| 摘要 |
<p>The phenolic resin (I) contains hexamethylene tetramine. Each sand particle is completely covered by (a) a liquid layer of (I), (b) a lubricant layer (II). (II) is a wax used in proportion of 0.5-15 wt.% of (I) and is added as powder, paste or in solution. The sand particles when coated are free running, have good storage life, are not powdery and do not stick together. The product is used in production of self lubricated shell moulds, and is an improvement on use of mixtures of sand and resin giving more uniform quality of moulds.</p> |
