Stress features for crack redirection and protection in glass containers

Abstract

A glass container includes a glass body comprising a first region under compressive stress extending from a surface of the glass body to a compressive depth, and a second region under tensile stress extending from the compressive depth into a thickness of the glass body. The glass container also includes a localized compressive stress region having a localized compressive stress extending from the surface to a localized compressive depth within the body. The localized compressive depth is greater than the compressive depth of the first region. The glass container also includes a crack redirection region extending in a predetermined propagation direction, wherein the crack redirection region has a tensile stress that is higher than a tensile stress within the second region in a sub-region of the crack redirection region extending substantially perpendicular to the predetermined propagation direction.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 053,860, filed July 20, 2020, pursuant to 35 USC §119, the contents of which are incorporated herein by reference in their entirety. Background Technology Technical Field

[0003] This specification generally relates to glass containers, such as glass containers for storing pharmaceutical compositions. Technical Background

[0005] One consideration for food and drug manufacturers is maintaining the sterility of the contents of the package from transportation and storage until use. While glass containers are superior to many alternative materials, they are not unbreakable and are sometimes damaged during handling and transportation. Cracks may form that extend through the wall thickness, jeopardizing the sterility of the contents, but not leading to catastrophic failure of the packaging. Other features of glass containers (e.g., adhesive labels) can make such cracks less noticeable to users, allowing for continued use despite compromised sterility. Summary of the Invention

[0006] A first aspect of this disclosure includes a method of manufacturing a glass container having a first surface and a second surface separated by a thickness, the method comprising: forming a first region under compressive stress on the first surface of the glass container, wherein the first region extends from the first surface into a compression depth within the glass container; forming a second region under central tension, the second region extending from the compression depth into the thickness, wherein the central tension is sufficient to cause a crack at the first surface to self-propagate from a crack initiation point; and forming a crack redirection region in the first surface, wherein the crack redirection region extends in a predetermined propagation direction of the crack and includes a higher central tension than the remainder of the glass article in a direction substantially perpendicular to the predetermined propagation direction, such that after the crack propagates and reaches the crack redirection region, the crack is redirected along the predetermined propagation direction.

[0007] The second aspect of this disclosure may include the first aspect, wherein the glass container includes a body having an inner surface and an outer surface, the inner surface defining an internal volume having an axis, wherein a predetermined propagation direction is substantially perpendicular to the axis.

[0008] A third aspect of the disclosure can include the first or second aspect, wherein the thickness of the glass container varies within the crack redirection region such that the crack redirection region comprises a thin region extending substantially parallel to the axis where the thickness is less than an average thickness of the glass container within the crack redirection region.

[0009] A fourth aspect of the disclosure can include any of the first through third aspects, wherein the crack redirection region extends around at least a portion of a perimeter of the glass container.

[0010] A fifth aspect of the disclosure can include any of the first through fourth aspects, wherein the thickness of the glass container varies within the crack redirection region in a sinusoidal manner parallel to the axis.

[0011] A sixth aspect of the disclosure can include any of the first through fifth aspects, wherein the crack redirection region extends around an entire perimeter of the glass container.

[0012] A seventh aspect of the disclosure can include any of the first through sixth aspects, wherein the first surface is an outer surface of the glass container.

[0013] An eighth aspect of the disclosure can include any of the first through seventh aspects, wherein the first surface is an inner surface of the glass container.

[0014] A ninth aspect of the disclosure can include any of the first through eighth aspects, wherein forming the first and second regions comprises forming the glass container from the glass composition; and forming the first region and the second region by subjecting the first surface of the glass container to a chemical tempering.

[0015] A tenth aspect of the disclosure can include any of the first through ninth aspects, wherein the glass composition comprises an aluminosilicate glass composition.

[0016] An eleventh aspect of the disclosure can include any of the first through tenth aspects, wherein forming the glass article from the glass composition comprises: forming a glass tube comprising the glass composition; and transforming the glass tube into the glass container, wherein the forming of the crack redirection region occurs during the transforming of the glass tube into the glass container.

[0017] A twelfth aspect of the disclosure can include any of the first through eleventh aspects, wherein the forming of the crack redirection region comprises scanning a pulsed laser beam in a predetermined pattern while heating the glass tube to a softening temperature of the glass composition during the transforming of the glass tube into the glass container.

[0018] A 13th aspect of the disclosure can include a method of forming a glass container having a crack redirection region, the method comprising: providing a stock formed of a glass composition; shaping the stock into a glass article having a main body defining an interior volume extending between an interior surface and an exterior surface; forming a compressive stress layer in the glass article extending from at least one of the interior surface and the exterior surface to a depth of compression in a thickness of the main body; and forming the crack redirection region in the glass article, wherein the crack redirection region includes a sub-region having a higher central tension than a remaining portion of the glass article, wherein the sub-region extends in a direction substantially perpendicular to a predetermined propagation direction.

[0019] A 14th aspect of the disclosure can include the 13th aspect, wherein: the stock comprises a glass tube; the method further comprises converting the glass tube into the glass article; forming the crack redirection region comprises forming the sub-region of the crack redirection region during the converting of the glass tube into the glass article; and the sub-region has a thickness less than an average thickness of the main body.

[0020] A 15th aspect of the disclosure can include any of the 13th to 14th aspects, wherein forming the sub-region comprises scanning a pulsed laser beam in a predetermined pattern on the glass article.

[0021] A 16th aspect of the disclosure can include any of the 13th to 15th aspects, wherein forming the sub-region comprises contacting the glass tube with a shaped element during the converting of the glass tube into the glass article.

[0022] A 17th aspect of the disclosure can include a glass container comprising: a glass main body comprising a first region in compressive stress extending from a surface of the glass main body to a depth of compression and a second region extending from the depth of compression into a thickness of the glass main body, the second region being under a tensile stress sufficient to cause self-propagation of a crack in a propagation direction from a crack initiation point; and a crack redirection region on the surface of the glass main body, the crack redirection region extending in a predetermined propagation direction of the crack. The crack redirection region comprises a tensile stress greater than the tensile stress in the second region in a sub-region of the crack redirection region. The sub-region extends substantially perpendicular to the predetermined propagation direction, such that upon the crack propagating into the crack redirection region, the crack is redirected in the predetermined propagation direction.

[0023] An 18th aspect of the disclosure can include the 17th aspect, wherein the glass container comprises one of: a bottle, a vial, an ampoule, a syringe, or a cartridge.

[0024] A 19th aspect of the disclosure can include any of the 17th to 18th aspects, wherein the predetermined propagation direction is a circumferential direction substantially perpendicular to an axis of the glass container.

[0025] A 20th aspect of the disclosure can include any of the 17th through 19th aspects, wherein the thickness is varied within the crack redirection region such that a sub-region of the crack redirection region comprises a thin region extending substantially parallel to the axis where the thickness is less than an average thickness of the glass container.

[0026] A 21st aspect of the disclosure includes a glass container comprising: a body comprising a glass composition, the body having an inner surface, an outer surface, and a wall thickness extending between the inner surface and the outer surface, wherein the body comprises a localized compressive stress region having a localized compressive stress extending from the outer surface into a localized compressive depth within the body, wherein: the localized compressive stress region extends deeper into the body than any region of compressive stress adjacent to the localized compressive region.

[0027] A 22nd aspect of the disclosure can include the 21st aspect, wherein the glass container comprises a pharmaceutical container.

[0028] A 23rd aspect of the disclosure can include any of the 21st through 22nd aspects, wherein the localized compressive depth extends greater than or equal to 2% of the wall thickness and less than or equal to 25% of the wall thickness.

[0029] A 24th aspect of the disclosure can include any of the 21st through 23rd aspects, wherein the localized compressive depth extends greater than or equal to 20% of the wall thickness and less than or equal to 25% of the wall thickness.

[0030] A 25th aspect of the disclosure can include any of the 21st through 24th aspects, wherein the localized compressive stress region comprises a compressive stress greater than or equal to 50 MPa.

[0031] A 26th aspect of the disclosure can include any of the 21st through 25th aspects, wherein the localized compressive stress region comprises a surface compressive stress greater than or equal to 75 MPa.

[0032] A 27th aspect of the disclosure can include any of the 21st through 26th aspects, wherein the surface compressive stress is greater than or equal to 100 MPa.

[0033] A 28th aspect of the disclosure can include any of the 21st through 27th aspects, wherein the localized compressive stress region overlaps a compressive stress layer of the glass container in compressive stress such that in the localized compressive stress region, the body comprises a compressive stress of the compressive stress layer to a first compressive depth and a localized stress depth from the first compressive depth to the localized compressive depth.

[0034] A 29th aspect of the disclosure can include any of aspects 21 to 28, wherein the glass composition comprises an aluminosilicate glass composition.

[0035] A 30th aspect of the disclosure can include any of aspects 21 to 29, wherein the glass container comprises a vial having a base, a barrel connected to the base via a heel, a shoulder extending from the barrel, and a neck extending from the shoulder, wherein the localized compressive stress region is disposed in at least one of the neck, the heel, and the barrel.

[0036] A 31st aspect of the disclosure can include any of aspects 21 to 30, wherein the localized compressive stress region is disposed in the heel.

[0037] A 32nd aspect of the disclosure can include any of aspects 21 to 31, further comprising an additional localized compressive stress region having an additional localized compressive stress, the additional localized compressive stress region extending from the interior surface to an additional localized compressive depth within the body.

[0038] A 33rd aspect of the disclosure can include any of aspects 21 to 32, wherein the localized compressive stress region and the additional localized compressive stress region are opposite one another such that a central tension region is formed between the localized compressive stress region and the additional localized compressive stress region, wherein the central tension region promotes branching of a crack propagating through the wall thickness such that the glass container is rendered unusable.

[0039] A 34th aspect of the disclosure includes a glass container comprising: a glass body comprising a first region in compression extending from a surface of the glass body to a compressive depth and a second region extending from the compressive depth into a thickness of the glass body, the second region being in tension; and a localized compressive stress region having a localized compressive stress extending from the surface to a localized compressive depth within the body, wherein: the localized compressive depth is greater than or equal to 2% of a wall thickness of the body and less than or equal to 25% of the wall thickness of the body, and the localized compressive depth is greater than the compressive depth of the first region.

[0040] A 35th aspect of the disclosure can include the 34th aspect, wherein the localized compressive stress region overlaps the first region such that, within the localized compressive stress region, the glass body has a compressive stress of the first region to a first compressive depth and a localized stress depth from the first compressive depth to the localized compressive depth.

[0041] A 36th aspect of the disclosure can include any of aspects 34 to 35, wherein the localized compressive stress region comprises a compressive stress greater than or equal to 50 MPa.

[0042] A 37th aspect of the disclosure can include any of aspects 34 through 36, wherein the surface of the glass body is an exterior surface of the glass container.

[0043] A 38th aspect of the disclosure can include a method of forming a glass container having a localized compressive stress region, the method comprising: providing a stock formed of a glass composition; shaping the stock into a glass article having a body with a thickness extending between an interior surface and an exterior surface, the body defining an interior volume; forming a localized compressive stress region in the glass article, the localized compressive stress region having a localized compressive depth extending from the interior surface or the exterior surface into the body, wherein the localized compressive depth is greater than or equal to 2% of the thickness and less than or equal to 25% of the thickness, wherein forming the localized compressive stress region comprises locally applying a cooling agent to a portion of the glass article when the glass article is heated to a starting temperature above a softening temperature of the glass composition, such that the localized compressive stress region extends more deeply into the body than any compressive stress region adjacent to the localized compressive region.

[0044] A 39th aspect of the disclosure can include aspect 38, further comprising subjecting the glass article to ion exchange strengthening after forming the localized compressive stress region to form a first region under compression on the exterior surface, the first region extending from the exterior surface to a compressive depth less than the localized compressive depth.

[0045] A 40th aspect of the disclosure can include any of aspects 38 through 39, wherein locally applying the cooling agent to the portion of the glass article comprises inducing transient tensile stresses in a central portion of the thickness that induce propagation of any cracks formed in the central portion.

[0046] A 41st aspect of the disclosure can include any of aspects 38 through 40, further comprising flame cleaning the entire exterior surface prior to forming the localized compressive stress region to eliminate transformation flaws induced by shaping the stock into the glass article.

[0047] A 42nd aspect of the disclosure can include any of the 38th through 41st aspects, wherein locally applying the coolant to the portion of the glass article comprises: positioning a collar proximate to the portion of the glass article when the glass article is heated to the starting temperature, the collar comprising at least one feeder for the coolant, wherein the collar is shaped in a manner corresponding to the portion of the glass article, wherein the collar comprises a contact point in contact with the portion of the glass article, thereby controlling a gap between a fluid manifold of the collar and the portion of the glass article; and providing the coolant to the portion of the glass article to form the localized compressive stress region.

[0048] A 43rd aspect of the disclosure can include any of the 38th through 40th aspects, wherein the glass article is not subjected to an anneal heat treatment after the localized compressive stress region is formed.

[0049] A 44th aspect of the disclosure can include any of the 38th through 43rd aspects, wherein the glass container comprises a vial having a base, a barrel connected to the base via a heel, a shoulder extending from the barrel, and a neck extending from the shoulder, wherein the portion of the glass article to which the coolant is applied comprises at least one of the neck and the heel.

