Claims
- 1. A non-drawn multifilament yarn of a thermoplastic polymer based on tetrafluoroethylene, with a Melt Flow Index (MFI) from 7 g/10' to 16.3 g/10' according to ASTM D2116 standard, said multifilament yarn consisting of a plurality of filaments produced by extruding said thermoplastic polymer through an extrusion die having a plurality of holes with a hole density of from 10 to 300 holes/cm.sup.2 , cooling said extruded polymer, and directly obtaining said yarn from the cooled extruded polymer,
- wherein each filament of said multifilament yarn has a diameter between 10 and 150 .mu.m, an ultimate tensile strength from 9.8 to 45 MPa at 200.degree. C. which is at least double with respect to the ultimate tensile strength of a specimen of the same polymer obtained by compression molding according to the ASTMD3307 or ASTM D2116 standard, and a maximum shrinkage at 200.degree. C. lower than 10%.
- 2. A multifilament yarn according to claim 1, wherein the hole density of said die utilized to extrude the thermoplastic polymer is between 10 and 150 holes/cm.sup.2.
Priority Claims (1)
Number |
Date |
Country |
Kind |
MI92A2476 |
Oct 1992 |
ITX |
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Parent Case Info
This is a divisional, of U.S. application Ser. No. 08/144,189, filed Oct. 27, 1993, now U.S. Pat. No. 5,460,882.
US Referenced Citations (15)
Non-Patent Literature Citations (3)
Entry |
Dictionary Of Fiber & Textile Technology, 1965, p. 143. |
European Search Report dated Mar. 1, 1994, with Annex to the European Search Report on European Patent Application No. EP 93 11 6783. |
Chem. Abstract vol. 110, No. 8, 20 Feb. 1989 Abstract No. 59434n, Hirotaka Nishiyama et al. |
Divisions (1)
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Number |
Date |
Country |
Parent |
144189 |
Oct 1993 |
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