| 摘要 |
<p>PURPOSE:To increase moisture resistance, oxygen barrier properties, transparency and shelf stability of an accommodated material by forming a sheet of specified overall light transmittance, haze and crystalline orientation of molecular chain axis by means of use of crystalline polyethylene family resin. CONSTITUTION:Crystalline polyethylene resin is melted and kneaded, and a film is manufactured by the forming method such as the T-die method or the inflation method, and rolling is applied to a sheet for rolling thus manufactured. Rolling is applied between a couple of rolls at the temperature of 15 deg.C lower than the melting point of polyolefin family resin, and selected pressurizing rate is usually 60 - 95%, preferably 70 - 90%. Thus, a packaging sheet having 85% or more overall light transmittance and 5% or less haze, preferably 90% or more overall light transmittance and 3% or less haze, and 0.65 or more crystalline orientation found out by the X-ray diffraction method, preferably 0.70 or more, is formed.</p> |
