| 摘要 |
PURPOSE:To obtain a polyolefinic resin foamed sheet reduced in thickness irregularity. CONSTITUTION:For example, a polyolefinic resin foamable sheet containing a foaming agent is irradiated with electron beam to crosslink the resin of the sheet. This crosslinked foamable sheet 1 is heated in a heating foaming oven 2 to be foamed and the foamed sheet 1' is pressed by a pair of press rolls 13 heated within a temp. range from the (m.p.-20 deg.C)-(m.p.+5 deg.C) of the resin and subsequently cooled, for example, by a pair of cooling rolls 14 to obtain a foamed sheet. In this case, the foamable sheet is pressed by a pair of press rolls 13 and subsequently quenched at a cooling speed of at least 5 deg.C/sec by a pair of cooling rolls 14 to obtain the foamed sheet still more reduced in thickness irregularity and good in surface treatment properties such as corona discharge treatment or the like. |
