RU2640517C2 - Method and device for manufacturing glass products of complex shape by centrifuging - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method for manufacturing glass products includes the following stages: a) providing moulds with a bottom and a top edge; downloading the molten glass drop to the bottom of the mould; bringing the mould into rotation about the vertical axis causes flowing of the drop along the bottom of the mould due to the centrifugation and getting thus a glass blank corresponding to the product form; and extracting the product from the mould immediately after its cooling. Prior to stage b) a restrictive ring is placed on the upper edge of the mould. In stage c) this restrictive ring is brought into rotation by means of the mould. This allows to stop the raising of glass by means of the restrictive ring, and also to obtain a glass product of complex shape. The restrictive ring (30) is brought into free rotation on the support (34), provided with the possibility of vertical movement in the direction of the vertical axis (XX) from the near position, where the restrictive ring is in contact with the top edge (16) of the mould, and the distant position, where the restrictive ring is at a distance from the top edge (16) of the mould.

EFFECT: improving the method of centrifugation for a greater variety of feasible forms and the ability to manufacture products of complex shapes.

15 cl, 5 dwg

Description

The present invention relates to glass products.

More specifically, it relates to a method and apparatus for the manufacture of glass products by centrifugation, as well as to products obtained by this method.

Products related to the present invention, primarily, but not exclusively, are utensils, that is, utensils, such as plates, bowls, salad bowls and the like.

In the field of glass production, there are various ways of making dishes, such as those described in the following patent documents: FR 1488518 A dated July 13, 1967 from the applicant CORNING GLASS WORKS, FR 1527168 A dated May 31, 1968 from the applicant LOING VERRERIES, GB 822627 A of October 20, 1959 of the applicant EGYESUELT IZZOLAMPA, DE 3444298 A1 of June 5, 1986 of the applicant WALTER MASCH J [DE], DE 102010034474 A1 of February 9, 2012 of the applicant SCHOTT AG [DE], JP S59164643 A of September 17, 1984 Applicant OTANI DENKI SEISAKUSHO KK; I KOMA GLASS KK. The main known methods for manufacturing glass products are as follows:

- a method of extrusion, in which the billet is pressed, placed in the mold, then blowing is carried out to form convex products. Examples of such products are glasses, goblets, candle holders, etc .;

- a pressing method in which a molten glass mass, referred to as a "glass drop", is pressed into a mold to form the so-called classic products. Examples of such products are windows of washing machines, cups, mugs, cups, ashtrays, etc .;

- a method called centrifugation, in which a "glass drop" is placed in a mold subjected to rotation in order to cause the drop to spread under the action of centrifugal force, which allows the formation of flat products such as plates, bowls, salad bowls, etc. .

The present invention relates to the last of these methods, that is, to the manufacture of glass products by centrifuging a glass droplet previously placed on the bottom of the mold.

It should be recalled that in the field of ceramics there are other methods of molding (slip casting, isostatic pressing, etc.), but these molding methods are not applicable in the glass industry.

Indeed, the manufacture of ceramic ware is always subject to the following scheme: 1) supply of raw materials, 2) molding, 3) heat treatment (baking / firing) and 4) free cooling.

On the contrary, in the glass industry the scheme is exactly the opposite: 1) supply of raw materials, 2) heat treatment (melting) and 3) molding / controlled cooling (at the same time).

Obtaining complex shapes of glass products, therefore, creates much more problems than in the manufacture of ceramic products, due to the fact that the molding of the product and its cooling must occur simultaneously, and are very interconnected. When the glass has cooled, it is no longer possible to form.

However, the known centrifugation method allows to obtain only products of simple shape, such as plates, salad bowls, bowls, etc., which usually have the shape of a cylindrical body of revolution.

In addition, the known centrifugation method allows to obtain only products with a thinned edge, also referred to as a “ringing edge”. Indeed, during centrifugation, the molten glass droplet is gradually distributed in the mold and fills it with successive waves, forming a spreading product, called a "blank", which has the indicated thinned edges.

