Cost of castings produced by lost-vaning mold process

Release time:

2021-02-02 11:55

Source:

Taking a single cylinder block with a single weight of 42KG, a size of 700*400, an annual output of 5000T, 400 pieces per day and cast iron material as an example, the cost analysis is as follows:

**1, white mold raw material cost.**

Since the density of molten iron is 7.8 kg/m and the density of EPS raw material is 0.02 kg/m, the mass ratio of EPS to molten iron with the same volume is about 1:400, and 2.5kgEPS raw material is required to produce 1 ton of cast iron. The market price of EPS raw materials is about 13000 yuan/ton, that is, 13 yuan/kg. Therefore, the EPS cost required to produce 1 ton of cast iron is about: 13*2.5=32.5 (yuan)

**2. Cost of lost form coating**

Take Ruiou gray iron coating as an example, the price of gray iron coating is 2500 yuan/ton, that is, 2.5 yuan/kg. The shape and complexity of the production castings are different, and the amount of coating required is different. According to production experience, 1 ton of paint can brush about 30 tons of castings. Therefore, the coating cost required to produce 1 ton of cast iron is about: 2500 ÷ 30=83.33 (yuan)

**3. Labor cost**

Every day to produce 400 pieces of single cylinder, 8 hours of production, need 400 white mold model.

It is preliminarily set that a set of lost matrix molds can produce 2 white models at a time and once every 6 minutes, I .e. the number of molding machines required is 400 ÷ 8 ÷[2 ×(60 ÷ 6)]= 2.5, I .e. 2-3.

There are about 10 people in the white area and about 5 people in the black area. White area because the labor intensity is relatively small, the working environment is better, so generally use female workers; black area with male workers. Wage levels vary from region to region, and here we take an average of $150 per day for male workers and $50 per day for female workers.

Therefore, the labor cost required to produce 1 ton of cast iron is about (150*5 50*10)/(42*400)= 74.4 (yuan)

**4. Consumables Cost**

▶ **Electricity**

Due to the different equipment selection of each production line, the installed power is not the same. Taking a single-shift 5000T/year production line as an example, the total installed power of the whole line is about 130KW, the power of sand treatment equipment is 70KW/hour, and it takes 8 hours to treat molding sand. The negative pressure system is 37KW * 2 motor and works 4 hours a day. That is, 70*8 37*2*4=856, that is, 856*0.8 yuan/degree = 684.8 yuan/day.

Therefore, the cost of electricity required to produce 1 ton of cast iron is about 684.8/16.7=41 (yuan)

▶ **Steam:**Mainly used in white area and drying process.

Take 1T coal-fired boiler as an example, coal is 300kg per day, and the unit price of coal is 0.9 yuan/kg.

Therefore, the coal cost required to produce 1 ton of cast iron is about 300*0.9/16.7T = 16.17 (yuan)

▶** ****Water, jewel sand**

Recycle use, the loss is very small, can be ignored.

**5. Sum of production cost of lost pattern**

The total cost of 1 ton cast iron lost mold production line is:

32.5 83.33 74.4 41 16.17=247.7 yuan

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