| 摘要 |
PURPOSE:To obtain the titled foam which has good air permeability without causing deterioration of foam, by placing an open-cell non-rigid polyurethane foam sheet on a porous substrate and blowing compressed air thereon to remove cell membranes. CONSTITUTION:A non-rigid polyurethane foam sheet 2 having open cells in such a proportion that the number of cells is 50/25mm or below and having air permeability of 80cc/sec/cm<3> or above is placed on a porous substrate (e.g. conveyor made of cloth of cloth or metal gauze). Compressed air at a pressure of 4g/cm<2> or above is blown on the foam sheet 2, e.g., by using a fishtail port 1 to thereby break and remove cell membranes with air pressure, thus obtaining a polyurethane foam having no cell membranes. The foam has improved air permeability as well as liquid (e.g. water0 permeability and hence it can be used as a filter.
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