초록 ▼

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 molec

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.

대표청구항 ▼

In the method of forming a molecularly oriented container from a molded preform made of an amorphous thermoplastic resin and having an open end finished neck tubular portion and a closed end body portion which method includes subjecting the preform body to a thermoforming orienting step while in a t

In the method of forming a molecularly oriented container from a molded preform made of an amorphous thermoplastic resin and having an open end finished neck tubular portion and a closed end body portion which method includes subjecting the preform body to a thermoforming orienting step while in a temperature range at which substantial molecular orientation occurs, the improvement which comprises heating said preform body to said substantial molecular orientation temperature range by first overheating the outside surface of said preform body, by exposing only said outside surface to external heating means, to an average outside surface temperature greater than said substantial molecular orientation temperature range thereby creating a temperature gradient across the wall thickness of said preform body and then cooling said heated preform body until the average outside surface 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 wherein said temperature gradient is significantly reduced.