1. The preparation and cleaning of the mold includes: checking the new model according to the standard. The oil stains and incomplete parts on the inner surface of the model must be cleaned up. The water content of the new model is generally 6-8%, but the complex shape, small and thin can be high Some, on the contrary, it can be lower, the minimum is not less than 4%; the drying of the model is generally controlled at room temperature 28 ~ 35 ℃, to prevent the product from being deformed due to uneven drying: before use, dust and other impurities attached to the model should be removed. Clean it up so that the model can fit tightly to avoid slurry and mud leakage; enhance the adhesion of the green body to the model, which is beneficial to prevent impurities from polluting the green body.
2. The method of brushing the model with water is generally used to wipe the mold with clean water when it is cold. The purpose is that the green body can shrink freely in the model without cracking; for new models, dry models or products with large planes such as For water tanks, roll grooves, ring tires of toilets, and concave parts of face washers, the mold should be wiped with mixed water, the purpose of which is to increase the adsorption force of the model to mud. At the same time, different mold wiping methods should be selected according to different products, such as water tank products, which need to be wiped with mixed water even if they are relatively wet. The concave model of the double-sided washbasin usually needs to be wiped with mixed water. In addition, you should also master the main parts of various products and their wiping skills. For large flat parts, such as the big tire of the toilet and the flat surface of the water tank, it must be wiped evenly, and there must be no leakage. The focus of mold wiping should be on the concave painting; the ring cover part of product parts should be the focus of mold wiping; the catchy parts such as squatting pans, water tanks, and large tires of toilets should be the focus. Wipe vigorously and evenly to prevent premature demoulding of the upper part. The amount of force used to wipe the old and new models is generally controlled according to the following principles: gravity should be used for new and dry models to ensure that their adsorption force is large; for models that have been used in the middle period, since the capillary pores are easier to expose, slurry suction should be used Force or light force to facilitate demoulding: For models or wet molds that have been used in the late stage, light force should be used to prevent cracking on the part where the mold is wiped.
3. Correct assembly. For the models that have been processed and need to be used in combination, align them tightly, clamp them firmly, and plug the grouting holes to prepare for grouting. Handle with care when working.
4. Remove the old mud and the air in the system at the mud venting point.
5. Fill the model with mud gently, and avoid spots, rings and other defects caused by “mud impact”.
6. Use the test pouring cup to judge the correct emptying time, so as to achieve the required casting thickness.
7. The air hole should be opened in advance for empty pulp (pulp discharge) to avoid “suction” phenomenon. There are currently three methods of emptying slurry: natural pressure slurry return, that is, using the slope of the pipeline to flow the released slurry back to the mud pool under natural pressure; using a mud pump to pump the excess slurry in the pipeline and the model back into the slurry through the slurry return pipeline Pool, this method often affects the effect due to pipeline leakage; vacuum grouting, that is, using the negative pressure grouting formed by the down-casting grouting pipeline with the help of a vacuum pump.
8. Judging the degree of curing (consolidation period) required for demoulding is too early, and the injection part will collapse; if it is too late, the injection part will shrink and split by itself at the place bound by the mold, resulting in waste products. Generally, this process is about half the time of eating pulp.
9. The moisture content of the green body is about 19% to 20% when demoulding, and the soft injection parts will not deform when demoulding, which must be achieved with superb skills.
10. Repair small cracks with mud and mud nails after demoulding.
Post time: Dec-27-2022