[0050] A 45th aspect of the disclosure can include a glass container comprising: a glass body comprising a first region in compressive stress extending from a surface of the glass body to a compressive depth and a second region extending from the compressive depth into a thickness of the glass body, the second region being in tensile stress; a localized compressive stress region having a localized compressive stress extending from the surface to a localized compressive depth within the body, wherein: the localized compressive depth is greater than the compressive depth of the first region; and a crack redirection region in the glass body, the crack redirection region extending in a predetermined propagation direction, wherein the crack redirection region has a tensile stress that is higher than a tensile stress in a sub-region of the crack redirection region, the sub-region extending substantially perpendicular to the predetermined propagation direction.

[0051] A 46th aspect of the disclosure can include any of the 45th aspects, wherein the sub-region of the crack redirection region comprises a thickness variation at the surface of the glass body.

[0052] A 47th aspect of the disclosure can include any of the 44th through 46th aspects, wherein the surface of the glass body is an exterior surface of the glass container.

[0053] A 48th aspect of the disclosure can include any of the 45th through 47th aspects, wherein the crack redirection region overlaps the localized compressive stress region in an overlap region.

[0054] A 49th aspect of the disclosure can include any of aspects 45-48, wherein the localized compressive stress region overlaps the first region such that, within the localized compressive stress region, the glass body has a compressive stress of the first region to a first compressive depth and a localized stress depth from the first compressive depth to a localized compressive depth.

[0055] A 50th aspect of the disclosure can include any of aspects 45-49, wherein the localized compressive stress region comprises a compressive stress greater than or equal to 50 MPa.

[0056] A 51st aspect of the disclosure can include any of aspects 45-50, wherein the glass body is formed of an aluminosilicate glass composition.

[0057] A 52nd aspect of the disclosure can include any of aspects 45-51, wherein the glass container comprises a vial having a base, a barrel connected to the base via a heel, a shoulder extending from the barrel, and a neck extending from the shoulder.

[0058] A 53rd aspect of the disclosure can include any of aspects 45-51, wherein the crack diversion region is disposed in the barrel proximate at least one of the heel and the shoulder.

[0059] A 54th aspect of the disclosure can include any of aspects 45-53, wherein the localized compressive stress region is disposed in at least one of the neck and the heel.

[0060] A 55th aspect of the disclosure can include a method of forming a glass container, the method comprising: providing a stock formed of a glass composition; shaping the stock into a glass article, the glass article having a body extending between an inner surface and an outer surface, the body defining an interior volume; forming a crack diversion region in the glass article, wherein the crack diversion region comprises a sub-region having a central tension higher than a remaining portion of the glass article, wherein the sub-region extends in a direction substantially perpendicular to a predetermined propagation direction; and forming a localized compressive stress region in the glass article, the localized compressive stress region having a localized compressive stress extending from the inner surface or the outer surface to a localized compressive depth within the body, wherein the localized compressive depth is greater than or equal to 2% of a thickness of the body and less than or equal to 25% of the thickness of the body, wherein forming the localized compressive stress region comprises locally applying a cooling agent to a portion of the glass article when the glass article is heated to a starting temperature above a softening temperature of the glass composition.

[0061] A 56th aspect of the disclosure can include the 55th aspect, further comprising forming a compressive stress layer in the glass article extending to a compressive depth in a thickness of the body from at least one of the inner surface and the outer surface.

[0062] A 57th aspect of the disclosure can include any of the 55th through 56th aspects, wherein forming the compressive stress layer comprises subjecting the glass article to ion exchange strengthening after forming the localized compressive stress region to form a first region under compressive stress on the outer surface extending to the compressive depth from the outer surface, wherein the compressive depth is less than the localized compressive depth.

[0063] A 58th aspect of the disclosure can include any of the 55th through 57th aspects, wherein the localized compressive stress region overlaps the first region on the outer surface.

[0064] A 59th aspect of the disclosure can include any of the 55th through 58th aspects, wherein the crack redirection region overlaps the localized compressive stress region on the outer surface.

[0065] A 60th aspect of the disclosure can include any of the 55th through 59th aspects, further comprising flame cleaning the entire outer surface prior to forming the localized compressive stress region to eliminate transformation flaws induced by shaping the stock into the glass article.

[0066] A 61st aspect of the disclosure can include any of the 55th through 60th aspects, wherein locally applying the coolant to the portion of the glass article comprises positioning a collar proximate to the portion of the glass article when the glass article is heated to the starting temperature, the collar comprising at least one feeder for the coolant, wherein the collar is shaped to correspond to the portion of the glass article; and providing the coolant to the portion of the glass article to form the localized compressive stress region.

[0067] A 62nd aspect of the disclosure can include any of the 55th through 61st aspects, wherein the collar comprises a contact point in contact with the portion of the glass article to control a gap between a fluid manifold of the collar and the portion of the glass article.

[0068] A 63rd aspect of the disclosure can include any of the 55th through 62nd aspects, wherein the glass container comprises a vial having a base, a barrel connected to the base via a heel, a shoulder extending from the barrel, and a neck extending from the shoulder, wherein the portion of the glass article to which the coolant is applied comprises at least one of the neck and the heel.

[0069] The 64th aspect of this disclosure may include any one of aspects 55 to 63, wherein forming a crack redirection region includes forming a sub-region of the crack redirection region during the process of forming the stock into a glass article, wherein the thickness of the sub-region is less than the average thickness of the body.

[0070] The 65th aspect of this disclosure may include any one of aspects 55 to 64, wherein forming a sub-region includes scanning a pulsed laser beam in a predetermined pattern on the glass article.

[0071] The 66th aspect of this disclosure may include any one of aspects 55 to 65, wherein forming a sub-region includes contacting the stock with a shape element having a shape corresponding to a predetermined shape of the sub-region during the process of forming the stock into a glass article.

[0072] The 67th aspect of this disclosure may include any one of aspects 55 to 66, wherein the thickness of a portion of the crack redirection region is greater than the average thickness of the body.

[0073] Other features and advantages of the processes and systems described herein are set forth in the following detailed description, some of which will be readily apparent to those skilled in the art from the description, or will be recognized by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0074] It should be understood that the foregoing general description and the following detailed description both depict various embodiments and are intended to provide an overall overview or framework for understanding the nature and characteristics of the claimed subject matter. The included drawings provide a further understanding of the various embodiments and are incorporated in and form a part of this specification. The drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. Attached Figure Description

[0075] The embodiments illustrated in the accompanying drawings are illustrative and exemplary in nature and are not intended to limit the subject matter defined by the claims. A detailed description of the illustrative embodiments can be understood by reading the following drawings, in conjunction with which the same structures are indicated by the same reference numerals, wherein:

[0076] Figure 1 The schematic diagram shows a cross-section of a glass container including a crack redirection region and a localized compressive stress region according to one or more embodiments described herein.

[0077] Figure 2 Schematic display Figure 1 A compressive stress layer in a portion of the sidewall of a glass container;

[0078] Figure 3 A schematic diagram showing a portion of the sidewall of a glass container formed by stacked glass;

[0079] Figure 4A Schematic illustration of one or more embodiments described herein Figure 1 The cross-section of the crack redirection region;

[0080] Figure 4B Schematic illustration of one or more embodiments described herein Figure 1 The cross-section of the crack redirection region;

[0081] Figure 4C Schematic illustration of one or more embodiments described herein Figure 1 The cross-section of the crack redirection region;

[0082] Figure 5 Schematic illustration of one or more embodiments described herein Figure 1 The cross-section of the alternative crack redirection region;

[0083] Figure 6A The illustration schematically shows a glass container including a crack redirection region according to one or more embodiments described herein;

[0084] Figure 6B This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0085] Figure 6C This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0086] Figure 6D This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0087] Figure 6E This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0088] Figure 6F This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0089] Figure 6G This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein.Figure 6A Glass containers;

[0090] Figure 6H This schematically illustrates a region containing another crack redirection according to one or more embodiments described herein. Figure 6A Glass containers;

[0091] Figure 7 The illustration schematically shows a glass container including a crack redirection region according to one or more embodiments described herein;

[0092] Figure 8A The illustration schematically shows a glass container comprising a first crack redirection region extending in a first direction, according to one or more embodiments described herein.

[0093] Figure 8B This illustration schematically shows a second crack reversal comprising extending in a first helical pattern, according to one or more embodiments described herein. Figure 8A Glass containers;

[0094] Figure 8C This illustration schematically shows a second crack reversal comprising extending in a second helical pattern, according to one or more embodiments described herein. Figure 8A Glass containers;

[0095] Figure 8D This schematically illustrates a method for redirecting a second crack extending in a second direction, according to one or more embodiments described herein. Figure 8A A glass container, wherein the second direction is perpendicular to the first direction;

[0096] Figure 9 The illustration schematically shows a conversion machine for converting a glass tube into a glass container according to one or more embodiments described herein;

[0097] Figure 10 Schematic illustration of one or more embodiments shown and described herein Figure 9 The processing workstation of the converter shown;

[0098] Figure 11 Schematic illustration of one or more embodiments described herein Figure 1 The localized compressive stress region of the glass container shown;

[0099] Figure 12A The illustration shows the functional relationship between compressive stress in a localized compressive stress region according to one or more embodiments described herein and the initial temperature and heat transfer coefficient of the glass composition.

[0100] Figure 12B The illustration shows one or more embodiments according to the present document. Figure 12Athe central tension of the localized compressive stress region of a glass composition as a function of the onset temperature and the heat transfer coefficient;

[0101] Figure 12C graphically showing the compressive stress in the localized compressive stress region of a glass composition as a function of the onset temperature and the thickness according to one or more embodiments described herein; Figure 12A

[0102] Figure 12D graphically showing the compressive stress in the localized compressive stress region of a glass composition as a function of the onset temperature and the thickness according to one or more embodiments described herein; Figure 12A

[0103] Figure 12E graphically showing the compressive stress in the localized compressive stress region of a glass composition as a function of the onset temperature and the thickness according to one or more embodiments described herein; Figure 12A

[0104] Figure 13A graphically showing a cooling apparatus for performing a localized thermal tempering process on a glass container according to one or more embodiments described herein;

[0105] Figure 13B graphically showing a cooling apparatus for performing a localized thermal tempering process on a glass container according to one or more embodiments described herein; and

[0106] Figure 14 a method of converting a stock of glass compositions into glass containers comprising at least one of a crack redirection region and a localized compressive stress region according to one or more embodiments described herein. DETAILED DESCRIPTION

[0107] ​​​Referring now to the embodiments in detail, the glass containers described herein have features that prevent cracks from initiating and propagating in the glass container in a manner that can compromise the sterility of an item disposed therein, such as a pharmaceutical. For example, the features of the glass containers described herein can prevent initial surface flaws from forming or propagating through the glass container in a manner that is not detectable or observable, thereby preventing the item disposed in the glass container from being compromised in a manner that is not detectable. Such surface flaws can be introduced to the glass container through contact with other surfaces during forming, shipping, filling, and handling. A crack under tension can propagate from the initiation point. For example, a crack formed in a glass container having a residual central tension can propagate in a direction that is dependent on the stress field within the glass container. For example, if the hoop stress of the glass container is higher than the axial stress, the crack can propagate in an axial direction rather than a hoop direction. Such axial cracks can be hidden by an adhesive label or other covering and can not be as detectable to handlers of the glass container if the crack propagates through the body of the glass container having the adhesive label. Various embodiments of the present disclosure introduce a central tension profile into the glass container that helps to redirect cracks that can initiate in the glass container to a more detectable and / or observable portion of the glass container or render the glass container unusable as a result of the crack redirection. For example, the glass container can include a crack redirection region having a central tension in a longitudinal direction that is greater than the central tension in a hoop direction, thereby helping to direct cracks to propagate in a hoop direction in a desired portion of the glass container, such as a portion of the glass container that is not typically hidden by an adhesive label.

[0108] In embodiments, the glass containers described herein can also include localized compressive stress regions that make the glass container more durable in the localized compressive stress regions. In particular, the localized compressive stress regions can be located in regions of the glass container that frequently contact external elements, such as forming equipment, other glass containers during shipping, capping devices, etc. Advantageously, the localized compressive stress regions described herein have a compressive depth that is greater than those found in conventional glass containers. Such deeper compressive depths advantageously prevent surface flaws from reaching the central tension region, which can be a core region in the glass container, and thus prevent the surface flaws from propagating through the glass container and compromising container integrity. According to the present disclosure, such localized compressive stress regions can be formed by subjecting selected regions of the glass container to a localized thermal strengthening process. Such thermal strengthening processes can have additional benefits, such as inducing transient tensile stresses in the glass container to aid in the identification of glass containers having deeper surface flaws that originated from the forming process of the glass container. Localized thermal tempering can be used to identify and eliminate defective glass containers from a population of glass containers.

[0109] In embodiments, the glass containers described herein can include both a crack diversion region and a localized compressive stress region to provide a synergistic effect. For example, embodiments can include a crack diversion region that enhances the central tension that overlaps with a localized compressive stress region at the outer surface of the glass container to provide both improved resistance to failure (e.g., resistance of surface flaws to reach the central tension region within the thickness of the glass container) and crack diversion in the overlapping region. In embodiments, the crack diversion region can be placed based on the localized compressive stress region included in the glass container such that the crack diversion region causes a crack initiated at a particular location on the glass container disposed between the crack diversion region and the localized compressive stress region to divert.

[0110] In embodiments of the glass containers described herein, the concentrations of the constituent components (e.g., Si02, AI2O3, and B203, etc.) that form the glass containers are specified as mole percent on an oxide basis (mol%) unless otherwise specified.

