| 摘要 |
PURPOSE:To eliminate various defects occuring in water-soluble glue mixing cold water-insoluble glue, cold water-soluble glue and a water-based phenolic resin. CONSTITUTION:A water-soluble glue binder softens with time as it absorbs water from the moisture in the atmospheric air and the water of green sand molds after molding of molds. In order to eliminate this defect, cold water-insoluble glue, cold water-soluble glue and a water-based phenolic resin are mixed in the water-soluble glue binder. The mixing weight ratios of the cold water- insoluble glue and the water-soluble glue are set at 99:1-20:80 and the mixing weight ratios of the mixture of the cold water-insoluble glue and the water- soluble glue and the water-based phenolic resin are set at 95:5-20:80. The water- based phenolic resin is a mixture of 1 or >=2 kinds of water-soluble phenolic resins, emulsion type phenolic resins and modified water-based phenolic resins. |
