Another class of tableware produced by a method of pressing the form is
known as “Pressed glassware.” The hot metal is gathered from the pot and
a portion cut off, and allowed to fall into an iron mould fixed within a
lever press, which carries a plunger fitting within the mould formed to
shape the interior and exterior, with the thickness of the glass as the
intermediate space between them. As the hot glass is introduced, the
workman brings down the lever arm and the plunger presses the hot metal
to shape. The plunger is then released and the mould reversed, turning
out the pressed form of glass, which is then carried away to be
fire-polished or further manipulated with tools before it goes to the
lehr. The case or mould portion is made in two halves, to facilitate the
removal of the hot glass after being pressed. Pressed glass tableware
can be recognised by the presence of seams, showing these divisions of
the mould. Many exquisite designs imitating cut-glass tableware are
executed in pressed glassware. The moulds are a very expensive item, as
there is much tool work in cutting the patterns and refacing them after
prolonged use. In making pressed goods, an oily, carbonaceous liquid is
used to give the moulds some protection and prevent the oxidation of the
iron. This liquid is from time to time applied, as the work of pressing
proceeds, by mopping the interior of the mould with a mop dipped in the
preparation.
Another process in glassmaking is that of bottle-making by automatic
machinery, in which the glass worker does little but gather the
requisite quantity of glass from the pot and place it into the revolving
clips of a bottle-making machine, which does the work of formation, by
the aid of compressed air delivered from a supply main. This is largely
of American introduction, and is the method adopted in making common
bottles. In some cases the bottle neck may be finished by a hand tool
after a mould has done its part of forming the bottle. Modern machines
have been perfected to do the whole work of gathering the metal, forming
the shape, and completing the bottle; a number of arms travelling round
a track carry the mould forms, which alternately dip into water to keep
them cool, open to receive the hot metal, close, deliver a requisite
pressure of air to extend the hot glass within the mould, and then
deliver the bottle on to a travelling belt, which takes them to be
annealed.
In the manufacture of bottles by machines, hand labour is practically
eliminated as far as the actual making of the bottle is concerned. The
bottle-making industry is undergoing great changes by the introduction
of such machinery. In some plants a ten-armed machine will produce
automatically 120 gross of 16 oz. bottles in twenty-four hours, at an
average cost of 1s. 6d. a gross.
Owen’s Bottle-making Machines are of this type. Such machines produce
700 bottles an hour, according to their size and the number of arms
fitted to the machine.
Public-domain text, read in full here on John Shaqi.
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