[0111] The term "substantially free" when used in reference to the concentration of a particular compositional component in a glass composition and / or the absence of that particular compositional component means that the compositional component is not intentionally added to the glass composition. However, the glass composition can contain trace amounts of the compositional component as a contaminant or an unspecified amount that is less than 0.05 mole percent.

[0112] As used herein, the term "chemical durability" refers to the ability of a glass composition to resist degradation upon exposure to a particular chemical condition. Specifically, the chemical durability of the glass compositions described herein are evaluated in accordance with three established material testing standards: DIN 12116 (dated March 2001, entitled "Testing of glass— Resistance to attack by a boiling aqueous solution of hydrochloric acid— Method of test and classification"); ISO 695:1911 (entitled "Glass— Resistance to attack by a boiling aqueous solution of mixed alkali— Method of test and classification"); ISO 720:1985 (entitled "Glass— Hydrolytic resistance of glass grains at 121 degrees C— Method of test and classification"); and ISO 719:1985 (entitled "Glass— Hydrolytic resistance of glass grains at 98 degrees C— Method of test and classification"). Each standard, as well as the ratings of each standard, are described in further detail herein. Alternatively, the chemical durability of the glass compositions can be evaluated in accordance with USP <660> (entitled "Surface Glass Test") and / or European Pharmacopoeia 3.2.1 (entitled "Glass Containers For Pharmaceutical Use") for evaluating the durability of a glass surface.

[0113] As used herein, the term "softening point" refers to the temperature at which the viscosity of a glass composition is 1 x 105 7.6 Poise.

[0114] As used herein, the term "CTE" refers to the coefficient of thermal expansion of a glass composition over a temperature range from about room temperature (RT) to about 300 °C.

[0115] As used herein, the term "about" means amounts, dimensions, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximated and / or larger or smaller, reflecting tolerances, conversion factors, rounding off, measurement error and other factors that are expected to occur when using tools and materials in real-world and experimental settings. When used in a context to describe a range or endpoint, the term "about" includes the specific value or endpoint referenced. Whether the end point of a range or a value in the specification is stated to be "about," both implementations are included: one modification with "about" and one without. It will also be understood that the endpoint values of each range, both in relation and in independence of the other endpoint values, are meaningful.

[0116] Directional terms as used herein - for example up, down, right, left, front, back, top, bottom - are made only with reference to the figures as drawn and not to absolute orientations.

[0117] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" component includes aspects having two or more such components unless the context clearly indicates otherwise.

[0118] Referring now to Figure 1 An embodiment of a glass container 100 for storing a pharmaceutical formulation is shown schematically in cross-section. The glass container 100 generally includes a body 102. The body 102 extends between an inner surface 104 and an outer surface 106, includes a central axis A, and generally encloses an interior volume 108. As shown in the embodiment of the glass container 100, Figure 1 In the embodiment of the glass container 100 shown, the body 102 generally includes a wall portion 110 and a floor portion 112. The wall portion 110 transitions to the floor portion 112 via a heel portion 114. In the embodiment shown, the glass container 100 includes a flange 126, a neck region 124 extending from the flange 126, a barrel 118, and a shoulder region 116 extending between the neck region 124 and the barrel 118. The floor portion 112 is connected to the barrel 118 via the heel portion 114. In embodiments, the glass container 100 is symmetrical about the central axis A, and each of the barrel 118, the neck region 124, and the flange 126 are substantially cylindrical in shape. The body 102 has a wall thickness T w extending between the inner surface 104 and the outer surface 106, as shown in Figure 1 .

[0119] In embodiments, the glass container 100 can be formed from Type I, Type II, or Type III glass as defined by USP <660>, including borosilicate glass compositions, such as Type IB borosilicate glass compositions under USP <660>. Alternatively, the glass container 100 can be formed from an alkali aluminosilicate glass composition, such as those described in U.S. Patent No. 8,551,898 (which is incorporated by reference herein in its entirety) or an alkaline earth aluminosilicate glass composition, such as those described in U.S. Patent No. 9,145,329 (which is incorporated by reference herein in its entirety). In embodiments, the glass container 100 can be constructed from a sodium calcium silicate glass composition.

[0120] While Figure 1 The glass container 100 illustrated has a particular shape form (i.e., a vial), but it should be understood that the glass container 100 can have other shape forms, including but not limited to, a syringe, a cartridge, an ampoule, a bottle, a flask, a jar, a tube, or a beaker, among others. Further, it should be understood that the glass containers described herein can be used for various applications, including but not limited to, pharmaceutical packaging or beverage containers, among others. The glass container 100 illustrated has a particular shape form (i.e., a vial), but it should be understood that the glass container 100 can have other shape forms, including but not limited to, a syringe, a cartridge, an ampoule, a bottle, a flask, a jar, a tube, or a beaker, among others. Further, it should be understood that the glass containers described herein can be used for various applications, including but not limited to, pharmaceutical packaging or beverage containers, among others.

[0121] The wall thickness T of the glass container 100 W may vary depending on the embodiment. In embodiments, the wall thickness T of the glass container 100 W may be less than or equal to 6 millimeters (mm), such as: less than or equal to 4 mm, less than or equal to 2 mm, less than or equal to 1.5 mm, or less than or equal to 1 mm. In some embodiments, the wall thickness T W may be: greater than or equal to 0.1 mm and less than or equal to 6 mm, greater than or equal to 0.3 mm and less than or equal to 4 mm, greater than or equal to 0.5 mm and less than or equal to 4 mm, greater than or equal to 0.5 mm and less than or equal to 2 mm, or greater than or equal to 0.5 mm and less than or equal to 1.5 mm. In embodiments, the wall thickness T W may be greater than or equal to 0.9 mm and less than or equal to 1.8 mm.

[0122] During the forming, shipping, and use of the glass container 100, various portions of the glass container 100 can be susceptible to surface flaws or cracks. For example, during the forming process, the glass tube can be subjected to a transformation process in which the glass tube is shaped, cut, and strengthened, thereby forming the glass container 100. The transformation process can include various processing stations in which various equipment (e.g., shaping devices, piercing devices, etc.) can come into contact with the inner surface 104 and the outer surface 106, potentially initiating flaws. In another example, in embodiments in which the glass container 100 is a pharmaceutical container, metal filling equipment can come into contact with the neck region 124 (e.g., a rotating metal disk crimp) or the heel region 114 and initiate surface flaws 120 at the outer surface 106. In another example, during shipping of the glass container 100, the outer surface at the barrel 118 can come into contact with another glass container and initiate surface flaws 122.

[0123] Various aspects of the glass container 100 can be designed to prevent or reduce the impact of flaws (e.g., surface flaws 120 and 122) on the functionality of the glass container 100. For example, see Figure 2 In embodiments, the body 102 includes a compressive stress layer 202 extending at least from the outer surface 106 of the body 102 into the wall thickness T w to a depth of compression DOC from the outer surface 106 of the body 102. The compressive stress layer 202 generally increases the strength of the glass container 100 and also improves the damage tolerance of the glass container 100. In particular, glass containers having a compressive stress layer 202 are generally able to withstand a higher degree of surface damage, such as scratches or chips, without failing as compared to an un-strengthened glass container, because the compressive stress layer 202 mitigates the propagation of cracks from the surface damage into the compressive stress layer 202.

[0124] A number of different techniques can be employed to form the compressive stress layer 202 in the body 102 of the glass container 100. For example, in embodiments where the body 102 is formed from an ion exchangeable glass, the compressive stress layer 202 can be formed by ion exchange in the body 102. In these embodiments, the compressive stress layer 202 is formed by placing the glass container in a molten salt bath to facilitate the exchange of larger ions in the molten salt with smaller ions in the glass. A number of different exchange reactions can be employed to achieve the compressive stress layer 202. In one embodiment, the bath can contain a molten KNO3salt, while the glass from which the glass container 100 is formed contains lithium ions and / or sodium ions. In this embodiment, the potassium ions in the bath exchange with the smaller lithium ions and / or sodium ions in the glass, thereby forming the compressive stress layer 202. In another embodiment, the bath can contain a NaNO3salt, while the glass from which the glass container 100 is formed contains lithium ions. In this embodiment, the sodium ions in the bath exchange with the smaller lithium ions in the glass, thereby forming the compressive stress layer 202.

[0125] In one particular embodiment, the compressive stress layer 202 can be formed by immersing the glass container in a molten salt bath of 100% KNO3or a mixture of KNO3and NaNO3. For example, in one embodiment, the molten salt bath can comprise KNO3with up to about 10% NaNO3. In this embodiment, the glass from which the container is formed can comprise sodium ions and / or lithium ions. The temperature of the molten salt bath can be greater than or equal to 350°C and less than or equal to 500°C. In some embodiments, the temperature of the molten salt bath can be greater than or equal to 400°C and less than or equal to 500°C. In other embodiments, the temperature of the molten salt bath can be greater than or equal to 450°C and less than or equal to 475°C. The glass container can be maintained in the molten salt bath for a period of time sufficient to facilitate the exchange of the larger ions in the salt bath with the smaller ions in the glass, and thereby achieve the desired surface compressive stress and layer depth. For example, the glass can be maintained in the molten salt bath for a period of time greater than or equal to 0.05 hours and less than or equal to 20 hours, to achieve the desired layer depth and surface compressive stress. In some embodiments, the glass container can be maintained in the molten salt bath for greater than or equal to 4 hours and less than or equal to about 12 hours. In other embodiments, the glass container can be maintained in the molten salt bath for greater than or equal to about 5 hours and less than or equal to about 8 hours. In one embodiment, the glass container can be ion exchanged in a molten salt bath comprising 100% KNO3at a temperature greater than or equal to about 400°C and less than or equal to about 500°C for a period of time greater than or equal to about 5 hours and less than or equal to about 8 hours.

[0126] Generally, the temperature at which the ion exchange process is performed is greater than the strain point (T 应变) low by more than 150°C, thereby minimizing stress relaxation due to the temperature increase. In some embodiments, however, the compressive stress layer 202 is formed in a molten salt bath having a temperature greater than the strain point of the glass. This type of ion exchange strengthening is referred to herein as "high temperature ion exchange strengthening." In high temperature ion exchange strengthening, smaller ions in the glass are exchanged with larger ions from the molten salt bath, as described herein. Because the exchange of the smaller ions with the larger ions occurs at a temperature above the strain point, the resulting stress is relaxed or "relaxed." However, the replacement of the smaller ions in the glass with the larger ions creates a surface layer in the glass having a coefficient of thermal expansion (CTE) lower than the remainder of the glass. As the glass cools, the difference in CTE between the surface of the glass and the remainder of the glass creates the compressive stress layer 202. This high temperature ion exchange technique is particularly useful for strengthening glass articles having complex geometries (e.g., glass containers) and generally reduces the time of the strengthening process and also achieves greater layer depth compared to typical ion exchange processes.

[0127] Referring to Figure 3 In embodiments, the glass container 100 can be formed from a layered glass that facilitates the formation of the compressive stress layer 202 at least in the outer surface 106 of the body 102. The layered glass 100 generally includes a glass core layer 204 and at least one glass cladding layer 206a. In Figure 3 In the illustrated embodiment of the glass container 100, the layered glass article includes a pair of glass cladding layers 206a, 206b. In this embodiment, the glass core layer 204 generally includes a first surface 205a and a second surface 205b opposite the first surface 205a. The first glass cladding layer 206a is fused to the first surface 205a of the glass core layer 204, and the second glass cladding layer 206b is fused to the second surface 205b of the glass core layer 204. The glass cladding layers 206a, 206b are fused to the glass core layer 204, and no additional material, such as an adhesive or coating, is disposed between the glass core layer 204 and the glass cladding layers 206a, 206b.

[0128] In Figure 3 the illustrated embodiment, the glass core layer 204 is formed from a first glass composition having an average core coefficient of thermal expansion CTE 芯 and the glass cladding layers 206a, 206b are formed from a second (different) glass composition having an average coefficient of thermal expansion CTE 包覆 In the embodiments described herein, the CTE 芯 is not equal to the CTE 包覆 such that a compressive stress layer is present in at least one of the core layer or the cladding layer. In some embodiments, the CTE 芯 is greater than the CTE 包覆This causes the glass cladding layers 206a, 206b to have compressive stress without the need for ion exchange or thermal tempering. In such embodiments, one of the cladding layers 206a, 206b can include a compressive stress layer 202 as shown in Figure 2 In some other embodiments, such as when the laminated glass includes a single core layer and a single cladding layer, the CTE 包覆 may be greater than the CTE 芯 This results in the glass core layer having compressive stress without the need for ion exchange or thermal tempering. The laminated glass can be formed from a fusion lamination process, such as the process described in U.S. Patent No. 10,450,214, which is incorporated herein by reference. When the laminated glass is used to form a container, these compressive stress layers extend from the outer surface 106 of the glass container 100 into the wall thickness T W and from the inner surface 104 of the glass container 104 into the wall thickness T W .

[0129] Referring to Figure 2 , the DOC (for which the compressive stress layer 202 extends into the wall thickness T W ) can depend on the method used to form the compressive stress layer 202. Depending on the embodiment, the compressive stress layer 202 can extend from the outer surface 106 of the body of the glass container into the wall thickness T W to a DOC that is greater than or equal to about 1 pm and less than or equal to about 90% of the wall thickness T W . In embodiments where the compressive stress layer 202 is formed as a sublayer of the laminated glass, the compressive stress layer 202 can extend from the outer surface 106 of the body 102 of the glass container into the wall thickness T W to a DOC that is greater than or equal to about 1 pm and less than or equal to about 33% of the wall thickness T W . In embodiments where the compressive stress layer 202 is formed by subjecting the glass container 100 to an ion exchange process, the compressive stress layer 202 can extend from the outer surface 106 of the body 102 of the glass container 100 into the wall thickness T W to a DOC that is greater than or equal to about 1 pm and less than or equal to about 10% of the wall thickness T W .

