涂挂、脱蜡控制
Coating and dewaxing control
(1)严格涂料浆品质控制和管理定期监测涂料浆中粘结剂提取液的胶凝时间,坚决废弃已经老化变质的涂料,特别是面层涂料。
(1) strictly control and manage the quality of the coating slurry, regularly monitor the gelation time of the binder extract in the coating slurry, and resolutely discard the aged and deteriorated coating, especially the surface coating.
(2)确保型壳导热性、透气性良好保证型壳导热性良好,确保蜡模表层在蜡模整体膨胀前熔化;同时保证型壳面层透气性良好,减轻蜡模整体受热膨胀对型壳产生的张力,防止型壳开裂。
(2) ensure the good thermal conductivity and air permeability of the shell, ensure the good thermal conductivity of the shell, ensure the melting of the wax mold surface before the overall expansion of the wax mold; at the same time, ensure the good air permeability of the shell surface layer, reduce the tension on the shell caused by the overall thermal expansion of the wax mold, and prevent the shell from cracking.
(3)提高型壳干燥率型壳越干燥,型壳强度越高,承受脱蜡时蜡模膨胀的能力越强,型壳越不容易开裂。同时适宜的型壳干燥率也确保型壳中残留水分少,在脱蜡时不会受蒸气高温作用而出现异常沸腾现象,从而避免型壳局部破损开裂。
(3) the more dry the shell is, the higher the strength of the shell is, the stronger the ability to bear the wax mold expansion when dewaxing, and the less likely the shell is to crack. At the same time, the proper drying rate of the shell also ensures that there is less residual water in the shell. When dewaxing, abnormal boiling phenomenon will not occur due to the high temperature action of steam, so as to avoid local damage and cracking of the shell.