FEEDING DEVICE FOR COATING APPARATUS, COATING APPARATUS COMPRISING IT AND PROCESS USING IT

Abstract

The present invention relates to a feeding device for a coating compound or a precursor of a coating compound. In particular it relates to a feeding device for coating apparatus also called coating tunnel or coating hood for applying the protective coatings to glass containers. More particularly the present invention relates to a feeding device for a coating apparatus also called coating tunnel or coating hood for applying the protective coatings to glass containers, a coating apparatus comprising such a feeding device and a process for applying the protective coatings to glass containers using such a feeding device.

Claims

1-21. (canceled)

22. A feeding device in form of a hollow tube comprising an entry where a coating compound or a precursor of a coating compound is introduced into the feeding device, and an exit where the coating compound is introduced into a coating apparatus.

23. Feeding device according to claim 22, further comprising a heating mechanism for heating the coating compound or the precursor of the coating compound.

24. Feeding device according to claim 23, wherein the heating mechanism comprises electrical heating or a hot fluid or gas or vapor that is circulated around a part of the tube.

25. Feeding device according to claim 23, wherein the heating mechanism is electrical heating.

26. Feeding device according to claim 23, wherein the heating mechanism is a hot fluid that is circulated around a part of the tube.

27. Feeding device according to claim 23, wherein the heating mechanism is a hot gas or vapor that is circulated around a part of the tube.

28. Feeding device according to claim 22, wherein the exit of the feeding device is prolonged with another or a thinner tube.

29. Feeding device according to claim 22, wherein the exit of the feeding device is prolonged with another tube.

30. Feeding device according to claim 22, wherein the exit of the feeding device is prolonged with a thinner tube.

31. Feeding device according to claim 28, wherein the other or a thinner tube for prolongation comprises a heating mechanism.

32. Feeding device according to claim 22, wherein the exit of the feeding device is split up by several tubes.

33. Feeding device according to claim 22, further comprising one or several valves.

34. Feeding device according to claim 22, further comprising a lateral entry.

35. A coating apparatus for applying a coating on glass containers with a chemical compound comprising: a housing with a coating tunnel, a conveyer belt moving the containers through the coating tunnel from an inlet to an outlet of the coating tunnel, at least one circuit for circulation of a coating compound, and a feeding device according to claim 22.

36. The coating apparatus according to claim 35, wherein a pressure inside the coating apparatus is at least 1 mbar less than a pressure outside of the coating apparatus.

37. The coating apparatus according to claim 36, wherein the pressure difference between the inside of the coating apparatus and the outside is between 1 mbar and 100 mbar.

38. The coating apparatus according to claim 35, further comprising at least one of the following: a blowing mechanism, at least one feed point, slots in the inner side wall.

39. The coating apparatus according to claim 35, wherein the apparatus further comprises at least two blowing mechanisms, wherein said blowing mechanisms are disposed on opposite sides of the coating apparatus.

40. A process of applying a coating on the surface of glass containers comprising the steps of: conveying the glass containers on a conveyer belt through a coating tunnel inside a housing from an inlet to an outlet, circulating a coating compound through the coating tunnel with a circuit, and feeding a coating compound into the coating apparatus with a feeding device according to claim 22.

Description

[0042] The invention is best understood from the following detailed description when read in connected with the accompanying drawings with the following figures:

[0043] FIG. 1: 1a) feeding device (100) comprising a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added and an exit (140). Variations are shown in FIGs. 1b) and 1c) comprising additionally heating means.

[0044] FIG. 2: variations of the tube (110) of feeding device (100) having different forms and lengths.

[0045] FIG. 3: tube (110) of feeding device (100) having heating means and a valve.

[0046] FIG. 4: schematic representation of one embodiment of the feeding device (100) having additionally a lateral entry (150).

[0047] FIG. 5a: schematic representation of existing hood from the state of the art.

[0048] FIG. 5b: schematic representation of another existing hood from the state of the art.

[0049] FIG. 6: schematic representation of existing hood from the state of the art with shown slots in the inner side wall.

[0050] FIG. 7: schematic representation of the hood according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0051] In a first aspect, the present invention relates to a feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into a coating apparatus.

[0052] In a second aspect, the present invention relates to a coating apparatus for applying a coating on glass containers with a chemical compound comprising: [0053] a housing (2) with a coating tunnel [0054] a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel [0055] at least one circuit (7) for circulation of a coating compound and [0056] a feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into a coating apparatus.

