavy inner surface formed when the billet is blown in a ribbed shape.

7. Jewelry in bulk. The heated workpiece is rolled over crushed colored glass, ĸᴏᴛᴏᴩᴏᴇ is melted to the surface.

8. Iridescent films (irrization) on the surface of products can be obtained when salts of tin chloride, barium, etc. are deposited on a hot product; these salts, decomposing, form transparent, shiny, iridescent films of metal oxides (reminiscent of mother-of-pearl).

9. Jewelry by free blowing - the product acquires a peculiar and unique shape.

10. Chandeliers - application of metal solutions to the surface of the product. Next, the product is annealed, the solvent evaporates, and the metal film is fixed on the surface.

11. Pressed products are decorated mainly due to the pattern from the mold.

Cold decoration carried out by mechanical treatment, chemical treatment (etching) and surface decoration using silicate paints, gold preparations, chandeliers.

Mechanically applied cuts include matte tape, numbered grinding, diamond cutting, flat cutting, engraving, sandblasting.

1. Matte tape is a strip 4-5 mm wide. A metal strip is pressed against the surface of the product during its rotation, under which sand and water are fed. In this case, the grains of sand scratch the glass.

2. Number grinding - matte surface (shallow) pattern of round, oval sections or notches. Applied with emery wheels.

3. A diamond face is a pattern of deep dihedral grooves, which, combined with each other, form bushes, nets, polygonal stones, simple and multi-beam stars and other elements. The pattern is applied on manual or automatic machines using an abrasive wheel with a different edge profile. After cutting the pattern, it is polished to full transparency. The diamond facet is especially effective on crystal products, where the brilliance and play of light in the facets are well revealed.

4. Flat edge - these are polished planes of various widths along the contour of the products.

5. Engraving - a surface matte or less often light drawing of a predominantly vegetative nature without large depressions. It is obtained using rotating copper disks or ultrasound.

6. Sandblasting - a matte pattern of various shapes, formed during the processing of glass with sand, which is fed under pressure into the cutouts of the stencil.

Cuts applied by etching, subdivided into simple (heliospheric), complex (pantograph), deep (artistic) etching. To obtain a pattern, products are covered with a layer of protective mastic, on which a pattern is applied with machine needles or manually, exposing the glass. Next, the dishes are immersed in a bath of hydrofluoric acid, which dissolves the glass in a naked pattern to various depths.

Simple, or heliospheric, etching is an in-depth transparent geometric pattern in the form of straight, curved, broken lines.

Complex, or pantographic, etching is a linear in-depth pattern, but of a more complex, often vegetative nature.

Deep, or artistic, etching is a relief pattern in the main plant plot on 2 or 3-layer glass. Due to the different depth of etching of colored glass, a pattern of different color intensity is formed.

Surface decoration can be carried out with silicate paints, gold preparations. Such decorations include painting, decalcomania (represents a multi-color drawing without brush strokes, applied using decals), silk-screen printing (a single-color drawing obtained by stenciling using a silk mesh), applying ribbons (4-10 mm wide), layering (1- 3 mm), antennae (up to 1 mm), photographic images, etc.
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New methods of jewelry are being developed - plasma spraying of metals, glass powders, photochemical engraving, etc.

The production process ends with acceptance control and labeling of products.

Glass products in accordance with the purpose are divided into three classes: household, architectural and construction and technical.

The range of household products is classified according to many criteria.

1. By purpose, household glass products are divided into 5 groups: household utensils, art products, household utensils, kitchen utensils, lamp products.

2. According to the composition of glass, products made of sodium - calcium - silicate, special household, crystal glass, etc. are distinguished.

3. According to the molding method, blown, pressed, press-blown products, as well as those obtained by centrifugal casting, are distinguished.

4. According to the color of the product, there are colorless, colored and with a color.

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

6. In terms of completeness, household glass products are piece and complete.

7. According to the method of applying jewelry (see earlier).

Modern trends in the decoration of glassware - the expansion of the range of colored glasses, the 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 patterns and silk-screen printing of various subjects, pictorial cuts with paints and gold, often in combination with matting. Harvest cuts and products are still popular.

