초록 ▼

A method and apparatus is provided for making a composite structural homogeneous resinous article having (a) a smooth, shiny non-cellular or homogeneous relatively thin injection compression molded liner on the outer surface and (b) a cellular relatively thicker injection molded core integral with t

A method and apparatus is provided for making a composite structural homogeneous resinous article having (a) a smooth, shiny non-cellular or homogeneous relatively thin injection compression molded liner on the outer surface and (b) a cellular relatively thicker injection molded core integral with the molded liner. One extruder is connected by valve controlled passages to a pair of injection devices, each device having an injection chamber. One chamber stores the homogeneous plastic resin and the other chamber stores the foam plastic resin. A first mold assembly having a movable upper mold part and a stationary lower mold part form a cavity, with a gap opening, at a first molding station. The cavity is in communication with the first injection chamber. A second mold assembly having a second cavity, which is closed, is provided at the second molding station and is formed by the aforementioned movable upper mold part of the first mold assembly, which is transferred thereto, and with another stationary lower mold part. The second cavity is in communication with the second injection chamber. Controls are provided for insuring the correct amount of each resin to be extruded and stored in the injection chambers. Fluid operated means are provided for energizing the first injection device to inject the homogeneous plastics material therein into the first mold cavity. This is followed automatically by rapidly applying a compressive force to the first mold assembly to compression mold the relatively thin injection compression molded liner. Thereafter the upper mold part of the first mold assembly, with the molded liner retained therein, is transferred to the second molding station and immediately the stored foam resinous material is injected into the second mold cavity to form with the solid liner the composite homogeneous-foam plastic article having an integral relatively thin, smooth, shiny and homogeneous molded outer surface.

대표청구항 ▼

A method of making a composite structural homogeneous foam resinous or plastic article having (a) a small, dense, homogeneous or non-cellular relatively thin injection compression molded plastic liner on the outer surface and formed in a mold assembly at a first molding station and (b) a foam or cel

A method of making a composite structural homogeneous foam resinous or plastic article having (a) a small, dense, homogeneous or non-cellular relatively thin injection compression molded plastic liner on the outer surface and formed in a mold assembly at a first molding station and (b) a foam or cellular relatively thicker injection molded inner plastic structure or core formed in a mold assembly supporting the outer plastic liner at a second molding station and formed integral with said liner to complete the plastic article comprising the steps of: (a) transferring a homogeneous or non-cellular resinous or plastic material from a plasticating extruder means into a first injection chamber; (b) transferring a foamable cellular resinous or plastic material from a plasticating extruder means into a second injection chamber; (c) establishing communication by a passageway having a first valve between said first injection chamber and a first mold assembly having a movable upper mold part and a stationary lower mold part forming the first cavity at a first molding station; said movable upper mold part being adapted to open the mold assembly and form a gap opening therebetween; (d) opening said first valve and injecting the non-cellular plastic material into the first cavity of the first mold assembly when the gap opening is provided therein; (e) applying a compressive force to the first mold assembly at said first molding station to close the gap opening of said first mold assembly and to distribute the non-cellular plastic material uniformly throughout said first cavity to form the non-cellular relatively thin outer molded plastic liner; (f) transferring the movable upper mold part carrying the formed non-cellular relatively thin outer molded liner to a second molding station where the aforesaid upper mold part forms with another stationary lower mold part a second mold assembly which is closed and having a second mold cavity therein which contains in the upper part thereof the previously molded liner; (g) establishing communication by a passageway having a second valve between said second injection chamber and the second mold cavity at the second molding station; (h) opening said second valve; and (i) injecting the foamable cellular plastic material from said second injection chamber into said second mold cavity to distribute the foamable cellular plastic material throughout said second mold cavity to form the cellular relatively thicker inner structure provided with said non-cellular plastic liner on the outer surface of the plastic article.