The main objective of the present invention is to improve the centrifugation method for a wider variety of feasible shapes and the ability to produce products of complex shapes, which until now could only be obtained by other methods, such as pressing.

Another objective of the present invention is the implementation through a method of advanced centrifugation of glass products of complex shapes with saving time and material.

Another objective of the present invention is the implementation through a method of advanced centrifugation of products of various shapes having thick edges, and not thinned, and products that do not necessarily have the shape of a body of revolution.

To this end, the invention provides a method for manufacturing a glass product, comprising the following steps:

a) providing a mold having a bottom and an upper edge;

b) loading the molten glass droplet onto the bottom of the mold;

c) bringing the mold into rotation about the vertical axis, causing the molten glass droplet to spread along the bottom of the mold due to centrifugation, and thereby obtaining a glass blank corresponding to the shape of the product; and

d) removal from the mold of the product immediately after cooling.

According to the invention, before step b), a restriction ring is mounted on the upper edge of the mold and, in step c), this ring is rotated by means of a mold, which makes it possible to stop the glass from rising through the restriction ring and to obtain a glass product of complex shape.

Thus, in the method according to the invention, the molten glass droplet spreads in the mold and the glass is stopped by the restrictive ring, which allows the accumulation of glass along the restrictive ring and form an edge of complex shape under controlled conditions.

Thus, it is possible to manufacture, in particular, products not with thinned, but with thickened edges to obtain shapes that do not necessarily represent a body of revolution.

Therefore, the method according to the present invention is fundamentally different from previously known centrifugation methods, in which the molten glass was lifted along the entire mold by centrifugation and stopped naturally without forced stopping, which led to a source edge.

As a result, the present method makes it possible to form glass products with greater productivity and speed due to the use of the centrifuge method.

Preferably, after step c), the rotation of the mold is stopped, which causes the rotation of the restriction ring to stop, then the restriction ring is removed to remove the article from the mold.

Indeed, since the restriction ring is rotated by the mold, it is preferable that the restriction ring be removed from the mold as soon as its rotation is stopped.

It is also preferable that, after the restriction ring has been removed, the mold is again rotated without the restriction ring to cool the article before it is removed from the mold.

Preferably, the restrictive ring is freely rotated on the support with the possibility of vertical movement in the direction of the vertical axis from the near position, in which the restrictive ring is in contact with the upper edge of the mold, in a distant position, in which the restrictive ring is at a distance from the upper the edges of the mold.

Preferably, in step d), the glass products are removed from the mold by vertical lifting.

According to another aspect, the present invention relates to a device for manufacturing a glass product by the above method, comprising:

a) a mold containing the bottom and top edge;

b) loading means for loading molten glass droplets to the bottom of the mold;

c) a drive mechanism for bringing the mold into rotation about the vertical axis, causing the molten glass droplet to spread along the bottom of the mold due to centrifugation, and thereby to obtain a glass blank corresponding to the shape of the product; and

d) extraction means for removing glass from the mold immediately after cooling.

According to the present invention, among other things, the device comprises a restriction ring mounted on the upper edge of the mold and rotated by means of the mold, and also capable of stopping the rising of the glass during the spreading of the glass droplet by centrifugation.

The following are other characteristics of the device according to the present invention.

- The restrictive ring is installed with the possibility of free rotation relative to the support with the possibility of vertical movement in the direction of the vertical axis from the near position, in which the restrictive ring is in contact with the upper edge of the mold, in a distant position, in which the restrictive ring is at a distance from the upper edge Press forms.

- Among other things, the device includes a drive mechanism for moving the support of the restrictive ring from the near position to the far and vice versa.

- The loading means comprises a funnel provided for calibrating the glass droplet before loading into the mold.

- The funnel is mounted on a support with the possibility of vertical movement in the direction of the vertical axis from the lower position, in which the funnel is located above the restrictive ring and in close proximity to it, when it is in contact with the upper edge of the mold, in the upper position in which the funnel removed from the restrictive ring.