8. 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 the products must be of different heights, shapes (straight or figured) and processing (faceted and even). 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.

Assortment of glassware.

The assortment of glassware is divided into the following groups based on the method of production and purpose: blown products, pressed products, press-blown products, crystal products, household utensils, kitchen utensils.

The range of blown dishes is very wide. These are glasses, glasses, glasses, glasses, wine glasses, jugs, decanters, sugar bowls, butter dishes, vases for table setting (for fruit, jam, cookies, cream, sweets, salad bowls), bowls, etc.

The range of pressed tableware is considerably narrower. These are saucers for jam, trays, vases, lemon squeezers, glasses, sugar bowls, glasses, salad bowls, sugar bowls, etc.

Press-blown tableware has a limited range. These are decanters of various styles and capacities, oilers, table bowls, etc.

Household utensils include products used for storing and preserving food products (thermoses, jars, jars for pickles and jams, kegs, bottles for storing liquids).

Cookware made of heat-resistant glass is represented by pots of various capacities, baking dishes, braziers, frying pans. For the manufacture of dishes for cooking on an open fire or in microwave ovens, heat-resistant glass (borosilicate glass) is used. Get such dishes by pressing. Products made of borosilicate glass are subjected to a special tempering treatment to increase thermal resistance and are not decorated. 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 arise in the glass, which increase the impact strength by 5–8 times, and the heat resistance by 2–3 times.

Crystal products. They are obtained mainly by blowing and pressing-blow method. The range of blown crystal products is close to blown glassware. They produce crystal products both piece and complete.

Assortment of decorative products- These are glass sculpture, flower vases, toilet utensils, horn-shaped glasses, dishes, etc.
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Each type of product is produced in several varieties (articles), differing in size and style.

Range of lamp products consists of table lamps, lamp tanks, lamp glasses.

The main consumer properties of glass household products are functional, ergonomic, aesthetic and reliability properties. The functional properties of glass products (using the example of a glassware) provide for the possibility of their performing two basic functions: "accept" and keep food and drinks in the same quantity and quality, and "give away" them in whole or in part as they are extremely important. These properties depend on the composition of the glass, the shape, size and purpose of the products, the characteristics of food and drinks.

The ability to "accept" and store food and drinks is determined by the following group indicators: chemical resistance to food and drinks, resistance to weathering, resistance to thermal effects, resistance to mechanical stress. The ability to "give away" food and drinks: the functionality of a volume-spatial solution and versatility.

Ergonomic properties predetermine, first of all, the convenience (comfort) of use and hygiene of glass products. The comfort of household utensils is determined by the convenience of holding, transferring, performing storage, washing functions, as well as ease of transportation and storage. Hygienic properties are primarily due to the nature and properties of glass and are characterized by such group indicators as harmlessness and contamination.

The aesthetic properties of glass household goods are determined by the integrity of the composition, the rationality of the form and information content.

The integrity of the composition characterizes the arrangement, addition and connection of parts into a single whole in a certain order. The rationality of the form characterizes the correspondence of the shape of the product to the functional purpose and environmental conditions, the compliance of the tonal and color solutions of individual elements with the requirements of ergonomics, the style solution - the interior, the manufacturing technology - the properties of the material. Informativeness of glassware is determined by the symbolism, originality and compliance with their style and fashion prevailing at the time.

The property of reliability of glass products is determined by their durability and storability. The most important is durability, which is characterized by physical and moral wear and tear.

Indicators of a number of consumer properties of products are indicators of the physical and chemical properties of glass.

According to GOST 4.75-82 ʼʼVarious glassware. The nomenclature of indicators to consumer properties and their indicators include the following: - indicators of purpose - the chemical composition and density of glass, the shape and main dimensions of products, their stability on a flat surface; - reliability indicators - impact strength, hardness, heat resistance, water resistance, fastening strength of parts, annealing quality indicators; - indicators of ergonomic properties - the content of harmful substances; - indicators of aesthetic properties - accuracy of reproduction of the author's sample, indicators of compositional integrity, informational expressiveness, perfection of industrial production of products, as well as refractive indices, average dispersion, light transmission ͵ faceting angle; - economic indicators - the mass of products (consumption of raw materials), cost.

