Methods are provided for measuring the asymmetry of glass-sheet manufacturing processes. The methods include subjecting glass sheets or test samples taken from glass sheets to an ion-exchange process and measuring warp values. Metrics for the asymmetry of the glass-sheet manufacturing process are then obtained from the warp values. In one embodiment, the metric is independent of the geometry of the glass sheets or the test samples (the BM.sub.1 metric); in another embodiment, the metric is independent of the geometry of the glass sheets or the test samples and substantially independent of the ion-exchange process used in the testing (the ASYM metric).

A method of making a glass having antimicrobial properties and high compressive stress. The method includes a first ion exchange step in which potassium cations are exchanged for sodium cations in the base glass to provide a surface layer under compressive stress, followed by a second ion exchange in which silver cations are exchanged for potassium and lithium ions in the glass to produce the antimicrobial glass. In some embodiments, the antimicrobial glass has a maximum compressive stress that is at least 80% of the maximum compressive stress obtained by the potassium-for-sodium exchange in the first bath. A base glass and an ion exchanged glass antimicrobial having antimicrobial properties are also provided.

A glass article including at least about 40 mol % SiO.sub.2 and, optionally, a colorant imparting a preselected color is disclosed. In general, the glass includes, in mol %, from about 40-70 SiO.sub.2, 0-25 Al.sub.2O.sub.3, 0-10 B.sub.2O.sub.3; 5-35 Na.sub.2O, 0-2.5 K.sub.2O, 0-8.5 MgO, 0-2 ZnO, 0-10% P.sub.2O.sub.5 and 0-1.5 CaO. As a result of ion exchange, the glass includes a compressive stress (σ.sub.s) at at least one surface and, optionally, a color. In one method, communicating a colored glass with an ion exchange bath imparts σ.sub.s while in another; communicating imparts σ.sub.s and a preselected color. In the former, a colorant is part of the glass batch while in the latter; it is part of the bath. In each, the colorant includes one or more metal containing dopants formulated to impart to a preselected color. Examples of one or more metal containing dopants include one or more transition and/or rare earth metals.

Glass-ceramics and precursor glasses that are crystallizable to glass-ceramics are disclosed. The glass-ceramics of one or more embodiments include rutile, anatase, armalcolite or a combination thereof as the predominant crystalline phase. Such glasses and glass-ceramics may include compositions of, in mole %: SiO.sub.2 in the range from about 45 to about 75; Al.sub.2O.sub.3 in the range from about 4 to about 25; P.sub.2O.sub.5 in the range from about 0 to about 10; MgO in the range from about 0 to about 8; R.sub.2O in the range from about 0 to about 33; ZnO in the range from about 0 to about 8; ZrO.sub.2 in the range from about 0 to about 4; B.sub.2O.sub.3 in the range from about 0 to about 12, and one or more nucleating agents in the range from about 0.5 to about 12. In some glass-ceramic articles, the total crystalline phase includes up to 20% by weight of the glass-ceramic article.

An antioxidant combined with UHMWPE prior to subjecting the UHMWPE to crosslinking irradiation. In one exemplary embodiment, the antioxidant is tocopherol. After the antioxidant is combined with the UHMWPE, the resulting blend may be formed into slabs, bar stock, and/or incorporated into a substrate, such as a metal, for example. The resulting product may then be subjected to crosslinking irradiation. In one exemplary embodiment, the UHMWPE blend is preheated prior to subjecting the same to crosslinking irradiation. Once irradiated, the UHMWPE blended product may be machined, packaged, and sterilized in accordance with conventional techniques.

Glass-ceramics and precursor glasses that are crystallizable to glass-ceramics are disclosed. The glass-ceramics of one or more embodiments include rutile, anatase, armalcolite or a combination thereof as the predominant crystalline phase. Such glasses and glass-ceramics may include compositions of, in mole %: SiO.sub.2 in the range from about 45 to about 75; Al.sub.2O.sub.3 in the range from about 4 to about 25; P.sub.2O.sub.5 in the range from about 0 to about 10; MgO in the range from about 0 to about 8; R.sub.2O in the range from about 0 to about 33; ZnO in the range from about 0 to about 8; ZrO.sub.2 in the range from about 0 to about 4; B.sub.2O.sub.3 in the range from about 0 to about 12, and one or more nucleating agents in the range from about 0.5 to about 12. In some glass-ceramic articles, the total crystalline phase includes up to 20% by weight of the glass-ceramic article.

An ion exchangeable glass having a high degree of resistance to damage caused by abrasion, scratching, indentation, and the like. The glass comprises alumina, B.sub.2O.sub.3, and alkali metal oxides, and contains boron cations having three-fold coordination. The glass, when ion exchanged, has a Vickers crack initiation threshold of at least 10 kilogram force (kgf).

Disclosed are alkali aluminosilicate glasses having unexpected resistance to indentation cracking. The glasses obtain this high resistance as a result of a high level of surface compression accompanied by a shallow depth of layer. The advantaged glasses show greater resistance to radial crack formation from Vickers indentation than glasses with the same compressive stress, but higher depths of layer.

A strengthened glass sheet product as well as process and an apparatus for producing the product. The process comprises cooling the glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened glass sheets having improved breakage properties.

Described herein are various antimicrobial glass articles that have improved strength and resistance to discoloration. The improved antimicrobial glass articles described herein generally include a glass substrate with a compressive stress layer and an antimicrobial silver-containing region that each extend inward from a surface of the glass substrate to a specific depth. In some embodiments, the compressive stress layer has a compressive stress at the surface of about 500 MPa or greater and the compressive stress decreases monotonically from the surface into the depth of the glass substrate. Methods of making and using the glass articles are also described and include forming a compressive stress layer and forming an antimicrobial silver-containing region by preferentially exchanging a plurality of silver cations in a silver-containing medium for a specific plurality of first cations ions in the glass substrate.