Abstract: A method and apparatus for forming foam articles is described. Thermoplastic resin beads containing a blowing agent are continually agitated in a heated pre-expansion chamber to a temperature near the fusion point of the beads and above the boiling point of the blowing agent at substantially atmospheric pressure. The beads soften and expand substantially in volume. A dry gaseous medium may be swept over the beads to remove moisture and any blowing agent which has escaped. Thereafter, the chamber is evacuated. Evacuation continues until a predetermined amount of blowing agent is removed from the beads. As a preferred embodiment of the invention, steam may be injected into the chamber prior to evacuation. This serves to further expand the beads, and facilitates the removal of the blowing agent. This embodiment also provides a means of manufacturing particularly stable low-density foam.

Abstract: The fouling of autorefrigeration polymerization systems because of entrained particles in the vaporized solvent-diluent is substantially reduced by returning the recycle solvent-diluent into the reaction zone through nozzles which provide a solvent-diluent spray of an average droplet size of less than 1000 microns, preferably between about 225 and 300 micron average particle size, which spray removes major amounts of entrained particles down to 5 microns in size. The solvent diluent may be an inert material or unreacted alpha-olefin, such as propylene.

Abstract: A method and product relating to a thermal insulation package wherein a container made from laminated sheet material including an inner layer of kraft paper, an outer layer of aluminum foil and an intermediate layer of fiberglass webbing is provided; the three layers are adhesively secured together and the inner surface of the kraft paper is coated with a heat-activated adhesive; the sheet material is formed into a tubular section by overlapping opposite edges of the sheet material and heat sealing the edges together; the tubular section thus formed is subsequently cut into tubular sections of smaller length, the bottoms of each of the smaller sections are then heat sealed, the containers thus formed are filled with polystyrene pellets and a hydrate compound is added; the open end of each of the containers is then closed and heat-sealed to form the completed package.

Abstract: Thermoplastic material in particulate form and containing a blowing agent is partially expanded by means of a mixture of steam and another hot dry gas such as air present in specified proportions in said mixture.

Abstract: An energy saving and material conserving apparatus is provided for expanding and molding expandable thermoplastic polymer particles. Especially significant is the ability to produce molded objects of generally uniform density in the higher density range in the order of 4 - 15 pounds per square inch, or greater, as well as lower density molded objects due to improved control of the particle expansion.The particles are partially expanded in a vessel in a heated substantially dry atmosphere and agitated in a manner to provide uniform heating thereof. After an initial heating period to soften and partially expand the particles they are subjected to superatmospheric pressure to substantially prevent further expansion and are discharged and conveyed to a mold for further expansion therein.

Abstract: The fouling of autorefrigeration polymerization systems because of entrained particles in the vaporized solvent-diluent is substantially reduced by returning the recycle solvent-diluent into the reaction zone through nozzles which provide a solvent-diluent spray of an average droplet size of less than 1000 microns, preferably between about 225 and 300 micron average particle size, which spray removes major amounts of entrained particles down to 5 microns in size. The solvent diluent may be an inert material or unreacted alpha-olefin, such as propylene.

Abstract: An energy saving and material conserving method and apparatus are provided for expanding and molding expandable thermoplastic polymer particles. Especially significant is the ability to produce molded objects of generally uniform density in the higher density range in the order of 4-15 pounds per square inch, or greater, as well as lower density molded objects due to improved control of the particle expansion.The particles are partially expanded in a vessel in a heated substantially dry atmosphere and agitated in a manner to provide uniform heating thereof. After an initial heating period to soften and partially expand the particles they are subjected to superatmospheric pressure to substantially prevent further expansion and are discharged and conveyed to a mold for further expansion therein.

Abstract: Molded articles are made from expandable thermoplastic resin material by pre-expanding the thermoplastic material in particulate or bead form containing as the principal expanding agent a liquid hydrocarbon by contact with steam until the desired degree of expansion is obtained, heating the beads in a stream of substantially dry, hot gas at a temperature above the boiling point of the hydrocarbon but below the fusion temperatures of the thermoplastic material while agitating the beads to prevent agglomeration upon softening until substantially all of the moisture is removed from the surfaces of the pre-expanded beads, and molding the article from the heated pre-expanded beads by placing them in a closed mold and heating them to a temperature above their fusion temperature, the temperature of the thermoplastic material being continuously maintained above the boiling point of the expanding agent from the time the beads are pre-expanded until they are molded into the shaped article.