Just comparing carbon emissions is not comprehensive. The reduction of carbon emissions in the casting production process does not mean that the casting production time will also be shortened. Due to the discreteness of time, the production time is calculated from the beginning of the sand mixing process to the end of the inspection process. According to the arrangement of the actual equipment of a factory, it takes 4 minutes for FE1 to process each hole, and 40 minutes for three machines to process together in the experiment, while FE2 and FE3 can complete the production of all sand cores in 5 minutes, and the core making time of FE2 and FE3 is the same, and this part of FE1 is relatively long. In addition, in the cleaning department, the cooling time is 24 hours. According to the formula, the production time under the influence of process design characteristics of three process plans is calculated, and the following figure is obtained.

As you can see from the figure, the production time of FE2 is 1.353% less than that of FE1, and the production time of FE1 FE3 is 1.454% less than that of FE1, and the production time of optimized FE3 is the least. FE1 needs a series of operations such as machining and drilling. It can be seen from the figure that although FE1 takes 0.13h and 0.097h less time in the sand engineering department than FE2 and FE3 respectively, the production time in the cleaning department is 0.667 h and 0.679h longer than that of FE2 and FE3. The production time of the FE1 cleaning department has great potential to save. It can be seen from the above that the total production time of the sand core process (FE2 and FE3) is less, which indicates that the production efficiency is higher when using the sand core hole-making scheme to produce 10 castings. At the same time, through the optimization of the correlation parameters of casting geometric structure characteristics, FE3 reduces the total production time, which further optimizes the production efficiency of sand core hole-making process.