Abstract: An improved process and apparatus for producing rigid cellular materials comprising polyvinyl chloride, wherein the controlled expansion of embryonic blocks obtained by molding, is carried out in a single expansion box closed throughout the whole duration of the expansion treatment, in several stages including pre-heating, pre-expanding and final expansion to the final dimensions of the block, the expansion box containing the block expanded to its final dimensions being then immersed in a bath of cold water for dimensional stabilization.The expansion box comprises at least two plates, with a frame attached to the lower face of each plate, to form, in use, a closed expansion box which is provided with a centering and holding mechanism to maintain the embryonic block in place within the expansion box, a device for opening and closing the expansion box being also provided, as well as a mechanism for transferring a plurality of expansion boxes assembled together from one bath to the other in succession.

Abstract: A method of forming a panel structure useful in building construction and the like includes the steps of heating a heat expandable plastic in a separable mold having a cavity with the configuration of the resultant panel to form a panel core and adhering thin reinforcing strips to the front and back surfaces of the core. Control over the dimensions and configuration of the panel is obtained by adhering the strips to the core in the mold while applying heat thereto whereby core shrinkage is minimized. The strips may be adhered to the core during initial heating of the plastic material to form the core or may be adhered to the core in the mold subsequent to core formation.

Abstract: A process of forming an embossed surface covering is disclosed. The process comprises forming a cross-linkable foam comprising at least one polymer and having a first phase region and a second phase region; heat the foam to a temperature at least equal to the flow temperature of the first phase region; compressing the heated foam and cooling the foam while compressed; cross-linking a portion of the compressed foam; and reheating the compressed foam to permit the noncross-linked portion of the foam to return or "pop back" to substantially its precompressed shape and thus form an embossed surface covering.

Abstract: A mold is described for the molding of substantially isotropic isocyanate-based polymer foam buns. The mold is a box mold which has sidewalls of which at least one pair disposed in parallel relationship is adapted to move outwardly when subjected to pressure exerted by the expanding foam during the molding operation. The outward movement of the sidewalls is controlled by stops provided on the periphery of the mold floor, said sidewalls being free to slide over the surface of the floor. The lid of the mold is supported in sliding engagement with the upper edges of the sidewalls. The mold and the process of fabricating foam buns therewith is particularly suitable for use in situations (e.g. operation in the field) in which it is not possible or practicable to employ continuous bunstock machines. The mold is relatively inexpensive and readily dismantled for transportation to a fabrication site.

Abstract: A method for preparing foams of chlorinated vinyl chloride polymers is provided. The foams are prepared by impregnating the chlorinated vinyl chloride polymer with an aliphatic alcohol of from 1 to 5 carbon atoms and thereafter heating the impregnated polymer.

Abstract: Foam insulated conductor is produced by heating the conductor to a temperature at which the conductor retains sufficient heat to effect crosslinking and foaming of a polymer composition, followed by extruding the polymer composition onto the conductor, with the crosslinking and foaming being effcted by the retained heat.

Abstract: Lightweight glass fiber reinforced plastic articles are produced in matched dies by combining fibrous reinforcing materials, such as glass fibers, with a foamable unsaturated polyester resin composition. The matched dies are closed and compressed so that the resin composition fills the mold cavity and wets the fibrous reinforcing material. Thereafter the matched dies are separated to increase the volume of the mold cavity by at least 50 percent greater than the closed volume. The matched dies are retained in this relationship until the unsaturated polyester resin composition has cured and expanded to fill the mold cavity. The resulting product has a density less than 67 percent of the density of a corresponding reinforced plastic article fabricated from the same composition (unsaturated polyester resin, fillers and reinforcement), which is not foamed. The unsaturated polyester resin composition preferably includes 0.

Abstract: The use of lightweight, elastomeric closed-cell foam elements can be of particular advantage in countercurrent flow gas-liquid contactors in order to provide aeratable non-breakable forms of mobile contacting surfaces. In particular, the use of elastomeric, spherical form, closed-cell foam elements made from heating and post curing a blend of nitrile polymer and polyvinyl chloride can provide resilience to preclude sphere breakage and also provide for softness and flexibility to effect self-cleaning characteristics.

Abstract: A mold is described for the molding of substantially isotropic isocyanate-based polymer foam buns. The mold is a box mold which has sidewalls of which at least one pair disposed in parallel relationship is adapted to move outwardly when subjected to pressure exerted by the expanding foam during the molding operation. The outward movement of the sidewalls is controlled by stops provided on the periphery of the mold floor, said sidewalls being free to slide over the surface of the floor. The lid of the mold is supported in sliding engagement with the upper edges of the sidewalls. The mold and the process of fabricating foam buns therewith is particularly suitable for use in situations (e.g. operation in the field) in which it is not possible or practicable to employ continuous bunstock machines. The mold is relatively inexpensive and readily dismantled for transportation to a fabrication site.

