Abstract: Solid particulate materials are bonded together to form a foundry mold or core byI. forming a mixture of the particles and an anaerobically-curing adhesive and moulding the mixture to the desired shape, andIi. causing the adhesive to cure and bond the particles together by maintaining the shaped article in a substantially oxygen-free environment.The anaerobic adhesive may comprise, as monomer, an ester of an acrylic acid, with a hydroperoxide or peroxide as a polymerization catalyst, and the oxygen-free environment may be produced by displacing air with nitrogen or other inert gas or vapor.The method described is particularly suited for the production of foundry moulds and cores from sand or other particulate material.

Abstract: A hollow multilayered article is rotationally molded by introducing into the mold particles of a hompolymer or copolymer of ethylene containing a crosslinking agent and heating the mold during rotation thereof to melt this first polymeric layer. Solid particles of a different polymer are then introduced into the mold at a time after at least substantially all of the particles of the first polymer have melted and prior to the time when the inner surface of the first layer would become smooth and glossy. The mold is then rotated and heated to melt the second polymer. The mold is then cooled and the multilayered article removed.

Abstract: An ornamental plastic article having a smooth rear exterior surface and a rough, randomly arranged layer of plastic particles or pellets forming the front outer surface is produced by placing a layer of plastic powder on one surface of a first mold form containing an outer wall having the configuration of the article, heating the powder until the powder becomes tacky in the form of a strip, placing this form on top of a mating second mold form having an outer wall containing various pockets of different colored plastic pellets of a compatible plastic material located in predetermined locations within the outer wall, rotating the two forms until the tacky powder form is on the bottom and the pockets of colored plastic pellets are on top, reversing the position of the two forms, and removing the first form which has a layer of plastic pellets affixed to the tacky layer in predetermined color arrangement corresponding to the pocket location on the second mold form, heating the pellets until they become soft, and

Abstract: A method for molding powder of ultra-high molecular weight, linear polyethylene comprising particles of less than 100 micron mean particle size having narrow particle size distribution is free-sinterable to form solid articles by a process comprising (a) molding a solid preform by compressing the polyethylene molding powder at a temperature below its crystalline melting point under pressure of at least 2,000 p.s.i., (b) releasing the pressure and (c) free-sintering the preform at temperature above its crystalline melting point.

Abstract: Polyesters of para-oxybenzoyl are infusible and very resistant to acids and solvents, thus limiting the means by which such polymers can be fabricated. Such a polyester is made more amorphous, thus improving compression moldability, by subjecting it to a high temperature treatment, followed by a rapid quench. The resulting polymer has reduced crystalline orientation, as evidenced by X-ray diffraction patterns, and molded articles thereof have improved flexural strength, without adversely affecting the modulus. The thermal treatment is carried out on the polymer by heating at a temperature of at least 300.degree.C, and up to just below the decomposition temperature of the polymer, followed by quenching of the hot polymer.

Abstract: A quantity of discrete particles of thermo-meltable material are heated to melt those particles at the surface of the charge for a predetermined distance inwardly of the charge. The particles remote from the surface of the charge remain in original and unmelted condition. While the melted particles are in a melted condition molding pressure is applied to the exterior of the charge to shape the melted material into a covering encapsulating, at least in part, the unmelted particles. In a further embodiment the particles remote from the surface of the charge may under heat and pressure be superficially tacked together.

Abstract: A method of moulding a drum or similar from a thermoplastic resin in powdered form, in which an appropriately shaped mould, after introduction of the thermoplastic material, is subjected to the actions of alternate direction rotation, tilting, heating and cooling in a predetermined sequence with the heating of the drum body and ends being effected and controlled independently.

Abstract: The present invention relates to a process for the manufacture of chip boards especially multi-layer chip boards, using condensation resins as binders, and the products thereof the improvement including wetting powdered adhesive particles before applying the adhesive particles to wood chips.

