| 摘要 |
PURPOSE:To form a thin film, good in longitudinal and transversal strength balance, by a method wherein the linear low-density polyethylene, having specified melt index, meting tension and the ratio of fluidity, is formed by inflation forming under a condition that the cooling speed index and the number of orientation, shown by specified formula, become within specified ranges. CONSTITUTION:The linear low-density polyethylene is the copolymer of ethylene and other alpha-olefin and is different from conventional ramificated low-density polyethylene resin. The linear low-density polyethylene, having the melt index (MI) of 0.1-2.0g/10min the melting tension (MT) of 3-10g and the ratio of fluidity of 35-80, is optimum for using in this invention. This specified linear low-density polyethylene is formed by inflation forming with the cooling speed index (tau...shown by formula (1)) of 2-7 and the orientation index (chi...shown by formula (II)) of 1.5-5. |
