| 摘要 |
<p>PURPOSE:To provide a polyethylene foam having a high rate of foaming and some continuous air bubbles by a method wherein a melt index, a mixing rate and an injection temperature of low density polyethylene and high density polyethylene are specified, volatile organic liquid is mixed with the polyethylene and injected. CONSTITUTION:To a resin mixed with a high density polyethylene having a melt index (MI) more than 10 and a low density polyethylene having a melt index (MI) less than 1 so as to cause a volume of the high density polyethylene to show 1.95/ (rho-0.9)wt%-3.5/(rho-0.9)wt% is mixed a volatile organic liquid having a boiling point (at normal pressure) lower than 100 deg.C under a high temperature and a high pressure. The mixture is cooled to such a temperature as higher than a melting point of the low density polyethylene and lower than a melting point of a high density polyethylene by 10 deg.C or more and thereafter injected into a low pressure zone. When MI is out of said range, a good foam may not be provided under such a condition as a mixing rate of a high density polyethylene is measured and noneven condition of the air bubbles is generated.</p> |
