A system for levitating a softened, viscous or viscoelastic material by near field acoustic levitation. The system includes a support structure having a rigid surface, and a vibration generator operatively connected to the rigid surface. The vibration generator transmits acoustic waves to the rigid surface at a frequency and an amplitude sufficient to vibrate the rigid surface and create a gas squeeze film between the material and the rigid surface. The gas squeeze film has a pressure greater than ambient air pressure and sufficient to levitate the material. The system is particularly suited for transporting, forming, or casting heated glass. Also disclosed are methods for transporting, forming, and casting heated glass using near field acoustic levitation.

Systems and methods for texturing substrates (e.g., glass, metal, and the like) and the textured substrates produced using such systems and methods are disclosed. An exemplary textured substrate includes a surface having a portion with a root-mean-square roughness between 40 to 1000 microns and an autocorrelation function greater than 0.5 for distances less than 50 microns. An exemplary system for texturing a substrate includes a plunger with a textured surface, where a portion of the textured surface has a root-mean-square roughness between 40 to 1000 microns and an autocorrelation function greater than 0.5 for distances less than 50 microns. An exemplary method for texturing a substrate includes the steps of generating a pattern defining a texture, and 3-D printing the pattern on the substrate to form the texture.

According to one or more embodiments disclosed herein, a glass sheet may be formed by a method which includes supplying a feed of molten glass to an upper surface of a pair of forming rolls, and rotating the pair of forming wheels to continuously form a glass sheet from the molten glass. The pair of forming rolls may be spaced apart by a forming gap, and the forming gap may have a width of less than or equal to about 800 microns. The molten glass may have a viscosity of less than or equal to about 200 poise. The glass sheet may have a thickness of less than or equal to about 800 microns immediately upon passing though the forming gap.

According to one or more embodiments disclosed herein, a glass sheet may be formed by a method which includes supplying a feed of molten glass to an upper surface of a pair of forming rolls, and rotating the pair of forming wheels to continuously form a glass sheet from the molten glass. The pair of forming rolls may be spaced apart by a forming gap, and the forming gap may have a width of less than or equal to about 800 microns. The molten glass may have a viscosity of less than or equal to about 200 poise. The glass sheet may have a thickness of less than or equal to about 800 microns immediately upon passing though the forming gap.

A roll forming apparatus includes at least one forming roll being spaced from a forming body to define a gap. The forming roll includes a working zone portion having a working zone surface with a length extending along a rotation axis of the forming roll and a thermal resistance boundary extending at an acute angle relative to the rotation axis. In further examples, methods include the step of feeding a stream of molten glass through the gap to form a glass ribbon including a formed thickness. The thermal resistance boundary facilitates substantial uniform radial expansion of the working zone surface relative to the rotation axis across the length of the working zone surface in response to heating of the working zone portion by the molten glass.

A roll forming apparatus includes at least one forming roll being spaced from a forming body to define a gap. The forming roll includes a working zone portion having a working zone surface with a length extending along a rotation axis of the forming roll and a thermal resistance boundary extending at an acute angle relative to the rotation axis. In further examples, methods include the step of feeding a stream of molten glass through the gap to form a glass ribbon including a formed thickness. The thermal resistance boundary facilitates substantial uniform radial expansion of the working zone surface relative to the rotation axis across the length of the working zone surface in response to heating of the working zone portion by the molten glass.

An apparatus and method for manufacturing glass include a heat extractor configured to extract heat from molten glass. The heat extractor includes a first conduit and at least one second conduit which may include a plurality of second conduits circumferentially surrounding the first conduit. The first conduit and the at least one second conduit are configured to flow a fluid therethrough.

A glass substrate molding method includes: preparing a rotatable or wheelable molding die having a die surface and contacting the die surface with one of a pair of principal surfaces of a glass substrate made of a glass material containing an alkali metal oxide, the die having conductivity; keeping the one of principal surfaces contacted with the die surface at a temperature over 100 C. and equal to or lower than Tg+50 C.; applying direct-current voltage to the substrate to be higher voltage on the contacted one of principal surfaces than voltage on an opposite surface of the contacted one of principal surfaces; and rotating or wheeling the die and simultaneously moving the die or the substrate in a direction parallel to the contacted one of principal surfaces in conformity with rotation or wheeling speed of the die, to mold the contacted one of principal surfaces of the substrate.

A glass substrate molding method includes: preparing a rotatable or wheelable molding die having a die surface and contacting the die surface with one of a pair of principal surfaces of a glass substrate made of a glass material containing an alkali metal oxide, the die having conductivity; keeping the one of principal surfaces contacted with the die surface at a temperature over 100 C. and equal to or lower than Tg+50 C.; applying direct-current voltage to the substrate to be higher voltage on the contacted one of principal surfaces than voltage on an opposite surface of the contacted one of principal surfaces; and rotating or wheeling the die and simultaneously moving the die or the substrate in a direction parallel to the contacted one of principal surfaces in conformity with rotation or wheeling speed of the die, to mold the contacted one of principal surfaces of the substrate.

A system for levitating a softened, viscous or viscoelastic material by near field acoustic levitation. The system includes a support structure having a rigid surface, and a vibration generator operatively connected to the rigid surface. The vibration generator transmits acoustic waves to the rigid surface at a frequency and an amplitude sufficient to vibrate the rigid surface and create a gas squeeze film between the material and the rigid surface. The gas squeeze film has a pressure greater than ambient air pressure and sufficient to levitate the material. The system is particularly suited for transporting, forming, or casting heated glass. Also disclosed are methods for transporting, forming, and casting heated glass using near field acoustic levitation.