| 摘要 |
<p>Cold-setting casting mould and core compsns. contg. a furan resin. phenoplast, polyesterol, polyetherol or alkyd resin binder system are admixed with pref. 0.5-5 wt. % , w.r.t. compsn,. of crude perlite, esp. having grain-size 0-2.5 (o.06-0.5) mm. The binders consist esp. of furan resins or phenoplasts and acid-acting cpds. or polyurethane reactants, opt. in combination with standard accelerators, e.g. amines or heavy metal cpds. Casting defects, e.g. foliated ripple effects, are prevented without causing increased gas formation in casting, smell and environmental pollution.</p> |
