| 摘要 |
To form a shaped foundry core or mould, a binder material comprising an ethylenically unsaturated monomer or polymer is distributed on a foundry aggregate, the aggregate is shaped into the desired foundry article, and the binding material is then polymerised by means of a free radical initiator comprising a peroxide and catalytic agent. The binding material is preferably a solution of an ethylenically unsaturated polymer in a solvent of unsaturated monomeric compound or compounds, in which vinyl or acrylic unsaturation is present. This binder is suitable as a foundry binder of the cold box type wherein a room temperature, rapid gas cure is utilized. The gas, preferably sulfur dioxide, serves as the catalytic agent of the free radical initiator. Alternatively the catalytic agent may be heat. The binder collapses readily after casting of aluminium and other lightweight metals to provide complete shakeout of the core with minimum application of external energy. |