Quality assessment and quality requirements for glass products.

The quality of glassware and decorative glass products must comply with the requirements of GOST 30407-96 ʼʼ Glassware and decorative glassware. OTU.ʼʼ. Quality assessment is carried out by organoleptic (appearance assessment) and physico-chemical methods (sizing, thermal stability, etc.). In terms of structural and dimensional features, household glassware must comply with approved samples. The product on a flat horizontal surface should not swing. Products that come into contact with hot food (tea glasses and saucers, hot food plates, etc.) must be thermally stable. Blown products should not be destroyed at temperature drops of 95-70-20C, pressed - at 95-60-20C.

Products are not allowed: chips; cut edges; stuck pieces of glass; cutting and crumbling glass particles when decorating products "in bulk"; through passages; foreign inclusions that have cracks and cracks around them. The end surface of the upper edge and the seams of the products must be smooth. The decorative coating applied to the inner surface of products in contact with food must be acid-resistant. The fastening of product handles and decorative elements must be durable. Permissible migration of harmful substances emitted from glass products in contact with food products is established by the State Sanitary and Epidemiological Supervision authorities in the relevant regulatory documents approved in the prescribed manner. Defects in glass products are divided into defects in glass mass, production and processing.

To glass defects include:

1. Gas inclusions (ʼʼmoshkaʼʼ diameter more than 0.8 mm and ʼʼʼʼʼ diameter less than 0.8 mm) are formed as a result of insufficient clarification of the glass mass. Turbid and squeezing bubbles in the product are not allowed.

2. Strands and schlieren are transparent inclusions that differ from the main mass of glass in composition or physical properties. Svili are thread-like inclusions, and schlieren are tubercles, nodules, glass clots.

3. Solid inclusions (stones, crystals). Occur as a result of crystallization of glass mass.

4. Insufficient discoloration - the result of the presence of metal oxides in the glass.

Production defects:

1. The difference in thickness in the glasses and the bottom of the product is the result of an uneven distribution of glass mass.

2. Chips and crevices;

3. Scree-small chips;

4. Forged-unevenness in the form of fine waviness of the surface;

5. Wrinkles - unevenness in the form of ripples on the surface;

6. Folds - uneven pocket shape.

Curvature, folds and wrinkles on products are not allowed.

Consumer properties and quality indicators of glass products - concept and types. Classification and features of the category "Consumer properties and quality indicators of glass products" 2017, 2018.

Raw materials for glass production

Main raw materials: quartz sand, sodium sulfate, soda, potash, chalk, lead oxides, cullet, etc.

Auxiliary materials: illuminators; bleaches; dyes (copper oxide, cobalt oxides, etc.); silencers give the glass an opaque or milky white color.

Types of silicate glasses:

Ordinary (lime-sodium, lime-calcium);

Crystal - has increased brilliance, strong refraction, high transparency;

Lead crystal is made up of oxides of silicon, potassium and lead.

Barium crystal contains barium oxide.

Heat-resistant glass withstands sudden temperature changes, contains boron compounds (up to 12.5%), is highly heat-resistant, and is used for the manufacture of kitchen utensils.

Glasses of all types have a high chemical resistance to all chemicals (except hydrofluoric acid).

Glass production

When preparing raw materials, a charge is made - a mixture of materials according to a certain recipe. The mixture enters the furnace and cooks for 10-15 hours at a temperature of 1200 degrees C.

Various methods of molding glass products are used: blowing, pressing, press-blowing, etc.

