Bone China 9 semi-finished product defects

( 5) Grouting spent at room temperature is high, low, ventilation inadequate cause bone China products, pulp thickness different absorption or for pulp shall not be more than the pulp sedimentary, at the bottom of the form at the bottom of the bone porcelain blank local too thick, indoor without windproof measures, cross ventilation through ( Severe cold wind) Indoor body wet not divide evenly, due to dry up a plate ware, not fit for the bone porcelain body contraction condition. ( 6) Bone China mud preparation, inadequate or excessive plastic clay dosage. Such as plastic clay will reduce bone porcelain body combining ability could not resist any stress and cracking; If plastic clay add too much, can increase bone porcelain body contraction, however, is the stress lead to cracking due to shrinkage difference but, because of the large viscosity optimum water is poorer, cause bone porcelain body moisture gradient in the thickness of the gap is too large and produce shrinkage stress caused by cracking. In addition because the viscosity is too large, also interfere with mud and bone China model of ion exchange and influence from the mold, if uneven drying will craze. ( 7) Bone China body moisture content is too big or moisture distribution is uneven, the drying temperature is too high, too fast, make the bone porcelain body surface shrinkage is too big, each place in dry uneven uneven or heated air circulation strength make uneven body contraction for moisture is in the air will condense on the bone porcelain blank, then make the bone porcelain body cracking easily dry. Bone China body within the mold deposit time is too long, not timely release, the bone porcelain body too dry and cracking. ( 8) Bone China parts cracking, arrange uneven CiHu eye, bone bone porcelain rims of hairy mouth and burrs, nozzle blade shank incision not sharp cutting not level off, the adhesive, the improper operation, adhesive ( Joint mud) Too thick or too thin, adhesive and unused article mud caused by stress. To overcome the way: ( 1) Adjust the bone porcelain clay glaze formula. 1) Compound bone porcelain clay material, plastic bone porcelain clay material content wants moderate, strong reducing neutral plastic bone porcelain clay, right to choose different kinds and quantities of electrolyte, the bone porcelain clay material adding organic adhesive glue solution, such as water reducing agent sodium humate, tanning, etc. , to enhance the adhesion strength of the bone porcelain clay material, choose the variety and dosage of glue solution, must according to the shape of a bone porcelain material nature of the product, size, thickness, dry wet and degree of old and new bone China gypsum model and mud casting method to decide, only from the raw material properties, including bone more bone China porcelain clay mud should use more glue solution, with clay for the conservation of the glue should be used less. 2) Bone China mud have enough stale period, time shall not be less a month, can prevent bone porcelain clay layer material and reduce the mud permeability. Ceramic slurry granularity control, hole screen more than 0. 05 - 0. More than 1% or 200 eye/inch screen 0. 01 - 0. 02%. Bone porcelain blank ingredients, pay attention to the plasticity and the plasticity material collocation is reasonable. 3) Bone China adhesive liquid ( Commonly known as joint mud) Preparation, increasing a small amount of flux, make the dry shrinkage rate and sintering temperature than bone porcelain body slightly low drying shrinkage rate and sintering temperature. Requirements: its moisture content block size 38 - Mud 24-40%, joint 34-25%, note the mud 36-35%, and the injection nozzle 38%. Regardless of dry, wet body and parts of dry wet degree, in order to avoid caused by different drying shrinkage cracking. - - - - - - - - - - - - - - - - - - Bone China cups