Ultra high molecular weight polyethylene fibers
View Patent ↗A method for the production of films/fibers of UHMWPE below 3 mils and preferably about 2 mils in thickness. The process involves calendering and/or drawing the materials of the prior art under careful tension control at a temperature above the melting point of the UHMWPE material. Before and after subsequent slitting, and/or fibrillation, UV resistance treatments, etc the thin films/fibers thus produced find use in such diverse applications as personal armor, dental floss, and sails for sail boats.
1. An ultrahigh molecular weight polyethylene slit film fiber produced by a method comprising drawing, calendering or drawing and calendering an input material of ultra high molecular weight polyethylene having a thickness equal to or greater than 3 mils at a temperature above its melting point under carefully controlled tension and slitting the material with knives, heated to a temperature above the melting point of the ultrahigh molecular weight polyethylene to provide an even or smooth cut surface on the slit film fiber.
2. The ultra high molecular weight polyethylene slit film fiber of claim 1 wherein said ultrahigh molecular weight polyethylene slit film fiber has a thickness below about 3 mils.
3. The ultra high molecular weight polyethylene slit film fiber of claim 2 wherein calendering is performed at a temperature of between about 145° C. and about 170° C.
4. The ultra high molecular weight polyethylene slit film fiber of claim 2 wherein calendering is performed at a temperature of between about 150° C. and about 163° C.
5. The ultra high molecular weight polyethylene slit film fiber of claim 3 wherein calendering is performed at a temperature of between about 152° C. and about 159° C.
6. The ultra high molecular weight polyethylene slit film fiber of claim 1 wherein said carefully controlled tension is between about 0.1 and about 6 g/denier.
7. The ultra high molecular weight polyethylene slit film fiber of claim 3 wherein said carefully controlled tension is between about 0.1 and about 2 g/denier.
8. The ultra high molecular weight polyethylene slit film fiber of claim 1 wherein drawing is performed at a temperature of between about 150° C. and about 170° C.
9. The ultra high molecular weight polyethylene slit film fiber of claim 8 wherein drawing is performed at a temperature of between about 150° C. and about 163° C.
10. The ultra high molecular weight polyethylene slit film fiber of claim 9 wherein drawing is performed at a temperature of between about 152° C. and about 159° C.
11. The ultra high molecular weight polyethylene slit film fiber of claim 8 wherein said carefully controlled tension is between about 2.0 and about 6.0 g/denier.
12. The ultra high molecular weight slit film fiber of claim 1 that has been fibrillated after drawing, calendering or drawing and calendering.
13. An ultra high molecular weight polyethylene slit film fiber having a generally rectangular cross-section and smooth cut edges.
14. The ultra high molecular weight polyethylene slit film fiber of claim 13 wherein said ultrahigh molecular weight polyethylene slit film fiber has a thickness below about 3 mils.