In the process of manufacturing glass products, internal stresses arise in them during cooling, which can cause the destruction of products. To relieve stresses, glass products are annealed after being worked out (heated to 580 degrees C, and then slowly cooled). Sometimes products that are not thermally processed enough, as a result of sharp fluctuations in temperature during storage in warehouses, collapse. Their glass products are tempered. Tempering is carried out in two stages: first, the product is heated, and then quickly cooled according to a certain regime (depending on the composition of the glass and the shape of the product).

Decoration (decoration) of glass products.

Decoration on glass can be applied during the manufacturing process of the product (in a hot state) and on finished products (in a cold state).

1. Decoration of glassware in a hot state is carried out in various ways: glass staining, attaching hot glass mass in the form of drops, threads, bubbles, natsvet, moldings, crackle or "frost" (the heated workpiece is lowered into spring water until cracks form, which are melted when blown products to the desired size and shape, metal products - the process of deposition of metals on the surface.

2. Jewelry when cold.

mechanical way. Abrasive materials are applied to glass products with a matte tape, numbered grinding, diamond cutting, engraving.

Number grinding - simple matte or transparent drawings, they are numbered.

Diamond face - patterns formed by two-, three-sided cuts (grooves) using an abrasive wheel. Crystal products are decorated with a diamond facet.

Chemical way. Jewelry is applied by etching with hydrofluoric acid. There is simple, complex and deep artistic etching.

Decorations are applied with paints: painting, gold decoration (antennae - 1mm, layering - up to 3 mm, tape - 4-10mm), decalmania (using decals), decoration with chandeliers (paints based on non-ferrous metal salts), etc.

Classification and range of glass products

The range of glassware is subdivided according to the composition of the glass mass, production method, purpose, types, styles, sizes and decoration methods.

The size of plates, saucers is determined by the upper diameter, mm; glasses and other hollow products - by capacity, cm3 or l; high products (vases) - in height, mm.

Tableware (sorted glass).

The range of tableware is divided by functional purpose:

Products for eating and drinking; this group includes glasses, goblets, glasses, glasses, wine glasses, plates, cups, etc.

Glasses for red wine - wide, capacious, with and without a stem, usually made of colorless glass to emphasize the color of the wine, with a capacity of 100-150 cm3.

Glasses for white wine are also wide and capacious, but smaller and elongated.

Champagne glasses - wide on the leg, elegant proportions, this is a classic. Lately I have been releasing tall, narrow champagne glasses of elegant elongated shape.

Glasses for vodka - especially capacious, 25-100 cm3.

Glasses for cognac - on a short leg, small capacity. The upper part of the glass is necessarily narrowed (a characteristic feature of the drink is the aroma). A cognac glass should be shaped so that it is comfortable to hold in your hand (when the drink is warmed by hand, the aroma is felt stronger).

Glasses for liquor - small, elegant, graceful, usually on a leg.

Glasses for beer - large, capacious, with a slightly narrowed top, taking into account the fact that the drink foams.

Glasses for soft drinks - high, elegant, capacious.

Glasses for water - wide, low, without legs, made of transparent glass, with a capacity of 200-300 cm3.

Sockets for ice cream (cremanka) - wide, roomy, usually on a leg.

Ice vessel - low and wide with thick walls, capacious and convenient for taking ice with tongs, it can be with or without a lid;

Products for serving food and drinks - bowls, dishes, vases, decanters, salt shakers, sugar bowls, herring bowls, salad bowls, butter dishes, etc.

Menazhnitsa - dishes with sections (3-5) for serving several types of cold appetizers.

Utensils for short-term storage of food: cheese caps, jugs, tea caddies.

Other products (trays, ashtrays, etc.), appliances and sets.

Crystal products are produced by blowing and pressing. The range of crystal tableware includes items for table setting, vases, salad bowls, etc.

Houstal products can be in a metal frame made of silver, cupronickel, nickel silver.

Household and kitchen utensils.

Household and kitchen utensils include canning jars, thermoses, thermos flasks, household siphons, etc.

Cookware is designed for cooking, made of heat-resistant glass by pressing with subsequent hardening. The range of kitchen utensils includes pots, braziers, frying pans, etc.

