Container having an internal liner together with method and apparatus for forming such container

Claim 3

A method according to claim 1 wherein said center core plug is withdrawn from said open mold cavity following completion of the coring of said foamable polyurethane and wherein said liner is separated from said center core plug during withdrawal thereof.

Claim 4

A method according to claim 2 wherein said liner is bonded to the inner surfaces of said foamable polyurethane container thereby to form a mechanically strong lined container and to facilitate separation of said center core plug from said liner during withdrawal thereof.

Claim 5

A method according to claim 2 wherein the container includes embossed areas on its outer surface and wherein the inner surfaces of said open mold cavity are formed in a removable inner casing formed of separate complementary parts having recessed areas for producing said embossed areas on the outer surface of the container and wherein said casing is removed from said container following withdrawal of said container from said open mold cavity.

Claim 6

A method according to claim 4 wherein said removable inner casing is disposed within an outer part of said open mold cavity and wherein fluid pressure is applied to the outer surface of said removable inner casing to facilitate removal thereof.

Claim 7

A method according to claim 5 wherein said removable inner casing is formed of silicone mold material.

Claim 8

A method according to claim 1 wherein said liner is preformed by injection molding.

Claim 9

A method according to claim 1 wherein said liner is vacuum formed.

Claim 10

An open container consisting essentially of an outer part formed of molded foamed polyurethane and an inner liner of preformed plastic material bonded to the inner surface of said outer part and made according to the method of claim 1.

Claim 11

A container according to claim 9 wherein said liner is formed of polystyrene.

Claim 12

A container according to claim 9 wherein said liner is formed of polypropylene.

Claim 13

An open container comprising an outer part formed of molded foamed polyurethane and an inner of preformed plastic material bonded to the inner surface of said outer part and wherein an outlet drain is formed via aligned passages in said outer part and in said inner liner and made according to the method of claim 1.

Claim 14

A container according to claim 9 wherein said outer part is of a thickness of approximately 5/8 inch to 3/4 inch and whose density is in the range of sixteen to eighteen pounds per cubit foot.

Claim 15

Apparatus for forming a container having an internal liner, said apparatus comprising an open mold including an outer casing formed of mechanically strong material and an inner casing formed of silicone mold material having an internal surface configured to form the external surface of the container, a center core plug having an outer surface which conforms generally to the configuration of the internal surface of said open mold and having external dimensions of less magnitude than the corresponding internal dimensions of said open mold so as to define a container forming cavity therebetween whereby a platic container liner initially disposed only about said center core plug an which is of such thickness as only partially to fill said container forming cavity thereby to provide space for receiving foramable polyurethane in said container forming cavity and forced into said space due to insertion of said center plug into said open mold with said liner thereon.

Claim 16

Apparatus for forming a container having an internal liner, said apparatus comprising an open mold including an outer casing formed of mechanically strong material and an inner casing formed of silicone mold material having an internal surface configured to form the external surface of the container, a center core plug having an outer surface which conforms generally to the configuration of the internal surface of said open mold and having external dimensions of less magnitude than the corresponding internal dimensions of said open mold so as to define a container forming cavity therebetween whereby a platic container liner initially disposed only about said center core plug an which is of such thickness as only partially to fill said container forming cavity thereby to provide space for receiving foramable polyurethane in said container forming cavity and forced into said space due to insertion of said center plug into said open mold with said liner thereon.

Claim 17

Apparatus according to claim 14 wherein said liner is bonded to the inner surface of the polyurethane container disposed thereabout due in part to shrinkage of said polyuretane during curing thereof whereby said liner is detached from said center core plug during withdrawal of said center core plug from said open mold cavity.

Claim 18

Apparatus according to claim 9 wherein said inner casing comprises a plurality of separate complementary parts whereby separation of the outer surface of the container from said inner casing is facilitated following completion of the curing of said polyurethane.

Claim 19

Apparatus according to claim 9 wherein at least one passage is formed in a part of said outer casing and arranged to establish communication between a source of fluid under pressure and an outer surface of said inner casing and wherein means are provided for controlling the flow of fluid under pressure through said passage thereby to facilitate removal of said inner casing from said outer casing following completion of a curing process.

Claim 20

Apparatus according to claim 14 wherein complementary registering means are formed on parts of said open mold and of said center core plug for establishing a proper positional relationship therebetween.

Claim 21

Apparatus according to claim 14 wherein a handle is mounted on said center core plug for facilitating removal thereof from said cavity following completion of a curing operation.

Claim 22

Apparatus according to claim 9 wherein the inner surface of said inner casing is formed with projections and recesses for forming complementary configurations on the outer surface of the container.