72 PROCESS, MATERIALS, AND MEASUREMENTS
manufacturing is a multistage process.
First, raw glass is heated until molten.
Next, the glass is formed in two steps.
Then, containers are annealed and
cooled. Finally, the containers are inspect-
ed and labeled. There are two common
forming processes for glass containers.
Historically, glass blowing
has been the most common method of
forming glass. A hollow pipe is dipped
into molten glass. The pipe is rotated to
gather glass and then rolled on an iron
slab to form a parison. Through the
process of rolling on the slab, reheating,
and blowing air into the tube the parison
is shaped into a hollow form. Iron or
wooden molds are used to create the
final shape of the object.
Press and blow
A process in which
molten glass is placed into a mold and is
pressed by a plunger to create a parison.
The parison is removed and transferred
to a blow mold, where air forces the
glass into the final shape.
Part of the
production process in which some
types of glass are subjected to second-
ary processing such as
involves controlled cooling processes
intended to prevent cracking;
which involves uniform reheating and
rapid cooling to induce tension in the
, which involves physi-
cal and chemical processes that change
optical qualities, enable scratch resist-
ance, or increase strength.
processes involve material removal
(physically or chemically), adding material
(low temperature glass, metal, or enamel
coatings, films, or printing), and
, which involves selective
reheating and manipulation of forms
PRESS AND BLOW
Dept : DTP D/
Job on:93996 CTP Title : RP_Process Material Measurements Client : Pro_Vision
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Dept : DTP D/O : 16.12.05 (Job on:000000 D/O : 00.00.01 Co: CM0)
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