Glass bottle concept and classification

Can be sealed with a lid or stopper and can be used to hold hollow glass products in a variety of materials. It is widely used as a packaging container for beverages, alcohol, chemicals, medicines, culture and education supplies, and cosmetics. The glass bottle is transparent, easy to clean, has good chemical stability, does not contaminate the contents, has high airtightness, has excellent storage properties, and is rich in design and decoration. It can be recycled and used for many times, and has a rich source of raw materials. However, glass bottles are easily broken and have a large weight ratio. These drawbacks are gradually improving with the development of process technology.

Glass products are produced with the highest yield of glass bottles and cans. In 1980, the world production of glass products was 68 Mt, of which glass bottle production was 40.8 Mt.

From 2000 BC to the first 500 years, humans could manufacture hollow glassware. After the use of blowpipes in 200 BC, the oil production and brewing industry subsequently used hollow glass containers. During the Roman Empire, the demand for glass containers increased, and most of the products were round-bottomed and supported by iron frames or wooden frames. Later, due to the development of blown glass molds, unsupported flat bottom bottles were manufactured. From the 5th to the 15th century, the suppression, drawing, and blowing technologies were greatly developed, laying the foundation for the mechanization of glass manufacturing. In 1867, the Siemens brothers in Germany applied continuous refrigerated chamber tank furnaces to the glass industry to make large-scale production of glass bottles and cans possible. From 1880 to 1890, the molding technology of the press-blow process for the manufacture of wide-mouth bottles and the blow-blow process for making small bottles was invented (see glass manufacturing). In 1900, the first bottle-making machine driven by a motor appeared. From 1904 to 1905, MJ Owens created an automatic vacuum suction type bottle-making machine. In 1910, the gob feeder started to develop. In 1914, the semi-automatic blow-blown process was developed. In 1925, the US-based Hadford-Enpel Company developed a successful bottle-making machine, which was produced by the blow-blow method. Later it was also developed to be able to be produced by the pressure-blowing method. This type of bottle-making machine is still the main model used today, and gradually developed toward multiple units and multiple drops of material.

During the Tang and Song dynasties, China used blowpipes to blow hollow glass containers. The glass industry in modern times was formed from 1904 to 1908. Shanghai Jinghua Glass Factory, established in 1931, is the first factory in China to manufacture glass bottles and cans using horizontal flame and horseshoe-shaped flame regenerator tank kiln and automatic bottle-making machine. After the 1950s, a number of larger modern bottle-making plants were built. In the 1980s, the biggest improvement in the production of glass bottles and bottles was the lightweighting of glass bottles, which could save raw materials and fuel, increase production speed, and reduce transportation costs.

There are a large variety of classification glass jars, there are a variety of classification methods. 1 According to the appearance, there are general bottles, cans, bottles and cans, etc., with a capacity of 1ml to 25l. 2 According to the shape of the bottom, there are round, oval, square, rectangular, flat and other bottles, mostly round. 3 According to the bottle mouth size, there are wide mouth, small mouth, spray mouth and other bottles. Bottles with an inner diameter of more than 30mm, no shoulders or less shoulders are called wide mouth bottles. They are commonly used for holding semi-fluid and powdery or bulk solid objects. Bottles with an inner diameter of less than 30mm are called small-mouthed bottles and are often used for holding various fluid items. 4 According to the form of the bottle mouth and bottle cap, there are continuous screw bottle mouth, cork bottle mouth, pouring bottle mouth, crown cap mouth, rolling cap mouth, plastic cap bottle mouth, spray bottle mouth , Pressure - Open the bottle, side seal - open the bottle, glass stopper frosted bottle, bottle with a handle and the mouth of the bottle. Bottle mouth size and tolerances are standardized. 5 According to the requirements of the use of bottles and cans, there are bottles and cans for recycling. The bottle cans are used once for disposal; the recycling bottles can be recycled many times and used in a working manner. 6 according to the molding method, there are molded bottles and control bottles. Molded bottles are made by molding the glass directly in the mold; the bottle is first drawn into a glass tube and then processed. 7 According to the bottle color, there are colorless, colored and opaque bottles. Most glass jars are clear and colorless, allowing the contents to maintain a normal image. Followed by green and brown. Green is usually filled with drinks; brown is used to hold medicines or beer. They absorb ultraviolet light and help protect the contents. The United States stipulates that the average wall thickness of the colored glass bottle should be such that the transmittance of the light wave having a wavelength of 290 to 450 nm is less than 10%. A few cosmetics, creams and ointments are filled with opaque glass jars.

