Process of making an aromatic polyetherketone fiber product

• US 4,747,988 A
• Filed: 06/14/1985
• Issued: 05/31/1988
• Est. Priority Date: 05/10/1985
• Status: Expired due to Term

• Current Assignee: Invista North America Sarl (Invista)
• Original Assignee: Hoechst Celanese Corporation (Sanofi )
• Inventors: Deeg, Martin H. G.
• Primary Examiner(s): Silbaugh, Jan H.
• Assistant Examiner(s): Lorin, Hubert C.
• Application Number:
  US06/744,858
• Time in Patent Office: 1,082 Days
• Field of Search: 528/125, 425/198, 264/211.17, 264/205, 264/176.1, 264/211.22
• US Class Current: 264/211.17
• CPC Class Codes: D01D 1/106 Filtering
• CPC Class Codes: D01F 6/665 from polyetherketones, e.g. PEEK

Abstract

Filaments are produced from polymers having an inherent viscosity of at least 0.7 measured in concentrated sulfuric acid and containing in the polymer chain at least 50 percent of the repeating units: ##STR1## by melting the polymer and heating the melt to a temperature of from about 20° C. to about 80° C. above the melting point of the polymer, passing the melt through a filter pack having a filtering area of at least about 8 in² and a total volume of at least about 1.2 in³ per pound of polymer extruded per hour, and containing inert, irregularly shaped particles having a mesh size of about 25 to 140 to provide a pressure drop at least about 800 psig., extruding the melt through spinning openings of desired shape to form filaments and passing the filaments immediately upon extrusion through a heating zone maintained at a temperature of about 200° to 320° C. and having a length of about 3 to 12 inches. The process is capable of producing fibers and yarns having a dpf of about 2.8 to just below 15, a tenacity of about 1 to 4.5 grams per denier, an elongation at break of about 15 to 200 percent and a modulus of about 20 to 80 grams per denier.

Claims

1. A process for producing filaments each having a denier of about 2.8 to 15 and superior heat and solvent resistance, excellent electrical properties, and satisfactory mechanical properties in the as spun state, from a polymer having an inherent viscosity of at least 0.7 measured in concentrated sulfuric acid and containing in the polymer chain at least 50 percent of the repeating units:

##STR10## said polymer having properties which cause it to be difficult to spin into filaments which comprises melting the polymer and heating the melt to a temperature in the range of from about 20°

C. above to about 80°

C. above its melting point, said heat melt having a high melt viscosity, passing the melt through a filter pack having a filtering area of at least about 8 in² and a total filter volume of at least about 1.2 in³ per pound of polymer extruded per hour, said filter pack containing inert irregularly shaped particles having a mesh size of about 25 to 140 to provide a pressure drop of at least about 800 psig, extruding the melt through spinning openings of desired shape and a diameter of about 0.009 to 0.013 inch to form said filaments, passing said filaments immediately upon extrusion through a heating zone maintained at a temperature of about 200°

to 320°

C. and having a length of about 3 to 12 inches and taking up said filaments at a speed of at least 325 mpm.

2. The process of claim 1 wherein the polymer consists solely of said repeating units in the polymer chain and the melt is heated to a temperature of from about 355°

C. to about 415°

C.

3. The process of claim 1 wherein the filter particles have a mesh size of about 25 to 140.

4. The process of claim 3 wherein the filter particles are shattered metal.

5. The process of claim 1 wherein the filter pack has a filtering area in the range of about 15 to 25 in², a total volume of about 1.6 to 2.1 in³ per pound of polymer extruded per hour and a pressure drop of about 950 to 3000 psig.

6. The process of claim 4 wherein the melt from the filter pack is further filtered by passing it through openings less than 20 microns in size prior to being passed through said spinning openings to form filaments.

7. The process of claim 5 wherein said filaments are collected at a point within about 15 to 50 inches from said spinning openings to form a yarn.