- Among other things, the device includes a drive mechanism for moving the funnel support from the lower position to the upper and vice versa.

- Among other things, the device contains cooling means provided for cooling the molded product contained in the mold before removing it.

- Among other things, the device includes a valve with the possibility of vertical movement relative to the bottom of the mold for lifting the cooled molded product in order to remove it from the mold.

According to another aspect, the present invention relates to an installation comprising a number of devices, as described above, arranged in the form of a circular conveyor and capable of continuously moving along an annular path.

Finally, the invention relates, inter alia, to a glass product obtained by the above method and / or by the above device and / or the above installation.

In the following description, given for illustrative purposes only, references are made to the accompanying graphic materials, on which:

- In FIG. 1 is a perspective view of an apparatus for manufacturing glass products according to the present invention;

- In FIG. 2A-2M show various successive phases of operation of the device of FIG. one;

- In FIG. 3 shows an installation comprising a series of devices of FIG. 1 arranged in a circular conveyor;

- In FIG. 4 shows a cross-sectional view of the obtained glass product, a mold and a restrictive ring are also shown; and

- In FIG. 5 is a perspective view of a glass product obtained by the method of the present invention.

Consider first FIG. 1, which shows a device 10 according to the present invention for producing glass products by centrifugation carried out in the method according to the invention. The device 10 includes a mold 12, driven in rotation relative to the vertical axis XX. Mold 10 contains a molding cavity corresponding to the external shape of the manufactured product. It contains a bottom 14 and an upper edge 16 in the shape of a shoulder. This upper edge 16 has an annular shape and extends in a plane perpendicular to the axis XX, as well as in the horizontal plane. In an embodiment, the mold has the shape of a body of revolution about axis XX. The edge 16 is generally rounded and passes into a cylindrical wall 18, forming a shoulder. However, other shapes are possible and the edge 16 may have non-rounded shapes, for example oval, square, rectangular, polygonal, etc.

The bottom 14 is concave and through its center passes a valve 20 provided for removing the molded product from the mold by vertical lifting.

The mold 12 is mounted on the frame 22 and is driven by a motor M (shown schematically), for example an electric motor, under controlled rotation conditions.

In the position shown in FIG. 1, the valve 20 is in the lower position and provides continuity of the bottom of the mold.

Among other things, the device comprises loading means, schematically shown in the form of a funnel 24, into which molten glass is fed from reservoir R, according to a technique known from the field of centrifugation. Such glass droplet loading means are described in the technical literature. Tank R is located above the tank and is designed to periodically supply glass mass, also referred to as “glass drop”, in controlled, accurate and reproducible conditions. Indeed, it is necessary that all the time there is the same amount of glass supplied, depending on the shape and size of the manufactured product, as well as the same quality of the glass used and its temperature at the outlet of the tank. This temperature is most often around 1200 ° C.

The loading means allows the molten glass drop to be loaded onto the bottom of the mold. Bringing the mold into rotation about axis XX after loading the glass droplet onto the bottom of the mold causes the glass droplet to spread, as is well known in the art.

A funnel 24 is provided for calibrating a glass droplet and for loading it into a central point on the bottom of the mold. This funnel is mounted on a support 26 of a generally cylindrical shape, referred to as a “window”, with the possibility of vertically moving in the direction of the axis XX from the lower position to the upper under the action of the drive mechanism 28, for example, such as a pneumatic or electric jack. The jack contains a housing and a vertical rod, while the rod forms the supporting column of the jack. In the position of FIG. 1, the funnel is shown in the upper position, that is, in the position farthest from the mold 12.

According to the present invention, the device, inter alia, comprises a restriction ring 30, also referred to as a “rim”, mounted on the upper edge 16 of the mold and rotated by the mold, and also capable of stopping the raising of glass, as will be described later.

This restrictive ring 30 is made of metal and contains a lower edge 32 in the form of a shoulder, which can rest on the upper edge 16 of the mold supported by the cylindrical wall 18 of the mold to ensure proper alignment of the restrictive ring relative to the mold.