[0130] In embodiments, the compressively stressed layer 202 (e.g., the two outer cladding layers 206a, 206b) can be under a compressive stress greater than or equal to 50 megapascals (MPa), greater than or equal to 75 MPa, greater than or equal to 100 MPa, or even greater than or equal to 150 MPa. For example, in embodiments, the compressively stressed layer 202 can be under a compressive stress greater than or equal to 50 MPa and less than or equal to 700 MPa, greater than or equal to 50 MPa and less than or equal to 500 MPa, greater than or equal to 50 MPa and less than or equal to 400 MPa, greater than or equal to 75 MPa and less than or equal to 750 MPa, greater than or equal to 75 MPa and less than or equal to 500 MPa, greater than or equal to 75 MPa and less than or equal to 400 MPa, greater than or equal to 100 MPa and less than or equal to 700 MPa, greater than or equal to 100 MPa and less than or equal to 500 MPa, or even greater than or equal to 100 MPa and less than or equal to 400 MPa.

[0131] In embodiments, the glass container 100 is under central tension in the remaining portions of the glass container 100 outside of the compressively stressed layer 202 (e.g., with respect to the Figure 3 The core layer 204 described can be under central tension that balances the compressive stress of the compressively stressed layer 202. For example, in embodiments, the core layer 204 can exhibit a central tension or tensile stress greater than or equal to 10 MPa and less than or equal to 50 MPa, for example: greater than or equal to 10 MPa and less than or equal to 40 MPa, greater than or equal to 10 MPa and less than or equal to 30 MPa, greater than or equal to 15 MPa and less than or equal to 50 MPa, greater than or equal to 15 MPa and less than or equal to 40 MPa, or greater than or equal to 15 MPa and less than or equal to 30 MPa, as a result of the CTE mismatch between the outer cladding layers 206a, 206b. In embodiments (e.g., where the compressively stressed layer 202 is formed by subjecting the glass container 100 to ion exchange), the core layer 204 can exhibit a central tension of 10-15 MPa.

[0132] Referring back to Figure 1 Where the stored central tension in the glass container 100 is above a threshold amount (e.g., 10 MPa), surface flaws 120 and 122 of the glass container 100 that extend into the central tension can form cracks that propagate from their initiation points. The direction of propagation of cracks initiated from the surface flaws 120 and 122 can depend on the orientation of the residual stress field in the glass container 100. For example, in embodiments, the wall thickness T WThe residual tensile stress is substantially constant throughout the barrel (e.g., about 1.5 mm) and is less in the axial direction (e.g., parallel to axis A) in the barrel 118 than in the circumferential direction (e.g., perpendicular to the central axis A and to the outer surface 106 extending in the barrel 118). In such cases, the surface flaw 122 can propagate in a direction perpendicular to the direction having the higher residual tensile stress. In this example, the surface flaw 122 can propagate in the axial direction. Even when a crack originating from the surface flaw 122 extends in the axial direction through the entire glass container 100, the glass container 100 can still have the strength necessary to maintain its overall structure (e.g., remain intact).

[0133] In these cases, a user of the glass container 100 can not notice such a crack propagating in the axial direction. In addition, in use, the glass container 100 can have any number of labels (e.g., adhesive labels) disposed on the outer surface 106. Such adhesive labels can hide cracks initiated by surface flaws (e.g., surface flaws 120 and 122). A crack propagating through the glass container 100 can also branch into multiple cracks extending generally in a direction perpendicular to the direction of the maximum residual tensile stress. Such cracks can compromise the sterility of the contents of the glass container 100. To this end, it is advantageous to prevent cracks from propagating from the surface flaws 120 and 122. In addition, in cases where such cracks do not enter regions of the glass container 100 under tensile stress, it is advantageous to ensure that such cracks propagate in a manner that is detectable so that defective glass containers 100 can be quickly identified and discarded.

[0134] In view of the foregoing, in embodiments, the glass container 100 includes a crack redirection region 130 and a localized compressive stress region 140. The localized compressive stress region 140 is a region of the glass container 100 under compressive stress extending from at least one of the outer surface 106 and the inner surface 104. In the illustrated embodiment, the localized compressive stress region 140 extends from the outer surface 106 into the wall thickness T W of the glass container 100 a greater amount than a compressive stress region adjacent the localized compressive stress region 140. For example, in embodiments where the glass container includes a compressive stress layer 202 as described with respect to Figure 2 the localized compressive stress region 140 can be under compressive stress to a localized compressive depth DOC L greater than the DOC of the compressive stress layer. The deeper compressive depth of compressive stress in the localized compressive stress region 140 advantageously prevents surface flaws from reaching and propagating in the glass container 100 under residual tensile stress.

[0135] WhileFigure 1 The illustrated embodiment includes a single localized compressive stress region 140 in the heel region 114, but it is understood that embodiments involving a greater number of localized compressive stress regions and / or localized compressive stress regions located at alternative locations on the glass container 100 (e.g., in the neck region 124, the barrel 118, the shoulder region 116, or any other location on the glass container 100) are contemplated. In embodiments, the localized compressive stress region 140 is formed by applying a localized thermal strengthening process to the glass container 100, which involves heating the glass container to a particular temperature (e.g., to the softening point of the glass composition from which the glass container 100 is formed), followed by a rapid cooling step in which at least one of the inner surface 104 and the outer surface 106 is cooled by a coolant applied thereto. Various methods of forming the localized compressive stress region 140 are described in greater detail herein.

[0136] Still referring to Figure 1 , the crack redirection region 130 includes a modified residual stress field as compared to the remainder of the glass container 100 (e.g., those portions of the glass container outside of the crack redirection region 130). The modification of the stress field can be such that the residual tensile stresses in the crack redirection region 130 are greater in a direction substantially perpendicular to the desired direction of crack propagation. For example, in embodiments, it can be desirable to redirect a crack that initially propagates in an axial direction (e.g., substantially parallel to the axis A) from the surface flaw 122 toward the floor portion 112 to instead propagate in a circumferential direction in a perceivable portion of the glass container 100 (e.g., in a region of the glass container 100 not covered by an adhesive label). In such embodiments, the crack redirection region 130 can have a residual tensile stress region with higher tensile stresses extending in the axial direction (as compared to the circumferential direction) to thereby redirect the crack as desired.

[0137] The residual stress field in the crack redirection region 130 can be directionally modified with respect to the remainder of the glass container 100 in a variety of different ways. For example, in Figure 1 the illustrated embodiment, the crack redirection region 130 is a thin region in which the wall thickness T W is reduced. Such a reduction in thickness can increase the central tension in the crack redirection region 130 when the glass container is strengthened. For example, the compressive stress layer 202 (e.g., formed by an ion exchange process) can extend through a greater portion of the wall thickness T WThis results in the glass container 100 having greater central tension outside the compressive stress layer 202 to balance the compressive stress (as compared to the case in other regions of the glass container 100). The crack redirection region 130 can include any number of such thin regions arranged in any manner to produce the desired directionality in the residual tensile stress field within the crack redirection region 130.

[0138] The glass container 100 can include any number of crack redirection regions having a variety of different structures. In embodiments, the crack redirection regions are positioned such that the crack redirection occurs through a portion of the glass container 100 that is not typically covered by adhesive labels or the like, thereby increasing the visibility of cracks propagating through the glass container 100 originating from a more common initiation point. Various different crack redirection regions and methods of forming the same are described in greater detail herein.

[0139] Still referring to Figure 1 , while both the crack redirection region 130 and the localized compressive stress region 140 are shown as extending on the outer surface 106, it should be understood that in alternative embodiments, at least one of the crack redirection region 130 and the localized compressive stress region 140 can be located on the inner surface 104. Further, certain embodiments can include multiple crack redirection regions or localized compressive stress regions. In embodiments, both the outer surface 106 and the inner surface 104 contain at least one localized compressive stress region and crack redirection region.

[0140] In embodiments, the crack redirection region 130 can overlap the localized compressive stress region 140. Such an arrangement can advantageously reduce the extent to which the glass container 100 is modified to form the crack redirection region 130 such that cracks are redirected in a desired manner. In the localized compressive stress region 140, in addition to having a layer of compressive stress that extends deeper into the wall thickness T W The glass container 100 can also have a region of greater central tension that overlaps the deeper layer of compressive stress. For example, Figure 1 The illustrated embodiment shows an overlapping region 150 located between the localized compressive stress region 140 and the crack redirection region 130. That is, the overlapping region 150 contains both the crack redirection region 130 and the localized compressive stress region 140 (i.e., is subjected to the processes used to form both the crack redirection region 130 and the compressive stress region 140 as described herein). The increase in central tension near the overlapping region 150 resulting from the localized heat strengthening process used to form the localized compressive stress region 140 can reduce the need to, for example, alter the thickness of the glass container in the crack redirection region 130 to achieve the desired modification in the residual stress field. In other words, a greater wall thickness T WTo achieve the same crack redirection effect, resulting in a stronger glass article compared to the crack redirection region 130 not overlapping with the localized compressive stress region 140, while providing the same crack redirection capability.

[0141] Referring now to Figure 4A , a cross-sectional view of an embodiment of the crack redirection region 130 at line I-I in Figure 1 is shown. Figure 4A A circumferential portion of the glass container 100 at the crack redirection region 130 is shown. The crack redirection region 130 includes a recess 400 such that the thickness of the glass container 100 in the recess 400 is less than the wall thickness T W of the remainder of the barrel 118. min The minimum wall thickness T min may be determined based on the overall dimensions and composition of the glass container 100. In embodiments, the crack redirection region 130 includes a plurality of recesses 400, creating a stress field above and below (e.g., into the axial direction A) the recesses 400 that is increasing in the axial direction in the circumferential direction, such that the crack redirection propagates through the glass container 100. Figure 4A

[0142] For example, Figure 4B and 4C a cross-sectional view of an embodiment of the crack redirection region 130 at line II-II in Figure 1 is shown. As shown, the crack redirection region 130 includes a plurality of recesses 400 extending in the axial direction 402. The plurality of recesses 400 are separated by peaks 404 such that the thickness of the glass container 100 varies in the crack redirection region 130 according to a sinusoidal curve. In the crack redirection region 130, the glass container 100 has a minimum thickness T min at the trough 406 in each recess 400 and a maximum thickness T max at the peaks between the recesses 400. In embodiments, T max is equal to the wall thickness T W of the remainder of the glass container 100. In embodiments, T min is equal to the wall thickness T W of the remainder of the glass container 100. In embodiments, the average thickness of the glass container 100 in the crack redirection region 130 is equal to the wall thickness T W of the remainder of the glass container 100.

[0143] Figure 4B An axial stress profile (e.g., extending in the axial direction) of the glass container 100 in the crack redirection region 130 is shown. Figure 4C ​This shows the circumferential stress distribution (e.g., extending in a circumferential direction) of the glass container 100 in the crack redirection region 130. For example... Figure 4B As shown, in the crack redirection region 130, the axial stress distribution includes the region of maximum axial stress at the groove 406 (corresponding to a local minimum in the thickness of the glass container 100, where the thickness is equal to T in the illustrated example). min ).like Figure 4C As shown, in the crack redirection region 130, the circumferential stress distribution includes the region of maximum circumferential stress at peak 404 (corresponding to a local maximum value in the thickness of the glass container 100, where the thickness is equal to T in the example shown). max In the implementation, unlike those with a substantially uniform wall thickness T... W In the remaining portion of the glass container 100, the axial stress at the groove 406 can be greater than the circumferential stress at the peak 404 in the crack redirection region 130. Consequently, multiple points of maximum axial stress at each groove 406 supply tensile stress in the axial direction, causing the crack to redirect circumferentially through the crack redirection region 130.

[0144] According to Figure 4A , 4B The embodiment shown in 4C modifies various aspects of the crack redirection region 130, thereby altering the stress field for a specific crack redirection effect. For example, the amplitude of the redirection sine curve (e.g., T) max With T min The difference in stress direction (or the period P of the sine curve) can affect the difference in stress direction, thereby changing the propagation path of cracks originating from various initiation points on the glass container 100 (e.g., decreasing the period P can increase the tensile stress in the axial direction). It should be understood that, in some embodiments, the thickness variation in the crack redirection region 130 may not be sinusoidal, but rather include an arbitrary distribution of thickness variations with different minimum and maximum thicknesses.

[0145] See Figure 5 In one embodiment, the crack redirection region 130 may also extend circumferentially around the circumference of the glass container 100 (e.g., tangentially to the inner surface 104), so that cracks originating from any circumferential portion of the glass container 100 can be redirected via the crack redirection region 130. Figure 5 As shown, the crack redirection region 130 includes a plurality of depressions 400 extending in a sinusoidal curve in the circumferential direction, similar to those described in this paper. Figure 4A , 4B And those shown in 4C. In the embodiment, the crack redirection region 130 extends circumferentially around the entire circumference of the glass container 100. Axial cracks encountering such crack redirection regions 130 (e.g., extending axially into or out of the crack)Figure 5 The page) can be redirected such that the glass container 100 is separated, such that the glass container 100 is not available for its purpose. In embodiments, rather than a single crack redirection region 130 extending around the entire glass container 100, the glass container 100 can contain multiple discrete crack redirection regions, each extending around only a portion of the glass container 100.

