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Abstract PET bottles have very good physic, mechanical and
airtight properties. It has been a favorite product for
beverages packer and consumer. Because of PET''s low melt
viscosity, the process of making hollow bottles by extrude-
molding can not be used. The suitable process is injection
stretch blow molding. A preform is needed for stretch blow
molding. The preform was made by injection molding then
reheating before blow molding. Therefor, it should have preform
been designed for the blow molding. This research suggests
that the design of the preform should be divided into four
parts: thread, neck, body and bottom. The design criteria for
the preform are based on the requirements of bottle. The neck of
preform is designed based on the shoulder of the bottle. The
"Drawing Method" is developed in this research for the design of
preform according to the hoop stretch ratio, longitudinal
stretch ratio, and the shape of the bottle. The preform designed
by drawing method can stretch to the bottle as req
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