Method of producing extrusion grade poly(arylene sulfide)

A method of processing a normally solid thermoplastic material for melt spinning into fibers comprising the steps of:

• passing molten poly(arylene sulfide) through primary filter means comprising depth type filter media comprising metallurgically bonded metal fibers and having an absolute micron rating in the range from about 45 to about 125 to provide molten primary filtered polymer;
• and
• passing said molten primary filtered polymer through secondary filter means having an absolute micron rating less than or a substantially equivalent filtration capacity greater than the absolute micron rating or the substantially equivalent filtration capacity of said primary filter means.

A method of forming fibers from a polymer comprising poly(arylene sulfide) which has previously been subjected to primary filtration through primary filter means comprising a depth type filter of metallurgically bonded metal fibers having an absolute micron rating in the range from about 45 to about 125 to form a primary filtered polymer, comprising:

• melting the primary filtered pellets to provide molten primary filtered polymer and passing said molten primary filtered polymer through secondary filter means having a maximum absolute micron rating of no more than about 80 or a substantially equivalent filtration capacity to provide molten secondary filtered polymer;
• and
• thereafter forming fibers from said secondary filtered polymer.

A method of processing a polymer comprising poly(arylene sulfide), comprising the steps of:

• passing molten polymer comprising poly(arylene sulfide) through primary filter means comprising a depth type filter comprising metallurgically bonded metal fibers and having an absolute micron rating in the range from about 45 to about 125 to provide molten primary filtered polymer;
• and
• passing said molten primary filtered polymer through secondary filter means to remove impurities which pass through said primary filter means and provide molten secondary filtered polymer.