Pressing of glass

Tools can be produced by electroforming for plastic injection molding. Electroformed molds have been used successfully for injection molding of thermoplastics, for the die casting of zinc, for the pressing of ceramic materials, and for the pressing of glass. 

Body Mould. In the pressing of glass, that part of the mould which gives shape to the outer surface of the ware. 

Laevsky, K.Y. (2003) Pressing of glass in bottle and jar manufacturing numerical analysis and computation, PhD thesis, Eindhoven University of Technology. 

Meanwhile, prepare a pellet of the substance, using a pellet press of the type shown in Fig. 78 (p. 431), but having the cylinder C of about 3 mm. internal bore to enable a pellet of 20-50 mg. to be compressed and then ejected. (Do not compress the pellet more than is necessary for manipulation, otherwise it may dissolve too slowly in the boiling solvent.) Transfer the pellet to a watch-glass, which preferably should be kept in a small desiccator before and after weighing. 

At the gob feeder, the forming operation begias. The gob feeder deUvers a glass gob shaped such that it enters the blank mold without excessive mold contact, distortion, or reshaping of the glass. Shears cut off a gob of glass. The gob is fed to either a blow and blow, press and blow, or press-only forming operation to produce a container. 

Small, complex-shaped glass articles such as thread guides for the textile industry and television gun mounts for the electronics industry are made by the multiform process. The dry-milled powder is mixed with an inorganic binder and a fluid vehicle, and then atomi2ed by a spray dryer into small, dried agglomerates of glass powder and binder with good flow characteristics. They are subsequently pressed to the desired shape and fired. 

N. P. Bansal and R. H. Doremus, Handbook of Glass Properties, Academic Press, Inc., New York, 1986. 

A. P. Piedot, "Influence of Glass Transition on the Felting Shrinkage of Wool Fabrics," Text. Res.J. (iu press May 1997). 

This is a material produced from the impregnation of glass fibre-mat (fibreglass, which is in the form of dry sheet, is commonly known as chopped stranded mat (CSM)) or rovings, with a liquid and unsaturated polyester resin, which thickens chemically to a dry sheet form. The total mix is sandwiched between polyethylene films and then roller-pressed to impregnate and consolidate it. 

Laminates produced by impregnation of glass and carbon fibre with polyimide resins followed by subsequent pressing have found important uses in the aircraft industry, particularly in connection with supersonic airliners. Such laminates can be used continuously at temperatures up to 250°C and intermittently to 400°C. 

The most convenient form of weighing bottle is one fitted with an external cap and made of glass, polythene or polycarbonate. A weighing bottle with an internally fitting stopper is not recommended there is always the danger that small particles may lodge at the upper end of the bottle and be lost when the stopper is pressed into place. 

Stanworth, j. E., 1950, Physical Properties of Glass Oxford, Clarendon Press. 

Karel, M., Buera, M.P., and Roos, Y. 1993. Effects of glass transitions on processing and storage. In The Glassy State in Foods (J.M.V. Blanshard and P.J. Lillford, eds), pp. 13-34. Nottingham Univ. Press, Loughborough, Leicestershire. 

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