Polymer Fiber, Its Use And Process For Its Manufacture

Abstract

The present invention relates to a novel polymer fiber obtainable by melt-spinning of a polymer, the use of the fiber and a process for the manufacture of the fiber.

1 . A process for improving the fire resistance of concrete, mortar, plaster, cement or refractory material comprising incorporating a polymer fiber as an additive in the concrete, mortar, plaster, cement or refractory material,
 wherein the polymer fiber is obtained by melt-spinning of a polymer and subsequent treatment of the fiber with ionizing radiation, wherein the polymer is a polypropylene homopolymer, a polypropylene copolymer or a mixture thereof, the polymer fiber has a length in the range of 0.1 to 40 mm, a diameter in the range of about 12 μm to about 170 μm and an MFI of more than 500 g/10 min, measured according to DIN EN ISO 1133.   
     
     
         2 . The process according to  claim 1 , wherein the material is concrete, and the polymer fiber has an MFI value of higher than about 1000 g/10 min, measured according to DIN EN ISO 1133. 
     
     
         3 . The process according to  claim 1 , wherein the treatment of the fiber comprises applying ionizing radiation to the polymer fiber in a dosage range of greater than 100 kGy to about 300 kGy. 
     
     
         4 . The process according to  claim 1 , wherein the polymer fiber has a diameter from about 12 μm to about 50 μm. 
     
     
         5 . The process according to  claim 1 , wherein the polymer fiber has a length from about 2 mm to about 20 mm. 
     
     
         6 . The process according to  claim 1 , wherein the polymer fiber has a length from about 8 mm to about 40 mm, optionally from about 8 mm to about 20 mm. 
     
     
         7 . The process according to  claim 1 , wherein the material is concrete, wherein the treatment of the fiber comprises applying ionizing radiation on the polymer fiber in a dosage range of greater than 100 kGy to about 300 kGy, and the polymer fiber is present in the amount of less than about 2 kg of the polymer fiber per cubic meter of the concrete material. 
     
     
         8 . The process according to  claim 1 , wherein the polymer fiber is present in the amount of less than about 2 kg of the polymer fiber per cubic meter of said material. 
     
     
         9 . The process according to  claim 1 , wherein the material is concrete, and the polymer fiber is present in the amount of less than about 2 kg of the polymer fiber per cubic meter of the concrete material. 
     
     
         10 . The process according to  claim 1 , wherein the material is concrete, and the polymer fiber is present in the amount of about 0.1 kg to about 1.5 kg, optionally about 0.1 kg to about 1 kg of the polymer fiber per cubic meter of the concrete material. 
     
     
         11 . The process according to  claim 1 , wherein the material is concrete, and the polymer fiber is present in the amount of about 0.25 kg to about 1 kg, optionally about 0.25 kg to about 0.75 kg of the polymer fiber per cubic meter of the concrete material.