型砂通过紧实获得强度和其它性能。本文对紧实过程中保压时间对型砂的压实变形和一些成型性能的影响进行了研究。压实的保压时间对型砂性能的影响以前很少有人研究,一般并不考虑它的影响。本文通过实验发现保压时间对型砂的某些重要的成型性能确有较大的影响。型砂是一个复杂的介质,兼有固体、液体和气体,在流变学中可以认为是一种粘弹性体和粘塑性体。通过研究,初步认识到了型砂这些流变特性。 The sand gets strength and other properties through compaction. In this paper, the effect of dwell time on the compaction deformation and some forming properties of sand during compaction is studied. The effect of compacted dwell time on the properties of sand has rarely been studied before, and its effects are generally not taken into account. In this paper, it is found through experiments that dwell time has some significant influence on some important formability of sand. Sand is a complex medium, both solid, liquid and gas, rheology can be considered as a viscoelastic body and viscoplastic body. Through the study, we initially recognized the rheological properties of molding sand.