Compositions, additives, and compounds for melt processable, foamable, and cellular fluoroploymers

The foamable composition of claim, 61 wherein said foamed cells having an average diameter of about 0.0008 inches.

A method for manufacturing foamable perfluoropolymer cellular insulation compositions, comprising:

• providing a mixture of a first composition that comprises up to about 20 weight percent of a blowing or foaming agent and a second composition that comprises up to 80 weight percent of one or more selected perfluoropolymers, heating said blend to cause melting of said first and second compositions to form a molten blend of said compositions, and extruding said molten blend to form a plurality of foamable pellets.

A process, comprising:

• extruding a composition capable of forming a cellular foamed article in an extruder wherein said extruder is specifically designed to minimize mechanical shear and increase heating thereby mitigating premature foaming during the process of melting, blending, extruding, and pelletizing said composition as well as mitigating corrosion of the extruder barrel due to passivation of acid and acidic gases evolving from the use of pellets together with the perfluoropolymers and fluoropolymers during said extrusion process.

A method of forming fluoropolymer compositions comprising:

• adding into an extruded melt of a base fluoropolymer resin, in sequential steps, sufficient talc to accomplish a loading of talc in a range of about 0.5 to 20 percent in combination with fluoropolymer resin to form a foamable composition;
• wherein said foamable composition are used for subsequent extrusion or molding processes providing cellular, foamed, or blown fluoropolymer end products.

A method of making a communications cable having flame retardant properties comprising the steps of:

• providing melt processable pellet(s) comprising fluoropolymer(s), talc, and magnesium carbonate, calcium carbonate, or both magnesium carbonate and calcium carbonate capable of forming foamed articles;
• melt processing said pellet(s) at a predetermined temperature exceeding about 525 degrees F. to ensure reaching the required temperature for foaming said pellets prior to entering an extruder, extruding a metered amount of said melted pellets around an advancing electrical conductor and allowing the composition to foam and expand to produce an insulated conductor with a chemically blown fluoropolymer insulation.