Seamless, self-insulated foam duct and an apparatus and method for manufacturing the same

An apparatus for manufacturing a seamless duct, said duct having a polymeric foam member having a first outer insulating layer in communication with a densified inner layer surrounding a hollow core, the apparatus comprising:

• an enclosure having one or more support bars and cross bars forming a receptacle to secure the foam member, and one or more fastening mechanisms,
• a drilling station having at least one rotating cutting tube, one or more support bars and cross bars, at least one rotating cutting tube guide and one or more fastening mechanisms,
• a densifying station having at least one probe, one or more support bars and cross bars, a pulley and one or more fastening mechanisms,
• wherein the enclosure is connectable to the drilling station and densifying station.

A method for manufacturing a seamless duct, said duct having a polymeric foam member having an outer insulating foam layer in communication with a densified inner foam layer surrounding a hollow core, comprising the steps of:

• (a) securing the foam member;
• (b) heating a probe to a temperature above the glass transition temperature of the foam member;
• (c) densifying the inner foam layer by moving the heated probe in one end of the foam member through and out of the opposing end of the foam member thermoforming the densified inner foam layer and the hollow core;
• and
• (d) shaping the outer insulating layer.