Abstract: A method for imparting increased mechanical strength to a glass object having imperfections in a surface thereof. The glass object is heated to a temperature above the strain point of the glass. A laser beam is generated having a wavelength absorbable by the glass and impinged on all portions of the surface containing the imperfections. The power density at which the beam is impinged is sufficient to rapidly heat a surface stratum of the glass to establish a thermal gradient therein whereby the viscosity at a depth from the surface sufficient to encompass the imperfections is low enough that the stress induced by the surface tension of the glass at the sites of the imperfections is sufficient to cause flow of glass and effect a reforming of the glass surface at said sites.

Abstract: A process for strengthening a glass object by chemical reaction at the glass surface of the object between the glass and a chemical strengthening agent reactive with the glass to alter its composition and thereby either directly generate compressive stress therein or reduce the thermal expansion coefficient thereof. The object is kinetically contacted with the chemical strengthening agent in a bed comprising gas-fluidized particulate solid material under conditions of temperature and active fluidization such that the reaction proceeds but the formation of either stress-concentrating surface defects or an adherent coating of solid material on the surface of the object is substantially avoided. The object is maintained in the bed for a time sufficient for the reaction to alter the composition of a marginal stratum of the object adjacent the surface. The object is thereafter cooled, producing an object of increased strength and toughness having the marginal stratum under compressive stress.

Abstract: A container having a high mechanical service strength and shatter resistance comprises a glass container body and an overlying containment coating constituted by a plastic film. The mechanical properties of the film are such that, when subjected to tensile testing at a film extension rate of 10 in./min., the film exhibits a tensile strength of at least about 300 lbs./sq. in., an elongation of at least about 80%, and a modulus of elasticity in tension of not more than about 1,000 lbs./sq. in. throughout the course of the extension of the film.

Abstract: A containment coating for glass containers. The composition includes a principal film-forming constituent comprising an acrylate latex containing a particulate resin comprising a copolymer of acrylonitrile and ethyl acrylate. The coating also contains at least one additional latex whose presence enhances the containment properties of the film after curing. Two such auxiliary latexes exhibit this capability and the coating composition contains either or both of them. One of these is a vinyl latex whose resin solids comprise a copolymer of ethylene and vinyl acetate. The other is a vinyl/acrylic latex whose resin solids comprise a copolymer of vinyl acetate and a lower alkyl acrylate. Hexamethoxymethylmelamine or a methylated urea-formaldehyde resin is included as a cross-linking agent and either polyacrylamide or a high molecular weight water-soluble polyethylene oxide resin is present as a thickener and a thixotrope.