[0057] In a third aspect the present invention relates to a process of applying a coating on the surface of glass containers comprising the steps of: [0058] conveying the glass containers (20) on a conveyer belt (3) through a coating tunnel inside a housing (1) from the inlet (5) to the outlet (6), [0059] circulating a coating compound through the coating tunnel with a circuit (7) [0060] adding the coating compound into the coating apparatus with the help of a feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into the coating apparatus.

[0061] In a fourth aspect, the present invention relates to the use of a feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into a coating apparatus for applying a coating on glass containers with a chemical compound comprising: [0062] a housing (2) with a coating tunnel [0063] a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel [0064] at least one circuit (7) for circulation of a coating compound.

[0065] According to another aspect the present invention relates to a glass container on which a coating has been applied on its surface by a process comprising the steps of: [0066] conveying the glass container (20) through a coating tunnel from the inlet (5) to the outlet (6), [0067] circulating a coating compound through the coating tunnel with a circuit (7) comprising (25) [0068] using feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into the coating apparatus.

[0069] According to an additional aspect the present invention relates to the use of a coating apparatus for applying a coating on the surface of a glass container, said coating apparatus is comprising: [0070] a housing (2) with a coating tunnel [0071] a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel [0072] at least one circuit(7) for circulation of a coating compound and [0073] feeding device (100) in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added into the feeding device (100) and an exit (140) where the coating compound is added into the coating apparatus.

[0074] By the generic term air as used is denoted the carrier gas that is used for the coating compound. It is obvious that any inert gas or a gas that is inert to the coating compound, the container and the interior of the coating hood, such as nitrogen could be used. Because of its convenience and low cost however the preferred gas is air.

[0075] By the term coating compound as used in the present invention is denoted a chemical compound that is introduced in the coating apparatus. The coating compound is used directly to coat a surface or it is transformed during the coating application in another compound that forms the coating. In the latter case it could also be called coating generating compound.

[0076] By the term exhaust as used is denoted the carrier gas that is still loaded with a minor quantity of the coating compound not applied to the glass container that escapes at the entry and especially the outlet of the coating tunnel, where the containers enter and sort.

[0077] By the term loop as used in the present invention is denoted a circuit for the carrier gas or air loaded with the coating compound that enters and leaves the coating tunnel. Such a loop comprises at least a jet slot and a least one receiving slot that are located on the opposite inner side walls of the hood. The loop could comprises also conduits in form of tubes and pipes. These conduits in form of tubes and pipes are necessary to transport the carrier gas from the receiving slot to the jet slot

[0078] By the term primary loop as used in the present invention is denoted a circuit that comprises at least a feed point of the coating compound and circulates the carrier gas loaded with the coating compound or air loaded with the coating compound. The loop or circuit enters and leaves twice the coating tunnel by respective jet slots and receiving slots. In other words the loop or circuit makes a complete 360 turn.

[0079] By the term recirculating loop as used in the present invention is denoted a circuit that does not comprise any feed point and that recirculates the carrier gas loaded with the coating compound or air loaded with the coating compound coming from the primary loop.

[0080] By the term circuit as used in the present invention is denoted a pathway for the circular flow of the carrier gas or air comprising the coating compound or coating generating compound through the respective parts of the coating apparatus.

[0081] With regard to the feeding device (100), it is in form of a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added and an exit (140) where the coating compound is added into a coating apparatus.

[0082] The feeding device comprises heating means (120) for heating the coating compound or the precursor of the coating compound. The heating means can be an electrical heating or by a hot fluid or gas or vapor that is circulated around a part of the tube (110). The heating means are for heating up the liquid coating compound or the precursor of the coating compound that enters the feeding device (100) through entry (130). The coating compound or the precursor of the coating compound leaves the feeding device (100) through exit (140) either as hot liquid or already vaporized.

[0083] In a first preferred embodiment the heating means (120) is an electrical heating.

[0084] In a second preferred embodiment the heating means (120) is made by a hot fluid that is circulated around a part of the tube (110).

[0085] In a third preferred embodiment is made by hot gas or vapor that is circulated around a part of the tube (110).

[0086] With regard to the feeding device (100), it is situated mainly outside of a coating apparatus. Only the exit (140) of the feeding device is inside the coating apparatus (1) defining the feed point (4) or the exit (140) of the feeding device is connected via another tubing for going inside the coating apparatus.

[0087] The exit (140) of the feeding device can be prolonged with another or a thinner tube (170) in order to feed the coating compound or the precursor of the coating compound to the feeding point (4) in the coating apparatus.

[0088] In a first preferred embodiment the exit (140) of the feeding device is prolonged with another tube (170).

[0089] In a second preferred embodiment the exit (140) of the feeding device is prolonged with a thinner tube (170).

