造成消失模铸造件浇注反喷的原因及防预办法
Reasons and prevention measures for reverse spraying during casting of lost foam casting parts
消失模铸造件在浇注的时候容易出现反喷的情况，这是什么原因造成的呢？下面，为您详细分析：
Lost foam casting parts are prone to backspraying during pouring. What is the reason for this? Here is a detailed analysis for you:
1、由于泡沫模样在粘接时使用粘接胶比多那么发气量也随之增大，在浇注时就产生大量气体溢出造成反喷。
1. As the foam pattern uses more adhesive during bonding, the gas generation will also increase, and a large amount of gas will overflow during pouring, resulting in backflushing.
2、避免浇注速度过快，促使裂解气体州苗木 保定电动门 保定空压机 化粪池模具 微型蠕动泵 保定强夯 收费岛模具大量迸发。
2. Avoid excessive pouring speed, which can cause a large amount of cracking gas to burst out.
3、由于烘干房排湿能力效果不好，湿气没有排出，甚至涂层没有干透，高温与湿气接触时产生反喷。
3. Due to the poor dehumidification ability of the drying room, moisture is not discharged, and even the coating is not fully dried, resulting in backspraying when high temperature comes into contact with moisture.
4、成型泡沫模样里面水分没有排透或放置的时间比较短就直接组模，造成浇注到相应时间时反喷。
4. When the water in the molded foam pattern is not completely discharged or placed for a short time, the mold is directly assembled, resulting in reverse spraying when pouring to the corresponding time.
5、造型前使用的醇基涂料与补刷的地方多，产生大量气体造成瞬间的反喷。
5. The use of alcohol based coatings and areas for repainting before styling can result in a large amount of gas, resulting in instantaneous backspraying.
6、涂料配制中添加的白乳胶多或使用了发霉发酵涂料造成反喷。
6. Excessive addition of white emulsion in coating preparation or use of moldy and fermented coatings resulting in backspraying.
那么，防预消失模浇注反喷的办法有哪些呢？
So, what are the methods to prevent reverse spraying during pre lost foam casting?
1、泡沫模型密度要小，在确定泡沫表面质量，确定模型强度的前提下，泡沫应做得越轻越好，以减少浇注时的发气量。
1. The density of the foam model should be small. On the premise of determining the surface quality of the foam and the strength of the model, the lighter the foam, the better, so as to reduce the gas generation during pouring.
2、泡沫模型上涂料前改成要烘干，每批泡沫模型应抽检其烘干过程的重量变化，做出烘烤重量变化曲线图，只有在重量不再发生变化情况下方可上涂料。
2. The foam model should be dried before coating. Each batch of foam models should be sampled to check the weight change during the drying process, and the baking weight change curve should be made. Coating can be applied only when the weight no longer changes.