Raw materials and chemical ingredients Bottles Glass batch materials generally consist of 7 to 12 kinds of raw materials. There are mainly quartz sand, soda ash, limestone, dolomite, feldspar, borax, lead and antimony compounds. In addition, there are auxiliary materials such as clarifiers, colorants, decolorizers, opacifiers (see glass manufacturing). The coarse-grained quartz is difficult to be completely melted; the fine particles are liable to produce scum and dust during the melting process, which affects the melting and easily blocks the regenerator of the melting furnace. The suitable particle size is 0.25-0.5mm. In order to use the waste glass, cullet is generally added, and the amount thereof is usually 20 to 60%, and up to 90%.

The chemical composition of glass bottle glass varies according to its use requirements, molding method, molding speed, process characteristics, and raw material varieties. The vast majority of bottles use soda lime silicate glass. The main components of soda lime silicate glass are SiO2, Na2O, and CaO. The introduction of appropriate amounts of Al2O3 and MgO can reduce the crystallization tendency of the glass, enhance the chemical stability and mechanical strength of the glass, and improve the glass forming properties. The chemical composition of the sodium-calcium bottle glass in most countries in the world is SiO270 to 74%, CaO and MgO 10 to 14%, Na2O and K2O13 to 16%, and Al2O3 1.5 to 2.5%. When producing colorless glass jars, the content of Fe2O3 in quartz sand is very low (usually about 0.03%). In common soda-lime glass, Cr2O3 and Fe2O3 are added, and the glass is greenish. Sulfur-carbon or MnO2 and Fe2O3 are added, and the glass is brown. Bottles containing drugs are required to have high chemical stability and are made of borosilicate glass. High-grade cosmetics bottles are made of crystallized glass containing lead, bismuth or zinc, some are opaque glass, and fluorides are generally used as opacifiers.

Quality requirements Glass bottles should have certain properties and meet certain quality standards.

1 Glass quality: pure and uniform, no defects such as sand, stripes, bubbles. The colorless glass has a high transparency; the color glass is uniform and stable in color and can absorb a certain wavelength of light energy.

2 Physical and chemical properties: It has a certain degree of chemical stability and does not interact with the contents. Has a certain degree of shock resistance and mechanical strength, can withstand washing, sterilization and other heating, cooling process and bear filling, storage and transportation, encountered general internal and external stress, vibration, impact, can be maintained without damage.

3 molding quality: to maintain a certain amount of capacity, weight and shape, uniform wall thickness, mouth smooth, smooth to ensure that the filling is convenient and a good seal. No defects such as twist deformation, surface roughness, unevenness, and cracks.

Manufacturing Process Glass bottle manufacturing mainly includes batch preparation, melting, forming, annealing, surface treatment and processing, inspection and packaging.

1 Preparation of batch materials: including the storage, weighing, mixing of the raw materials and the transportation of the batch materials. The mixing materials are required to be evenly mixed and the chemical composition is stable.

2 Melting: The melting of bottle glass is mostly carried out in a continuously operating flame tank furnace (see glass melting furnace). The daily production of horizontal flame tank kiln is generally more than 200t, and large-scale 400-500t. The horseshoe-shaped flame tank kiln produces more than 200t daily. Glass melting temperature up to 1580 ~ 1600 °C. Melting energy consumption accounts for about 70% of the total energy consumption in production. It can effectively conserve energy by means of comprehensive insulation of the tank kiln, increasing the capacity of the regenerator cells, improving the distribution of the material piles, improving the combustion efficiency, and controlling the convection of the glass liquid. Bubbling in the melting tank can improve the convection of the glass liquid, strengthen the clarification and homogenization process, and increase the discharge amount. The use of electric heating in the kiln can increase the output and increase the quality without increasing the melting furnace.

