Stress features for crack redirection and protection in glass containers

A method of forming a glass container having a crack re-direction region, the method comprising:

• providing a stock material formed from a glass composition, the stock material comprising glass tubing;
• converting the glass tubing into a glass article having a body extending between an interior surface and an exterior surface defining an interior volume;
• forming a compressively stressed layer in the glass article, the compressively stressed layer extending from at least one of the interior surface and the exterior surface to a depth of compression in a thickness of the body;
• and
• forming the crack re-direction region within the glass article, wherein the crack re-direction region comprises a sub-region having a higher central tension 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 re-direction region comprises forming the sub-region of the crack re-direction region during the converting of the glass tubing into the glass article, and
• wherein forming the sub-region comprises contacting the glass tubing during the conversion of the glass tubing into the glass article with a shaping element.

A glass container comprising:

• a glass body comprising a first region under a compressive stress 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 under a tensile stress sufficient for self-propagation of a crack from an origination point of the crack in a propagation direction;
• and
• a crack re-direction region on the surface of the glass body, the crack re-direction region extending in a predetermined propagation direction for the crack, wherein the crack re-direction region comprises a greater tensile stress than the tensile stress in the second region in a sub-region of the crack re-direction region, the sub-region extending substantially perpendicular to the predetermined propagation direction such that, upon the crack propagating into the crack re-direction 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 varies within the crack re-direction region such that the sub-region of the crack re-direction region comprises a thin region extending substantially parallel to the axis where the thickness is less than an average thickness of the glass article.

A method of forming a glass container, the method comprising:

• providing a stock material formed from a glass composition;
• shaping the stock material into a glass article having a body extending between an interior surface and an exterior surface, the body defining an interior volume;
• forming a crack re-direction region within the glass article, wherein the crack re-direction region comprises a sub-region having a higher central tension than a remainder 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 interior surface or the exterior surface to a localized depth of compression within the body, wherein the localized depth of compression is greater than or equal to 2% of a thickness of the body and less than or equal 25% of the thickness of the body, wherein forming the localized compressive stress region comprises locally applying a coolant 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.