POLISHING PROCESS AND POLISHING APPARATUS FOR GLASS PRODUCT

Abstract

Disclosed are a process and apparatus for polishing a glass article (1201).

The polishing process comprises bringing a rotating article (1201) to be polished into contact with various centrifugally outspread flexible flaps of a rotating flexible flap grinding wheel (1101), with a grinding wheel (1101) rotation shaft being parallel to an article (1201) rotation shaft; and pneumatically controlling the feed of the flexible flap grinding wheel (1101) relative to the surface of the article (1201) to be polished, such that the outer edges of the flaps of the flexible flap grinding wheel (1101) are in pressure contact with the surface to be polished of the article (1201) to be polished, and polishing same. This polishing process can restore a worn glass bottle, particularly a glass bottle having a profiled contour, to the extent that same looks like new at a lower cost. The corresponding polishing apparatus can realize automatic and continuous grinding polishing of worn glass bottles.

Claims

1. A polishing process comprising: bringing a rotating article to be polished into contact with various centrifugally outspread flexible flaps of a rotating flexible flap grinding wheel, with a grinding wheel rotation shaft being parallel to an article rotation shaft; and pneumatically controlling the feed of the flexible flap grinding wheel relative to the surface of the article to be polished, such that the outer edges of the flaps of the flexible flap grinding wheel are in pressure contact with the surface to be polished of the article to be polished, and polishing same.

2. The polishing process of claim 1, characterized in that said pneumatic controlling of the feed of the flexible flap grinding wheel relative to the surface of said article to be polished is performed by pneumatically applying a force, in the radial direction, to said article rotation shaft by means of said grinding wheel rotation shaft.

3. The polishing process of claim 1, characterized in that the feed of said flexible flap grinding wheel relative to the surface of said article to be polished can be automatically compensated according to the surface contour of the article to be polished, so that each of the flaps of said flexible flap grinding wheel is in pressure contact with the surface to be polished of the article to be polished at a constant pressure.

4. The polishing process of claim 3, characterized in that said grinding wheel rotation shaft can advance and retract, so that the feed of said flexible flap wheel relative to the surface of said article to be polished is automatically compensated by the contour of the article to be polished.

5. The polishing process of claim 1, characterized in that the direction of rotation of said grinding wheel rotation shaft is the same as that of the article rotation shaft, but the speed of rotation thereof is different.

6. The polishing process of claim 1, characterized in that the speed of rotation of said article rotation shaft is 1-100 r/min, and the speed of rotation of said grinding wheel rotation shaft is 500-3000 r/min.

7. The polishing process of claim 1, characterized in that the pressure of the pressure contact of the flaps of said flexible flap grinding wheel with the surface to be polished of the product to be polished is 2-6 kgf.

8. The polishing process of claim 1, characterized in that said flexible flap grinding wheel comprises a hub and a plurality of flexible flaps with an inner edge fixed on the hub and an outer edge that can be outspread, each flexible flap comprising a substrate and an abrasive layer, and the abrasive layer being bonded to the substrate and comprising an abrasive and a binder.

9. The polishing process of claim 8, characterized in that the material of said substrate is selected as having the same or a similar rate of consumption with respect to said abrasive layer.

10. The polishing process of claim 8, characterized in that the process further comprises bringing the rotating article to be polished sequentially into contact with a plurality of rotating flexible flap grinding wheels in the descending order of the grain sizes of abrasives of the grinding wheels, where the width of a grinding wheel flap with a smaller abrasive grain size is greater than the width of a grinding wheel flap with a larger abrasive grain size.

11. The polishing process of claim 10, characterized in that the abrasive grain size of each of said plurality of flexible flap grinding wheels is selected from 300-1 m.

12. The polishing process of claim 1, characterized in that the abrasive of the flexible flap grinding wheel is selected from abrasives with a Mohs hardness of 6-10.

13. The polishing process of claim 1, characterized in that the abrasive of the flexible flap grinding wheel is selected from silicon carbide, aluminum oxide, diamond or cerium oxide.

