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Claim 1

A METHOD OF MAKING A FOAMED MATERIAL CONSISTING ESSENTIALLY OF POLYETHYLENE HAVING SUBSTANTIALLY UNIFORM CELLS OF AVERAGE SIZE OF 5-20 MILS COMPRISING THE STEPS OF: (1) INTIMATELY INCORPORATING WITHIN POLYETHYLENE (A) 1-5 PARTS BY WEIGHT OF SAID POLYETHYLENE OF A NITROGEN RELEASING BLOWING AGENT SELECTED FROM THE GROUP CONSISTING OF DINITROSOPENTAMETHYLENETETRAMINE, P,P'' - OXYBIS(BENZENESULFONYLHYDRAZIDE), AND AZODICARBONAMIDE, AND (B) 0.1-4 PARTS BY WEIGHT OF SAID POLYETHYLENE OF A BLOWING AGENT ADJUNCT SELECTED FROM THE GROUP CONSISTING OF GLYCERYL ONOSTEARATE, PROPYLENEGLYCOL MONOSTEARATE, ETHYLENEGLYCOL MONOSTEARATE, DIETHYLENEGLYCOL MONOSTEARATE, POLYETHYLENEGLYCOL MONOSTEARATE AND POLYDIMETHYLSILOXANE, (2) MOLDING THE EXPANDABLE POLYMER COMPOSITION AT A TEMPERATURE AT LEAST AS HIGH AS THE AS THE SOFTENING POINT OF SAID POLYETHYLENE AND THE NITROGEN GENERATING TEMPERATURE OF THE BLOWING AGENT, (3) MAINTAINING THE TEMPERATURE FOR A TIME SUFFICIENT TO CAUSE EXPANSION OF CELLS TO THE DESIRED SIZE, AND (4) SAID PROCESS BEING CHARACERTIZED BY THE ABSENCE OF ANY APPRECIABLE CROSS-LINKING OF SAID POLYETHYLENE WITH SAID BLOWING AGENT, WHEREBY SAID RESULTING FOAMED MATERIAL IS SOLUBLE IN XYLENE AT 95*C.

Claim 2

A METHOD OF MAKING A FOAMED MATERIAL CONSISTING ESSENTIALLY OF POLYETHYLENE HAVING SUBSTANTIALLY UNIFORM CELLS OF AVERAGE SIZE OF 5-20 MILS COMPRISING THE STEPS OF: (1) INTIMATELY INCORPORATING WITHIN POLYETHYLENE (A) 1-5 PARTS BY WEIGHT OF SAID POLYETHYLENE OF A NITROGEN RELEASING BLOWING AGENT SELECTED FROM THE GROUP CONSISTING OF DINITROSOPENTAMETHYLENETETRAMINE, P,P'' - OXYBIS(BENZENESULFONYLHYDRAZIDE), AND AZODICARBONAMIDE, AND (B) 0.1-4 PARTS BY WEIGHT OF SAID POLYETHYLENE OF A BLOWING AGENT ADJUNCT SELECTED FROM THE GROUP CONSISTING OF GLYCERYL ONOSTEARATE, PROPYLENEGLYCOL MONOSTEARATE, ETHYLENEGLYCOL MONOSTEARATE, DIETHYLENEGLYCOL MONOSTEARATE, POLYETHYLENEGLYCOL MONOSTEARATE AND POLYDIMETHYLSILOXANE, (2) MOLDING THE EXPANDABLE POLYMER COMPOSITION AT A TEMPERATURE AT LEAST AS HIGH AS THE AS THE SOFTENING POINT OF SAID POLYETHYLENE AND THE NITROGEN GENERATING TEMPERATURE OF THE BLOWING AGENT, (3) MAINTAINING THE TEMPERATURE FOR A TIME SUFFICIENT TO CAUSE EXPANSION OF CELLS TO THE DESIRED SIZE, AND (4) SAID PROCESS BEING CHARACERTIZED BY THE ABSENCE OF ANY APPRECIABLE CROSS-LINKING OF SAID POLYETHYLENE WITH SAID BLOWING AGENT, WHEREBY SAID RESULTING FOAMED MATERIAL IS SOLUBLE IN XYLENE AT 95*C.