冷法覆膜工艺研究

STUDY ON COLD FRECOATED PROCESS

本文分析了各种覆膜工艺的优缺点,指出了冷法覆膜工艺在一定条件下的必要性。并通过对覆膜砂表面覆膜情况的显微分析和硬化强度的测定,对影响(冷法)覆膜砂质量的一些主要因素及其影响结果进行了研究。认为尽可能地采用圆砂、粗砂(如45/75)和干砂(如含水重≤0.15～0.20％)、控制酒精含水量(如不高于5％)、正确使用树脂和乌洛托品的加入量以及采用混合液加料方式混砂等对获得高质量的覆膜砂均有重要作用。

Based on the authors' investigation and other researchers' articles the adva-ntages and shortcomings in various precoating process were reviewed. And thenecessity of the cold process in specified conditions was discussed. Some mainfacts effecting on the quality of (Cold Process) precoated sand their effectingresults were investigated by analyzing microscopically the resin film on the sur-face of precoated sand and measuring the strength of precoated sand. It was poi-nted out that it's importent to use round sand, coarse sand (e.g.45/75) anddry sand (e.g.moisture capacity≤0.15% or 0.20%) and to control moisturecapacity of alcohol (e.g.≤5.0%), to collect proper additive quantity of resinand it's hardener and to mill with feeding mixed liquid raw meterials in orderto high=quality coated sand.