FORMATION OF GLASS DEFECTS RELATED TO FLOW OF MELT IN FEEDER CHANNEL AND DROP FORMATION PECULIARITIES
One kind of the most abundant glass defects is cord. Cord is the place of concentration of internal stress in the glass and that reduce mechanical and thermo mechanical strength of glass. The reasons of cords formation can be different. The origin of cords formation is commonly examined only by indirect modeling methods of formation processes and its mechanisms. The determination of cords formation reasons is especially important for the production of electrovacuum glass, when the rate of change of the temperature of glass details is big. In this work a new kind of glass defect – thread type cord, which forms in the central part of screen – is determined and examined. The formation of this cord can be explained by heterogeneous crystallization of glass on the surface of plunger solid phase, when plunger vertically gains height. The problems of homogenization of glass melt in the feeder channel also have been discussed.