[0146] Considerations are made for different locations on a glass container than the crack redirection region 130 described herein, as well as crack redirection regions having different structures. For example, Figure 6A-6H A cross-sectional view of a glass container 600 is shown having a neck region 602 and a plurality of different crack redirection regions therein. For example, Figure 6A An embodiment of a glass container 600 is shown that includes a crack redirection region 608 that includes a notch in the neck region 602. The glass container 600 has a reduced thickness in the crack redirection region 608, creating a central tension difference in the axial direction to cause an axial crack to redirect in the circumferential direction.

[0147] Figure 6B An embodiment of a glass container 600 is shown that includes a crack redirection region 610 that includes a plurality of grooves in both the inner surface 606 and the outer surface 604 of the neck region 602. Including grooves in both the inner surface 606 and the outer surface 604 can result in additional peaks in the axial stress, increasing the likelihood that a crack propagating through the crack redirection region 610 will redirect in the circumferential direction. Including grooves in both the inner surface 606 and the outer surface 604 can also reduce the overall thickness of the glass container 600 within the crack redirection region 610, which can increase the residual tensile stress difference in the axial and circumferential directions.

[0148] Figure 6C An embodiment of a glass container 600 is shown that includes a crack redirection region 612 that includes grooves in the inner surface 606 and the outer surface 604 at the transition between the neck region 602 and the shoulder region 614 of the glass container 600. Such an arrangement of grooves can place a minimum thickness at the base of the neck region 602, such that the neck region 602 can separate from the rest of the glass container 600 when in the event of a crack passing through the neck region 602. Figure 6DAn embodiment of a glass container 600 is shown including a crack redirection region 616 including a groove in the inner surface 606 and the outer surface 604 at the transition between the neck region 602 and the flange 618. Such an arrangement of a groove can place a minimum thickness at the base of the flange 618, such that the flange 618 can separate from the remainder of the glass container 600 when in the event of a crack propagating through the neck region 602 or the flange 618.

[0149] Figure 6E An embodiment of a glass container 600 is shown including a crack redirection region 620 including a rim protruding from both the inner surface 606 and the outer surface 604. Such a rim can concentrate stress during the ion exchange process of the glass container, inducing an axial difference in tensile stress. Such an embodiment can be advantageous for situations where it can be desirable to preserve the structural strength of the neck region 602 without requiring a thickness reduction region. Figure 6F An embodiment of a glass container 600 is shown including a crack redirection region 622 including a graded cavity on both the inner surface 606 and the outer surface 604 of the neck region 602.

[0150] Figure 6G An embodiment of a glass container 600 is shown including a crack redirection region 624 including a cavity on the outer surface 604 in the shoulder region 614. Such placement of the crack redirection region 624 can result in the separation of the glass container 600 at the shoulder region 614 in the event of a crack propagating axially through the barrel portion 626 of the glass container. Figure 6H An embodiment of a glass container 600 is shown including a crack redirection region 628 including an opening in the neck region 602. The opening creates two regions of minimum thickness in the crack redirection region 628 (e.g., the first between the inner surface 606 and the opening, and the second between the outer surface 604 and the opening), resulting in multiple axial peaks in the residual tensile stress therein. In embodiments, the opening can include a material having a CTE lower than the glass composition in contact with the opening, further enhancing the tensile stress.

[0151] It should be understood that any of the crack redirection regions described Figure 6G-6H may include features on the inner surface 606, on the outer surface 604, or on both the inner surface 606 and the outer surface 604. Further, any of the crack redirection regions described Figure 6G-6H may be placed at any location on the glass container 600 (e.g., in the barrel portion 626, at the heel, etc.).

[0152] In embodiments, the crack redirection region described herein can not include a change in the thickness of the glass container, but can include other features that cause a change in the residual stress field in the glass container. For example, in embodiments, the crack redirection region can be formed by a surface blockage of ions (e.g., potassium ions) during the ion exchange strengthening process, resulting in a change in the residual tensile stress in the axial direction to induce crack redirection. In another example, a density change in the glass container can be used to form the crack redirection region. A region of decreased density in the glass container can result in an increase in the depth of the compressive layer resulting from ion exchange strengthening, resulting in a region of increased tensile stress. In embodiments, the crack redirection region can be formed by subjecting a selected region of the glass container to differential annealing or cooling. For example, in certain embodiments, crack redirection can be formed by shielding a region of the glass container during an annealing heat treatment process (e.g., after the glass container is initially formed), by contacting a desired region of the glass container with a cooling tool during the transition of a stock (e.g., tube) to a glass container, or during a post heating / cooling process after bulk annealing of the glass container. Any technique that is capable of forming a region of directional residual tensile stress in a desired region of the glass container can be used to form a crack redirection region as described herein. In embodiments, the crack redirection region can be formed by localized modification of fictive temperature via flame or laser processing. In embodiments, energy from an energy source (e.g., a flame or a laser, etc.) can be incident on a location of a desired crack redirection region to locally heat. Subsequent cooling of the desired location can result in a localized density change in the glass container, resulting in a different stress profile of the glass container at the crack redirection region. Such a difference in stress profile between the crack redirection region and other regions of the glass container can be increased by subsequent chemical strengthening (e.g., via ion exchange), providing the desired crack redirection effect.

[0153] The above discussion of crack redirection regions herein primarily describes localized features in the glass container for creating a region of higher residual tensile stress extending in the axial direction of the glass container. Such localized features can extend in any direction to have the desired crack redirection effect.

[0154] For example, Figure 7A perspective view of a glass container 700 is shown, including a crack 702 propagating through the glass container 700 in an axial direction. The glass container 700 includes a crack redirection region 704 extending generally in a circumferential direction about a neck region 706 of the glass container 700. The crack redirection region 704 can include any feature (e.g., a recess, a groove, a region of reduced density). In the illustrated embodiment, however, the crack redirection region 704 does not extend directly in a circumferential direction, but rather follows a zigzag path. For example, the crack redirection region 704 can include a plurality of grooves arranged in a zigzag pattern (e.g., such that the thickness of the glass container 700 varies according to a sinusoidal curve along the zigzag pattern). Such a pattern is advantageous because a crack 702 extending in an axial direction does not intersect the crack redirection feature at a 90 degree angle. As such, the amount of adjustment required for the crack 702 to extend along the crack redirection region 704 is less than in embodiments in which the crack redirection region extends in a straight line along a circumferential direction. Such a decrease in the amount of adjustment required can better facilitate crack adjustment.

[0155] Figure 8A-8D An embodiment of a glass container 800 including a first crack redirection feature 802 is shown. The first crack redirection feature 802 can include a plurality of features (e.g., recesses) extending in a circumferential direction about a neck region of the glass container 800 such that an axial crack is redirected in a circumferential direction, as described herein. In embodiments, additional crack redirection features can be added to the crack redirection region 802 to redirect cracks extending in a variety of different directions.

[0156] For example, Figure 8B An embodiment of a glass container 800 is shown, including a crack redirection region 804 extending in a first spiral pattern. In embodiments, the crack redirection region 804 includes a plurality of features (e.g., grooves, recesses, cavities) extending along the crack redirection region 804. The first spiral pattern can be relatively tight, such that the crack redirection region 804 extends at least once around the entire circumference of the glass container between a floor portion 810 of the glass container and the crack redirection region 802. Such a pattern helps to ensure that a crack originating from any axial location within the glass container 800 encounters the crack redirection region 804 at an angle less than 90 degrees, which facilitates a perceptible redirection of the crack such that the glass container 800 can be discarded if defective.

[0157] Figure 8C An embodiment of a glass container 800 is shown, including a crack redirection region 806 extending in a second spiral pattern. In contrast to the relatively Figure 8B The second spiral pattern extends at a smaller angle relative to the axial direction than the first spiral pattern described, and generally facilitates redirection of cracks propagating in the axial direction. Figure 8DEmbodiments of glass containers 800 are shown that include a crack redirection region 808 that extends in an axial direction, thereby facilitating a crack that propagates in a circumferential direction around the glass container to be redirected in an axial direction. The crack redirection region 808 can expose a crack that would otherwise be hidden by an adhesive label disposed on an outer surface of the glass container 800.

[0158] In embodiments, a crack redirection region as described herein can be formed during a process of converting stock material (e.g., a glass tube) into a glass container. Such conversion processes are described herein with respect to, for example, Figure 9 In further detail. Figure 9 A conversion machine 900 is shown that can be used to produce glass articles from glass tubes (e.g., glass containers 100 described herein with respect to, for example, Figure 1 It should be understood that the conversion machine 900 shown is merely exemplary and is not intended to be limiting. Glass containers as described herein can be formed by any type of conversion process. The conversion machine 900 includes a base 902 having a plurality of processing stations 904, a main tower 906 disposed on the base 902 and rotatable about a central axis A relative to the base 902, and a glass tube loading tower 908 disposed above the main tower 906 for feeding glass tubes 910 to the main tower 906. The conversion machine 900 can also include a plurality of secondary processing stations 912 on the base 902, and a secondary tower 914 that is rotatable relative to the base 902.

[0159] The plurality of processing stations 904 are spaced apart from one another and arranged in a main circuit 916. In one or more embodiments, the main circuit 916 can be circular such that the main tower 906 can draw the glass tubes 910 through the plurality of processing stations 904 by rotating the main tower 906 about the central axis A. Alternatively, in other embodiments, the main circuit 916 can be linear. Although described herein with respect to a circular arrangement of processing stations 904, it should be understood that the subject matter disclosed herein can be equally well adapted to conversion machines having other arrangements of processing stations 904. Depending on the embodiment, the plurality of processing stations 904 can include any number of processing stations. The processing stations 904 can include, for example and without limitation, one or more heating, shaping, polishing, cooling, separating, piercing, re-coating, trimming, measuring, in-feeding, or out-feeding stations, or other processing stations for producing glass articles from the glass tubes 910. The type and / or shape of the articles to be manufactured from the glass tubes 910 can also affect the type of processing stations 904 and / or the order of the processing stations 904 of the conversion machine 900.

[0160] The main tower 906 includes a plurality of holders 918 configured to removably secure each glass tube 910 to the main tower 906. The holders 918 may be clamps, suction cups, or other holding devices, or combinations thereof. The holders 918 may orient each glass tube 910 component such that the glass tube 910 is substantially parallel to the central axis A of the main tower 906. The glass tube loading tower 908 may include a plurality of loading channels 920 arranged in a circular pattern and configured to accommodate the length of the glass tube 910. The glass tube loading tower 908 may be positioned such that one of the loading channels 920 is vertically aligned (i.e., parallel to the axis A). Figure 9 (The main tower 906 is aligned with the central axis A and / or the direction parallel to the Z axis) The processing station 904 of the main line 916 of the converter 900 and the corresponding loading device 918 of the traction device on the main tower 906 through the processing station 904 of the main line 916.

[0161] See now Figure 10 The diagram schematically shows a processing workstation 1000. In this embodiment, processing workstation 1000 is referred to herein in relation to... Figure 9 One of the processing workstations 904 of the converter 900. For example, in one embodiment, the processing workstation 1000 may be located in the main line 916 after the first processing workstation 904 (which is a heating workstation) and the second processing workstation 904 (which is a forming workstation). Figure 10 As shown, the partially formed glass container 1002 is fixed to the container 1004 (e.g., corresponding to the description of this article relative to...). Figure 9 (One of the aforementioned containers 918). In an embodiment, a first processing station 904 (which is a heating station) can preheat the glass tube to a target temperature (e.g., a softening point or processing point) at which the glass tube becomes malleable and can be effectively shaped without causing the glass to crack or shatter. After the glass tube is preheated, a second processing station 904 (which is a forming station, or multiple forming stations in addition to the separating station) can shape the glass tube into a partially formed glass container 1002.

[0162] After the glass tube is formed into a partially formed glass container 1002, the partially formed glass container 1002 can be subjected to an additional processing workstation 904 for reheating. In one embodiment, after the glass tube is formed into a partially formed glass container 1002, the partially formed glass container 1002 can be transferred to a processing workstation 1000 to form a crack redirection region.

[0163] like Figure 10As shown, the processing workstation 1000 includes a first laser beam source 1006 emitting a first laser beam 1008 and a second laser beam source 1010 emitting a second laser beam 1012. The processing workstation 1000 can be advantageously positioned within a converter 900 such that when the partially formed glass container 1002 arrives at the processing workstation 1000, the partially formed glass container 1002 is at an elevated temperature (e.g., above the softening point of the glass composition that forms the partially formed glass container 1002). This elevated temperature facilitates the use of lower power laser beam sources for the first and second laser beam sources 1006 and 1010. In an embodiment, the first and second laser beam sources 1006 and 1010 are CO2 laser sources emitting pulsed laser beams 1008 and 1012. Depending on the nature of the desired crack redirection region, the pulsed laser beams 1008 and 1012 can have various pulse lengths and spot sizes. For example, this can be based on the minimum thickness of the glass container in the desired crack redirection region (e.g., relative to...). Figure 4A , 4B T as described in 4C min The pulse lengths and / or power of the first and second laser beam sources 1006 and 1010 can be adjusted based on the desired thickness variation size in the crack redirection region (e.g., relative to the value). Figure 4C The period P is used (using, for example, an optical element not shown, located between laser beam sources 1006 and 1012) to adjust the spot size of the pulsed laser beams 1008 and 1012.