14. The polishing process of claim 1, characterized in that said article to be polished is a glass article.

15. A polishing apparatus comprising: at least one set of grinding wheel rotation mechanisms, each set of grinding wheel rotation mechanisms comprising a servo motor and a grinding wheel rotation shaft driven by the servo motor; an article rotation mechanism for driving an article rotation shaft to rotate, said article rotation shaft being parallel to each grinding wheel rotation shaft; and at least one set of automatic feed compensation mechanisms, characterized in that said servo motor and said grinding wheel rotation shaft are fixed on a baseplate; and each set of automatic feed compensation mechanisms comprises: a pneumatic supply for controlling the feed of said servo motor and said grinding wheel rotation shaft relative to the article rotation shaft by means of pneumatic pressure, and a linear guide rail, with a sliding block on which said baseplate is fixed being capable of moving linearly along the linear guide rail.

16. The polishing apparatus according to claim 15, characterized in that the apparatus further comprises an automatic article loading and unloading mechanism and an automatic article conveying mechanism.

17. The polishing apparatus according to claim 15, characterized in that the apparatus further comprises a cooling system for water-cooling the polished surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The particular embodiments of the present invention will be further described below in detail in conjunction with the drawings.

[0038] FIGS. 1 and 2 are schematic views of the flexible flap grinding wheel of the present invention when in contact with a glass bottle.

[0039] FIGS. 3 and 4 are schematic views of a production line of the polishing apparatus according to the present invention.

[0040] FIG. 5 is a partial schematic view of the polishing apparatus according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0041] In order to more clearly illustrate the present invention, the present invention will be further described below in conjunction with the preferred embodiments and the accompanying drawings. A person skilled in the art should understand that the following contents which are described in detail are illustrative rather than limiting, and should not thus limit the scope of protection of the present invention.

[0042] FIGS. 1 and 2 show a schematic view of the process for grinding and polishing a glass bottle using a flexible flap grinding wheel according to the present invention.

[0043] As shown in the figures, the flexible flap grinding wheel 1101 comprises a hub and a plurality of flexible flaps. Each flexible flap comprises a substrate and an abrasive layer, the abrasive layer being bonded to the substrate and comprising an abrasive and a binder. The substrate is a flexible material and may be, for example, a cloth, a non-woven fabric or a metal, or an organic high molecular material, etc. The abrasive layer comprises an abrasive and a binder. The hardness of the abrasive is a Mohs hardness of 6-10, and the abrasive may be, for example, silicon carbide, aluminum oxide, cerium oxide or artificial diamond. The abrasive of the flexible flap grinding wheel is abrasive grains with a grain size that is selected from 300-1 m, and may respectively be, for example, but are not limited to, 150-180 m, 35-40 m, 20-25 m, 15-20 m, or 10-13 m, and the density of the abrasive layer is 2.8-4.2 g/cm.sup.3. The inner edge of the flexible flap is fixed on the hub, and the installation interval between the flaps is preferably constant. Flaps on the same grinding wheel are preferably the same size. A small portion of the outer edge of and the end face of each flap are exposed when the grinding wheel is rotating in the rotation direction, and the exposed portion is in contact with the surface of the article to be polished and thus polishes the surface of the article. With regard to an article 1201 to be polished which has a complicated structure, such as a ring and a groove, or a glass article which has an irregular three-dimensional or profiled shape, the flexible flaps of the grinding wheel are outspread under the centrifugal action of rotation, so that the outer edge thereof can reach each portion of the surface of the article and thus polishes same. The material and thickness of the substrate and the material and thickness of the abrasive layer are chosen to have the same or a similar rate of consumption with respect to said abrasive layer. In this case, the material of the substrate is ground off with the grinding of the abrasive, which, on the one hand, ensures the uniformity of the grains of the abrasive layer which are in contact with the surface of the article being polished, and on the other hand, avoids the risk of the abrasive failing to be in uniform contact with the surface of the article to be polished or even the grinding wheel shaft or the article shaft stopping rotating due to the fact that the material of the substrate has been wound around the grinding wheel shaft or the article shaft for an extremely long time.