Abstract: A poly(meta-phenylene isophthalamide) powder is provided which is coalescible under the influence of pressure followed by heating at temperatures below its crystalline melting point to provide molded objects of a solid and homogeneous nature. A process for preparing coalescible powders of poly(meta-phenylene isophthalamide) also is provided wherein a solution of said polymer in a solvent such as DMAC is added to a precipitant such as water to provide a slurry which is filtered, followed by washing and drying the resulting filter cake to provide a crumb which is ground and screened through a sieve of 35 mesh size (U.S. Standard).

Abstract: A method of producing shaped articles of thermoplastic resin having a non-foam layer and foam layer, which comprises introducing into a mold thermoplastic resin particles not containing a heat-decomposable blowing agent and thermoplastic resin particles containing such a blowing agent and having a greater heat capacity than said resin particles not containing a blowing agent, heating the mold and, in the meantime, moving said particles in said mold to effect the heat-melting of said particles as well as the heat-decomposition of said blowing agent.

Abstract: A process for free sintering parts made from mixtures of poly(phenylene sulfide) and at least one selected filler by subjecting molded parts to gradually increasing temperatures and then curing at an elevated temperature. Precured poly(phenylene sulfide) is first mixed with the selected filler and then compression molded to form a part of a desired shape. The part is then free sintered by being subjected to a gradually increasing temperature in an oven and cured. After curing, the part is cooled and is ready for use.

Abstract: A process for producing a decorative surface covering wherein granular dryblend is deposited on a releasable carrier and heated to form a porous cohesive layer. Settable resinous inks are then applied to selected surface portions of the dryblend to form design areas which may overlap at the points of application. The inked areas extend partially or completely through the layer so that they are visible from the bottom surface of the sheet which ultimately becomes the face of the surface covering, after final fusion of all of the resinous materials. The ink may optionally be set by heat prior to or simultaneously with the subsequent application and gelling of a resinous back coating, if one is used. The back coating may be reinforced by included or attached material to form a permanent carrier. Depending on the backing used, heat may be applied to fuse the composite structure before or after the release carrier is removed.

Abstract: The properties of arylene sulfide polymers are improved by treating the polymer with a fluid treating agent selected from the group consisting of hydrogen peroxide, an alkali metal or alkaline earth metal hypochlorite, sulfuric acid, chlorine, sulfuryl chloride, nitrogen dioxide, chromium trioxide, alkali metal permanganates and nitric acid under conditions of concentration of treating agent, time and temperature to effect the desired improvement.

Abstract: Molding is performed by directing streams of comminuted plastic material against surfaces of a heated form or mold, while repeatedly sweeping the form or mold across the streams, progressively depositing the material in one or more predetermined zones, so that the material assimilates progressively along the form or mold surfaces. Apparatus for so molding large receptacles, such as drum liners, includes a series of open molds supported on a turntable for rotation of the molds about their horizontal axes, with the open ends facing radially outward. The table is indexed relative to the various stations, at which successive steps of preheating, deposition, post-heating, cooling and stripping are performed. The deposition apparatus is on a carriage reciprocable radially of the table.

Abstract: A process for producing a decorative surface covering wherein granular dryblend is deposited on a releasable carrier and heated to form a porous cohesive layer. Settable resinous inks are then applied to selected areas of the dryblend to form a design which may extend partially or completely through the layer to the bottom surface thereof which ultimately becomes the face of the surface covering. The ink may optionally be set by heat prior to or simultaneously with the subsequent application and gelling of a resinous back coating which may be reinforced by included or attached material to form a permanent carrier. The release carrier is then removed. A multi-level wear surface is achieved on the surface covering by removing the non-ink-containing portions of the dryblend either before or after the composite structure is turned over and heat is applied to fuse the remaining resinous material.

Abstract: A method for draining water or moisture from a substratum for a waterproofing layer in buildings comprising applying to the substratum such as concrete or mortar a sintered product of a thermoplastic resin, having a capillary structure comprising numeral, fine and interconnecting pores and voids of 20 to 70 percent, selected from the group consisting of a sintered plate and a sintered hollow product in a form of a belt or tube, wherein at least a part of the sintered product is protruded into the atmosphere and applying thereto a waterproofing layer, and thereby making the water or moisture contained in the substratum evaporate through the sintered product.