[0090] The other or a thinner tube (170) for prolongation can comprise heating means. These heating means are the same as listed before for the feeding device.

[0091] The exit (140) of the feeding device can be split up by several tubes in order to feed the coating compound or the precursor of the coating compound at several feeding points inside the coating apparatus.

[0092] The feeding device can comprise one or several valves (160).

[0093] The feeding device can also comprise a lateral entry (150). The lateral entry (150) can be used to add other compounds to coating compound or the precursor of the coating compound. Through the entry (150) for example a gas or a liquid.

[0094] In a first preferred embodiment air is added through the lateral entry (150) in the feeding device (100).

[0095] Additionally the coating apparatus for applying a coating on glass containers with a chemical compound comprises blowing means (12), slots (30) in the inner side wall (80).

[0096] A circuit (7) for circulation the coating compound is also called loop. The coating apparatus can also comprise several circuits or loops. It comprises at least one circuit or primary loop, where the coating compound or coating generation compound is added. This place where the coating compound or coating generation compound is added is called feed point. This feed point corresponds to the exit (140) of the feeding device (100).

[0097] According to a variation of the present invention the coating apparatus can also comprise one or more recirculating loops (8). The recirculating loop or loops (8) is or are after the primary loop (7a) and before the carrier gas flow that is separated, in the sense of the direction of the passing containers on the conveyer belt. Such a recirculating loop (8) is not shown in FIGS. 2 and 3, but is well known from prior art as presented in FIG. 1.

[0098] The coating apparatus of the present invention comprises a feeding device (100).

[0099] Preferably the pressure inside the coating apparatus is lower than in comparison to the outside. By inside the coating apparatus is meant the circuit where the coating compound circulates, preferably close to the primary loop. In that case the coating compound or the precursor of the coating compound is sucked out if the feeding device through the exit (140), via the feeding point (4) into the coating apparatus.

[0100] Preferably the pressure inside the coating apparatus is at least lmbar less than on the outside of the coating apparatus. More preferably the pressure inside the coating apparatus is at least 2 mbar, still more preferably at least 3 mbar and most preferably 5 mbar less than on the outside of the coating apparatus.

[0101] Preferably the pressure inside the coating apparatus is at most 100 mbar less than on the outside of the coating apparatus. More preferably the pressure inside the coating apparatus is at at most 99 mbar, still more preferably at most 98 mbar and most preferably at most 95 mbar less than on the outside of the coating apparatus.

[0102] Advantageously the pressure difference between the inside of the coating apparatus and the outside is between 1 mmbar and 100 mbar. More advantageously the pressure difference between the inside of the coating apparatus and the outside is between 2 mmbar and 99 mbar, still more advantageously between 3 mmbar and 98 mbar and most advantageously between 5 mmbar and 95 mbar.

[0103] It is obvious that the pressure p of gases is a function of the temperature T, but the relation between the two of them is well known by the respective physical gas laws.

[0104] With regard to a coating apparatus from the prior art, an embodiment of said coating apparatus is shown in FIG. 1a. The coating apparatus comprises a housing (2) with coating tunnel, a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel, one circuit being the primary loop (7) with a least one feed point (4) for the coating compound, one or more circuits being recirculating loops (8), blowing means (12) and exhaust means (11) in proximity of the inlet (5) end outlet (6). Details of such a coating apparatus and its components can be found in document U.S. Pat. No. 4,668,268 or U.S. Pat. No. 4,389,234.

[0105] Still with regard to a coating apparatus from the prior art, another embodiment of such a coating apparatus is shown in FIG. 1b. Said coating apparatus comprises a housing (2) with coating tunnel, a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel, one primary loop (7) with a least one feed point (4) for the coating compound, blowing means (12), optionally one or more recirculating loops (8) and a half open loop (9) going from the outlet (6) to the inlet (5) of the coating tunnel. Details of such a coating apparatus and its components can be found in document WO2014/177651.

[0106] Still with regard to a coating apparatus from the prior art, another embodiment of such a coating apparatus is shown in FIG. 2. Said coating apparatus comprises a housing (2) with coating tunnel, a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel, blowing means (12) comprising a blower wheel (12a) and a motor (12a) for turning the blower wheel, for circulating the coating compound through the circuits or respective loops of the coating tunnel and inner side wall (80) with slots (30). Details of such a coating apparatus and its components can be found in document U.S. Pat. No. 5,140,940.

[0107] With regard to the coating apparatus of the present invention, it is shown schematically in FIG. 7, said coating apparatus (1) comprises a housing (2) with coating tunnel, a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel, one primary loop (7) with a least one feed point (4) for the coating compound, blowing means (12), and the feeding device (100).

