Abstract: Molecular biaxially oriented hollow articles are obtained by injection blow molding using a novel apparatus. The technique involves the use of an inline, single stage injection blow molding apparatus wherein injection molding and cooling, and conditioning and stretch blow molding of parisons are all performed simultaneously at a single station at different positions within that station.
Abstract: Process for making transparent hollow bodies of terephthalate of polyethyleneglycol in which a preform is made, the preform is cooled rapidly to a temperature at least equal to the crystallization temperature, and is then rapidly expanded to obtain bi-orientation and solidification prior to substantial crystallization of the material. The preform can also be axially stretched during the operation. The apparatus for preforming the process includes a rotatable turret with mandrels, which operates to slightly expand the material on a mandrel.
Abstract: A method is disclosed for blow molding polyethylene terephthalate preforms, such as injection molded parisons, to achieve exterior surface indentations on blown containers without using profiled mold cavity walls. In the method, a profile is molded or otherwise formed in the exterior wall of the preform, defining a preform wall portion having sections of different thicknesses. Then, the preform is blow molded under conditions so that the polyethylene terephthalate material strain hardens in order to cause the different wall thicknesses to expand and stretch proportionately. As a result, the blown containers formed by this method include a surface contour which is essentially proportionately shaped to the surface profile formed on the pre-existing preforms.
Abstract: A blow mold for producing bottles or similar hollow containers from parisons of synthetic plastic material comprises two mirror-symmetrically arranged blow mold halves movable toward and away from each other between a closed and an open position. Each of the mold halves includes an outer mold part and an inner mold part guided for independent movement relative to the outer mold part in an endless inner face of the latter, the inner mold part having a concave end face which forms together with an adjacent portion of said inner face of the corresponding outer mold part in the closed position of the mold half of the mold cavity for forming a bottle. Each of the concave end faces of the inner mold part may also be provided with an island-shaped sharp edged projection aligned with and engaging in the closed position of the mold a corresponding projection on the inner mold part of the other mold half for forming a grip opening in the bottle.
Abstract: Thermoplastic pre-forms which are obtained as a result of expansion of parisons in a pre-form blow mold are transformed into bottles or analogous hollow shaped articles in a final blow mold. The first stage of transformation involves mechanical stretching of the pre-form in the cavity of the final mold simultaneously with or prior to admission of a compressed blowing fluid to expand the major portion of the pre-form into contact with the adjacent surface of the final mold. The next stage involves admission of the blowing medium at a higher pressure to effect abrupt biaxial expansion of the closed end and of the portion intermediate the closed end and the major portion into contact with the adjacent surfaces of the final mold.
Type:
Grant
Filed:
April 6, 1978
Date of Patent:
December 4, 1979
Assignee:
Bekum Maschinenfabriken GmbH
Inventors:
Franz Gittner, Arnaldo Glaser, Klaus D. Kotke
Abstract: 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.degree. to 400.degree. F. Typically, a blowable shape formed of polyethylene terephthalate is blown while the shape is at a temperature within the range of 165.degree. to 200.degree. F. by the introduction into the shape of hot blow air at a temperature within the range of about 165.degree. to 200.degree. 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.
Abstract: Foamable synthetic resin materials are plastified and injected into a mold cavity in an amount less than the volume of mold cavity and a body of gas under pressure is charged in the mold cavity in such manner that it is enclosed by said resin materials. When the injected resin materials sets at least at its outer surface layer, the gas is discharged out of the mold cavity so that the foamable resin materials can be expanded in the hollow portion formed by the pressure of the charged gas. Said foamable resin materials may be surrounded by unfoamable resin materials in the mold cavity.