Manufacture of foamed compartmented structures

Claim 1

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of random shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials, each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure enclosing a core of unfoamed polyethylene having a diameter of between about 5 to 50mm. containing a foaming agent and a cross-linking agent, and heating said aggregate in a mold to cause foaming of said polyethylene cores and to bond said materials with one another at said layer thereof into an integrated three-dimensional array of foam-filled compartments.

Claim 2

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of random shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials, each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure enclosing a core of unfoamed polyethylene having a diameter of between about 5 to 50mm. containing a foaming agent and a cross-linking agent, and heating said aggregate in a mold to cause foaming of said polyethylene cores and to bond said materials with one another at said layer thereof into an integrated three-dimensional array of foam-filled compartments.

Claim 7

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of random shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure and, surrounded with said layer, a cylinder of unfoamed polyethylene having a diameter of between about 5 to 50mm. containing foaming agent having a decomposition temperature higher than the softening point of said polyethylene and a cross-linking agent having a decomposition temperature lower than that of said foaming agent, and heating said aggregate in a mold to cause foaming of said polyethylene and to bond said materials with one another at said layer thereof to form an integrated three-dimensional array of foam-filled compartments.

Claim 8

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of random shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure and, surrounded with said layer, a cylinder of unfoamed polyethylene having a diameter of between about 5 to 50mm. containing foaming agent having a decomposition temperature higher than the softening point of said polyethylene and a cross-linking agent having a decomposition temperature lower than that of said foaming agent, and heating said aggregate in a mold to cause foaming of said polyethylene and to bond said materials with one another at said layer thereof to form an integrated three-dimensional array of foam-filled compartments.

Claim 14

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of randon shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials, each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure enclosing a core of unfoamed polyethylene having a diameter of between about 5 to 50 mm. containing a foaming agent and a cross-linking agent, and heating and expanding said aggregate in a furnace having a conveyor belt therein while being compressed into a desired shape thereby bonding materials in said aggregate into an integrated three-dimensional array of foam-filled compartments.

Claim 15

A method for the manufacture of foamed moldings comprising a compartmented structure formed of a multiplicity of compartments of randon shape joined together in a three-dimensional array, each compartment being defined by a solid wall the average thickness of which is at least 0.1mm., each compartment being substantially completely filled with foamed polyethylene which comprises: providing an aggregate of foamable materials, each comprising a layer of thermoplastic material having a thickness of at least 0.1mm. capable of forming compartment walls of said structure enclosing a core of unfoamed polyethylene having a diameter of between about 5 to 50 mm. containing a foaming agent and a cross-linking agent, and heating and expanding said aggregate in a furnace having a conveyor belt therein while being compressed into a desired shape thereby bonding materials in said aggregate into an integrated three-dimensional array of foam-filled compartments.