[0164] The second laser beam 1012 is guided to the outer surface 1014 of the partially formed glass container 1002. Thus, the second laser beam source 1010 can be used to form a recess on the outer surface 1014 (e.g., relative to this description). Figure 4A , 4BThe second laser beam 1012 can be configured to form the desired pattern of recesses 400 on the outer surface 1014 of the partially-formed glass container 1002. In embodiments, the second laser beam 1012 can be configured to form the desired pattern of recesses 400 on the outer surface 1014 of the partially-formed glass container 1002 in a single pass. In embodiments, the second laser beam 1012 can be configured to form the desired pattern of recesses 400 on the outer surface 1014 of the partially-formed glass container 1002 in multiple passes. In embodiments, the second laser beam 1012 can be configured to form the desired pattern of recesses 400 on the outer surface 1014 of the partially-formed glass container 1002 in a single pass, and the first laser beam 1008 can be configured to form the desired pattern of recesses 400 on the inner surface 1016 of the partially-formed glass container 1002 in a single pass. In embodiments, the second laser beam 1012 can be configured to form the desired pattern of recesses 400 on the outer surface 1014 of the partially-formed glass container 1002 in multiple passes, and the first laser beam 1008 can be configured to form the desired pattern of recesses 400 on the inner surface 1016 of the partially-formed glass container 1002 in multiple passes.

[0165] Still referring to FIG. 10, it should be understood that the processing station 1000 can include any number of laser beam sources, depending on the embodiment. For example, in embodiments, the processing station 1000 can include multiple laser beam sources positioned at various axial positions of the partially-formed glass container 1002 for simultaneously forming multiple crack redirection regions on the outer surface 1014 and the inner surface 1016. In embodiments, a single laser beam source can be used to simultaneously form crack redirection regions on both the inner surface 1016 and the outer surface 1014. Figure 10

[0166] Alternative processing stations for forming crack redirection regions as described herein during a transformation process are also contemplated. For example, one processing station can include a forming and shaping element that is in mechanical contact with a surface (e.g., the outer surface 1014 and the inner surface 1016) of the partially-formed glass container 1002 while the partially-formed glass container 1002 is at an elevated temperature. The forming element can have a surface that includes a first portion that conforms to the outer surface (e.g., the outer surface 1014) of the partially-formed glass container 1002 and a second portion that corresponds in shape to the desired profile of the features (e.g., recesses, ledges) of the crack redirection region. The forming element can be pressed into the partially-formed glass container 1002 at various positions to form a crack redirection region as described herein. Another alternative processing station can include a localized heat source (e.g., a laser beam, a flame) to locally modify the fictive temperature in a region of the partially-formed glass container 1002 to form a crack redirection region.

[0167] ​While the foregoing examples describe the formation of the crack redirection region described herein during the transformation process of turning a glass tube into a glass container, it should be understood that the crack redirection feature described herein can be formed at different times. For example, any crack redirection feature can also be formed after the transformation process, during the step of heating the completed glass container.

[0168] See now Figure 11 A, schematically showing relative to an exemplary embodiment Figure 1 The glass container 100 described herein includes a region 1100. Region 1100 includes a localized compressive stress region 140. In the illustrated embodiment, the glass container 100 includes a compressive stress layer 1104 extending over the entire region 1100. In this embodiment, it can be described in relation to… Figure 2 The compressive stress layer 1104 can be formed in any manner as described in the illustration of the compressive stress layer 202. In embodiments, the glass container 100 may not include the compressive stress layer 1104. For example, in larger embodiments of the glass container (e.g., defined as having an internal volume greater than or equal to 20 mL and less than or equal to 50 mL), the glass container 100 may not be chemically strengthened by ion exchange and may not include the compressive stress layer 1104, provided that the localized compressive stress region is located in a common contact area of ​​the glass container (e.g., heel region 114, neck region 124, shoulder region 116). That is, the localized compressive stress region described herein can eliminate the need for ion exchange in certain glass containers and reduce processing costs.

[0169] exist Figure 11 In the embodiment shown in A, the compressive stress layer 1104 extends from the outer surface 106 into the wall thickness of the glass container 100, reaching the first compression depth DOC1. In this embodiment, the glass container 100 is under maximum compressive stress CS at its outer surface 106. max Maximum compressive stress CS max The value can vary depending on how the compressive stress layer 1104 is formed and the composition of the glass container 100. For example, in one embodiment, the maximum compressive stress CS... max The range can be from 50MPa to 750MPa (e.g., 750MPa, 700MPa, 500MPa, 400MPa, 300MPa, 200MPa, 100MPa, 50MPa or any value in between).

[0170] exist Figure 11 At line A shown in Figure A, the residual stress distribution of the glass container 100 transitions to tension at the first compression depth DOC1. That is, the compressive stress layer 1104 extends from the outer surface 106 into the wall thickness T. WThe first compression depth DOC1 is reached. The first compression depth DOC1 can vary depending on the implementation method. For example, in an embodiment where the compressive stress layer 1104 is formed by ion exchange, the first compression depth DOC1 can be greater than or equal to about 3 μm. In some embodiments, the layer depth can be greater than or equal to about 25 μm or even greater than or equal to about 30 μm. For example, in some embodiments, the first compression depth DOC1 can be greater than or equal to about 10 μm and greater than or equal to about 200 μm. In some other embodiments, the first compression depth DOC1 can be greater than or equal to about 30 μm and less than or equal to about 150 μm. In other embodiments, the first compression depth DOC1 can be greater than or equal to about 30 μm and less than or equal to about 80 μm. In some other embodiments, the first compression depth DOC1 can be greater than or equal to about 35 μm and less than or equal to about 50 μm. In embodiments, the compressive stress layer 1104 can be formed in the cladding layer of the laminated glass. In such embodiments, the coating layer may also be subjected to ion exchange enhancement to generate a superimposed compressive stress distribution in the compressive stress layer 1104.

[0171] In this embodiment, the first compression depth DOC1 can extend from the outer surface 106 into the wall thickness T of the glass container 100. W The first compression depth DOC1 can be less than or equal to 25% of the wall thickness T. In an implementation, the first compression depth DOC1 can be less than or equal to the wall thickness T. W 2%, less than or equal to the wall thickness T W 3%, less than or equal to the wall thickness T W 5%, less than or equal to the wall thickness T W 10% less than or equal to the wall thickness T W 15% less than or equal to the wall thickness T W 20% less than or equal to the wall thickness T W 25%, or any value in between.

[0172] like Figure 11 As shown in Figure A, within the localized compressive stress region 140, the glass container 100 is under compressive stress, reaching a second compressive depth DOC2 greater than the first compressive depth DOC1 of the compressive stress layer 1104. Consequently, within the localized compressive stress region 140, the residual compressive stress extends to a greater depth than the wall thickness T. WThe localized compressive stress region 140 can also increase the depth of compressive stress within the localized compressive stress region 140 relative to the depth of compressive stress in regions of the glass container 100 outside (or adjacent to) the localized compressive stress region 140. Such greater depth of compressive stress within the localized compressive stress region 140 can increase the resistance to crack propagation of the glass container 100, given that surface flaws imparted on the outer surface 106 can branch and propagate under tensile stress. That is, the greater depth of compressive stress in the localized compressive stress region 140 effectively increases the amount of damage threshold required to cause the glass container 100 to fail. As such, the glass container 100 is effectively imparted with greater durability against contact with an external object (e.g., a capper, other glass containers, etc.) in the heel region 114 given the location of the localized compressive stress region 140 adjacent to the heel region 114 (see Figure 1 ).

[0173] In embodiments, the localized compressive stress region 140 is formed by applying a localized thermal strengthening process to a portion of the glass container 100. For example, the glass container 100 can be heated to a target temperature (e.g., to the softening point) and then rapidly cooled in a controlled manner (e.g., exposing the outer surface 106 to a coolant such as a gas or liquid). Such rapid cooling causes a surface layer of the glass container 100 exposed to the coolant to harden, while the interior of the glass container 100 is in a softer state. The cooled surface layer forms a rigid structure that prevents the interior of the glass container 100 from shrinking upon cooling, resulting in a tensile region that offsets the compressive state of the surface layer exposed to the coolant. The depth of compressive stress resulting from such a localized thermal strengthening process can be greater than what is achievable by chemical strengthening techniques such as ion exchange.

[0174] In embodiments, the stress profile of the compressive stress within the localized compressive stress region 140 can differ from the stress profile of the compressive stress outside the localized compressive stress region 140 as a result of the localized thermal strengthening process applied to the localized compressive stress region 140. In embodiments, the compressive stress in the localized compressive stress region 140 is substantially parabolic in shape, and the distance from the outer surface 106 at which the compressive stress is approximately 20% of the wall thickness T W In embodiments, the second depth of compressive stress DOC2 is greater than the first depth of compressive stress DOC1 outside the localized compressive stress region 140. In the illustrated example, the compressive stress layer 1104 overlaps (or extends through) the localized compressive stress region 140. Such a structure can result from a process in which the glass container 100 is subjected to a localized thermal strengthening process (e.g., at a temperature of approximately 600 °C) that is greater than the temperature at which the glass container 100 is subjected to a chemical strengthening process (e.g., at a temperature of approximately 400 °C). In embodiments, the compressive stress layer 1104 is formed by the chemical strengthening process, and the localized compressive stress region 140 is formed by the localized thermal strengthening process. Figure 9The cooling process station of the reformer 900 described above) to form the localized compressive stress region 140, followed by chemical strengthening via ion exchange. As a result, the outer surface 106 at the localized compressive stress region 140 can be exposed to both thermal tempering and ion exchange. In embodiments, exposure to both ion exchange and thermal tempering can result in a maximum compressive stress at the outer surface 106 being greater in the localized compressive stress region 140 than outside the localized compressive stress region 140.

[0175] While the foregoing examples include a compressive stress layer 1104 and a localized compressive stress region 140, it should be understood that various alternative embodiments are contemplated. For example, certain embodiments can not include a compressive stress layer 1104 that extends through the entire glass container 100. The localized compressive stress region 140 can also be formed via localized chemical strengthening, such that in certain embodiments, the second compressive depth DOC2may be less than 50% of the wall thickness T Figure 11 B. For example, in embodiments in which a localized ion exchange process is used to form the localized compressive stress region 140, the second compressive depth DOC2may be less than 3% (e.g., 1%, 2%, 2.5%) of the wall thickness T W The second compressive depth DOC2depends on the method used to form the localized compressive stress region 140 and can vary from greater than or equal to 2% of the wall thickness T W to less than or equal to 25% of the wall thickness T W depending on the embodiment.

[0176] Further, it should be understood that the glass containers described herein can include multiple different localized compressive stress regions at different locations. Certain embodiments of the glass container 100 can include a localized compressive stress region on the inner surface 104. Further, the crack redirection regions described herein can overlap with the localized compressive stress regions. The benefit of such a structure is that the localized thermal tempering process used to form the localized compressive stress region can work in concert with the structural changes of the crack redirection region to create a tensile stress differential in a direction perpendicular to the desired propagation direction. Such a tensile stress differential as a result of overlapping crack redirection regions and localized compressive stress regions can reduce the amount of structural (e.g., thickness) modification in the crack redirection region and preserve the structural strength of the glass container 100 while providing similar crack redirection effects.

[0177] As described herein, the localized compressive stress regions described herein can be formed via localized thermal tempering of the glass container 100. Such a process is non-trivial for glass containers as uniform cooling of complex glass shapes is typically challenging. Thermal tempering processes can rely on the application of a gas coolant to the heated glass surface to uniformly cool the glass and achieve. See, e.g., U.S. Patent No. 6, 1 12, 647, which is incorporated herein by reference in its entirety. Figure 1The glass container 100 has a complex shape (e.g., flange 126, shoulder region 116, heel region 114), making it difficult to apply such a coolant. Consequently, it is difficult to achieve the heat transfer rate required for heat strengthening of the entire glass container 100. Furthermore, heat strengthening treatment may be more effective for glass compositions with a high coefficient of thermal expansion (CTE). Conventional glass containers may be constructed from compositions incompatible with heat strengthening techniques (e.g., alkaline borosilicate glass). Some glass containers may also have a wall thickness T greater than or equal to 0.6 mm and less than or equal to 3 mm. W Due to the low heat transfer rate, conventional thermal strengthening techniques are also incompatible with this thickness.

[0178] Therefore, the glass containers described herein can be made of glass compositions more suitable for heat strengthening than those of conventional glass containers. In embodiments, the glass containers described herein have a CTE greater than or equal to 5 x 10⁻⁶. -6 ℃ -1 The glass composition comprises several methods to provide the required heat transfer rate to achieve the desired compression depth within the localized compressive stress region described herein. Firstly, by performing heat strengthening treatment only on specific areas of the glass container 100, problems arising from the geometric complexity of the glass container 100 can be avoided. Furthermore, a coolant can be applied to the glass container to increase the heat transfer rate.

[0179] Figure 12A , 12B The illustrations of 12C and 12D show the various aspects that affect the thermal strengthening efficiency of glass containers as described herein. Figure 12A The graph illustrates the relationship between surface compressive stress (e.g., at 106 on the outer surface) and the initial temperature reached by the glass container during thermal strengthening. Each curve represents the heat transfer coefficient (cal / (cm²)) during the glass cooling process. 2 *seconds*K)). In the illustrated embodiment, the glass container 100 is made of an alkaline aluminosilicate glass composition, which typically comprises a combination of SiO2 and one or more alkaline oxides (e.g., Na2O and / or K2O). The glass composition may also contain Al2O3 and at least one alkaline earth oxide. In the illustrated example, the glass container 100 has a wall thickness T of 1.1 mm. W In the example shown, the glass container 100 is not strengthened by ion exchange.