[0044] As shown in the figures, the grinding wheel rotation shaft 110 for allowing the flexible flap grinding wheel to rotate and the article rotation shaft 120 for allowing the article 1201 to be polished to rotate are arranged in parallel to each other, and the grinding wheel rotation shaft and the article rotation shaft rotate in the same direction, e.g., clockwise. The speed of rotation of the article rotation shaft is, for example, 1-100 r/min, and the speed of rotation of the grinding wheel rotation shaft is, for example, 500-3000 r/min. At the position of the contact between the flaps and the article, the flaps and the article move toward each other. Under the centrifugal action of the high-speed rotation, the outer edge of the flaps moves away from the grinding wheel rotation shaft, and thus tangentially grinds the article. By using this flexible flap grinding method, abrasive grains falling off during grinding can be taken away from the article being polished, thus avoiding the phenomenon of the abrasive grains emerging during hard grinding wheel grinding and being embedded in the polished article, so that the polishing effect can be effectively improved. In order to bring the portion of the outer edge of the surface of the flaps, which is exposed to the article, into full contact with the surface of the article, the present invention involves pneumatically applying a force, in the radial direction, to the article shaft by means of said grinding wheel rotation shaft, so that the flaps of the grinding wheel are in pressure contact with the surface to be polished of the article to be polished. The radial force not only brings the outer edge of the flaps into full contact with the outer surface of the article to be polished, but also results in radial grinding of the article, which facilitates effectively removing deeper scratches which exist on the surface of the article, thereby significantly improving the grinding efficiency. The rotating article to be polished is sequentially brought into contact with a plurality of grinding wheels with different abrasive grain sizes in the descending order of the grain sizes of abrasives of these grinding wheels, so as to complete the polishing process from grinding to polishing for the surface of the article to be polished. The width W of the flaps of these wheels may be the same or different. According to a preferred embodiment of the present invention, the smaller the grain size of the abrasive grains of the flaps of each grinding wheel, the greater the width of the flaps, i.e., the width of the flaps of the grinding wheel, which is the first to polish the article to be polished, is the narrowest, and the width of the flaps of the flap grinding wheel used in the next polishing procedure is greater than the width of the flaps of the grinding wheel in the previous polishing procedure. In this way, while grinding and polishing the scratches of the article to be polished, the next polishing procedure polishes the grinding traces that may be generated by the grinding wheel in the previous polishing procedure, finally resulting in a polished article with a surface that is as smooth, bright and clean as if it were new.

[0045] In the present invention, a force is applied pneumatically by means of the grinding wheel shaft, so that the flexible flaps of the grinding wheel are in pressure contact with the outer surface of the article, and the loss of the flaps is compensated by the feed of the grinding wheel shaft to ensure that the speed and amount of feeding of the exposed portions of the flaps are constant. Where the article to be polished has a profiled outer surface having grooves, in particular having axially extending grooves, if the outer edge of the grinding wheel is only pneumatically brought into pressure contact with the surface of the article and the force provided by the pneumatic supply is kept constant, the pressure of the flaps exerted on a protruding portion of the outer surface of the article to be polished and the contact area thereof are greater than the pressure exerted on a recessed portion of the surface of the article and the contact area thereof as the article rotates. If the constant power value is too large, excessive grinding polishing of the protruding portion of the outer surface may be caused, reducing the thickness of part of the wall of a thin-walled article such as a glass bottle, and resulting in the shape of the bottle body being changed or the strength thereof being reduced. If the constant power value is too small, the outer edge of the flaps cannot reach the recessed portion due to the presence of the protruding portion of the article to be polished, resulting in the recessed portion not being polished, which affects the polishing effect. According to a preferred embodiment of the flexible flap according to the present invention, the flexible flap can be bent and deformed so that the pressure exerted on the surface of the article is automatically compensated by the appearance of the article, causing each portion of the flap to be in contact with the surface of the article at similar pressures for uniform polishing of the surface of the article, whereby a polished product with a smooth surface can be obtained.