The restriction ring 30 is installed with the possibility of free rotation relative to the support 34 with the possibility of vertical movement in the direction of the vertical axis XX from the near position, in which the restriction ring is in contact with the upper edge of the mold, in a distant position, in which the restriction ring is at a distance from the upper edge of the mold, as shown in FIG. one.

The restriction ring is located under the support 34, usually in the form of a ring, which provides a central passage for the funnel 24.

The restriction ring 30 is mounted on the support 34 by means of a ball bearing 36 containing a ball bearing or other brake, allowing fixation of the position of the ring.

Among other things, the device includes a drive mechanism 38 for moving the support 34 of the restrictive ring 30 from a near position to a far and vice versa.

This drive mechanism 38 is preferably in the form of a pneumatic or electric jack. The jack contains a housing and a vertical rod, while the rod forms the supporting column of the jack.

As can be seen from FIG. 1, the drive mechanisms 28 and 38 are located next to each other and their directions of action are parallel to each other and parallel to the axis of rotation XX.

Among other things, the device comprises cooling means 40 (shown schematically) provided for cooling the glass product before removing it. Preferably, cooling is provided by nozzles (not shown) provided to direct the flow of the respective cooling fluid, in particular air, under controlled conditions.

Turning now to FIG. 2A-2M for describing the operation of the device of FIG. 1.

In FIG. 2A shows a device at the beginning of a work cycle before loading, that is, before placing a glass drop. In this position, the mold is not rotated, the restriction ring 30 is in a distant position, at a distance from the mold and the funnel 24 is also in the upper position.

In FIG. 2B shows a further phase in which the drive mechanism 38 has moved the support 34 from a distant position to the near one for the restriction ring 30 to contact the mold 12. In this position, the lower edge of the restriction ring 32 is placed in the upper edge 16 of the mold and the cylindrical wall 18 of the press -forms. Mold 12 is still locked and funnel 24 is still in the up position.

In FIG. 2C shows a further phase in which the funnel 24 is lowered to the lower position by means of the drive mechanism 28. Thus, the funnel 24 is located above and in the immediate vicinity of the restriction ring 34, and passes through it. As a result, the funnel is in the proper position, allowing you to direct a glass drop (not shown) to load it in the Central part of the bottom of the mold.

FIG. 2D corresponds to FIG. 2C and shows a glass droplet G on a vertical loading path before its direction by means of a funnel 24.

In FIG. 2E shows a further phase in which the funnel 24 is again raised to its upper position by the action of the drive mechanism 28. It can be seen that the glass droplet G forms a lump at the bottom of the mold.

In FIG. 2F shows a further phase in which a glass drop G reached the bottom of the mold and the mold was rotated in the direction of the arrow F1, in this case counterclockwise, subject to a controlled speed.

Since the restriction ring 30 is in contact with the upper edge 16 of the mold, bringing the mold into rotation automatically rotates the restriction ring 30, which is set to rotate freely under the support 34. The temperature of the restriction ring is maintained suitable for contact with the mold.

In FIG. 2G shows how, under the action of rotation of the mold, the glass drop G begins to spread into the blank, forming successive waves that rise along the mold in the direction of the restriction ring 30.

In FIG. 2H shows a further phase in which the mold still rotates, the molten glass contacts the restriction ring 30, stopping the glass from rising and allowing material to build up under the retaining ring. As a result, this makes it possible to form, for example, a product with thickened edges, which would be impossible in the absence of such a restrictive ring.

In FIG. 2I shows the device in a further phase similar to that shown in FIG. 2H, except that the rotation of the mold is stopped. Accordingly, this causes the stop ring to stop.

In FIG. 2J shows a further phase in which the restriction ring 30 is brought to a distant position, thanks to the drive mechanism 38, by means of an upward vertical movement. Thus, an article 42 is obtained, the edge 44 of which is formed by a restrictive ring, which leads to the accumulation of glass opposite this restrictive ring.