[0180] like Figure 12A As shown, the higher the heat transfer coefficient and the initial temperature, the greater the compressive stress level at the outer surface 106 in the localized compressive stress region 140. 0.2 kcal / (cm²) 2A heat transfer coefficient of *seconds*K provides a compressive stress of approximately 225MPa at 106°C on the outer surface. Conversely, 0.001 kcal / (cm²) 2 A heat transfer coefficient of *seconds*K provides a compressive stress of approximately 30 MPa at the outer surface. In an embodiment, to achieve the desired resistance to failure in the localized compressive stress region 140, the compressive stress at the outer surface 106 (e.g., relative to...) is... Figure 11 B describes CS max The pressure can be greater than or equal to 50 MPa (e.g., greater than or equal to 75 MPa, greater than or equal to 100 MPa, greater than or equal to 125 MPa, greater than or equal to 150 MPa, or greater than or equal to 200 MPa). Therefore, for the shown alkaline aluminosilicate composition, an initial temperature greater than or equal to about 750 °C can be used. Furthermore, after heating to an initial temperature of at least about 750 °C, for cooling the glass container, a pressure greater than or equal to 0.01 kcal / (cm²) can be used. 2 The heat transfer coefficient is calculated as *seconds*K.

[0181] Figure 12B The graphic representation originates from relative to Figure 12A The center tension of the heat-strengthened glass container 100 (e.g., relative to the center tension of the glass container 100) is as follows: Figure 11 Various curves in the adjacent region 1110 described in A. As shown, hot tempering to achieve the compressive stress required at the outer surface 106 also provides a central tension greater than or equal to approximately 30 MPa. Such central tension can promote crack branching and propagation if surface defects can penetrate the localized compressive stress region 140. Figure 12C Graphical display relative to Figure 12A Various curves depicting the maximum surface tensile stress occurring during the described heat strengthening process. In other words, the heat strengthening process described herein results in instantaneous tensile stress at the outer surface 106. This instantaneous tensile stress can isolate surface defects imposed on the glass container during the transformation process, eliminating defective containers. As shown, the compressive stress required by heat tempering to achieve the desired surface stress at the outer surface 106 also results in a surface tensile stress greater than or equal to approximately 40 MPa, which is sufficient to render the glass container 100 unsuitable for use in events where surface defects have been imposed on it during the transformation process.

[0182] Figure 12D The display assumes a heat transfer coefficient of 0.06 kcal / (cm²). 2 Under the condition of *seconds*K), the compressive stress at the outer surface 106 in the localized compressive stress region 140 of glass containers 100 with various thicknesses. As shown, a thicker glass container 100 generally results in a higher compressive stress at the outer surface 106. Figure 12E The display has, for example Figure 12DThe central tension in the localized compressive stress region 140 of the glass container of the specified thickness. As shown, the greater the thickness, the greater the central tension (e.g., relative to...). Figure 11 (Among the adjacent regions 1110 mentioned in A).

[0183] To achieve the desired compressive stress and depth in the localized compressive stress region 140 within the glass container 100, various coolants can be applied to the glass container 100 at the localized compressive stress region 140. In embodiments, helium, air, machine oil, and evaporative vapor have high heat transfer coefficients, making them well-suited for potential applications in the heat-strengthening processes described herein. In embodiments, the coolant can be delivered at a specific temperature to the localized compressive stress region 140 via a workpiece specifically designed for a region on the glass container 100, in which the localized compressive stress region 140 is located.

[0184] Figure 14 A and 14B schematically show a cooling device 1400 for performing the localized heat enhancement treatment as described herein. In embodiments, the cooling device 1400 may be integrated into a converter (e.g., herein relative to...). Figure 9 In the processing station of the aforementioned conversion machine 900, the glass container 100 is thermally strengthened during the process of converting the glass tube into a glass container 100. As described herein, the conversion machine 900 may include a heating station that heats the glass tube to a suitable forming temperature (e.g., a temperature greater than or equal to 870°C). Such a temperature is greater than the initial temperature (e.g., greater than or equal to 750°C) to achieve the desired level of compressive stress in the alkaline aluminosilicate glass container. Thus, placing a cooling device 1400 in the conversion machine 900 can result in high efficiency because the glass composition has already been heated to the required initial temperature; however, it should be understood that the cooling device 1400 can be separate from the conversion machine 900 and can be used after subsequent heating steps of the fully converted glass container 100.

[0185] In the illustrated embodiment, the cooling device 1400 is designed to apply a coolant to specifically cool the neck region 1404 of the glass container 1402. The cooling device 1400 includes a coolant manifold 1408 sized to contact the outer surface 1410 of the neck region 1404. The coolant manifold 1408 extends from the body 1412. The dimensions of the coolant manifold 1408 (e.g., in both the axial and circumferential directions of the glass container 1402) can correspond to the desired dimensions for placing a localized compressive stress region on the glass container 1402.

[0186] like Figure 14 As shown in Figure B, the main body 1412 includes a first part 1414 and a second part 1416. Figure 14In section B, the first portion 1414 and the second portion 1416 are separated from each other (e.g., within a processing workstation on the converter 900), thereby providing space for inserting a glass container 1402 (e.g., a glass tube or a partially formed glass container) therebetween. The first portion 1414 and the second portion 1416 can be respectively connected to brakes that facilitate displacement along an axis 1418 perpendicular to the glass container 1402. For example, once the glass container 1402 is positioned in the desired axial position (such that the cooling device 1400 axially overlaps with the region of the glass container 1402 where localized compressive stress is desired to be integrated), the first and second portions 1414 and 1416 can be displaced toward each other until the minimum separation distance required for the inner surfaces 1420 and 1422 of the cooling device 1400 to separate from the outer surface 1410. Figure 14 In the embodiment shown in B, the cooling device 1400 can surround the glass container 1402 to impart a localized compressive stress region extending around the entire glass container 1402 in the neck region 1404.

[0187] In the implementation method, such as Figure 14 As shown in Figure A, the cooling device includes contact points 1424 and 1426, which control the precision of the minimum separation distance between the cooling device 1400 and the outer surface 1410. In one embodiment, contact points 1424 and 1426 may include pressurized gas points (e.g., coolant or other gases originating from the coolant inlet 1430). In another embodiment, contact points 1424 and 1426 may include wheels or other rotatable elements to aid in the placement of the cooling device 1400 on the glass container 1402. In yet another embodiment, contact points 1424 and 1426 may include rims extending from the coolant manifold 1408 (e.g., made of the same or different material as the body 1412) to provide a controlled minimum separation distance. As the first and second portions 1414 and 1416 are displaced toward each other, contact points 1424 and 1426 may contact the outer surface 1410 to create a coolant cavity 1428 disposed between the coolant manifold 1408 and the outer surface 1410. The main body 1412 includes a coolant inlet 1430 extending therethrough. In one embodiment, the coolant inlet 1430 fluidly connects the coolant chamber 1428 to a coolant source (not shown). Coolant (e.g., water vapor, helium, air, oil) from the coolant source can be supplied through the coolant inlet 1430 into the coolant chamber 1428, thereby allowing the coolant to contact the glass container 1402 to increase the heat transfer coefficient achieved via the cooling device 1400.

[0188] The body 1412 also includes a fluid passage 1432 extending therethrough. The fluid passage 1432 can receive a cooling fluid from a fluid source (not shown) to thereby reduce the temperature of the cooling apparatus 1400. By sizing various components of the cooling apparatus 1400 (e.g., the coolant manifold 1408, the body 1412) in a manner corresponding to a particular location on the glass container 1402, intimate contact between the glass container 1402 and the cooling apparatus 1400 can be achieved, thereby providing a high enough heat transfer coefficient to induce compressive stress in the glass container 1402. That is, by tailoring the heat strengthening process for a sub-region on the container, the intimate contact and coolant application of the sub-region provides a high heat transfer rate for efficient heat strengthening in the localized compressive stress region.

[0189] While the foregoing examples described with respect to Figure 14 A and 14B adjust the neck region of the glass container 1402. It should be understood that similar sizing and configurations can be used for various other locations, depending on the type of glass container being strengthened. Several other regions where it can be desirable to integrate a localized compressive stress region include, but are not limited to, the heel region of a bottle (e.g., the heel region 114 described herein with respect to Figure 1 A and 14B), the foot region of a barrel, the neck region of a syringe, the flange of a syringe, or anywhere in a glass container. In embodiments, the glass container can include multiple localized compressive stress regions. In such embodiments, the multiple localized compressive stress regions can be formed in a single processing step (e.g., a single cooling apparatus can include multiple axial portions, each portion designed to intimately contact a sub-region of the container) or in separate processing steps. For example, each processing step can include a cooling apparatus similar to the cooling apparatus 1400 described with respect to Figure 14 A and 14B, designed to provide intimate contact with a separate region of the glass container. In embodiments, the separate processing steps to form each localized compressive stress region can be separated by a heating step that reheats the glass container to an initial temperature required for the heat strengthening process.

[0190] Different cooling apparatuses than Figure 14Alternative methods to the cooling equipment shown in A and 14B are used for the localized heat strengthening process described herein. For example, the designated application of coolant to specific areas of the glass container can be used to create localized compressive stress regions. Such embodiments may include a coolant applicator that applies coolant to the glass container in a desired pattern without contacting it to achieve the desired cooling effect. For example, the coolant may include a condensing coolant (e.g., snow) or similar applications that can be controlled to various areas (e.g., the inner and outer surfaces of the glass container). In such embodiments, water, steam, air, oil, and various other potential coolants can be used. In embodiments, the amount of coolant circulated to contact the glass container (e.g., determined by controlling the coolant supply inlet) and / or the amount of coolant evaporated after contact with the glass container (e.g., determined by the cooling effect of the coolant used) can control the heat transfer rate. In embodiments, controlled cooling of the glass container for heat strengthening can be combined with other aspects of the conversion process to provide further processing efficiency. For example, in one embodiment, the forming equipment (e.g., having a shape that comes into contact with the glass container at the forming temperature to form the glass container) may have an integrated coolant inlet, allowing coolant to be supplied to the forming area while the area is being formed, thereby thermally strengthening that area. In such embodiments, oil may be used to establish the contact surface between the forming equipment and the glass container, so that the contact surface of the glass container is simultaneously formed and cooled.

[0191] It should also be understood that the localized compressive stress region described herein can also be located on the inner surface of the outer container. For example, when the glass container is transported via this method relative to... Figure 14 When the cooling equipment described in A and 14B is subjected to heat strengthening, the inner surface 1434 of the glass container 1402 (see...) Figure 14 B) Convective cooling can be achieved via airflow through a processing workstation in which cooling equipment 1400 is integrated, resulting in a degree of thermal tempering. In embodiments, the method of cooling the inner surface 1434 may differ from that of the outer surface 1410. For example, in one embodiment, a region of the outer surface 1410 is thermally strengthened by cooling equipment 1400, while a region of the inner surface 1434 is thermally strengthened by applying a controlled coolant (e.g., snow). In another embodiment, the strengthened regions of the outer surface 1410 and the inner surface 1434 may overlap (e.g., be opposite each other) to provide a balanced distribution of compressive stress and increased central tension, thereby contributing to crack branching in events where surface defects in the glass container 1402 exceed a threshold amount. For example, the bottom of the container may be externally and internally cooled to provide such a balanced stress distribution, thereby ensuring separation in events involving bottom surface defects.

[0192] Referring now to Figure 15, a flowchart of a forming method 1500 for a glass container including at least one crack redirection region or a localized compressive stress region is shown. Method 1500 can be used to form a glass container as described herein. Figure 1 The glass container 100 described herein. Performing method 1500 can result in the localization of the glass container in desired areas where defects may propagate via localized thermal strengthening processes as described herein. Furthermore, a glass container derived from performing method 1500 can redirect cracks propagating in portions of the container that are difficult for the user to detect, allowing the user to notice such cracks and discard the cracked container.

[0193] In step 1502, a stock for forming the glass composition is provided. The composition of the glass article can vary depending on the practice. As described herein, a glass container incorporating a crack redirection region can provide a region of increased center tension resulting from CTE mismatch due to ion exchange strengthening. Thus, embodiments incorporating a crack redirection region can be formed from a glass composition capable of chemical strengthening via ion exchange. In embodiments, the glass composition is an alkaline aluminosilicate glass composition, which typically comprises a combination of SiO2 and one or more alkaline oxides (e.g., Na2O and / or K2O). The glass composition may also contain Al2O3 and at least one alkaline earth oxide. In embodiments, a borosilicate glass composition or other aluminosilicate compositions may be used. In embodiments, the stock for forming the glass composition may comprise a glass tube formed from the glass composition. The glass tube may be produced using the Vello process (e.g., the process described in U.S. Patent No. 4,023,953). Other processes (e.g., the Danner process) may be used to produce the glass tube.

[0194] In step 1504, the stock is formed into a glass container having a body. It should be understood that the processing steps used to form the glass container may vary depending on the stock and the shape of the glass container formed from it. For example, in embodiments, the stock can be transformed into glass containers of various shapes, such as bottles, vials, syringes, ampoules, tubes, and other glass articles for pharmaceutical applications. The stock can also be transformed into glass containers for uses other than pharmaceutical applications, such as food packaging. In embodiments, a conversion machine (e.g., as described herein) can be used. Figure 9The forming steps are performed in the converter 900 described herein. As described herein, the converter 900 includes a plurality of processing workstations 904, including, for example, one or more heating, forming, polishing, cooling, separating, piercing, recoating, trimming, measuring, feeding, or discharging workstations, or other processing workstations for producing glass articles from glass tubes. In an embodiment, the stock is heated to a forming temperature above the softening point of the glass composition via a heating workstation among the plurality of processing workstations 904. After heating, the stock may undergo multiple different forming workstations to form the stock into the desired glass container. For example, for a glass container that is Figure 1 In the case of the bottle, various forming workstations can be used to form the flange 126, neck region 124, shoulder region 116, barrel 118, and heel region 114 of the glass container 100. After forming and subsequent steps (e.g., measuring, polishing, coating), the formed glass container can be separated from the storage via a separation (e.g., scribing) workstation.

