Abstract: Cellular ceramic bodies are produced by frothing a crystal-containing, ion-exchanged gel and setting the gel. An aqueous gel is prepared from a water-swelling mica and is blended in conjunction with a large cation donor, e.g., a potassium salt or silicate glass, and a surfactant to effect frothing of the gel by a shearing action and exchange of large cations with lithium and/or sodium ions from the mica to produce an ion-exchanged gel that sets in controllable manner.

Abstract: A system is provided for forming small accurately-spherical objects. Preformed largely-spherical objects (18) are supported at the opening of a conduit (16) on the update of hot gas emitted from the opening, so the object is in a molten state. The conduit is suddenly jerked away at a downward incline, to allow the molten object to drop in free fall, so that surface tension forms a precise sphere. The conduit portion that has the opening, lies in a moderate-vacuum chamber 40, and the falling sphere passes through the chamber and through a briefly-opened valve (30) into a tall drop tower (32) that contains a lower pressure, to allow the sphere to cool without deformation caused by falling through air.

Abstract: A system is described for forming hollow spheres containing pressured gas, which includes a cylinder device (14) containing a molten solid material (20) and having a first nozzle (18) at its end, and a second gas nozzle (24) lying slightly upstream from the tip of the first nozzle and connected to a source (26) that applies pressured filler gas that is to fill the hollow spheres. High pressure is applied to the molten metal, as by moving a piston (22) within the cylinder device, to force the molten material out of the first nozzle and the same time pressured gas fills the center of the extruded hollow liquid pipe that breaks into hollow spheres (12a). The environment (54) outside the nozzles contains gas at a high pressure such as 100 atmospheres, the gas is supplied to the gas nozzle (24) at a slightly higher pressure such as 101 atmospheres, and the pressure applied to the molten material (20) is at a still higher pressure such as 110 atmospheres.

Abstract: A method of controllably varying the dimensions of cavitated objects such as hollow spherical shells wherein a precursor shell is heated to a temperature above the shell softening temperature in an ambient atmosphere wherein the ratio of gases which are permeable through the shell wall at that temperature to gases which are impermeable through the shell wall is substantially greater than the corresponding ratio for gases contained within the precursor shell. As the shell expands, the partial pressures of permeable gases internally and externally of the shell approach and achieve equilibrium, so that the final shell size depends solely upon the difference in impermeable gas partial pressures and shell surface tension.

Abstract: Non-fused hollow glass microspheres that consist primarily of silicate are rendered more water-resistant by treatment with multivalent metals. The hollow microspheres are slurried with water and then a solution of a multivalent metal salt such as Al.sub.2 (SO.sub.4).sub.3 is added to the slurry. The rate of the addition is controlled so that the pH can be regulated. Separating, washing and drying complete the preparation.

Abstract: A method of manufacturing gel powder suitable for use as a starting material in the manufacture of hollow glass microspheres having a high concentration of silica. The powder is manufactured from a gel containing boron in the amount of about 1% to 20% (oxide equivalent mole percent), alkali metals, specifically potassium and sodium, in an amount exceeding 8% total, and the remainder silicon. Preferably, the ratio of potassium to sodium is greater than 1.5.

Abstract: An expanded glass aggregate has a granulometry of 0.2 to 3 mm and 10.sup.6 to 10.sup.7 cavities filled with gas per cm.sup.3. The diameter of the larger cavities is substantially smaller than 0.1 mm. All or a majority of the cavities are closed cells having a similar size. The expanded glass aggregate may contain in addition up to 85% of concrete, lava and/or tuff. For the preparation, the raw material is ground into a flour, mixed with a blowing organic and/or inorganic material appropriate to hot release gas, and a semi-finished aggregate is formed with a diameter of the granules of 0.1 to 1.5 mm. This aggregate is heated in a vibrating or suspended furnace during 5 to 180 seconds at a temperature of 600.degree. to 900.degree. C. The expanded glass aggregate is removed away from the furnace before a significant number of small cavities formed during the blowing gather to form larger cavities.

Abstract: A method of forming hollow glass spheres S shaped by the effects of surface tension acting on bubbles of glass in its molten state; the method is characterized by the steps of establishing a downwardly flowing stream of air accelerated at a one-G rate of acceleration through a drop tower 10, introducing into the stream of air free-falling bubbles B of molten glass, and freezing the bubbles in the stream as they are accelerated at a one-G rate of acceleration.

Abstract: Hollow plastic microspheres made from thermoplastic or thermosetting plastic compositions are described.The hollow plastic microspheres are made by forming a liquid film of thermoplastic or thermosetting plastic composition across a coaxial blowing nozzle, applying a blowing gas at a positive pressure to the inner surface of the plastic film to blow the film and form an elongated cylinder shaped liquid film of plastic. A transverse jet is used to direct an entraining fluid over and around the blowing nozzle at an angle to the axis of the blowing nozzle. The entraining fluid as it passes over and around the blowing nozzle fluid dynamically induces a pulsating or fluctuating pressure field at the opposite or lee side of the blowing nozzle in the wake or shadow of the coaxial blowing nozzle.