Artistic products are made from high quality glass and crystal. These include small sculptures, vases, decorative dishes, toiletry (tray for toiletries, powder boxes, etc.).

Requirements for the quality of glassware

Glassware is subject to technical, functional, ergonomic and aesthetic requirements.

Technical requirements for the quality of glass, production, processing, dimensions must comply with the requirements of regulatory and technical documentation.

The surface of the product must be smooth, foreign inclusions and other external glass defects are not allowed.

The product, placed on a flat surface, should not swing, cutting, sharp edges are not allowed. The lids must fit freely into the product, without noticeable swing. When checking the quality of products, the quality of processing and decorations is taken into account; product dimensions and volume are checked.

Aesthetic requirements: originality, fashion, high quality processing. Compliance with ergonomic requirements is especially important for dishes: convenience and safety in use. Usability depends on the size and design. According to the standard, products made of ordinary glass of one grade are good, and their crystal products are divided into 1st and 2nd grades.

Marking, transportation, storage of glass products

Glass products are marked with a brand, which indicates the name of the manufacturer, trademark, standard number, cutting group, article, on crystal products - the content of lead and barium oxides in percent. Glassware with the inscription "Caution, glass!", "Top", "Do not ditch" are transported.

Glass products cannot be stored for a long time in damp rooms, as the transparency of the glass is partially lost, a white coating may form on the surface.

The technological process of production of glass products is divided into the following main stages: preparation of glass mass, melting of glass mass, production of products, annealing, processing and cutting of glass products.

Glass melt preparation consists of preparation of raw materials, blending and melting of glass.

Raw materials used for the production of various types of glass are divided into two groups with some conventionality: basic, or glass-forming, and auxiliary.

Glass-forming materials include silica, boric anhydrite, alumina, sodium sulfate, soda, potash, limestone, dolomite, minium and litharge, witherite, and zinc oxide.

Auxiliary materials include clarifiers, bleaches, dyes, opacifiers, oxidizing and reducing agents, cooking accelerators.

Clarifiers contribute to the release of glass mass from large and small bubbles, give it uniformity. Clarifiers are sodium sulfate, arsenic trioxide and saltpeter.

Decolorizers are used to reduce or remove color shades of glass. Arsenic trioxide, saltpeter, sulfate, sodium chloride, antimony oxide, etc. are used as bleaching agents.

Dyes are added during the glass melting process to color it in a certain color. There are staining of glass with molecular dyes (oxides of heavy and light metals) and colloidal dispersion dyes (compounds of gold, silver, copper, selenium, antimony).

Silencers are used to make glass opaque. These are fluorine, phosphate compounds, compounds of tin and antimony. Silencers paint the glass white.

Oxidizing and reducing agents are added when melting colored glass to create an oxidizing and reducing environment. These include sodium and potassium nitrate, arsenic trioxide, carbon, cream of tartar, stannous chloride.

Melting accelerators contribute to the acceleration of glass melting (fluorine compounds, boric anhydride, aluminum salts).

All raw materials needed for glass production are processed. Quartz sand is enriched, i.e., the content of iron and other impurities in it is reduced. Then sand, soda, saltpeter are dried, dolomite, chalk, limestone are crushed and sifted through sieves - vibrators. After preparation of raw materials proceed to the preparation of the mixture.

A charge is a mixture of raw materials in a given proportion. To speed up the cooking process, 25-30% of cullet (of the same composition) is added to the mixture. Raw materials are thoroughly mixed and sent to glass melting furnaces.

The main methods for producing household dishes are: blowing, pressing, press blowing and centrifugal casting.

Blow method workings can be manual (for products of complex shapes) and mechanized. In the manual method, metal self-blowing tubes are used, into which air is supplied with a special rubber balloon. The heated end of the tube is lowered into the glass mass, which sticks to the heated metal. A certain amount of glass is wound onto the tube, leveled on a metal table, and then a “jar” is blown into a small vial, from which products are finally blown in a metal detachable form.

The mechanized blowing method using a vacuum machine is used for glasses.