[0046] The present invention further provides an automated continuous polishing apparatus, as shown in FIGS. 3-5, for polishing articles such as glass bottles to be polished. The polishing apparatus comprises at least one set of grinding wheel rotation mechanisms 310, 410, 510, an article rotation mechanism 420, 520, an automatic feed compensation mechanism 430, 530, an automatic article loading and unloading mechanism and an automatic article conveying mechanism. Each set of grinding wheel rotation mechanisms 510 comprises a servo motor 501, a grinding polishing motor multi-wedge belt 502 and a grinding wheel rotation shaft 503. The grinding polishing servo motor is connected with the grinding wheel rotation shaft via a multi-wedge belt, and is used for driving the grinding wheel rotation shaft to rotate. One or more flexible flap grinding wheels may be arranged axially on each grinding wheel rotation shaft. A plurality of grinding wheels are arranged at different heights to perform grinding polishing on different positions of the article, and as shown in FIG. 1, two grinding wheels are arranged on one grinding wheel rotation shaft, or multiple grinding wheels are stacked to increase the grinding wheel width for polishing the article (not shown). The grinding polishing servo motor and the grinding wheel rotation shaft are fixedly mounted on a fixation baseplate 504, without any relative movement between the two. The automatic feed compensation mechanism comprises a gas cylinder 511 and a linear guide rail 513 equipped with a linear bearing or sliding block 512. The gas cylinder pushes the fixation baseplate on which the grinding polishing servo motor and the grinding wheel rotation shaft are mounted, so that the grinding wheel rotation shaft thereon is fed toward the article rotation shaft, and the exposed outer edge of the flaps of the flexible flap grinding wheel is in pressure contact with the surface to be polished. By controlling the gas pressure of the gas cylinder, the speed and amount of feeding of the grinding wheel on the grinding wheel rotation shaft can be controlled. By respectively controlling the speed of rotation of the grinding wheel rotation shaft and the speed of rotation of the article rotation shaft, the intensity of the abrasion can be controlled for the polishing of the surface of the article. The linear bearing or sliding block 512 integrally supporting the servo motor and the rotation shaft can linearly move back and forth along the linear guide rail. During polishing, the force provided by the gas cylinder brings the outer edge of the flexible flaps into pressure contact with the outer surface of the article via the grinding wheel rotation shaft, and since the grinding wheel can move linearly, the grinding wheel driven by the gas source cylinder as the power advances and retreats according to the contour of the outer surface of the article, keeping the contact force and the contact area at which the flaps are in contact with different positions of the surface of the glass bottle constant, and achieving the same grinding polishing effect at different positions of an article having a profiled structure, which effectively solves the problem of uneven grinding of various glass bottles with different circumferential sizes. The automatic feed compensation mechanism according to the present invention has a simple structure, a good stability and a low cost, which makes it possible to carry out standardized grinding polishing processing of profiled articles, and can result in a polished article with a neat and highly uniform appearance. The article rotation mechanism according to the present invention drives the article rotation shaft, causing the article located thereon to rotate. In the method of the present invention, the article rotates simultaneously with the grinding wheel, so that a uniform polished surface can be obtained. Preferably, the article loading and unloading mechanism of the present invention, for example, having an automated mechanical arm opening-closing-type loading and unloading structure for automatically loading and unloading the article to be polished, further comprises a beam work station moving switching mechanism which is capable of moving and switching the loaded glass article between work stations, and the automatic article conveying mechanism can convey the article to be polished to multiple different polishing work stations where the surface of the article is sequentially ground and polished by means of flexible flap grinding wheels of different grain sizes to realize the polishing of the surface of the article. According to one embodiment of the present invention, the grinding wheel rotation mechanism may be located on one side of the article rotation shaft, and two or more flexible flap grinding wheels located at different heights of the grinding wheel rotation shaft can perform grinding polishing on different positions of the article, as shown in FIG. 1. According to another embodiment of the present invention, two or more grinding wheel rotation mechanisms may be oppositely arranged about the rotation shaft for the article to be polished, as shown in FIGS. 3 to 5, and may respectively drive the grinding wheel rotation shafts to allow the grinding wheels thereon to perform grinding polishing on different positions of the article. The polishing apparatus according to the present invention further comprises a cooling mechanism for cooling the flexible flap grinding wheel. For the cooling system, water is preferably used as the cooling medium, or a polishing liquid comprising an abrasive and water is used as the cooling medium. During polishing of the glass article using the flexible flap grinding wheel, continuously rinsing the flexible flap grinding wheel and the surface being polished using a cooling medium on the one hand cools the grinding wheel, and on the other hand, flushes the abrasive material falling off of the grinding wheel away from the surface being ground and polished, so as to ensure the polishing quality. After the spent cooling medium is collected and the abrasive material is separated from the water, the medium can be continuously recycled.