[0195] In step 1506, crack redirection is formed in the glass container. As described herein, crack redirection regions can be formed at various points during the process of converting the stock into a glass container, or they can be formed after the conversion process is complete. For example, in an embodiment, the conversion machine 900 includes a forming station that forms at least one crack redirection region in the glass container while heating the stock to a temperature above the forming temperature of the glass composition. For example, in an embodiment, the conversion machine 900 may include, as described herein, […]. Figure 10 The processing workstation 1000. At least one of the first laser beam source 1006 and the second laser beam source 1010 can scan a laser beam (e.g., a pulsed CO2 laser beam) on the surface of the storage material to form a plurality of recesses on the surface of the storage material, such that the glass container derived from the conversion process includes a plurality of recesses, wherein the glass container has a minimum thickness T. min Its thickness is less than the wall thickness T of the glass container outside the crack redirection region. W .

[0196] In implementations, the crack redirection region can be formed simultaneously with or after the formation of the localized compressive stress region. For example, as described herein, the crack redirection region can be formed by creating a region of decreased density within the glass container through heat treatment that exposes the crack redirection to a heat treatment different from that of the remainder of the glass container. Thus, in implementations, a method similar to that described herein can be used... Figure 11The thermal strengthening steps described in A-14B create crack redirection regions. For example, a cooling device can contact the storage material in such a way that it generates a tensile stress difference substantially perpendicular to any desired propagation direction (e.g., axial, circumferential, or any combination thereof). In another example, regions of decreased density can be formed by shielding the glass container during an annealing step following the formation of the glass container (e.g., during step 1510).

[0197] In embodiments, crack redirection regions can be formed during the chemical strengthening process of the glass container (e.g., during step 1512 described herein). For example, in addition to creating one or more features on the surface of the storage material during the transformation process, various portions of the crack redirection regions can impede the ion exchange process to create a complex central tension distribution for crack redirection. In embodiments, any combination of features and their formation methods can be used to form any number of crack redirection regions on the glass container.

[0198] In step 1508, a localized compressive stress region is formed in the glass container. In an embodiment, the localized compressive stress region is formed during the process of converting the storage material into a glass container. For example, in an embodiment, after passing through the heating station of the converter 900 and being heated to the initial temperature, the storage material can be inserted into the container containing the contents described herein. Figure 14 In the heat-enhancing workstation of the cooling device 1400 described in A and 14B, the cooling device 1400 can be specifically designed such that its surface corresponds to the outer surface of the storage material, thereby providing close contact between the outer surfaces at the desired location of the localized compressive stress region to enhance the heat transfer rate. Furthermore, the cooling device 1400 can supply coolant to the coolant chamber 1428 on the surface of the storage material via the coolant inlet 1430, thereby controllingly and rapidly cooling the storage material to create a localized compressive stress region having a compression depth greater than any region of the storage material adjacent to the localized compressive stress region. Alternative methods can be used to cool the storage material. For example, a different coolant (e.g., oil, snow, etc.) can be applied to a portion of the storage material to form a localized compressive stress region at the desired location on the glass container. In an embodiment, the localized compressive stress region can be formed after the glass container is formed, wherein the newly formed glass container is subsequently heated to the desired initial temperature and rapidly cooled via any of the methods described herein.

[0199] In embodiments, the crack redirection region can overlap with the localized compressive stress region. For example, a crack redirection region comprising a plurality of indentations can be subsequently subjected to a localized thermal strengthening treatment as described herein. Such practice can increase the central tension in the crack redirection region (as compared to embodiments in which the localized compressive stress region does not overlap with the crack redirection region), thereby enhancing the crack redirection capability of the crack redirection region. Further, the glass container can comprise any number of crack redirection regions and localized compressive stress regions on the interior surface, the exterior surface, or both the interior and exterior surfaces.

[0200] In step 1510, an additional heat treatment is formed on the glass container. For example, after the glass container is formed, the glass container can be subjected to an annealing step. Such an annealing step can remove thermal tempering residual stresses induced during the transformation process in the glass container. In embodiments in which the localized compressive stress region is integrated in a region of the glass container comprising such residual stresses, such an annealing step can not be necessary for the glass container because the region of the glass container that is most subject to failure can have improved failure protection. Further, as described herein with respect to Figure 12C the heat strengthening treatment described herein can induce temporary tensile stresses in the localized compressive stress region during its formation. Such temporary tensile stresses can induce failure in a defective glass container. That is, only the more robust glass containers that are free of flaws can survive the heat strengthening treatment, reducing the need for an annealing step.

[0201] In embodiments, the glass container can be subjected to a flame cleaning after the transformation process. Such a flame cleaning step can remove or reduce surface flaws on the glass container that originate from the transformation process. In embodiments, such a flame cleaning step can be performed prior to forming the localized compressive stress region in step 1508, thereby removing flaws that can have propagated as a result of the temporary tensile stresses induced by the heat strengthening treatment used to form the localized compressive stress region.

[0202] In step 1512, the glass container can be subjected to a chemical strengthening treatment. In embodiments, the glass container can be ion exchanged strengthened while immersed in a molten salt bath. Such ion exchange strengthening can form a compressive stress layer (e.g., the compressive stress layer 202 described herein with respect to Figure 2 After the chemical strengthening step, the crack redirection region described herein can have a tensile stress profile that balances out the compressive stresses induced via the chemical strengthening step, with a stress differential in a direction normal to the desired propagation direction. In embodiments in which the localized compressive stress region is integrated, the chemical strengthening step can be eliminated because the glass container can have sufficient durability for use as a result of the localized compressive stress region.

[0203] Based on the foregoing, it should be appreciated that the integration of at least one of a crack redirection region and a localized compressive stress region in a glass container advantageously improves the durability of the glass container and / or improves the visibility of a crack propagating through the glass container. The crack redirection region can direct a crack originating from a common location of surface flaws on the container to a region of the glass container that does not contain a visual obstruction (e.g., a cling label, etc.), such that a user of the glass container can notice the crack and discard the defective glass container before the product contained therein is contaminated. The localized compressive stress region advantageously increases the damage threshold of a glass flaw propagating through the glass container at a region of routine contact with external elements (e.g., a filling apparatus, other glass containers, a carrier), and makes the glass container more durable. As such, the glass containers described herein have improved durability over existing glass containers, and in the event of a crack propagating through the glass container, such a crack is redirected to a portion of the container that can be more quickly noticed (as compared to a crack propagating through an existing glass container).

[0204] Unless specifically stated otherwise, any method described herein is not constrained to being performed in a particular order, nor is it required that any apparatus have a particular orientation. Thus, if a method claim does not actually recite a step order, or if an apparatus claim does not actually recite an order of components or an order or orientation of steps, no order or orientation should be inferred. This same principle applies to any possible non- explicitly stated interpretation of any claim limitation, including: logical progression of steps, general meaning of components, and number or kinds of embodiments described in the specification.

[0205] 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 modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. A method of making a glass container having a first surface and a second surface separated by a thickness, the method comprising: forming a first region in compression stress on the first surface of the glass container, wherein the first region extends from the first surface to a depth of compression in the glass container; forming a second region in central tension extending into the thickness from the depth of compression, wherein the central tension is sufficient to cause self-propagation of a crack at the first surface from a point of initiation of the crack; and forming a crack redirection region in the first surface, wherein: the crack redirection region extends in a predetermined propagation direction of the crack, the crack redirection region contains central tension higher than a remainder of the glass article in a direction substantially perpendicular to the predetermined propagation direction, such that upon propagation of the crack and arrival at the crack redirection region, the crack is redirected along the predetermined propagation direction, the glass container comprises a body having an inner surface and an outer surface, the inner surface defining an interior volume having an axis, wherein the predetermined propagation direction is substantially perpendicular to the axis, and the thickness of the glass container varies within the crack redirection region, such that the crack redirection region comprises a thin region extending substantially parallel to the axis where the thickness is less than an average thickness of the glass container within the crack redirection region.

2. The method of claim 1, wherein, the crack redirection region extends around at least a portion of a periphery of the glass container.

3. The method of claim 2, wherein, the thickness of the glass article varies in the crack redirection region in a sinusoidal manner parallel to the axis.

4. The method of claim 2, wherein, the crack redirection region extends around an entire periphery of the glass container.

5. The method of claim 1, wherein, the first surface is an outer surface of the glass container.

6. The method of claim 1, wherein, the first surface is an interior of the glass container.

7. The method of claim 1, wherein, forming the first and second regions comprises: forming the glass container from a glass composition; and forming the first region and the second region by subjecting the first surface of the glass container to a chemical tempering.

8. The method of claim 7, wherein, forming the glass article from a glass composition comprises: forming a glass tube comprising the glass composition; and transforming the glass tube into the glass container, wherein the crack redirection region is formed during the transformation of the glass tube into the glass container.

9. The method of claim 8, wherein, forming the crack redirection region comprises scanning a pulsed laser beam in a predetermined pattern while heating the glass tube to a softening temperature of the glass composition during the transformation of the glass tube into the glass container.

10. A method of forming a glass container having a crack redirection region, the method comprising: providing a stock formed from a glass composition, the stock comprising a glass tube; transforming the glass tube into a glass article having a body extending between an inner surface defining an interior volume and an outer surface; forming a compressive stress layer in the glass article extending from at least one of the inner surface and the outer surface to a depth of compression in the thickness of the body; and forming a crack redirection region in the glass article, wherein the crack redirection region comprises a sub-region having a central tension higher than a remainder of the glass article, wherein the sub-region extends in a direction substantially perpendicular to a predetermined propagation direction and the thickness of the sub-region is less than an average thickness of the body, wherein forming the crack redirection region comprises forming the sub-region of the crack redirection region during the transformation of the glass tube into the glass article, and The forming the sub-region includes contacting the glass tube with a shape element during a process of converting the glass tube into the glass article.

11. The method of claim 10, wherein, The forming the sub-region includes scanning a pulsed laser beam in a predetermined pattern on the glass article.

12. A glass container comprising: a glass body comprising a first region extending from a surface of the glass body to a depth of compression and a second region extending from the depth of compression into a thickness of the glass body, the second region being under a tensile stress sufficient to cause self-propagation of a crack from a crack initiation point in a propagation direction; and A crack redirection region on a surface of a glass body, the crack redirection region extending in a predetermined propagation direction of a crack, wherein, the tensile stress comprised by the crack redirection region is greater than the tensile stress within the second region in a sub-region of the crack redirection region, the sub-region extending substantially perpendicular to the predetermined propagation direction, such that upon the crack propagating into the crack redirection region, the crack is redirected along the predetermined propagation direction, wherein the predetermined propagation direction is a circumferential direction substantially perpendicular to an axis of the glass container, and wherein the thickness is varied within the crack redirection region, such that the sub-region of the crack redirection region comprises a thin region extending substantially parallel to the axis, where the thickness is less than an average thickness of the glass article.

13. The glass container of claim 12, wherein, The glass container comprises one of: a bottle, a vial, an ampoule, a syringe, or a cartridge.

14. A glass container produced by the method of any one of claims 1 to 13, the glass container comprising: a body comprising a glass composition, the body having an inner surface, an outer surface, and a wall thickness extending between the inner surface and the outer surface, wherein, the body comprises a localized compressive stress region having a localized compressive stress extending from an outer surface to a localized depth of compression within the body, wherein: the localized compressive stress region extends deeper into the body than any region of compressive stress adjacent to the localized compressive region.

15. The glass container of claim 14, wherein, The glass container comprises a pharmaceutical container.

16. The glass container of claim 14, wherein, The localized depth of compression extends greater than or equal to 2% of the wall thickness and less than or equal to 25% of the wall thickness.

17. The glass container of claim 16, wherein, The localized depth of compression extends greater than or equal to 20% of the wall thickness and less than or equal to 25% of the wall thickness.

18. The glass container of claim 14, wherein, The localized compressive stress region comprises a compressive stress greater than or equal to 50 MPa.

19. The glass container of claim 15, wherein, The localized compressive stress region comprises a surface compressive stress greater than or equal to 75 MPa.

20. The glass container of claim 16, wherein, The surface compressive stress is greater than or equal to 100 MPa.

21. The glass container of claim 14, wherein, The localized compressive stress region overlaps a compressive stress layer of the glass container under a compressive stress, such that in the localized compressive stress region, the body comprises a compressive stress of the compressive stress layer to a first depth of compression and a localized stress from the first depth of compression to the localized depth of compression.

22. The glass container of claim 14, wherein, The glass composition comprises an aluminosilicate glass composition.

23. The glass container of claim 14, wherein, The glass container comprises a vial having a base, a barrel connected to the base via a heel, a shoulder extending from the barrel, and a neck extending from the shoulder, wherein the localized compressive stress region is disposed in at least one of the neck, the heel, and the barrel.

24. The glass container of claim 14, further comprising an additional localized compressive stress region having an additional localized compressive stress extending from an inner surface to an additional localized depth of compression within the body.

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