The present disclosure is directed to glass containers, manufacturing processes for glass containers, and to coating processes for glass containers including methods and materials for coating glass containers (e.g., glass bottles and jars).
Various processes have been developed to apply coatings to glass containers for different purposes, including decoration, adhesion and glass strengthening for damage prevention. For example, U.S. Pat. No. 3,522,075 discloses a process for coating a glass container in which the container is formed, coated with a layer of metal oxide such as tin oxide, cooled and annealed through a lehr, and then coated with an organopolysiloxane resin-based material over the metal oxide layer. In another example, U.S. Pat. No. 3,912,100 discloses a method of making a glass container by heating the glass container and applying a polyurethane powder spray to the glass container.
A general object of the present disclosure, in accordance with one aspect of the disclosure, is to provide an improved method of coating containers to impart insulating properties to the containers to maintain colder or lower temperatures of contents in the containers for a longer time without changing aesthetics of the containers, for instance, by using a separate, external insulation sleeve or label.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A process for applying a low-e coating to a glass container in accordance with one aspect of the disclosure includes the following steps: (a) preparing a low-e coating including at least one of a metal or a transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, SnO2:F, In2O3:Sn, ZnO:F, ZnO:Al, and ZnO:Ga; and (b) applying the low-e coating to the external surface of the glass container.
A method of coating a glass container in accordance with one aspect of the disclosure includes the following steps: (a) depositing on an exterior surface of the container, a coating including at least one of a metal or a transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, SnO2:F, In2O3:Sn, ZnO:F, ZnO:Al, and ZnO:Ga, to impart insulating properties to the container; and (b) applying a cold-end coating to the exterior surface of the container after step (a).
In accordance with another aspect of the disclosure, a method of coating an exterior surface of a glass container includes the following steps: (a) depositing a hot-end coating on an exterior surface of the container; and (b) applying a low-e coating to the exterior surface of the container after step (a), wherein the low-e coating includes particles composed of at least one of metal or transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, In2O3:Sn, ZnO:Al, and ZnO:Ga.
In accordance with a further aspect of the disclosure, there is provided a glass container that includes a closed base at one axial end of the container, a body extending axially from the closed base and being circumferentially closed, and an open mouth at another axial end of the container opposite of the base. An exterior surface of the container includes an infrared insulative coating including at least one of a metal or a transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, SnO2:F, In2O3:Sn, ZnO:F, ZnO:Al, and ZnO:Ga.
In accordance with an additional aspect of the disclosure, there is provided a method of manufacturing a glass container including the following steps: (a) forming the container; and then (b) applying a coating to an exterior surface of the container to impart insulating properties to the container, wherein the coating includes at least one of a metal or a transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, SnO2:F, In2O3:Sn, ZnO:F, ZnO:Al, and ZnO:Ga, to impart insulating properties to the container; and then (c) applying a cold-end coating to the exterior surface of the container.
In accordance with yet another aspect of the disclosure, there is provided a method of manufacturing a glass container including the following steps: (a) forming the container; and then (b) applying a hot-end coating to an exterior surface of the container; and then (c) annealing the container; and then (d) depositing a low-e coating on the container to impart insulating properties to the container, wherein the low-e coating includes particles composed of at least one of metal or transparent conductive oxide (TCO), wherein the metal is selected from the group consisting of silver, gold, and aluminum, and wherein the TCO is selected from the group consisting of SnO2:Sb, In2O3:Sn, ZnO:Al, and ZnO:Ga.
The disclosure, together with additional objects, features, advantages and aspects thereof, will be best understood from the following description, the appended claims and the accompanying drawings, in which:
For example, as shown in
A prior art glass container with conventional hot-end and cold-end coatings would allow substantial transmission of infrared (IR) and near-infrared (NIR) radiation. As used herein, for the sake of simplicity, the term “infrared” includes infrared and near-infrared radiation. In one example, the IR wavelength includes 800 nm to 1,000 μm, and the NIR wavelength includes 800 nm to 2 μm. In a more particular example, the IR wavelength includes 800 nm to 30 μm.
According to the present disclosure, however, the glass container 10 may include the low-e coating 15 (or 15′) to replace a conventional hot-end coating applied before application of the cold-end coating 16 (e.g.
Although the various coatings 14 through 17 are shown as adjacent layers overlying one another sequentially, one or more of the coatings 14 through 17 may penetrate into or even through one or more of the other coatings. Accordingly, the various coatings 14 through 17 may be fairly described as being applied generally to the glass container 10, regardless of how or to what extent any given coating contacts any of the other coatings and/or the substrate 12. Similarly, when a material is described as being applied to an exterior surface of the glass container 10, the material may be applied over one or more of the coatings 14 through 17 and/or the glass substrate 12 itself.
