Method and apparatus for forming an article from recyclable plastic materials

A method for forming an article having a multiple open cell structure in which a network of interconnecting walls define a plurality of openings through said article, comprising:

• delivering a flow of molten plastic material to an extruder;
• pressurizing said molten plastic material;
• forcing said material, under pressure, through an extrusion die, said die being shaped to form an elongated continuous member having a cross section consisting of internally disposed interconnected wall surfaces defining elongated cavities within said continuous member, and said die being positioned such that said elongated continuous member is discharged from said die in a vertically downward direction;
• immersing said elongated continuous member in water;
• cooling said elongated continuous member in said water to a temperature sufficient for the member to be self-supporting when placed in a horizontal position;
• removing said elongated continuous member from the water;
• and,
• cutting said elongated continuous member into a plurality of transverse sections each of which form an article having a multiple open cell structure in which the interconnected wall surfaces defining the elongated cavities within the continuous member define a plurality of openings through the multiple open cell structure of the article.

An apparatus for simultaneously heating, mixing, melting and conveying recyclable thermoplastic materials, comprising:

• an elongated shell having a first end, a second end, and a cylindrical interior wall surface concentrically disposed about a longitudinal axis and extending between said first and second ends;
• a rotor rotatably mounted in said shell in coaxial alignment with said longitudinal axis and having a predefined length, an exterior cylindrical wall surface spaced radially inwardly from the interior wall surface of said shell and extending along said length and cooperating with said exterior wall surface to form an annular cavity therebetween, and a plurality of elongated members each extending radially outwardly from said exterior wall surface of said rotor to a position proximate the interior wall surface of said shell, said elongated members being arranged in radially and axially spaced relationship in a spiral pattern around and along said longitudinal axis;
• an inlet port forming an opening through said shell at a position adjacent the first end of said shell;
• a discharge port forming an opening proximate the second end of said shell;
• a means for heating the interior wall surface of said shell;
• and,
• a means for rotating said rotor.

A die for continuously forming an elongated member having a cross sectional structure consisting essentially of a plurality of internally disposed interconnected wall surfaces defining elongated cavities within said member, comprising:

• a top wall;
• a plurality of side walls cooperating with said top wall to define an open-ended cavity and having an opening through at least one of said side walls communicating with a pressurized source of fluid material;
• and,
• a plurality of internal surface forming members, said members being disposed within said open-ended cavity in spaced relationship with said side walls and with each other and having one end attached to said top wall of the die and at least one material shaping surface adjacent the open end of said cavity.