摘要 |
Substantially all of the cellular membranes of polyurethane foam are ruptured by impinging a water jet upon at least one surface of a foam sheet, the applied hydrodynamic force being sufficient to rupture the cellular membranes without destroying the skeletal structure of the foam. The resistance of the cellular membranes to rupture by the hydrodynamic force is lessened by stretching the foam sheet in at least one direction prior to impinging the water jet. |