The present specification generally relates to spray coating apparatuses and, more particularly, to spray coating apparatuses with turn nozzle assemblies and method of coating glass objects using turn nozzle assemblies.
Historically, glass has been used as the preferred material for packaging pharmaceuticals because of its hermeticity, optical clarity, and excellent chemical durability relative to other materials. Glass packaging for pharmaceuticals can include objects such as vials, cartridges and syringes. Specifically, the glass used in pharmaceutical packaging must have adequate chemical durability so as not to affect the stability of the pharmaceutical compositions contained therein. Glasses having suitable chemical durability include those glass compositions within the ASTM standard ‘Type 1B’ which have a proven history of chemical durability.
However, use of glass for such applications is limited by the mechanical performance of the glass. In the pharmaceutical industry, glass breakage is a concern, not just for product quality, but also for the end user. Even non-catastrophic breakage (i.e., when the glass cracks but does not break) may cause the contents to lose their sterility which, in turn, may result in costly product recalls.
It is known to coat the glass with a low coefficient of friction (COF) material. The glass objects may be, for example, dip coated by submerging at least a portion of the glass objects into the low COF material. Dip coating, however, can lead to material waste and variations in product appearance. Conventional spray coating can be difficult due, at least in part, to the coating material being expensive and applied thinly due to cost and functionality, and uniformly for visibility (e.g., to determine amount and color of medicines). Moreover, a thicker application of coating material can render the film of coating material applied more mobile, which can lead to substantial variability in thickness and appearance. These reasons, in combination of the complex shapes of vials, syringes and the like, can make spray coating difficult as the uniformity of the droplets by shape/area is difficult to control repeatably and accurately. Using multiple spray nozzles to account for the different application geometries of the shapes of vials can also bring the issue of overlapping sprays. Overlapping sprays can leave a visible defect from a thickness variation as well as irregular distribution of droplets that coat the surface. Furthermore, different spray times of impact of particles can alter the coverage and appearance of the coatings.
Accordingly, a need exists for spray coating apparatuses with turn nozzle assemblies and methods of coating glass objects using turn nozzle assemblies. The turn nozzle assemblies can utilize a single distribution of droplets from a single atomizer (an airless sprayer for example) can be modified by an air turn to keep the benefits of a droplet distribution designed for a particular portion of the vial geometry (like a side wall) and utilize the portion that is designed to “miss” the vial to redirect it to another direction to coat surfaces that are not directly accessible to the spray nozzle such as the heel and footprint at the bottom of the glass objects.
According to one embodiment, a spray coating apparatus that applies a coating material onto outer surfaces of glass objects includes a coating material source that includes a coating material. A spray nozzle assembly includes a spray nozzle fluidly connected to the coating material source. The spray nozzle is arranged and configured to direct the coating material in a first direction toward the glass object and provide an overspray amount of the coating material by the glass object such that the overspray amount bypasses a non-line of sight area of the glass object. A turn nozzle assembly includes a turn nozzle fluidly connected to a pressurized gas source. The turn nozzle is arranged and configured to direct pressurized gas in a second direction different than the first direction toward the non-line of sight area of the glass package to redirect the coating material onto the non-line of sight area.
According to another embodiment, a method of coating a glass package with a coating material using a spray coating apparatus is provided. The method includes gripping the glass package with a clamping device. The coating material is directed onto an outer surface of the glass package using a spray nozzle of a spray nozzle assembly. The spray nozzle is arranged and configured to direct the coating material in a first direction toward the glass package and provide an overspray amount of the coating material that bypasses a non-line of sight area of the glass package. The overspray amount of the coating material bypassing the glass package is redirected toward the non-line of sight area of the glass package using a turn nozzle of a turn nozzle assembly. The turn nozzle is arranged and configured to direct pressurized gas in a second direction different than the first direction toward the non-line of sight area of the glass package changing direction and momentum of coating material toward the non-line of sight area.
Additional features and advantages of the glass articles and methods and processes for manufacturing the same will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.
Embodiments described herein are generally directed to spray coating apparatuses that are used to apply a coating material onto an outer surfaces of an object, such as a glass package or a pharmaceutical container. The spray coating apparatuses include a coating material source comprising a coating material. A spray nozzle assembly includes a spray nozzle that is fluidly connected to the coating material source. The spray nozzle is arranged and configured to direct the coating material in a first direction toward the glass object and provide an overspray amount of the coating material that misses the glass object. A turn nozzle assembly includes a turn nozzle that is fluidly connected to a pressurized gas source. The turn nozzle is arranged and configured to direct pressurized gas in a second direction different than the first direction toward a non-line of sight area of the glass object to redirect the overspray amount of the coating material.