[0047] With the polishing apparatus of the present invention and the polishing process according to the present invention, continuous automated high-quality polishing of glass bottles is made possible.

Example 1

[0048] By means of flexible flap grinding wheels using commercially available epoxy resin binder silicon carbide sandpapers of respective models of #80, #320 and #800 as flexible flaps, glass bottles are ground and polished with different contact forces using the polishing process according to the present invention, and the resulting grinding results are as shown in following table.

TABLE-US-00001 Grain Contact Grinding Abrasive size Porosity force effect Flap service life Silicon #80 Low 6 kgf Good The flap can be used carbide continuously for a long time Silicon #320 High 2 kgf Poor The service life of the carbide flap is short Silicon #800 Low 4 kgf Good The flap can be used carbide continuously for a long time

[0049] It can be seen that a silicon carbide abrasive with an epoxy resin as the main binder can be used for polishing glass articles. Polishing a glass article by selecting an appropriate contact grinding force and using flaps with an abrasive layer having a low porosity can result in a good grinding polishing effect, and the service life of the flap is long. When the article is ground and polished with a smaller contact grinding force using high-porosity flaps, the grinding polishing effect is not good, the abrasion loss of the abrasive of the flap is great, and the service life is short. A person skilled in the art would understand that the material and grain size of the abrasive and the density of the abrasive layer of the grinding wheel can be selected according to the material and the degree of wear of the article to be polished. For example, flexible flaps of different abrasive grain sizes, such as about 300 m, about 200 m, about 160 m, about 155 m, about 50 m and several micrometers, are used for the rough grinding, medium grinding and fine grinding of bottles, and silicon carbide powder is finally used for polishing. The pressure of the pressure contact of the flaps of said flexible flap grinding wheel with the surface to be polished of the product to be polished is controlled to be 2-6 kgf. Specifically, by means of controlling the pressure of the gas source that provides the feed power and by means of the action of the centrifugal force on the flaps due to the high-speed rotation of the grinding wheel rotation shaft, the contact force between the flaps and the glass bottle and the polishing effect can be controlled. From this example, it can be seen that low-cost silicon carbide can be effectively used for polishing glass.

Example 2

[0050] The process for polishing a glass article according to the present invention will be specifically described with reference to Example 2 below. The glass article is sequentially polished using six flexible flap grinding wheels of different abrasive grain sizes. In this example, the diameter of the hub of each flexible flap grinding wheel is 150 mm, the ratio of the length of the flaps to the diameter of the hub is 1:6, and the length of the flaps is 25 mm. The widths of the first to sixth flaps are respectively 8 mm, 10 mm, 12 mm, 15 mm, 18 mm and 19 mm, and the substrate material of the flexible flaps is a fabric. The flaps of the first to fifth grinding wheels are flexible flaps in which the abrasives in the abrasive layers are silicon carbide and the grain sizes are respectively, for example, about 300 m, about 200 m, about 160 m, about 155 m, and about 50 m. The abrasive of the flaps of the sixth grinding wheel is cerium oxide, and the grain size is about 1 m. By using a binder comprising an epoxy resin and talcum powder, abrasive grains form an abrasive layer and adhere to the substrate, with the density of the abrasive layer being about 3.2 g/cm.sup.3. During the grinding process, the grinding wheel rotation shaft and the article rotation shaft rotate clockwise in the same direction. The speed of each article rotation shaft is 23 r/min. The speeds of rotation of the first to sixth grinding wheel rotation shafts are respectively 800 r/min, 1000 r/min, 1200 r/min, 1600 r/min, 1800 r/min, and 2000 r/min. By controlling the gas source pressure of the gas cylinder, the force applied to bring the outer edge of the flexible flaps onto the article is controlled to be 2-6 kgf, and the forces of the flaps of the first to sixth grinding wheels in this example are respectively about 4 kgf; said flexible flap grinding wheel is kept in contact with the surface to be polished of the glass article, and an appropriate intensity of abrasion is applied to the surface to be polished.

[0051] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than for limiting the embodiments of the present invention. For a person of ordinary skill in the art, on the basis of the above description, other variations or changes in different forms may also be made, it is impossible to exhaustively provide all the embodiments herein, and any obvious variation or change derived from the technical solution of the present invention is still within the scope of protection of the present invention.