Abstract: The hollow glass vacuum microspheres are made by forming a liquid film of molten glass across the coaxial blowing nozzles, applying the metal vapor blowing gas at a positive pressure on the inner surface of the glass film to blow the film which combines with the centrifugal force to form an elongated cylinder shaped liquid film of molten glass. A transverse jet is used to direct the inert entraining fluid over and around the blowing nozzle at an angle to the axis of the blowing nozzle. The entraining fluid as it passes over and around the blowing nozzle fluid dynmically induces a pulsating or fluctuating pressure field at the opposite or lee side of the blowing nozzle in the wake or shadow of the coaxial blowing nozzle.

Abstract: Hollow glass microspheres made from a low heat conductivity glass composition containing a high vacuum and a thin metal coating deposited on the inner wall surface of the microspheres are described. The hollow glass microspheres are used to make superior insulation materials in the construction of highly efficient solar energy collectors.The hollow glass microspheres are made by forming a liquid film of molten glass across a coaxial blowing nozzle, applying a metal vapor blowing gas at a positive pressure on the inner surface of the glass film to blow the film and form an elongated cylinder shaped liquid film of molten glass. A transverse jet is used to direct an inert entraining fluid over and around the blowing nozzle at an angle to the axis of the blowing nozzle. The entraining fluid as it passes over and around the blowing nozzle fluid dynamically induces a pulsating or fluctuating pressure field at the opposite or lee side of the blowing nozzle in the wake or shadow of the coaxial blowing nozzle.

Abstract: A method for compressing gases in a contained volume consisting of hollow glass microspheres is described. The gases are compressed under high pressure and can be easily handled and stored. The gases to be compressed and contained in the microspheres are used as blowing gases to blow the microspheres.The hollow glass microspheres are made by forming a liquid film of molten glass across a coaxial blowing nozzle, applying the blowing gas at a positive pressure on the inner surface of the glass film to blow the film and form an elongated cylinder shaped liquid film of molten glass. A transverse jet is used to direct an entraining fluid over and around the blowing nozzle at an angle to the axis of the blowing nozzle. The entraining fluid as it passes over and around the blowing nozzle fluid dynamically induces a pulsating or fluctuating pressure field at the opposite or lee side of the blowing nozzle in the wake or shadow of the coaxial blowing nozzle.

Abstract: Hollow spheres with precisely concentric inner and outer spherical surfaces are formed by applying vibrations to a nonconcentric hollow sphere while it is at an elevated temperature at which it is fluid or plastic, the vibrations producing internal flows which cause the inner and outer surfaces to become precisely concentric. Concentric spheres can be mass produced by extruding a material such as glass or metal while injecting a stream of gas into the center of the extrusion to form a gas-filled tube. Vibrations are applied to the extruded tube to help break it up into individual bodies of a desired uniform size, the bodies tending to form spherical inner and outer surfaces by reason of surface tension, and the continuing application of vibrations causing these surfaces to become concentric.

Abstract: A method for producing small hollow spheres of glass having an outer diameter ranging from about 100.mu. to about 500.mu. with a substantially uniform wall thickness in the range of about 0.5-20.mu.. The method involves introducing aqueous droplets of a glass-forming solution into a long vertical drop oven or furnace having varying temperature regions. In one embodiment, one of the temperature regions is lower than both the preceeding region and the subsequent region. One region utilizes a temperature of at least 200.degree. C. higher than the melting point of the glass-forming material in the solution and, for example, may be at least 3 times higher than the temperature of the preceeding region. In addition, there is a sharp temperature gradient between these regions.

Abstract: A method for producing small hollow glass spheres filled with a gas by introduction of the gas during formation of the hollow glass spheres. Hollow glass microspheres having a diameter up to about 500.mu. with both thin walls (0.5 to 4.mu.) and thick walls (5 to 20.mu.) that contain various fill gases, such as Ar, Kr, Xe, Br, DT, H.sub.2, D.sub.2, He, N.sub.2, Ne, CO.sub.2, etc. in the interior thereof, can be produced by the diffusion of the fill gas or gases into the microsphere during the formation thereof from a liquid droplet of glass-forming solution. This is accomplished by filling at least a portion of the multiple-zone drop-furnace used in producing hollow microspheres with the gas or gases of interest, and then taking advantage of the high rate of gaseous diffusion of the fill gas through the wall of the gel membrane before it transforms into a glass microsphere as it is processed in the multiple-zone furnace.