Abstract: A mold for forming a container from a sheet of deformable material has upper and lower mold parts with die surfaces in conforming relation to one another. Upper and lower keys, each having a shear surface, are mounted in said upper and lower mold parts, respectively, so that the shear surfaces confront each other to form an opening in the container as the mold parts close. At least one of said keys is mounted so that its shear surface pivots on a plane normal to the motion of the closure of the mold parts.

Abstract: A volatile foaming agent for thermoplastic foam is a blend of about 65 to 75 weight percent chlorodifluoro-methane and from about 25 to 35 weight percent pentane.

Abstract: A thermoformed plastic carton constructed from two half sections which are integrally connected along one side by a hingable joint to allow the half sections to be folded upon each other. The carton further includes resiliently deflectable latches extending up from an edge of one carton half which mate with and become lodged in a receptacle formed in the other carton half section when the carton half sections are folded one upon another.

Abstract: An egg carton made from expanded polystyrene with a nonexpanded skin on one side includes integrally formed cover and tray portions interconnected together by a pair of hinges adjacent opposite sides of a hingeband. The tray is divided into a plurality of cells by a plurality of partitions. At least some of the partitions have a top flap portion hinged to the top of the partition by the skin of the polystyrene. Each cell further has a pliant inside surface provided by one or more grooves in the interior cell walls. A post extending from the inside surface of the cover is formed opposite a tray support surface using a thermo molding method by which a protrusion in a top mold is inserted into a nonvented cavity of a bottom mold. A pair of integrally molded hinge posts extend above the hingeband a distance less than the width of the hingeband between hinges and seat into a groove in the hingeband when the top is in closure relationship to the tray.

Abstract: An egg carton made from expanded polystyrene with a nonexpanded skin on one side includes integrally formed cover and tray portions interconnected together by a pair of hinges adjacent opposite sides of a hingeband. The tray is divided into a plurality of cells by a plurality of partitions. At least some of the partitions have a top flap portion hinged to the top of the partition by the skin of the polystyrene. Each cell further has a pliant inside surface provided by one or more grooves in the interior cell walls. A post extending from the inside surface of the cover is formed opposite a tray support surface using a thermo molding method by which a protrusion in a top mold is inserted into a nonvented cavity of a bottom mold. A pair of integrally molded hinge posts extend above the hingeband a distance less than the width of the hingeband between hinges and seat into a groove in the hingeband when the top is in closure relationship to the tray.

Abstract: A bowl and cover assembly includes a bowl with an annular sealing lip depending radially outwardly from the upper annular rim of the bowl. The sealing lip has an annular top sealing surface and an annular edge sealing surface. The cover has a flared annular skirt about its periphery which defines a down facing mating surface and an infacing mating surface adjacent thereto. When the cover is placed over the sealing lip the top sealing surface seats against the downfacing mating surface and the edge sealing surface seats against the infacing mating surface to form an airtight seal. An annular depression in the interior surface of the bowl extends upward from an upfacing interior shoulder to provides an air bypass region to prevent vacuum locking between adjacent stacked bowls.

Abstract: Containers are formed with latch openings and a reinforced region adjacent to each opening, molded in one operation from a softened sheet of organic polymer material. The latch opening is formed by vertical shearing of the sheet from a predetermined area of one of the mold dies during the closure of the molds. The sheared-off material is compressed against adjacent portions of the sheet to define a reinforced edge of the aperture. Accretion of sheet material adjacent the aperture region adds strength and rigidity to the container wall and eliminates removal of waste material separated during formation of the latch opening.

Abstract: Containers are formed with latch openings and a reinforced region adjacent to each opening, molded in one operation from a softened sheet of organic polymer material. The latch opening is formed by vertical shearing of the sheet from a predetermined area of one of the mold dies during the closure of the molds. The sheared-off material is compressed against adjacent portions of the sheet to define a reinforced edge of the aperture. Accretion of sheet material adjacent the aperture region adds strength and rigidity to the container wall and eliminates removal of waste material separated during formation of the latch opening.

Abstract: An improved container construction, particularly useful for arranging and securing a plurality of separable items therein. The unassembled container has a generally planar configuration and contains a bottom wall defining a floor upon which the items to be packaged are placed. The container includes side walls which are connected to adjacent floor edges by hinge lines. Shoulder members are formed on the floor and surfaces of the side walls adjacent each hinge line, and serve to define closure limits for the side walls when the container is assembled.

Abstract: An improved container, particularly useful for containing plants, seeds, or seedlings in soil for shipment, is formed of a blank which when unassembled is in a generally planar configuration. A plurality of hinge lines formed in the blank divide the blank into a minimum of three parts and enable the member to be folded into a configuration having a generally U-shaped cross-section. The hinge lines consist of lines of weakness interposed with cut-out tabs which break away from the center section of the blank when it is folded to form feet for the container. A plurality of indentations formed in the blank meet when the blank is folded to divide the container into a plurality of discreet compartments. Opposite side edges of the blank can be continued and folded from hinge lines thereat to form lids for the compartments.

Abstract: A carton comprising a pair of space-defining members with confronting closing edges which lock by means of a tab latch. The latch includes a tab which extends from one of the closing edges to pass through a loop formed on a wall adjacent the opposite closing edge. The tab includes a terminal portion which extends through the loop and which has a rear surface that conforms to the wall region rearwardly adjacent the loop. The tab also includes a protuberance on its front, outer surface which is insertable through the loop by deformation of the loop and which is retained thereby. In particular embodiments, the carton is integrally formed in one piece of expanded plastic material with sections of the closing edges hinge-connected. In a specific configuration, the walls of the space defining members taper inwardly from the closing edges so that the tab forms an acute angle with the closing edge from which it extends.

Abstract: A packaging device forming an insulative structure for hot food sandwiches. The packaging device includes a pair of identical members, which when interconnected, form an insulative food container. Each of the members comprise a dish-shaped portion whose periphery has a planar flange. The inner surface of the dish-shaped portion is stipled to define a plurality of protuberances interconnected by a plurality of valleys. Moisture from the food or sandwich is allowed to accumulate in the valleys, thus preventing the food and sandwiches from becoming soggy. Channels can also be formed on the planar surface for enabling moisture to escape from the packaging device. A bayonet locking arrangement for the members comprises studs formed on the planar surfaces of the members, each of the studs interacting with locking slots formed opposite the studs on the opposite planar surface of the other member. The diameter of the studs is slightly greater than the width of the slots providing a tight friction fit therebetween.

Abstract: An improved container, particularly useful for containing plants, seeds, or seedlings in soil for shipment, is formed of a member which when unassembled is in a generally planar configuration. A plurality of hinge lines formed in the member enable the member to be folded into a configuration having generally a U-shaped cross-section and divide the member into a plurality of predetermined compartments. The container, which can be stacked when unassembled due to the planar configuration, contains a plurality of tab members integrally formed with one of the edges of the container. The free end of the tab is formed with a protuberance for abutting the outer side of the other free edge of the container for assembling the container in the generally U-shaped cross-sectional configuration.