Referring to
Referring briefly to
Referring back to
The gripping device 46 holds the glass object O in a generally vertical orientation such that the sidewall 30 extends in a straight, vertical direction like a cylinder and the bottom 40 extends generally parallel with the floor. While a straight sidewall 30 is illustrated any other suitable sidewall shapes may be used, such as rounded, stepped, ribbed, etc. The coating material is sprayed onto the glass object O by the spray nozzle 14 in the direction D1. The directions D1 and D2 can be determined by a line passing through a geometric center the associated nozzle orifice and perpendicular to a plane containing the nozzle tip opening. As can be seen, the spray nozzle 14 is oriented along a generally downward slope, pointing toward the sidewall 30 providing a spray direction angle θ1 from horizontal of between about 30 degrees and about 65 degrees, such that the overspray amount 25 of the coating material misses the glass object O. The gas (e.g., air, nitrogen, etc.) is directed onto the glass object O by the turn nozzle 18 in the direction D2. As can be seen, the turn nozzle 18 is oriented along a generally upward slope, pointing generally toward the heel 42 and the bottom 40 providing a jet direction angle θ2 of between about 45 degrees and about 65 degrees. Due to the orientation of the glass object O, the heel 42 and bottom 40 may be referred to as the non-line of sight area 24 of the glass object O.
Any suitable spray and jet direction angles may be selected based on desired and/or known spray characteristics and shape and orientation of the glass object O during a coating procedure. In the illustrated example, the gripping device 46 is operatively connected to a motor 54 that is used to rotate the glass object O at a high velocity during the coating process to improve uniformity of the coating material applied to the glass object O. Uniformity of the coating material across exterior surfaces of the glass object O including the shoulder 36, body 26, heel 42 and bottom 40 is a consideration in determining the spray characteristics of the coating material and the jet characteristics of the gas. In this regard, the turn nozzle 18 uses the pressurized gas to redirect an amount of overspray of the coating material. As used herein, the term “overspray amount” refers to an amount of coating material which misses the glass object O. The orientation and jet characteristics of the turn nozzle 18 are selected to turn the overspray amount 25 back toward the heel 42 and spread over the bottom 40. The orientation and jet characteristics of the turn nozzle 18 may also be selected to turn a portion of the coating material that migrates down the sidewall 30 of the glass object O toward and onto the heel 42 and bottom 40.
In a high speed or high volume manufacturing environment, deposition of the coating material on the turn nozzle 18 can be a concern. Deposition of the coating material on the turn nozzle 18 can occur through direct impingement of the overspray on the turn nozzle 18 or through indirect deposition and entrainment of suspended droplets of the coating material. Droplets of the coating material are suspended as a result of Bernouli's principle in that high speed airflow through the turn nozzle 18 creates a low pressure outside the turn nozzle that creates the low pressure that leads to the entrainment of the droplets. Over time, the buildup on the turn nozzle 18 can become substantial enough to affect performance by causing a small deflection of the jet flow, which over the operating distance, can shift and misplace the impingement location of the jet nozzle on the glass object O from a desired set point. Small departures (e.g., 10 mm or less) from the desired set point can adversely affect coating performance on the heel 42 and bottom 40 (i.e., under-turned) areas of the glass object O. To this end, the turn nozzle 18 may be provided with a shield or shroud which is described in further detail below.
Referring to
The turn nozzle 18 further includes a connector portion 60 that connects to a connector 62 of a manifold 64. The manifold 64 includes a body 66 having multiple passageways 68, 70 and 72 that extend therethrough. Passageway 70 is an air delivery passageway that is in fluid communication with the connector 62 for delivering the pressurized air to the turn nozzle 18. Passageways 68 and 72 are gas purge passageways that are in fluid communication with a pressurized air source (or other gas source) for providing purge air therethrough. While two gas purge passageways 68 and 72 are shown, there may be one or more than two gas purge passageways.
Referring to
Two interrelated design considerations for the turn nozzle assembly 16 are the dimensions of the nozzle opening 88 and the recess depth of tips 90 of the sub-nozzles 58 relative to the nozzle opening 88. It may be desirable to minimize the size of the nozzle opening an amount that does not affect the mean and turbulent flow characteristics of the turn nozzle 18 air jet. This is because a small area between the nozzle opening 88 and the core jet of the turn nozzle 18 results in increased speed of the purge air from the gas purge passageways 68 and 72 (
Referring particularly to
Regarding the recess depth of the turn nozzle tip 94 from the nozzle opening 88, it has been found that a reduced distance of the turn nozzle tip 94 from the nozzle opening 88 is desired for providing a desired jet direction while increasing the recess depth can further remove the turn nozzle tip 94 from falling coating material. Thus, it may be desired to provide some limited recess depth d. For example, a suitable recess depth d may be between about one millimeter and about five millimeters. However, the recess depth d may vary depending on the particular turn nozzle tip dimensions, flow rates and shroud configuration.
