How to choose modeling and core making?

Modeling and core-making methods should be considered comprehensively according to the shape, size, quantity, production batch and actual production conditions of the factory. Under the possible production conditions in the factory, the molding and core-making methods that can meet the quality requirements of castings and are efficient and economical should be adopted as far as possible. The selection of modeling and core-making methods should refer to the following principles:

(1) If the wet mold can meet the quality requirements of castings, priority should be given to the wet mold.

The green sand does not need to be dried, the material cost is low, the production cycle is short, it is easy to organize mechanization and automatic production, and the production efficiency is high. On the premise of satisfying the quality of castings, priority should be given to wet production.

Problems that should be paid attention to when applying wet production;

① When the casting height is large, the static pressure of the metal may exceed the strength of the wet mold, which may lead to the collapse of the mold after pouring. Therefore, the castings with higher height should adopt dry sand mold or self-hardening sand mold with higher strength.

(2) When the casting has a large horizontal plane at the pouring position, it is not suitable to use wet mold to avoid sand inclusion caused by long-term baking.

(3) The sand mold that has not been poured for a long time should not be wet, so as not to cause water evaporation and reduce the strength of the sand mold.

(2) The production batch of castings should be considered in the selection of modeling and core-making methods.

① The automatic boxless high pressure molding production line with high productivity should be adopted for the mass production of small castings. Box-less high pressure molding production line occupies a small area and does not need a sand box. It has high productivity and is suitable for producing a large number of small castings.

② high pressure molding production line with box can be used for mass production of medium-sized castings, and core-making methods such as cold and hot box or shell core with high precision and production efficiency can be adopted.

③ Resin self-hardening sand molding and core-making can be used to ensure the quality of large-scale castings produced in medium batch. For long-term molded products, multi-box molding and split-box molding should be used to improve efficiency and product quality.

④ For large castings produced in small batches, only manual molding or pit molding can be used.

(3) Determine the modeling and core-making method according to the production conditions of the factory.

The variety, quantity and quality of the main products produced by different foundries are different, and the production equipment and production conditions also have their own characteristics. When choosing the molding and core-making methods, we should choose the production method that can not only ensure the quality of castings, but also be economical and efficient according to the production conditions and casting requirements of our factory.