[0108] Optionally the coating apparatus of the present invention can comprise one or more recirculating loops.

[0109] In a one embodiment the coating hood according to the invention comprises additionally one or more recirculating loops.

[0110] The position of the recirculating loop or recirculating loops can be behind the primary loop (in view of the movement of the conveyer belt) or around the primary loop, latter possibility as shown in FIGS. 5 and 6 of the coating apparatus from the prior art.

[0111] Additionally the coating apparatus comprises at least one jet slot (30a) and receiver slot (30b) in the inner side wall (80), which are not shown in the FIG. 5. The slots (30) are respectively the entry or exit of the circuit (7) or each respective loop towards or from the central chamber of the coating tunnel, where the conveyer belt (3) with the containers (20) passes. By the jet slot (30a) the coating compound or carrier gas enters this chamber. By the receiver slot (30b) the coating compound or carrier gas leaves this chamber.

[0112] Preferably each circuit or loop of the coating apparatus (1) comprises at least one jet slot (30a) and receiver slot (30b).

[0113] Additionally the coating apparatus comprises blowing means or blowers (12). These blowers (12) keep the carrier gas with the coating compound circulating inside the hood and make it passing through the respective loops. The blower can either push the carrier gas with coating compound forward inside the centre section of the tunnel where the conveyer belt with the container passes or suck it outside. The blowing means (12) comprises a blower wheel (12b) and a motor (12a) for rotating the blower wheel. Depending on the sense of the rotation of the blower wheel and its blades, the carrier gas with the coating compound is either pushed or sucked.

[0114] Preferably the circuit (7) or loop comprises at least one blowing means (12). More preferably the coating apparatus of the present invention comprises at least two blowing means (12), the blowing means are on opposite sides of the coating apparatus, as shown in FIG. 3.

[0115] Preferably the two on opposite sides situated blower wheels (12b) of the at least two blowing means circulate in different meaning opposite directions. When looking from one side at the coating apparatus, one blower wheel rotates clockwise, while the other blower wheel on the other side rotates counter clockwise.

[0116] Preferably the blower wheel or blower wheels rotate between 100 rpm and 10,000 rpm, more preferably between 200 rpm and 9,000 rpm.

[0117] Optionally the coating apparatus according to the invention can comprise means for exhaust. This can be either at the inlet or at the outlet or at the inlet and the outlet additional exhaust means are present.

[0118] The coating compound is introduced through at least one feed point (4) in to the coating apparatus. This can be an internal feed point as in FIG. 1 or 3 or an external feed point.

[0119] In one embodiment the feed point (4) is based at the primary loop (7) as an internal feed point as shown in FIG. 3. The coating compound is introduced by the means of pipes, latter are not shown in the figure.

[0120] In another embodiment the coating compound is introduced by hot recirculating air as a side stream to dose the coating compound in, which is an external feed.

[0121] The hollow glass containers are transported in a single or double line by a conveyer through a tunnel formed in the coating hood under the housing. The conveyer carries the bottles in the direction designated by the arrow, in FIGS. 1, 2 and 3 from left to right.

[0122] With regard to the coating compound introduced with the feeding device (100) in the coating apparatus at one or more feedings points, it can be chosen from organometallic compounds, metal halides or other suitable compounds as coating compound precursor.

[0123] Preferably the coating compound is an organic tin halogenide, advantageously it is monobutyl tin trichloride.

[0124] With regard to the coating formed at the surface of the containers and applied in the hood it is a metal oxide as SnO2, TiO2, Al2O3 or ZnO. The metal oxide is derived from the decomposition inorganic or organometallic compounds. Latter are the before mentioned coating generating compounds.

[0125] In a first preferred embodiment the coating is tin oxide. The tin oxide is derived from the decomposition inorganic or organic tin compound advantageously of an organic tin halogenide, more advantageously from monobutyl tin trichloride.

[0126] With regard to the process of applying a coating on the surface of glass containers, it comprises the steps of: [0127] conveying the glass containers (20) on a conveyer belt (3) through a coating tunnel inside a housing (1) from the inlet (5) to the outlet (6), [0128] circulating a coating compound through the coating tunnel with a circuit (7) [0129] feeding a coating compound into the coating apparatus with a feeding device (100).

[0130] The process comprises preferably additionally the step of: [0131] using blowing means (12), said blowing means are on opposite sides of the coating apparatus said blowing means (12) comprise a blower wheel (12b) which circulate in different directions.

[0132] The process comprises comprising additionally the step of: [0133] keeping a lower pressure inside the coating apparatus in comparison to the outside.