With reference to
Typical glass container manufacturing also involves a “cold end” that may include an end portion of an annealing lehr, inspection equipment, and packaging machines. Also, the cold end may include application of a cold-end coating to the glass containers downstream of the annealing lehr. For example, the glass containers may be coated with the cold-end coating, which may be a protective organic coating applied downstream of the annealing lehr. The cold-end coating may include a polyethylene material, like a polyethylene wax or the like, stearate, oleic acid, and/or any other suitable cold-end coating material(s). After the cold-end coating is applied, production also may include inspecting the glass containers for any suitable characteristics and using inspection equipment. For example, the glass containers may be manually or automatically inspected for cracks, inclusions, surface irregularities, hot end and/or cold-end coating properties, and/or the like. After inspection, the glass containers may be packaged using any suitable packaging machines.
Accordingly, a “hot end” coating is a coating applied at the hot end of the glass container manufacturing process, and a “cold end” coating is a coating applied at the cold end of the glass container manufacturing process.
With general reference to
The low-e coating 15 may be an inorganic coating and may be applied to the container by chemical vapor deposition (CVD), or by any other suitable technique. Also, the low-e coating 15 may be applied as a stack of multiple layers.
In one implementation of the hot end low-e coating embodiment, the low-e coating 15 may include a CVD stack including a transparent conductive oxide (TCO). In one example, the TCO CVD coating stack may be applied as a “hot end” coating upstream of the annealing lehr using latent heat of the containers to affect decomposition of precursors of the coating 15. Accordingly, the CVD stack may be applied in a pyrolytic process, and may include a relatively thick TCO layer on the order of 250 to 400 nm and one or more relatively thin color suppression layers having a total thickness on the order of 10 to 30 nm.
For instance, the TCO may include an oxide of tin (Sn), indium (In), or zinc (Zn), and the low-e coating 15 of this embodiment also may include any suitable dopants. Examples follow.
In a first example, the metal oxide may include SnO2 and the dopant may include fluorine (F) or antimony (Sb). In a particular example, a tin oxide may be provided from a gaseous form of monobutyl tin trichloride. The resulting coating 15 may have a generic formula of SnO2:D where D is the dopant atom. The dopant atoms may be provided from any suitable dopant molecules. For example, hydrogen fluoride, tri-fluoro acetic acid (TPA), or the like, may be used to provide a fluoride dopant. In another example, antimony trichloride (SbCl3), antimony pentachloride (SbCl5), triphenyl antimony ((C6H5)3Sb), or the like, may be used to provide an antimony dopant. A simplified example of a CVD low-e coating stack may include glass/SnO2/SiO2/SnO2:F, wherein the glass is the container glass, the SnO2 and the SiO2 are the relatively thin color suppression layers, and the SnO2:F is the relatively thick TCO layer.
In a second example, the metal oxide may include In2O3 and the dopant may include tin. In other words, the coating 15 may be a tin-doped indium oxide, or indium tin oxide (ITO). The dopant atoms may be provided from any suitable dopant molecules.
In a third example, the metal oxide may include ZnO and the dopant may include fluorine (F), aluminum (Al), or gallium (Ga). The dopant atoms may be provided from any suitable dopant molecules. For ZnO based TCOs, it may be desirable to deposit a protective layer over the CVD stack. For example, the protective layer may include SiO2 or any suitable inert metal oxide.
During deposition of the low-e coating 15, molecular precursors of the dopant may be added into a gas phase of the metal oxide precursor, for example, by CVD. Any suitable source of the dopant molecules or precursor and any suitable means to vaporize the dopant precursor may be used. In one embodiment, the dopant precursor may be vaporized in a hot-end coating hood depending on vapor pressure of the precursor. In another embodiment, the precursor may be volatilized separately and then delivered to the hot-end coating hood. Once vaporized, the dopant precursor gas may be mixed with the metal oxide gas, for example, in the hot-end coating hood. Where the resulting low-e coating ay be deposited onto the containers.
