Untersuchungen an Normdüsen

Ohne Zusammenfassung VDI     

TRANSMITTANCE OF NEAR-INRARED ENERGY BY BINARY GLASSES*

A study has been made of the transmittance of near-infrared energy by a number of binary glasses. Of the systems studied, the lithia-silica and lead oxide-silica glasses were found to have the highest transmittance of energy in the range of wave lengths from 3.0 to 5.0 microns. The transmittance of lithia-silica glass is compared with that of the other alkali-silica glasses. Values of transmittance are given for lead silicate glasses of higher lead content than previously reported in the literature.     

USE OF DOLOMITE AS AN AUXILIARY FLUX IN FLOOR TILE*

It is a recognized fact that dolomite is a valuable addition as an auxiliary flux in white ware bodies, and an excellent glaze ingredient providing another RO member which imparts low thermal expansion to the glaze. There is evidence that the addition of dolomite to sanitary-ware bodies has resulted in the lowering of the firing temperature without daunting or other ill effects. The present investigation involved a study of the use of dolomite in floor-tile bodies. A review of the literature showed that little or no work has been done in this field, and it was, therefore, necessary to follow somewhat closely investigations carried on in the vitreous sanitary ware and dinnerware fields to determine the optimum percentages of dolomite to be incorporated in the test batches. A typical floor-tile composition was taken as standard and dolomite was substituted in increasing amounts at the expense of the accepted flux. The purpose of this investigation is to ascertain if economies could be effected in lowering the firing temperature of the body by the addition of small amounts of a less costly constituent.     

MEASUREMENT OF ENAMEL-SLIP CONSISTENCY BY MEANS OF THE BROOKFIELD VISCOSIMETER*

An instrument commonly employed to measure the viscosity of truly viscous liquids was tested to determine its applicability for evaluating consistencies of enamel slips which are solid suspensions in a water medium. Within wide limits of specific gravity differences and variations in set resulting from electrolyte additions, the Brookfield vis-cosimeter afforded comparable information with the pick-up and slump tests employed as references.