Other exemplary turn nozzle assembly 16 considerations include jet impingement location, turn nozzle distance to the glass object, and jet flow rate. Referring again to
The turn nozzle distance Dt is the distance from the nozzle tip 94 to the glass object O. A suitable turn nozzle distance Dt may be selected from ten millimeters to 30 mm, such as between 15 mm and 25 mm, such as about 20 mm. The turn nozzle distance Dt may depend on any number of factors such as glass object size and shape and the coating material used. Another factor that may affect the turn nozzle distance Dt is the jet flow rate. A suitable jet flow rate may, for example, be selected between one cubic foot per minute and five cubic feet per minute, such as about three cubic feet per minute.
Details on various coating materials, such as polyimide-based coatings, may be found in U.S. Patent Application Publication No. 2013/0171456, filed Feb. 28, 2013, and entitled “Glass Articles with Low-Friction Coatings,” U.S. Patent Application Publication No. 2013/0224407, filed Feb. 28, 2013, and entitled “Glass Articles with Low-Friction Coatings,” U.S. Patent Application Publication No. 2014/0001076, filed Mar. 14, 2013, and entitled “Delamination Resistant Glass Containers with Heat-Tolerant Coatings,” U.S. Patent Application Publication No. 2014/0001143, filed Jun. 28, 2013, and entitled “Delamination Resistant Glass Containers with Heat-Tolerant Coatings,” U.S. Patent Application Publication No. 2014/0151320, filed Nov. 8, 2013, and entitled “Glass Containers with Delamination Resistance and Improved Damage Tolerance,” U.S. Patent Application Publication No. 2014/0151321, filed Nov. 8, 2013, and entitled “Glass Containers with Improved Strength and Improved Damage Tolerance,” U.S. Patent Application Publication No. 2014/0151370, filed Nov. 8, 2013, and entitled “Strengthened Glass Containers Resistant to Delamination and Damage,” U.S. Patent Application Publication No. 2015/0329416, filed Jul. 29, 2015, and entitled “Glass Articles with Low-Friction Coatings,” U.S. Patent Application Publication No. 2015/0360999, filed Jul. 29, 2015, and entitled “Glass Articles with Low-Friction Coatings,” U.S. Pat. No. 9,034,442, filed Oct. 11, 2013, and entitled “Strengthened Borosilicate Glass Containers with Improved Damage Tolerance,” and U.S. Pat. No. 9,428,302, filed Oct. 18, 2013, and entitled “Delamination Resistant Glass Containers with Heat-Tolerant Coatings,” each of which are hereby incorporated by reference in its entirety.
Referring to
Once the turn nozzle 118 is in place on the mounting structure 104, the shroud 174 may be slid over the turn nozzle 118. The shroud 174 may have an opening 175 through its bottom 178 that the bottom 178 can be slid through a slot 130 provided by the base 108. The shroud 174 may further include a mounting flange 132 having mounting openings 176 that receive dowel pins 134. Again, thumb screws 136 or other suitable fasteners may be used to secure the shroud 174 around the turn nozzle 118. A removable wall section 140 may be used to secure the connector 120 within the slot 122 of the manifold 124 and seal off the enclosure of the shroud 174.
Particular turn nozzle arrangements with a linear array of sub-nozzles are discussed above; however, other turn nozzle configurations are contemplated. For example, referring to
A distance Dt of the sub-nozzles 202 and 204 from the glass object O may be between six millimeters and 18 mm, such as about 12 mm. A distance from heel 208 to a top of the first sub-nozzle 202 may be between zero and three millimeters. Referring briefly to
The above-described apparatuses and methods provide a turn nozzle that is used to redirect liquid coating material bypassing and/or sprayed onto a sidewall around a corner and along an underside of a glass object in order to coat the underside of the glass object. Redirecting the coating material, as opposed to directing two sprays of coating material, can reduce the amount of coating material used to coat the glass object and can reduce or even eliminate visible marks of overlapped coating material layers on the glass object. Redirecting the coating material can also use less coating material and can simplify the coating process by eliminating a liquid spray nozzle. Use of a shroud can protect the turn nozzle from contamination thereby decreasing nozzle maintenance time and frequency and can avoid disruption of turn nozzle setup even after multiple maintenance cycles.
