Process for preparing moulded polyurethane material

摘要

Process for preparing a polyurethane material in a mould in which process the following steps are conducted: 1. an external mould release agent is applied onto at least those surfaces of the mould which will be in contact with the ingredients used for preparing the polyurethane material and/or the finished polyurethane material; 2. the ingredients to be used for preparing the polyurethane material are fed into the mould; 3. the ingredients are allowed to react and to form the polyurethane material; 4. the polyurethane material so formed is removed from the mould and 5. steps 2,3 and 4 are repeated at least 10 times without repeating step 1, wherein at least 25% by weight of the ingredients used to make the polyurethane material, excluding water in this calculation when used, consist of polyether polyol having a functionality of 2-6, an equivalent weight of 500-5000 and an oxyethylene content of at least 50% by weight.