| 摘要 |
Molecularly oriented containers are formed from molded preforms made of an amorphous thermoplastic resin and having a finished neck tubular portion and a body portion which method includes subjecting the preform body to a thermoforming orienting step while at a temperature at which substantial molecular orientation occurs, said temperature being arrived at by first overheating the outside of said preform body using external heating means to an average outside temperature greater than the substantial molecular orientation temperature range thereby creating a temperature gradient across the thickness of said preform body and then cooling said headed preform body until the average outside temperature is within said,substantial molecular orientation temperature range and the entire preform body is at a temperature within said substantial molecular orientation temperature range and whereas said temperature gradient is significantly reduced.
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