| 摘要 |
A non thixotropic aqueous slurry for the production of investment moulds which comprises silica sol, water insoluble fibres, 10-50 % by weight uncalcined clay and a refractory material. Also disclosed is an aqueous binder which comprises silica sol, water insoluble fibres and 10-50 % by weight uncalcined clay and a dry mix of water insoluble fibres, 10-50 % by weight uncalcined clay and refractory material. The fibres can be nylon, polypropylene, acrylic, polyester, modified acrylic, viscose, rayon, carbon or aramid with a dernier of 3-20, a length of 0.25-1.5 mm and formed by grinding. The refractory can be calcined mullite, Mollochite-200 or fused silica. The clay can be uncalcined china clay. |
