초록 ▼

A method for forming a molecularly oriented thermoplastic container, wherein a thermoplastic blowable shape such as a parison or a blown pre-form is blown to the configuration of the container within a blow mold cavity. The temperature of the blowable shape is within a range conducive to molecular o

A method for forming a molecularly oriented thermoplastic container, wherein a thermoplastic blowable shape such as a parison or a blown pre-form is blown to the configuration of the container within a blow mold cavity. The temperature of the blowable shape is within a range conducive to molecular orientation during the blowing step, which is rapidly performed by hot blow air at a temperature between about 100°to 400°F. Typically, a blowable shape formed of polyethylene terephthalate is blown while the shape is at a temperature within the range of 165°to 200°F. by the introduction into the shape of hot blow air at a temperature within the range of about 165°to 200°F. If desired, the blowable plastic shape may be axially stretched mechanically in addition to being blown in order to improve the biaxial orientation of the thermoplastic material in the final article.

대표청구항 ▼

In a method of making a clear blown article by blow molding a blowable plastic shape consisting essentially of polyethylene terephthalate, which tends to develop a haze of stress whitening when rapidly blown at a temperature conducive to molecular orientation, the steps of: closing the sections of a

In a method of making a clear blown article by blow molding a blowable plastic shape consisting essentially of polyethylene terephthalate, which tends to develop a haze of stress whitening when rapidly blown at a temperature conducive to molecular orientation, the steps of: closing the sections of a blow mold around a blowable plastic shape consisting essentially of polyethylene terephthalate; injecting blow fluid under pressure into the blowable shape while said shape is at a temperature conducive to molecular orientation within the range of about 165°to about 200°F., the blow fluid being (a) at a pressure of between about 400 and about 500 psi and (b) at a temperature between about 150 degrees F. and about 400 degrees F. when injected into the blowable shape prior to any adiabatic expansion, and the injecting step being performed in less than about three seconds; and removing the blown article from the blow mold.