In FIG. 2K shows a further phase in which the article 42 is cooled by means of cooling means 40, the mold being rotated in the direction of arrow F1, as before. This cooling can be carried out, for example, by air blowing, in a manner known per se. After cooling, the temperature of the product is usually around 500 ° C, which allows manipulation.

FIG. 2L is similar to FIG. 2K, except that the rotation of the mold was stopped.

In FIG. 2M shows the last phase of the process in which the article 42 is removed from the mold. Extraction from the mold is carried out by means of a valve 20 acting vertically in an upward motion. The valve allows you to separate the product from the mold for its further extraction by any suitable means, for example, vacuum gripping devices (not shown). The valve immediately returns to its original position, closing the bottom of the mold.

Turning now to FIG. 3, which shows an installation 46 containing a series of devices 10, as described above, arranged in a circular conveyor and capable of continuously moving along an annular path. In this embodiment, there are 14 devices 10 arranged at the same angle relative to the center (not shown.) Along the aforementioned circular path, allowing continuous production of glass products from loading the material (position in Fig. 2A) to removing the product from the mold (position in Fig. 2M).

In FIG. 4 shows a cross-sectional view of an article 42 that can be obtained by the method according to the invention. It is seen from the cross-section that the product was molded by means of the mold 12 and that its edge 44 was formed by a restrictive ring 30, allowing the material to accumulate and thereby obtain a thickened edge in this embodiment.

In FIG. 5 shows a perspective view of an embodiment of one such product. In this embodiment, the product is presented in a generally rectangular shape, rather than the shape of a body of revolution. This embodiment can be made, in particular, in the form of a dish or plate.

The method according to the present invention also allows you to create complex shapes, in particular with thickened edges, by centrifugation, which was not possible in the prior art.

Due to the fact that production is carried out by centrifugation, it is performed at a higher speed, leading to increased productivity. Also the result is a reduction in the weight of the products compared to the weight of products that can be obtained by conventional pressing methods.

It should be noted that in the present invention it is the mold that rotates the restrictive ring and sets it at an angle before it stops and lifts. Before raising to a distant or upper position, the restrictive ring is stopped by means of a brake mechanism or any other device, while maintaining its position at an angle.

The product is cooled by vertical ventilation, so that the retaining ring remains in the upper or lower position.

If necessary, control the temperature of the restrictive ring by adjusting the contact time between the glass of the product and the metal of the restrictive ring. The pressure reduction system of the descent chamber allows easy lifting by means of a spring to release the ring in contact with the glass.

The temperature of the mold is controlled by lateral ventilation with the possibility of spraying water through the air supply channels and central spraying through a calibrated nozzle.

The present invention will now be described by means of the following embodiment, given for illustrative purposes only.

In this embodiment, the plates are generally square in shape.

Use a glass drop at a temperature of 1200 ° C, which is placed on the bottom of the mold. The latter is brought into rotation at a speed of 1500 rpm for 7 seconds.

As soon as the rotation is stopped, the restrictive ring is lifted, and then the resulting product is cooled by rotating the mold for 6 seconds at a speed of 300 rpm.

Cooling is carried out, for example, by air spraying in the direction of the obtained product.

The above parameters of this embodiment can be changed depending on the shape and size of the glass product being manufactured, as well as the type of glass used.

Indeed, the present invention is applicable to the manufacture of products from various types of glass, in particular sodium-calcium, fluorosilicate, borosilicate and, in general, any types of glass whose viscosity curve is compatible with the centrifugation process.

In particular, the invention is applicable to the manufacture of cookware, such as tableware, such as plates, bowls, salad bowls and the like. It can also be applicable for the manufacture of glass products for other purposes, for example, such as windows of washing machines, etc.