With reference to
With specific reference to
In one implementation of the post-anneal low-e coating embodiment, the low-e coating 15 may be applied by physical vapor deposition (PVD), for example PVD sputtering. Accordingly, the low-e coating 15′ may include a PVD stack including an active layer between dielectric layers, which may serve as anti-reflective and/or protective layers. In one example, the active layer may include a metal, for example, silver (Ag), gold (Au), or aluminum (Al), and the dielectric layers may include silica (SiO2). Accordingly, a simplified example of a PVD low-e coating stack may include glass/SiO2/metal/SiO2, wherein the glass is the container glass, the SiO2 are silica layers that may be applied in any suitable manner, and the metal layer is the active layer.
In another implementation of the post-anneal low-e coating embodiment, the low-e coating 15′ may include a CVD stack including a transparent conductive oxide (TCO). In this implementation, assisted or activated CVD techniques may be used and may include combustion CVD, plasma enhanced CVD, or the like. Accordingly, the CVD stack may be applied in a pyrolytic process, and may include a relatively thick TCO layer on the order of 250 to 400 nm and one or more relatively thin color suppression layers having a total thickness on the order of 10 to 30 nm. The CVD stack may include doped metal oxides, as already discussed above with respect to the hot end low-e coating 15.
With specific reference to
The low-e coating 17 may be applied to exterior surfaces of the glass containers in any suitable manner and by any suitable equipment for IR/NIR protection. The coating 17 may be applied, for example, before inspection. The post-anneal low-e coating 17 may be applied by spraying, dipping, powder coating, electrostatic coating, or other suitable techniques. The post-anneal low-e coating 17 may be based on one or more of a variety of polymers including acrylates, epoxies, urethanes, and/or the like. The coating 17 instead may be based on one or more of a variety of silanes.
In a first example of the second implementation of the post-anneal coating embodiment, the second post-anneal coating 17 may include metal particles dispersed in a polymer base or silane base. For example, the coating 17 may include nano-particles of silver (Ag), gold (Au), or aluminum (Al).
In a second example of the second implementation of the post-anneal coating embodiment, the post-anneal low-e coating 17 may include TCO particles dispersed in the polymer base or silane base. For example, the TCO may include oxides of indium (In), zinc (Zn), or tin (Sn). Also, the TCO low-e coating 17 of this embodiment also may include a suitable dopant. In a first example, the metal oxide may include In2O3 and the dopant may include tin. In a second example, the metal oxide may include ZnO and the dopant may include aluminum (Al) or gallium (Ga). In a third example, the metal oxide may include SnO2 and the dopant may include antimony (Sb).
Also, for good distribution of the metal or TCO particles within the polymer or silane and to prevent agglomeration, the particles may be capped, passivated, and/or functionalized with a suitable organic based ligand.
The metal or TCO particles may represent 1 to 10 by weight of the coating material before it is applied to the containers. More particularly, the metal or TCO particles may be about 2 to 7% by weight of the coating material before application. In a more specific implementation, the metal or TCO particles may be about 3 to 5% by weight of the coating material before application.
In one embodiment, the post-anneal low-e coating 17 may be applied in conditions under 150 degrees Fahrenheit and, preferably, at an ambient temperature. As used herein, the terminology “ambient temperature” may include the temperature of the surrounding container manufacturing environment.
After applying the post-anneal low-e coating 17, the glass containers may be cured in any suitable manner. For example, the post-anneal low-e coating 17 may be a radiation-curable organic coating cured by any suitable type of radiation like, for instance, ultraviolet or electron beam radiation. In another embodiment, the post-anneal low-e coating 17 may be a thermally-curable coating cured by convection oven, infrared lamps, or the like.
After curing, the glass containers may be filled and packaged or simply packaged in any suitable manner.
The glass container manufacturing process may or may not include all of the disclosed steps or be sequentially processed or processed in the particular sequence discussed, and the presently disclosed manufacturing process and coating methods encompass any sequencing, overlap, or parallel processing of such steps. Also, the various embodiments may be provided in any suitable combinations with one another.
The present disclosure provides an advancement in the art. Conventionally, it has been understood that successful insulation of glass containers required separate, external insulating elements like foam sleeves or labels to impart insulating properties to the containers. Contrary to conventional wisdom, it is now possible to produce transparent, substantially colorless, glass containers with improved insulating properties, but without having to use separate, external insulating elements that are opaque and detract from the transparent, pure appearance of a glass container. In contrast, the use of at least one of the low-e coatings of the presently disclosed method provides a simple but elegant solution to a problem in the art of glass container manufacturing that has long been experienced but apparently unappreciated.
There thus has been disclosed methods of coating glass containers and methods of manufacturing glass containers that at least partially satisfy one or more of the objects and aims previously set forth. The disclosure has been presented in conjunction with several illustrative embodiments, and additional modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing discussion. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.