초록 ▼

The molded shell of an article, while still warm from being molded, and while remaining within the mold or fixture in which it has been created, for instance by blow-molding of a parison of polyolefin plastic material into contact with the mold walls, is filled with a fluid, settable foaming plastic

The molded shell of an article, while still warm from being molded, and while remaining within the mold or fixture in which it has been created, for instance by blow-molding of a parison of polyolefin plastic material into contact with the mold walls, is filled with a fluid, settable foaming plastic material, for instance polyurethane. This may be done by injecting the foaming mixture directly into the cavity of the shell. In this manner time, labor and materials are saved, and the resulting product is characterized by better adhesion of the foamed core to the internal wall surface of the shell.

대표청구항 ▼

1. A method for producing a molded hollow article with a filling of foamed plastic thermal insulating material, comprising: inserting a hot precursor, made of polyolefin, for a polyolefin article shell into a relatively cool mold having a mold cavity with an internal molding surface therein; con

1. A method for producing a molded hollow article with a filling of foamed plastic thermal insulating material, comprising: inserting a hot precursor, made of polyolefin, for a polyolefin article shell into a relatively cool mold having a mold cavity with an internal molding surface therein; conforming the hot precursor against the internal molding surface to define an article shell having an internal cavity bounded by an internal surface of the article shell; introducing through the mold and through the article shell into the internal cavity of the article shell, a quantum of activated, foamable, settable plastic thermal insulation material while said article shell remains hot, so that as the article shell is being cooled from about 350° F. by contact with the mold, the thermal insulation material foams, fills the internal cavity of the article shell, adhering to the internal surface of the article shell, and sets to form a foamed core of polyurethane that is extensively adhered to the article shell to define an article; and removing the article from the mold. 2. The method of claim 1, wherein the inserting step is performed by opening said mold, extruding a generally tubular parison within the open mold, and closing the mold onto the parison to perimetrically trappingly ring a portion of the parison within the mold cavity. 3. The method of claim 2, wherein: the conforming step is performed, at least in part by inflation of said parison portion. 4. The method of claim 3, wherein: the conforming step further includes drawing a vacuum through the mold externally of the parison portion. 5. The method of claim 1, wherein: the introducing step comprises piercing the article shell with a hollow needle and injecting said activated, foamable, settable plastic thermal insulation material through the hollow needle into the article shell. 6. The method of claim 5, wherein: the activated, foamable, settable plastic thermal insulation material comprises a mixture of an isocyanate, a polyether polyol, a catalyst and a blowing agent. 7. An article produced by the process of claim 1. 8. A food container produced by the process of claim 7. 9. A picnic chest part produced by the process of claim 1. 10. A food serving tray produced by the process of claim 1. 11. Apparatus for producing a molded hollow article with a filling of foamed plastic thermal insulating material, comprising: means for inserting a hot precursor, made of polyolefin, for a synthetic thermoplastic article shell into a relatively cool mold having means defining a mold cavity with an internal molding surface therein; means for conforming said hot precursor against said internal molding surface to define said article shell having an internal cavity bounded by an internal surface of the article shell; means for introducing through said mold and through said article shell into said internal caivty of said article shell, a quantum of activated foamable, settable polyurethane thermal insulation material while said article shell remains hot, so that as said article shell is being cooled from about 350° F. by contact with the mold, the thermal insulation material is foaming, filling said internal-cavity of the article shell, adhering to said internal surface of said article shell, and setting to form a foamed core of polyurethane that is extensively adhered to the article shell to define an article. 12. The apparatus of claim 11, wherein: the means for inserting a hot precursor for a synthetic thermoplastic article shell into the relatively cool mold is a parison extruder. 13. The apparatus of claim 12, wherein: the extruder is equipped with an annular die for producing a tubular parison. 14. The apparatus of claim 11, wherein: the mold is a blow mold having two complementary halves, each with a perimetrical rim, the halves being movable away from one another to permit introduction of a tubular parison therebetween, and the rims being constructed and arranged to clamp a perimetrically bounded, hollow portion of the parison between them upon moving toward one another; and the conforming means includes air needle means for projecting through the bounded parison portion and means for introducing compressed air internally of said parison portion while said mold is closed. 15. The apparatus of claim 14, further including: means for drawing a vacuum through the mold while compressed air is being injected through the mold into said parison portion. 16. The apparatus of claim 15, wherein: said means for introducing a quantum of activated foamable, settable plastic thermal insulation material into said internal cavity of said article shell comprises at least one hollow needle connected to a supply of resin and a supply of activator via means for mixing said supplies according to a selected proportion; and means defining a bore through said mold into said mold cavity; said hollow needle being adapted to be projected into said mold cavity through said bore for injecting said quantum into said article shell cavity.