PREPARATION OF POLYETHYLENE DRAWN FILAMENT AND DRAWN FILM

摘要

PURPOSE:To obtain high strength and high modulus, by carrying out molding of the mixture of a specific polyethylene powder and a solvent at a temp. below the m.p. and then carrying out hot-drawing. CONSTITUTION:A polyethylene powder used has a wt. average MW of 4X10<5> or more and has no history of melting or dissolving after polymerization. A sheet-like material obtained by compressing the polyethylene powder under the condition of 130 deg.C and 400kg/cm<2> by means of a flat plate press has a characteristics in which the max. draw ratio in an air bath at 130 deg.C is 40 times or more. The compounding ratio of the polyethylene powder and the solvent is good when the solvent is in the range of 49-10 pts.wt. against 51-90 pts.wt. of polyethylene powder. The above described mixture is molded by adding a pressure at a temp. below the m.p. The molding is done by extrusion from a dice and it is preferable that the side cross-sectional area of an outlet of the dice hole is not larger than the side cross-sectional area of an inlet, and the cross-sectional area of the outlet is in the range of 6-80% of the cross-sectional area of the inlet.