Cracks refer to the striae defects formed by the cracking of the tire and glaze of the ceramic water cup products. Once the ceramic water cup body is disturbed by external force, it will crack.
The following are the main reasons for the occurrence of various cracks in Winwin Ceramics according to the location of the cracks in the ceramic water cup.
1. Spalling Spalling refers to the cracking of the carcass due to the phenomenon of delamination. The middle layer of the grouting green body is also called heavy skin.
① The billet itself contains air, and there is an interlayer;
② Improper forming operation.
2. Mouth crack Crack refers to the cracking of the mouth of the product.
①The plasticity and bonding of the green mud is poor; the moisture content is too low or uneven;
② During hot rolling forming, the temperature of the rolling head is too high; during spinning and rolling forming, the cutting edge is uneven and unclean, and there is residual mud adhered to the edge of the green body, which causes uneven drying and shrinkage of the edge of the green body;
③ During grouting, the mud performance is poor; the gypsum mold is too dry or the water is absorbed too quickly at the mouth edge;
④ The mold release is too dry or too late, and the operation of the doubling mold is improper, so that the edge of the green body is damaged;
⑤ When repairing the blank, glazing, underglaze decoration, and glaze removal, the edge of the blank body is too thin, not dry, not placed smoothly, improper operation, and excessive force may damage the blank or damage it. When loading the blank, take the blank with one hand and break the blank with the thumb;
⑥ Mechanical equipment is not sophisticated. Great vibration.
3. Bottom cracking Bottom cracking refers to the bottom cracking of the product.
① During spinning and rolling forming, the mud is too hard or the moisture is uneven; the material is added after the feeding is not enough; the mud feeding is not correct; the pressing action is too violent;
② During the processing of semi-finished products, the blank is too wet, the area of the blank suction device used is too small, and the force is too large when suctioning and releasing the blank;
③ When digging the bottom, the mechanical equipment vibrates and the force on the green body is unbalanced, which causes cracks on the inner surface of the green body, or the cracks are in the form of long inner surface and short outer surface, and the green body is sunken inward.
4. Shoulder cracks Shoulder cracks refer to the cracking of the shoulders of the products.
①The plasticity and bonding of the blank are poor, which makes the drying strength of the blank low; the moisture content of the blank is too low; the position of the mud is not correct during forming;
② In the process of semi-finished product processing, the shoulder of the blank is damaged when the blank is placed on the blank seat; the diameter of the blank seat is too large, too small or its shape is not suitable for the blank;
③ When sucking the blank with the blank suction device, the pressing force is too strong or the blank is not sucked firmly, and the blank falls accidentally and damages its shoulder.
5. Cracked soles Cracked soles refer to the cracking of the soles of the products.
① The moisture content of the green mud is too low, and the plasticity and bonding are poor; when forming, the diameter of the mud cake is too small, the mud throwing position is not correct, and the forming pressure is too large;
②The drying time of the belt mold is too long, the demoulding is too late, and the green body is cracked in the bottom foot of the model; when demoulding, the foot is stuck by the residual mud in the exhaust hole of the model, causing the bottom foot to crack;
③ Improper operation of digging the bottom and taking out the glaze; the knife is not sharp; the force is too strong or uneven; the mechanical equipment used vibrates, so that the bottom of the green body is hit and injured;
④ When grinding the grey cloth, the technique is improper, and the fingers are too hard on the blank bottom plate, which will damage the blank body, and the cracks are generally from the bottom foot to the shoulder;
⑤ Too little sintered powder at the bottom of large products will affect the shrinkage of the green body during sintering, resulting in uneven sintering and shrinkage of the green body.
6. Mouth and ear handle splits and ear handle splits refer to the cracks at the joints between the mouth, ears, handle attachments and the main body.
①The main body of the bonding parts is too thin or too wet; the moisture content of the mouth, ears, the accessories and the main body is too different, or the shapes of the joints do not match; or the bisque firing temperature of the accessories and the main body is different , the water absorption rate is different.
②The formula of the bonding mud is improper, and the viscosity is poor; the mixing of the bonding mud is not good, and the moisture content is too low.
③ The bonding technique is not skilled, and the bonding force is too strong or too light, so that the bonding mud around the joints of the mouth, ear and handle is unevenly sprayed or not sprayed out, resulting in poor bonding; bonding the spout , Excessive force when applying mud, etc., will damage the bonding parts; during bonding operation, taking and placing the green body is incorrect, which will cause the body to be impacted.
7. Eye cracks Eye cracks refer to the formation of cracks locally around the leaking holes of pot products, or the cracking of the edges of the exquisite eyes.
①The plasticity and bonding of the mud is poor, and the dry strength of the green body is low.
② Punch holes when the moisture content of the green body is too low; the punching machine itself is faulty, the punching tube does not meet the requirements, the punching equipment is not sharp, and the punching force is too large.
Post time: Oct-28-2022