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The Key Issues Of Terracotta Cladding Tiles Extrusion
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The Key Issues Of Terracotta Cladding Tiles Extrusion
The key issues of terracotta cladding tiles extrusion forming process
1. In terms of mud
(1) Particle gradation of raw materials. For example, if some hard raw materials have large particles, explosion points will appear on the surface of the product after firing, and the edges of the green body will crack during the extrusion process.Get more news about terracotta panel cladding,you can vist our website!
(2) Whether the mud itself is suitable for extrusion molding. Some clays are prone to cracking or deformation due to their plasticity is too high or too low, or their thixotropic properties are not ideal.
(3) The uniformity of mud mixing and the plasticity of the mud. The clay plate has good plasticity to ensure that the mud is not easy to crack during the extrusion process, and the uniform mixing can ensure that the product is not deformed during the drying and firing process.
2, extruder aspect
The angle and length of the stirring blade of the extruder, the withdrawal degree of the outlet, and the degree of vacuum have an influence on the extrusion molding. Selection of reasonable extrusion equipment is an important guarantee to ensure extrusion molding.
(1) Vacuum
The main function of vacuum mud practice is to remove the gas in the mud and improve the performance of the mud. Due to the removal of gas and the kneading and squeezing of the mud, the mud structure tends to be uniform and dense, which greatly improves the plasticity of the green body. If the vacuum is not reached, the extruded body will crack. Generally, the vacuum degree should not be greater than 0.09MPa. The reasons for the reduction of the vacuum degree are air leakage and blockage in the vacuum chamber; the consistency of the lubricating oil in the vacuum pump is not suitable or not replaced in time; the piston of the vacuum pump is worn out.
(2) Mud adding speed
If the feed is too fast, the vacuum chamber is easy to block, the mud stays in the vacuum chamber for a short time, and the gas removal is insufficient; if the mud is added too slowly, disconnection will occur, resulting in uneven density. The amount of mud added should be controlled according to the capacity and length of the extruder. The mud adding speed is controlled by adjusting the speed of the automatic feeding belt.
(3) Moisture of mud
Too much water in the mud, too soft, and easy to block the vacuum chamber; too little water in the mud will increase the extrusion pressure, which will easily cause the extruder to heat up, which is not conducive to the maintenance of the extruder equipment, so in the production of ceramic plates The moisture content is generally controlled at 16%~18%.
3, mold aspect
Whether the terracotta cladding tiles mold structure is reasonable. For example, in the mold design, mold A has a square shape around the mud, while mold B is arc-shaped, and mold B is designed with arcs on both sides of the mud, which can buffer the mud and better control the amount and speed of mud.