Method of preparing polyamide

Abstract

When the polyamide film is slit and wound, moisture absorption of the polyamide film in the slitting process is controlled, thereby preventing wrinkles from being mixed into the product roll, and obtaining a polyamide film roll with less wrinkles on the winding core . When slitting a rolled polyamide film into strips, use a polyamide film with a hygroscopic elongation of 2.0% or less, and control the environment at the time of slitting to an absolute humidity of 0.006 to 0.018 kg / kg.

Description

technical field [0001] The present invention relates to a method for the manufacture of polyamide membranes. Background technique [0002] Polyamide films containing polyamide resins generally have excellent mechanical properties, optical properties, thermal properties, gas barrier properties, and toughness, and are widely used mainly for packaging purposes, especially food packaging applications. [0003] Polyamide membranes are generally manufactured as follows. That is, after the polyamide resin is extruded from a T-die or a circular die to form a film, it is biaxially stretched by a flat simultaneous biaxial stretching method, a flat sequential biaxial stretching method, a blow molding stretching method, etc. After stretching and heat setting, it is temporarily wound up into a wide and long original roll (original roll) with a winder. Then, the film fed out from the original roll is cut into a desired width and length by a slitter, and shipped and sold as a finished ro...

AI Technical Summary

Problems solved by technology

[0008] However, in the method described in Patent Document 1, it is difficult to uniformly and rapidly cool the film with a spray gun, and therefore there is a problem that various physical properties of the film vary.

In addition, the slipperiness decreases due to moisture absorption, and various defects may occur in the slitting process or conversion process

[0009] The method described in Patent Document 2 is effective when the width is very small after being cut into strips like a tape, but there is a problem that it is difficult to control each tension when it has a certain width like a packaging film.