Pressing- an easier way to produce products than blowing. The pressing process is as follows: a certain weight drop of glass mass is fed into a mold (matrix), into which a punch is lowered, exerting pressure on the glass mass during its movement, the latter filling the space between the mold and the punch. Products are pressed on manual, semi-automatic and automatic presses.

Press blow method manufacturing of products is carried out in two stages: first, the workpiece is pressed out and the edges of the product are trimmed, and then the workpiece is blown with compressed air to the specified dimensions. The production of these products is carried out on automatic machines.

After the product is made, it is sent for annealing. The annealing process for household glass products consists in heating them and keeping them at a temperature of 530-580°C. Then the products are cooled to room temperature.

TO product processing includes the separation of caps from blown products, the processing of the edge and bottom of the product.

Decorations are applied to the bulk of blown glassware, i.e., they are cut. Products are decorated either in the process of their development (in a hot state), or when they are ready (in a cold state).

Decorations applied to glass products during their production (when hot)

Colored glass obtained by adding dyes to the glass mass.

Colored products made from one layer of glass and covered with one or two layers of intensely colored glass.

Marble decoration obtained in the process of melting milk glass, to which ground unmixed colored glass is added, due to which the impression of veining in marble is created. Malachite-like glassware is decorated in a similar way.

Glass fabric decoration is considered a promising type of product decoration. Glass fabric of a certain size is applied to an almost finished product, the fabric is fused to the glass surface, and the product is blown out.

Colored embankment decoration consists in the following: the heated workpiece is rolled on the table over the poured crushed colored glass, which envelops the workpiece and fuses to its surface, after which the workpiece is heated again.

Guten work typical for products made by blowing without a mold. According to the artist's intention, the surface of the product may have recesses, bulges and sticks.

Crackle decoration obtained in the case when the workpiece is lowered into cold water, then it is heated in a furnace and blown out. At the same time, the surface of the product is covered with small and large cracks, creating a peculiar pattern.

Filigree or lace decoration give the product openwork, has the form of two or three colored spiral threads.

Chandeliers obtained by applying solutions of organic metal compounds in organic solvents to the surface of products and subsequent firing. During firing, solvents burn out, and a film of metals or their oxides is fixed on the surface.

The surface of products with cutting "irrization" has iridescent tints. Products are heated in a muffle furnace in an atmosphere of vapor mixture of tin chloride, strontium nitrate and barium chloride, which, settling on the surface of the product, are firmly connected to it and give different shades with overflows (reminiscent of mother-of-pearl).

Decorations applied to finished products (when cold)

All decorations applied to finished products (in a cold state) are made by mechanical, chemical methods and painting.

Matte tape, numbered grinding, diamond cutting, engraving, a straight wide edge are applied to products mechanically.

matte tape- This is the simplest type of decoration. A metal strip is pressed against the surface of the product, under which sand and water are fed; grains of sand scratch the glass, and a matte stripe is obtained.

Number grinding is a pattern in the form of pits, grooves connected by inclined slots. The drawing is applied using sand, corundum and emery circles.

diamond face This is glass carving. The drawings consist of deep trihedral slits and grooves that form a complex geometric pattern. The diamond face is applied using corundum and electrocorundum single- and multi-blade wheels, sharpened at a certain angle. Then the product is polished.

Engraving- the drawing is flat, without large recesses, matte, more often of a plant theme; the pattern is applied using copper or alundum disks of different diameters.

Straight wide edge is one of the varieties of faceting. It is applied to products with cast-iron or sand washers.

Chemically, etching is applied to products: simple, complex (pantograph) and deep.

Simple and complex etching is carried out as follows: the product is covered with a mastic consisting of wax, paraffin, rosin and turpentine, then a pattern is drawn in it with a thin needle, after which the exposed glass surface is etched in a hydrofluoric acid bath. Simple etching is characterized by a simple pattern, a more complex pattern is applied on pantographic machines (complex etching).

deep etching– is performed on two-, three-layer glass manually with a brush. By repeated treatment with hydrofluoric acid, a relief pattern is obtained on the surface of the product.

