SENSTAT PRODUCTS & TECHNOLOGIES, INC.;BENJAMINSEN, EDWARD
发明人:
BENJAMINSEN, EDWARD
申请号：
WO2008US69486
公开号：
WO2010005432(A1)
申请日:
2008.07.09
申请国别(地区):
世界知识产权组织国际局
年份:
2010
代理人:
摘要：
A foam form sheet material having a first large surface comprising substantially only closed cells and an opposite large surface and an interior comprising substantially only open cells. This material comprises at least one of a cross linked olefin polymer or copolymer. The sheet material is made by thoroughly admixing a suitable polymer with a blowing agent and a cross linking agent. The mixture is brought to and maintained under positive pressure and elevated temperature in a two roll mill means for a time sufficient to enable the cross linking agent to initiate cross linking and for the blowing agent to initiate the formation of a plurality of substantially similarly sized and shaped closed cells. The sheet material containing closed cells is then disposed in a second two roll mill means having a nip that is larger than the thickness of the partially foamed sheet material and maintained under elevated temperature and pressure conditions sufficient to initiate further cross linking and foaming. The fully cross linked closed cell foam form material is then compressed by applying sufficient mechanical pressure, such as by an additional two roll mill means, to rupture the closed cells that are disposed in the interior of the foam form sheet material into an open cell configuration while maintaining the cells that constitute the outer large surfaces of the material in closed cell form. The mechanical pressure is then released whereby enabling the foam form material to at least partially revert to its pre cell rupture thickness. This material is then longitudinally sliced to form at least two separate layers of foam form material each having a large surface that is composed predominantly of closed cells and an opposite large surface and an interior that are composed predominantly of open cells of substantially the same geometry. This material is well suited to be used as a filter medium.