Embodiments can be described with reference to the following numbered clauses, with preferred features laid out in the dependent clauses:
Clause 1: A spray coating apparatus that applies a coating material onto outer surfaces of glass objects, comprising: a coating material source comprising a coating material;
a spray nozzle assembly comprising a spray nozzle fluidly connected to the coating material source, the spray nozzle arranged and configured to direct the coating material in a first direction toward the glass object and provide an overspray amount of the coating material by the glass object such that the overspray amount bypasses a non-line of sight area of the glass object; and a turn nozzle assembly comprising a turn nozzle fluidly connected to a pressurized gas source, the turn nozzle arranged and configured to direct pressurized gas in a second direction different than the first direction toward the non-line of sight area of the glass package to redirect the coating material onto the non-line of sight area.
Clause 2: The spray coating apparatus of clause 1, wherein the turn nozzle assembly further comprises a shroud forming an enclosure that partially envelops the turn nozzle.
Clause 3: The spray coating apparatus of clause 2, wherein the shroud has an outlet opening at an end of the shroud, wherein a tip of the turn nozzle is offset from the outlet opening within the enclosure.
Clause 4: The spray coating apparatus of clause 3, wherein the turn nozzle comprises a tip having a width that is greater than a height of the tip.
Clause 5: The spray coating apparatus of clause 4, wherein the outlet opening has a width that is greater than a height of the outlet opening.
Clause 6: The spray coating apparatus of clause 3 or 4, wherein the shroud is engaged with a manifold that includes a gas inlet through which pressurized gas is directed through the enclosure.
Clause 7: The spray coating apparatus of any of clauses 1-6 further comprising a clamping device that is configured to clamp onto the glass package and hold the glass package alongside the turn nozzle, the glass object being a vial and the under-turned area comprising a heel providing a transition between a bottom of the vial and a side of the vial.
Clause 8: The spray coating apparatus of any of clauses 1-7, wherein the turn nozzle directs the pressurized gas in the second direction at a flow rate of between one cubic foot per minute and five cubic feet per minute.
Clause 9: The spray coating apparatus of any of clauses 1-8, wherein the turn nozzle comprises an array of sub-nozzles.
Clause 10: The spray coating apparatus of any of clauses 1-9, wherein the turn nozzle is a first turn nozzle, the apparatus further comprising a second turn nozzle arranged and configured to direct pressurized air in a third direction different than the first direction toward the non-line of sight area of the glass package.
Clause 11: A method of coating a glass package with a coating material using a spray coating apparatus, the method comprising: gripping the glass package with a clamping device; directing the coating material onto an outer surface of the glass package using a spray nozzle of a spray nozzle assembly, the spray nozzle arranged and configured to direct the coating material in a first direction toward the glass package and provide an overspray amount of the coating material that bypasses a non-line of sight area of the glass package; and redirecting the overspray amount of the coating material toward the non-line of sight area of the glass package using a turn nozzle of a turn nozzle assembly, the turn nozzle arranged and configured to direct pressurized gas in a second direction different than the first direction toward the non-line of sight area of the glass package changing direction and momentum of coating material toward the non-line of sight area.
Clause 12: The method of clause 11 further comprising spinning the glass package during the step of re-directing some coating material.
Clause 13: The method of clause 11 or 12 further comprising enclosing the turn nozzle in a shroud that partially envelops the turn nozzle thereby shielding the turn nozzle from coating material.
Clause 14: The method of clause 13, wherein the shroud has an outlet opening at an end of the shroud, wherein a tip of the heel turn nozzle is offset from the outlet opening within the enclosure.
Clause 15: The method of clause 14, wherein the turn nozzle comprises a tip having a width that is greater than a height of the tip.
Clause 16: The method of clause 15, wherein the outlet opening has a width that is greater than a height of the outlet opening.
Clause 17: The method of any of clauses 14-16 further comprising directing pressurized gas through the enclosure.
Clause 18: The method of any of clauses 11-17 wherein, the glass package is a vial and the under-turned portion being a heel providing a transition between a bottom of the vial and a side of the vial.
Clause 19: The method of clause 18 further comprising a motor operatively connected to the clamping device that spins the vial as the coating material is applied using the spray nozzle.
Clause 20: The method of any of clauses 11-19, wherein the turn nozzle is a first turn nozzle, the apparatus further comprising a second turn nozzle arranged and configured to direct pressurized air in a third direction different than the first direction toward the non-line of sight area of the glass package.
It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.
This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/284,159, filed on Nov. 30, 2021, the content of which is relied upon and incorporated herein by reference in its entirety.
Number | Date | Country | |
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63287159 | Dec 2021 | US |