(A) ;1-(3-SUBSTITUTED BENZYL)-3-HALOGENO-4-(1-HALOGENOALKYL)-2-PYRROLIDINONE DERIVATIVE AND HERBICIDE CONTAINING THE SAME DERIVATIVE AS ACTIVE INGREDIENT

摘要

PURPOSE:To uniformize the mesh of a net-like body and enhance its draw ratio by a method wherein the ratio of the surface speeds of a pair of pressure roller is set to be equal to the aimed-at draw ratio in order to longitudinally press and stretch the net-like body between the roll on low speed side and that on high speed side by running the net-like body along the low speed side of the pressure rollers. CONSTITUTION:The surface speed of a pressure roller 6' is faster than that of a pressure roller 6 by the ratio equal to the longitudinal draw ratio. The temperatures of heated preheating rollers 2 and 3 and of the pressure rolls 6 and 6' are determined experimentally within the temperature range which is lower than the crystal melting point or softening point of the thermoplastic resin of which a net-like body put into operation is made. The nip between the pressure rollers 6 and 6' is a magnitude, which is smaller than the thickness of a net-like body 1 and causes to flatten the intersections of the warps and woofs of the net-like body to the same thickness as that of the remaining thread-like materials without narrowing the width of the net-like body 1. Because the net-like body 1 is rolled (stretched) by passing through the nip of the pressure rollers 6 and 6', which is smaller than the thickness of the unstretched net-like body 1, the region to be stretched is very narrow and the stretching is performed in the perfectly lateral straight line 1. Consequently, the meshes are neatly made uniform and at the same time the draw ratio can be enhanced.