With the continuous in-depth research on green sand casting, combined with the degree of mixing of green sand GS high-efficiency rotor sand mixer, as well as green sand sand recycling equipment upgrade and perfection, sanzhuji research shows that the direct impact on casting quality and molding process of wet type performance are moisture, permeability, wet state strength, fluidity, toughness and crushing index, resistance to sand trapping, the ability to scarring type defects, the amount of effective bentonite determination method, hair gas and effective coal dust content, etc.
The various properties of the type (core) sand are interrelated and mutually constrained, in the performance adjustment, must take into account the other performance changes, and affect the comprehensive performance of the sand and the use of performance, until the quality of the casting, the following correlation is sanzhuji after many tests to verify the results.
1. type (core) compact rate and the relationship between moisture: when the clay content in the sand, the sand, too little or too much moisture, the permeability of the sand will be reduced.
2. Relationship between air permeability and compacting rate: When the wet compressive strength and clay content of the sand are certain, the air permeability of the sand decreases with the increase of compacting rate.
3. Relationship between wet compressive strength and moisture: when the amount of clay is certain, with the increase of moisture, the wet compressive strength of type sand first increases, reaches the highest value and then gradually decreases, usually water/soil = 2.5:10; water/(water + clay) = 20%.
4. Relationship between wet compressive strength and clay amount: When the moisture of the sand is appropriate, the wet compressive strength increases with the increase of clay amount, and when it increases to a certain degree, the wet compressive strength no longer increases.
5. Relationship between wet compressive strength and compactness: when the moisture of the sand is certain, the wet compressive strength of the sand increases with the increase of compactness.
6. Relationship between moisture CB value and fluidity: when the amount of clay is certain: with the increase of moisture of the sand, the fluidity of the sand decreases continuously.
7. Relationship between air permeability and mud content: When the moisture of the sand is appropriate: the air permeability of the sand decreases with the increase of the mud content in the sand.
8. Relationship between moisture and mud content: When the mud content in the sand increases, the moisture in the sand also increases. The mud content of sand for high pressure molding can be generally controlled within ≤12%; the mud content of sand for vertical line: can be generally controlled between 10% and 11%; the sand for manual molding can be controlled at 12% to 13%.
9. The relationship between compacting rate and mud content: when the moisture of the sand is suitable: the compacting rate of the sand decreases with the increase of the mud content of the sand.
10. Relationship between wet compressive strength and fluidity: under the condition of constant clay type and the same CB value: the wet compressive strength of the sand increases with the increase of fluidity of the sand.
11. Relationship between hot and wet tensile strength and moisture.
11.1 The higher the moisture of the type sand, the greater the migration rate and the migration amount of moisture at high temperature, the lower the thermal wet tensile strength.
11.2 The thermal wet tensile strength of sodium bentonite is higher than that of calcium bentonite.
12. The relationship between crushing index and moisture and mud content.
12.1 When the amount of moisture and clay in the sand: the crushing index decreases with the increase in the amount of clay in the sand
12.2 When the moisture in the sand increases, the mud content also increases, and the crushing index of the sand also increases, and the toughness increases.
13. The relationship between hot and wet tensile strength and wet compressive strength: when the type of clay of type sand is constant and the moisture of type sand is certain: the hot and wet tensile strength and wet compressive strength are positively related.
Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of sand reclamation equipment,foundry machines,Sand casting equipment,GS high efficiency rotary mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.
