Relations Between Heat Losses of Glass, Forming Times, and Bottle Production in Blowing Machines

The critical review of production numbers and forming times of different glass‐container machines is a problem of technical and economic importance that is recognized in nearly all glassworks. An exact technical and scientific investigation of these forming times is not possible because of ( a ) the limited knowledge of the heat transfer and flow of glass, ( b ) the great difficulties encountered in making measurements of the process, and ( c ) the influence of ordinary variations in the plant. Some simple relations between the timetable of operations and heat losses of glass during the forming process are given. Quite exact data for heat losses and operating times permit the assignment of standard values which characterize the special properties of the glass during forming. V. Summary Critical judgment of the capacities and forming times of various glass‐processing machines is a task that has to be carried through almost daily in glassworks, since it is closely‐related to the necessity of finding out the best way of operation. An exact technical and scientific evaluation of the forming times is hardly possible for the following reasons: (a) the meager knowledge of heat transfer and flow during forming, (b) the great, nearly insurmountable difficulties with respect to the technical problems of measurement, and ( c ) the variety of the manifold operational influences. Therefore an attempt has been made to describe in simple relations the chronological sequence of the individual operations of the forming process, and the cooling of the glass during the process. On the basis of exact time studies of the individual operations, and with the aid of many calorimetric measurements of the heat rates in the individual forming stages, which were made on numerous fully automatic blowing machines, one can, by means of classification and comparison of the findings, set up approximate operational values. It is hoped that such an analysis has afforded some new ideas and suggestions concerning the technical principles of fully automatic bottle blowing.