Picturesque drawings are applied manually and semi-automatically with paints, 12% gold solution, enamels, chandeliers, followed by firing at a temperature of 580-600°C.

Chemical composition and properties of glass

Lime-soda-potassium, lead-potassium and borosilicate glass are used for dishes.

The approximate composition of the glass is expressed by the "normal glass formula" R 2 O · RO · 6SiO 2 , which is a trisilicate, R 2 O being the monovalent oxides Na 2 O, Ka 2 O; RO - bivalent CaO, MgO, PbO, etc., along with silicon oxides, the composition of the glass includes Al 2 O 3, Fe 2 O 3, etc. The most common glass compositions contain 14-16% monovalent oxides; divalent - 11-12% and silica - 71-75%.

There are chemical and physical properties of glass.

The chemical properties include the chemical stability of glass, i.e., its ability to withstand the destructive action of various media and reagents. Glass is a chemically resistant material.

Physical properties of glass: viscosity, density, strength, brittleness, hardness, heat resistance, etc. Viscosity for each type of glass at a certain temperature is a constant. The density of various glasses ranges from 2.2 to 6.0 (Mg/m³). Soda-lime glass has a density of 2.5, and crystal is about 3.0 and higher.

The tensile strength of glass is low - from 35 to 90 MN / m², and in compression - from 500 to 2000 MN / m². Brittleness - the property of glass to break under the action of an impact load without plastic deformation. Glass has increased brittleness, MgO and Al 2 O 3 oxides reduce it. Hardness is the ability of glass to resist the penetration of another body into it. According to the mineralogical scale, the hardness of the glass is 4.5-7.5.

The thermal conductivity of glass is very low and ranges from 0.7 to 1.34 W/m deg. The thermal expansion of glass is characterized by a linear expansion coefficient, which for various glasses ranges from 5.8·10 -7 to 151·10 -7 , for many glasses of mass use it is 100·10 -7 . Thermal stability - the ability of glass to withstand sudden changes in temperature without breaking.

Of the optical properties of glass, the main ones are transparency and the refractive index of glass. The transparency of glass depends on the chemical composition of the glass and on the presence of iron oxides in it. The refractive index of glasses of various compositions ranges from 1.475 to 1.96; for ordinary glass it is 1.5, for crystal - 1.55 and higher.

Classification and range of glass products

Household glass products are classified according to the main features: purpose, production method, type of glass, color, size, cutting method, completeness, etc.

By appointment household glass products are divided into five groups: household utensils; art products; household utensils, kitchen utensils; lamp products.

By way of production household glass products are divided into blown, pressed, press-blown and centrifugally cast.

By type glass products are soda-potassium-lime (ordinary), potassium-lead (crystal) and borosilicate (heat-resistant).

by color they can be colored and with a color.

By size products are divided into small, medium, large and extra large.

Cutting plays a leading role in the creation of products, which gives ample opportunities for decorating it. Cutting is not always applied to products, and the desired effect is achieved using only shape and color. The greatest variety in terms of cutting, of course, has blown utensils and cuts on press-blown utensils are less interesting. Decorations on the latter are applied during the development process.

By completeness household glass products can be piece and complete (sets and services).

The range of glassware, depending on the method of production and purpose, is divided into the following groups: blown products; pressed products; press-blown products; crystal products; household utensils; kitchen dishes.

blown glassware is very diverse: its range includes hundreds of items. Blown tableware can be piece and complete.

Assortment of pressed dishes significantly narrower. Pressed products are distinguished by their simplicity of form and decor.

Press-blown tableware has a limited range.

Household utensils include products used for cooking and storing food, pickles, jam, kvass, water, etc. (jars, bottles, kegs of various capacities).

Kitchen utensils made of heat-resistant glass (borosilicate) and glass ceramics are intended for cooking. Its range includes: braziers, pots, pans and baking dishes.