Claims (25)

1. A method of manufacturing a glass product, comprising the following steps: a) providing a mold (12) having a bottom (14) and an upper edge (16); b) loading the molten glass droplet (G) onto the bottom of the mold; c) bringing the mold (12) into rotation relative to the vertical axis (XX), causing the molten glass droplet to spread along the bottom of the mold due to centrifugation and thereby obtaining a glass blank corresponding to the shape of the product (42); and d) removal from the mold of the product immediately after cooling, characterized in that before step b), a restriction ring (30) is mounted on the upper edge (16) of the mold and, in step c), this restriction ring (30) is rotated by means of the mold (12), which makes it possible to stop the glass from rising by means of a restrictive ring (30) and to obtain a glass product of complex shape, the restrictive ring (30) being freely rotated on a support (34) with the possibility of vertical movement in the direction of the vertical axis (XX) from a near position at which the restrictive ring ditsya in contact with the upper edge (16) of the mold, and a distal position in which the stop ring is spaced from the upper edge (16) of the mold. 2. The method according to p. 1, characterized in that after step c) the rotation of the mold (12) is stopped, which causes the rotation of the restriction ring (30) to stop, then the restriction ring is removed to remove the product from the mold. 3. The method according to p. 2, characterized in that after removing the restrictive ring (30), the mold (12) is again rotated without a restrictive ring to cool the product before it is removed from the mold. 4. The method according to p. 1, characterized in that in step d), the glass products are removed from the mold by vertical lifting. 5. A device for the manufacture of glass products by the method according to PP. 1-4, containing: a) a mold (12) containing a bottom (14) and an upper edge (16); b) loading means (24) for loading the molten glass droplet (G) onto the bottom (14) of the mold (12); c) a drive mechanism (M) for bringing the mold (12) into rotation about the vertical axis (XX), causing the molten glass droplet (G) to spread over the bottom of the mold due to centrifugation, and thereby obtain a glass blank corresponding to the shape products (42); and d) extraction means (20) for removing glass from the mold immediately after cooling, characterized in that it further comprises a restriction ring (30) mounted on the upper edge (16) of the mold and rotated by means of the mold, and also capable of stopping the raising of the glass during the spreading of the glass droplet (G) during centrifugation, wherein the restrictive ring (30) is installed with the possibility of free rotation relative to the support (34) with the possibility of vertical movement in the direction of the vertical axis (XX) from the near position at which the restrictive ring is in contact those with the upper edge of the mold to the back position in which the stop ring is spaced from the upper edge of the mold. 6. The device according to claim 5, characterized in that it further comprises a drive mechanism (38) for moving the support (34) of the restrictive ring (30) from the near position to the far and vice versa. 7. The device according to claim 6, characterized in that the drive mechanism (38) is a pneumatic or electric jack. 8. The device according to paragraphs. 5-7, characterized in that the means of loading contain a funnel (24) provided for calibrating the glass droplet (G) before loading into the mold. 9. The device according to claim 8, characterized in that the funnel (24) is mounted on a support (26) with the possibility of vertical movement in the direction of the vertical axis (XX) from the lower position, in which the funnel is located above the restrictive ring (30) and in the immediate proximity to it when it is in contact with the upper edge of the mold, in the upper position, in which the funnel is removed from the restrictive ring (30). 10. The device according to p. 9, characterized in that it further comprises a drive mechanism (28) for moving the support (26) of the funnel (24) from the lower position to the upper and vice versa. 11. The device according to p. 10, characterized in that the drive mechanism (28) is a pneumatic or electric jack. 12. The device according to p. 9, characterized in that it further comprises cooling means (40) provided for cooling the molded product (42) located in the mold before removing it. 13. The device according to p. 12, characterized in that it further comprises a valve (20) with the possibility of vertical movement relative to the bottom (14) of the mold for lifting the cooled molded product (42) in order to remove it from the mold. 14. Installation containing a number of devices (10) according to paragraphs. 5-13 located in the form of a circular conveyor and capable of continuously moving along an annular path. 15. The glass product obtained by the method according to paragraphs. 1-4 and / or by means of the device according to paragraphs. 5-13, and / or through the installation of claim 14.

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