[0134] The circulation step of said process, circulates the coating compound or coating generating compounds that is introduced by a feed point (4) with the carrier gas by the help of blowing means (12). The circuit of the circulation step comprises the passage of the side wall (80) via the slots (30) inside the side wall. For entering the inner part of the coating tunnel where the container (20) are on the conveyer belt, the circuit leaves the compartment (70), via the jet slots (30a). On the opposite side the circuit leaves the inner part of the coating tunnel where the container (20) are on the conveyer belt, via receiver slots (30b) and enter the opposite compartment comprising (70). To return to the initial departing point the circuit continues in the same manner as described.

[0135] With regard to the glass container on which a coating has been applied on its surface by a process comprising the steps of: [0136] conveying the glass containers (20) on a conveyer belt (3) through a coating tunnel inside a housing (1) from the inlet (5) to the outlet (6), [0137] circulating a coating compound through the coating tunnel with a circuit (7) [0138] feeding a coating compound into the coating apparatus with a feeding device (100).

[0139] Preferably the glass container on which a coating has been applied on its surface by a process that comprises additionally a step of blowing the gas comprising the coating generating compound with one or more recirculating loops (8) through the coating tunnel, after the circuit of primary loop (7).

[0140] With regard to the glass container on which a coating has been applied on its surface by a coating apparatus comprising: [0141] a housing (2) with a coating tunnel [0142] a conveyer belt (3) moving the containers (20) through the coating tunnel from the inlet (5) to the outlet (6) of the said coating tunnel [0143] at least one circuit (7) for circulation of a coating compound and [0144] the feeding device (100).

[0145] The coating apparatus according to the invention is used to apply a coating on the surface of a glass containers.

[0146] The present invention concerns as well an improved method for applying a hot end coating integrated in the glass container manufacturing process.

Figures

[0147] FIG. 1: 1a) feeding device (100) comprising a hollow tube (110) comprising an entry (130) where a coating compound or a precursor of a coating compound is added and an exit (140). Variations are shown in FIGS. 1b) and 1c) comprising additionally heating means either electrical heating means as in FIG. 1b or by circulating a hot fluid or gas or vapor that is around a part of the tube (110).

[0148] FIG. 2: variations of the tube (110) of feeding device (100) having different forms and lengths. Other possibilities and combinations are possible not shown in FIG. 2

[0149] FIG. 3: tube (110) of feeding device (100) having heating means (120) and a valve (160). There could be more valves at different positions.

[0150] FIG. 4: schematic representation of one embodiment of the feeding device (100) having additionally a lateral entry (150).

[0151] FIG. 5a: schematic representation of one existing coating apparatus or hood from the state of the art with a recirculating loop.

[0152] Coating compound is introduced into the coating apparatus (1) or hood at a feed point (4). The hood (1) comprises a housing (2) and a conveyer belt (3) running there through. Containers (4) are transported on the belt that moves them from the entrance or inlet (5) to the exit outlet (6) of the hood (1).

[0153] The containers (20) are only presented diagrammatically by circles.

[0154] The hood also comprises one primary loop (7) with a least one feed point (4) for the coating compound, one or more recirculating loops (8) and exhaust means (11) in proximity of the inlet (5) end outlet (6).

[0155] FIG. 5b: schematic representation of one existing coating apparatus or hood with an additional half loop (9).

[0156] Coating compound is introduced into the coating apparatus (1) or hood at a feed point (4). The hood (1) comprises a housing (2) and a conveyer belt (3) running there through. Containers (4) are transported on the belt, that moves them from the entrance or inlet (5) to the exit outlet (6) of the hood (1).

[0157] The containers (20) are only presented diagrammatically by circles.

[0158] The hood also comprises one primary loop (7) with a least one feed point (4) for the coating compound, one or more recirculating loops (8) and a half open loop (9) going from the outlet (6) to the inlet (5) of the coating tunnel.

[0159] FIG. 6: schematic representation of another existing coating apparatus or hood from the state of the art where the inner side wall (80) with the slots (30) is more detailed. The hood (1) comprises a housing (2) and a conveyer belt (3) running there through. Containers (4) are transported on the belt that moves them from the entrance or inlet (5) to the exit outlet (6) of the hood (1). Behind the inner side wall (80) with the slots (30) blowing means (12) are shown, comprising a blower wheel (12b) and a motor (12a).

[0160] FIG. 7: schematic representation of a coating apparatus according to one embodiment of the present invention with the coating apparatus or from the state of the art of FIG. 6 in combination with the feeding device (100) of FIG. 1a. Other combinations of different embodiments of feeding device (100) and coating apparatus.