Abstract: The process for the production of closed-cell, extra soft polyvinylchloride foam plastics having improved volume stability at elevated temperatures. The process includes heating a plastisol or plastigel comprised of a plasticizer and foaming agent containing polyvinyl chloride or vinyl chloride copolymerizate in a pressure mold at a pressure of up to 300 atm. to a temperature of 150.degree. to 180.degree. C. for 1 to 2 hours. The plastigel or plastisol is cooled, at an unchanged closing force of the press of said pressure mold, to a temperature of 20.degree. to 70.degree. C. The plastigel or plastisol is removed from the pressure mold, a crude foam plastic forming. The crude foam plastic is heated under a gas pressure of 2 to 10 atm. to a temperature of 140.degree. to 170.degree. C. The crude foam plastic is cooled at said pressure of 2 to 10 atm. to a temperature of 100.degree. to 130.degree. C. The pressure is lowered to atmospheric pressure, the foam plastic simultaneous expanding.

Abstract: In a method for the preparation of crosslinked polyolefin foams by charging a polyolefin or its blend with other thermoplastic resins containing a crosslinking agent, foaming agent and if necessary a filler into the heated mold having a changeable cavity and, after decomposition of the crosslinking and foaming agents, retracting the moving-plate of the mold by a definite distance to increase the cavity and at the same time cooling the mold, an improvement for the preparation of the crosslinked polyolefin foams having excellent appearance and dimensional stability, comprising using a mold of which the moving-plate is constructed with a body and a sliding-piece, the body holding the piece slidably whereby the sliding-piece is left behind owing to sliding between the two even on rapid retraction of the body and then retracts at the rate corresponding to the foaming pressure of the resin, in other words, at a self-controllable rate and the mold for the preparation thereof.

Abstract: A method of making a foam-filled tire wherein a resilient elastomeric foam is formed and cured within a tire carcass while the carcass interior is at super-atmospheric pressure. Such superatmospheric pressure is believed to support the cell walls against internally generated gas (blowing) pressures, thereby stabilizing the cells at higher than usual internal cell pressure. The foaming operation is carried out so that the foam only partially fills the carcass interior. After the elastomeric foam has been cured the tire carcass interior is depressurized down to the pressure to be used in service. During the depressurization process the internal cell pressures cause the cells to expand and further fill the tire interior space. The depressurization processis carried out after the elastomeric foam has been cured, i.e. when the cell walls have attained their full potential strength.

Abstract: Foam styrene polymer sheet is expanded to form foam products having lower density by a process which includes (a) contacting the foam styrene polymer sheet with an aqueous composition, (b) maintaining the aqueous composition in contact with the sheet to effect impregnation of the sheet by the aqueous composition, and thereafter (c) heating the impregnated sheet to expand the sheet. The expanded products are useful as thermal insulation and packaging material.

Abstract: An improved method for forming bodies of foamed plastisol resin characterized by the steps of solidifying a flowable plastisol containing a chemical blowing agent to form a solidified body, grinding the body to form a body of uniformly sized aggregate, depositing the aggregate in a mold, and heating the mold to a temperature above that at which the plastisol fuses and the blowing agent decomposes.

Abstract: A hard foamed material having a small specific gravity and a high mechanical strength is produced by mixing vinyl chloride resin with a large amount of inorganic powdery substances and a solvent, heating and kneading the resulting mixture in a closed kneader at a given temperature, adding a liquefied butane with a solvent thereto, and heating and foaming the resulting mixture in a mold.

Abstract: The invention relates to sheet-like plastic packaging particles formed with a normally curved configuration having two spaced apart, curved coextensive surfaces, one of said surfaces being a substantially unfoamed skin and the remainder of said particle including the other surface being foamed, and to methods for producing packaging particles which comprise warped or distorted, foamed sheet particles suitable for use as packaging particles from an extrudable, expandable synthetic plastic material, such as, a polymerized vinyl aromatic monomer, e.g.

Abstract: Foamed thermoset articles are produced by introducing a thermosettable organic resin, a specific class of blowing agents, inorganic particulate filler, and glass fiber in a mold at a given temperature and pressure, and then lowering the mold pressure to a predetermined reduced pressure to cause foaming, and completing the foaming before gelation. The foamed thermoset articles are also disclosed.

Abstract: Shaped, foam plastic parts are made in a lightweight shaped, open trough-like mold having a coherent sheet metal interior comovable insert and related comovable floating lid, wherein said insert is positioned and adapted to slidably elevate within the interior surface of said trough coincident with the expansion of an internally housed and expandable foamable reaction mixture. As the reaction mixture expands, the foam freely expands upwardly during a first stage of the method to at least a height of approximately 50% of that desired for the plastic part. At that point the expanding foam engages an inwardly projecting flange portion of the comovable insert upon which is seated a comovable floating lid.