Quality assessment of glass products

The quality of glass products is influenced by many factors: structural and dimensional features, mechanical strength, thermal stability, hygienic, aesthetic properties, etc. In terms of structural and dimensional features, household glassware must comply with approved samples. Products on a flat horizontal surface should not swing. Glass products must have good mechanical strength. The thermal stability of products is considered satisfactory if 99% of the tested products pass the tests provided for by GOST 30407-96.

It is necessary that glass products have transparency and no color shades (especially crystal). Products made of colored glass and glass with a color must be evenly colored.

It is important that the product has a clean, smooth surface without burrs and scratches and a clearly defined pattern. The edge of the product should not be cutting, for this it is melted, ground and polished.

In accordance with the current GOST, glass tableware and decorative items are produced in one grade. Crystal products are divided into grades I and II. When determining the grade of a product, the type of defect, its size, quantity and location are taken into account. On glass products there are defects in glass mass, working out and processing. These defects occur during the process of cooking, molding the product and its processing, they significantly reduce the quality of finished products.

TO glass defects include the following:

1. Gas inclusions appear due to insufficient clarification of the glass mass. These include defects - midge and bladder. Turbid and squeezing bubbles in the product are not allowed.

2. Swirl, schlier are transparent inclusions that differ from the main mass of glass in chemical composition or physical properties. The striae are filiform, hairy, in the form of knots and bundles.

3. Crystalline inclusions have a crystalline structure (white) glass particles.

Defects formed during the molding of glass products. The variation in thickness in the walls and bottom of the product is the result of the uneven distribution of glass mass during the production of the product. Chips, chips - damage with a conchoidal structure, located at the intersection of the product with its end face. Scree - small chips. Forged - unevenness, manifested as a fine waviness of the surface. Wrinkles are irregularities that appear as ripples on the surface. A fold is an uneven surface of a pocket-shaped shape. Curvature, folds and wrinkles on products are not allowed.

Defects in processing and decoration of products are edge remelting, asymmetry of patterns, under-finishing and translations on products (allowed), breaks, blockage of the diamond edge, blots, fading of paints and films, swelling, cracking, streaks on products are not allowed, as they sharply reduce the aesthetic and hygienic properties of products. The total number of permissible defects in terms of appearance in one product should be no more than 2 for small ones, 3 for medium ones and 4 for large ones. For especially large products, the total number of permissible defects that do not spoil the presentation is not regulated.

For crystal products, the total number of permissible defects in terms of appearance should not exceed 2 for small products grade I, 3 for medium products and 4 for large products, and 3, 4 and 5 for grade II, respectively.

Marking, packaging, transportation and storage of glass products

Blown products are marked with a paper label, which is applied to the product indicating the manufacturer, trademark, GOST, drawing number, processing group.

Pressed and molded products are marked during the production process. The marking includes the manufacturer's name or trademark.

Glass products are packed in cardboard or corrugated containers with nests or in bags made of wrapping paper or shrink film. Blown products when packed in bags must be pre-wrapped in paper, lined with shavings or other materials. Glasses, glasses and other small and medium-sized products are wrapped in paper in pairs, laying the paper between the bottoms of the products. Complete products are placed in one box or one bag. Souvenir and gift items are not wrapped in paper, but placed in specially designed boxes. Paper bags tied with twine have a glued label, which indicates: trademark or name of the manufacturer; product name; drawing number or processing group; the number of products in a packaging unit (for group packaging); number of controller and packer; packing date; standard designation.

Glass products are transported by rail in clean covered wagons or containers, on which the plant puts the inscription in large print: "Do not turn over the top!", "Caution, fragile!". When placing glass products in wagons or containers, boxes and packages are shifted with packaging materials through two rows tightly, without gaps. Products that are shipped to the Far North and other remote areas must be packaged in accordance with special requirements established by standards.

Glass products are stored indoors, protected from the influence of atmospheric precipitation. When placing products in a warehouse, heavy products are recommended to be placed on the lower shelves located at a height of 15-20 cm from the floor, and lighter products on the upper ones.