High tenacity, high modulus filament

• US 6,448,359 B1
• Filed: 03/27/2000
• Issued: 09/10/2002
• Est. Priority Date: 03/27/2000
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kavesh, Sheldon
• Primary Examiner(s): Wu, David W.
• Assistant Examiner(s): Cheung, William K
• Application Number:
  US09/537,461
• Time in Patent Office: 897 Days
• Field of Search: 526/352, 525/55
• US Class Current: 526/352
• CPC Class Codes: D01D 4/02 Spinnerettes alloys therefor C22C
• CPC Class Codes: D01F 6/04 from polyolefins
• CPC Class Codes: F41H 5/0471 Layered armour containing fibre- or fabric-reinforced layers in combination with ceramic layers F41H5/0428, with metal layers F41H5/0457
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 442/2623 Ballistic resistant
• CPC Class Codes: Y10T 442/3667 Composite consisting of at least two woven fabrics bonded by an interposed adhesive layer [but not two woven fabrics bonded together by an impregnation which penetrates through the thickness of at least one of the woven fabric layers]
• CPC Class Codes: Y10T 442/622 Microfiber is a composite fiber
• CPC Class Codes: Y10T 442/629 Composite strand or fiber material

Abstract

Polyethylene solutions are extruded through a multi-orifice spinneret into a cross-flow gas stream to form a fluid product. The fluid product is stretched at a temperature at which a gel will form at a stretch ratio of at least 5:1 over a length of less than about 25 mm with the cross-flow gas stream velocity at less than about 3 m/min. The fluid product is quenched in a quench bath consisting of an immiscible liquid to form a gel. The gel is stretched. The solvent is removed from the gel to form a xerogel and the xerogel product is stretched in at least two stages to produce a polyethylene yarn characterized by a tenacity of at least 35 g/d, a modulus of at least 1600 g/d and a work to break of at least 65 J/g. The yarn is further characterized by having greater than about 60% of a high strain orthorhombic crystalline component and, optionally, a monoclinic crystalline component greater than about 2% of the crystalline content. Composite panels made with these yarns exhibit excellent ballistic resistance, e.g., SEAC of 300 J-m²/Kg or higher against 0.38 caliber bullets using test procedure NILECJ-STD-0101.01.

Claims

1. A polyethylene multi-filament yarn having a tenacity of at least about 35 g/d, a modulus of at least 1600 g/d, a work-to-break of at least about 65 J/g, as measured by ASTM D2256, wherein said yarn has a microstructure containing a high strain orthorhombic crystalline component comprising more than about 60% of the orthorhombic crystalline component.

2. The multi-filament yarn of claim 1 wherein the yarn has a modulus between about 1800 g/d and about 2500 g/d.

3. The multi-filament yarn of claim 1 wherein the yarn has a tenacity between about 35 g/d and about 60 g/d.

4. A polyethylene multi-filament yarn having a tenacitly of at least about 35 g/d, a modulus of at least 1600 g/d, a work-to-break of at least about 65 J/g, as measured by ASTM D2256, wherein said yarn has a microstructure containing a monoclinic crystalline component greater than about 2% of the crystalline content.

5. The multifilament yarn of claim 4 wherein the yarn has a modulus between about 1800 g/d and about 2500 g/d.

6. The multi-filament yarn of claim 4 wherein the yarn has a tenacity between about 35 g/d and about 60 g/d.

7. A polyethylene multi-filament yam having a tenacity of at least about 35 g/d, a modulus of at least 1600 g/d, a work-to-break of at least about 65 J/g, as measured by ASTM D2256, wherein said yarn has a microstructure containing a high strain orthorhombic crystalline component comprising more than about 60% of the orthorhombic crystalline component and a monoclinic crystalline component greater than about 2% of the crystalline content.

8. The yarn according to claim 7 comprising about 60 polyethylene filaments and having a tenacity of about 45 g/d and a modulus of about 2200 g/d.

9. A composite panel comprising the polyethylene yarn of claim 7.