3 Molding: The molding method is mainly adopted. Blow-blow molding of small-mouthed bottles and pressure-blow molding of wide-mouth bottles (see glass manufacturing) are used. Less regulation is used. Modern glass bottles are widely used in high-speed molding of automatic bottle machines. This bottler has certain requirements on the weight, shape and uniformity of the gob, so the temperature in the feed tank must be strictly controlled. There are many types of automatic bottle-making machines, among which the bottle-type bottle-making machines are most commonly used. This bottler feeds the bottler, not the bottler, so there is no rotating part and the job is safe, and any branch can be parked separately for maintenance without affecting other operations (Figure 1). ). The range of bottle-making machines for the manufacture of bottles and cans has a wide range of flexibility and has been developed into 12 groups, double-dropping or triple-drop molding and computer control.

4 Annealing: Annealing of the glass jar is to reduce the permanent stress of the glass residue to a permissible value. Annealing is usually carried out in a mesh belt type continuous annealing furnace, and the maximum annealing temperature is about 550 to 600°C. The mesh belt type annealing furnace (Fig. 2) uses forced air circulation heating to make the cross-section temperature distribution of the furnace uniform and form an air curtain, which limits the movement of the longitudinal air flow and ensures uniform and stable temperature of each zone in the furnace.

5 Surface treatment and processing: The glass jars are generally surface-treated by coating on the hot and cold ends of the annealing furnace. The hot end coating is to put the jars in the hot state (500-600 DEG C) after being molded into the atmosphere of vaporized tin tetrachloride, titanium tetrachloride or tin tetrabutyl tetrachloride, so that these metal compounds are The surface of the hot bottle can be oxidized to an oxide film after being decomposed to fill in micro-cracks on the surface of the glass, and at the same time prevent the generation of surface microcracks and improve the mechanical strength of the glass bottle. The cold end coating uses monostearate, oleic acid, polyethylene emulsion, silicone, or silane to spray the surface of the jar at a temperature of about 100-150°C at the exit of the annealing furnace to form a layer of lubricating film. To improve the wear resistance, lubricity and impact resistance of the bottle surface. In production, cold end coatings are often used in conjunction with hot end coatings. For large-capacity jars of more than 1 l, some are covered with foamed polystyrene or polyethylene film. The jacket is heat-shrinkable, tightly wrapped on the bottle after heating, tough and elastic, anti-shock, anti-friction, and no debris flying debris when the bottle is broken, which can avoid personal injury.

Glass bottles, reagent bottles, sample bottles, perfume bottles, etc. are used to grind and sand plugs with mortar or corundum plus water as abrasive. Advanced cosmetics and perfume bottles are often polished and polished to eliminate dents and increase gloss. High-grade wine bottles or artistically decorated bottles and pots are corroded with hydrofluoric acid, resulting in surface light diffusion and delicate touch. In order to print logos and decorations on the surface of glass, spray color, screen printing, and decal processing methods can be adopted. The glass glaze can be applied to the surface of bottles and cans and baked at 600°C. The glaze and glass are fused to form a permanent pattern. . If you paint with organic pigments, simply bake it at 200-300°C.

6 Inspection: Identify defective products to ensure product quality. The defects of glass jars are divided into two major categories, glass defects and can forming defects. The former includes bubbles, stones, stripes and color irregularities; the latter is cracks, uneven thickness, deformation, cold spots, wrinkles and so on. In addition, the bottle weight, capacity, bottle mouth and bottle size tolerances, internal stress resistance, thermal shock resistance, and stress relief levels need to be checked. Beer bottles, beverage food bottles, etc. Due to high production speed, large quantities, visual inspection can not be adapted, there are automatic inspection equipment, such as pre-selector (inspect the bottle shape and size tolerances), bottle inspection, cracks Inspectors, wall thickness inspection devices, extrusion testers, pressure testers, etc.

7 Packaging: Corrugated cardboard box packaging, plastic box packaging and pallet cartridge packaging. All have been automated. Corrugated cardboard box packaging uses the same cartons from empty bottle packaging until filling and sales. The plastic box used for plastic box packaging can be recycled for reuse. Pallet container packaging is to arrange the bottles that are inspected into a rectangular bottle array, move them to the trays and store them one by one until the specified number of layers is packed. Usually covered with plastic film sleeves, heated to shrink, tightly wrapped into a solid overall, and then tied, this also known as thermoplastic packaging.

Posted on