Disclosed is an injection molding device and process for a test tube shaped preform, that can laminate a colored layer at certain positions with a certain thickness accurately. Included is a nozzle section, in which a molten main resin and second resin are joined together to form a joined resin mass, the nozzle section including: an outer flow channel through which the main resin flows, an inner flow channel through which the second resin flows, a cylindrical column-shaped flow channel where the second resin joins the main resin, a first confluence where the main resin flows into the joined flow channel, a second confluence where the second resin flows into the joined flow channel wherein the first confluence is downstream of the second confluence, and a cylindrical shutoff pin inserted in the joined flow channel to open or close one or both the first and second confluences.

A preform-molding device has a nozzle section including three cylindrical layer-forming flow channels, which include an inner flow channel and an outer flow channel for forming the substrate layers of the main resin, and a middle flow channel for forming the intermediate layer, and also includes a predetermined number of vertical blocking rib pieces disposed at a downstream end of the middle flow channel, in parallel in the circumferential direction, so that the intermediate layer would be segmented in the circumferential direction into a predetermined number of vertically running streams, wherein flow behavior of the intermediate-layer resin flowing through the middle flow channel is adjusted by positioning the vertical blocking rib pieces in the circumferential direction so as to minimize a difference in height between a maximum height point and a minimum height point that appear in a leading edge of the intermediate layer of the preform.

A molded article suitable for subsequent blow-molding into a final-shaped container. The article includes a neck portion; a gate portion; and a body portion extending between the neck portion and the gate portion, at least a majority of the body portion having an overall shape which is symmetric about a body axis extending longitudinally through a center of the body portion. The body portion includes an inner exterior layer and an outer exterior layer of a first polymeric material; and a core layer of a second polymeric material disposed between the inner exterior layer and the outer exterior layer. A radial thickness or a material of the core layer is selectively varied to govern non-uniform blow molding of the molded article into the final-shaped container.

Disclosed herein, amongst other things, is a molded article, such as a preform that is blow moldable to form a container, and a related method of forming and recycling a container. The structure and steps includes injection molding a molded article having tubular body.

A molded article suitable for subsequent blow-molding into a final-shaped container. The article includes a neck portion; a gate portion; and a body portion extending between the neck portion and the gate portion, at least a majority of the body portion having an overall shape which is symmetric about a body axis extending longitudinally through a center of the body portion. The body portion includes an inner exterior layer and an outer exterior layer of a first polymeric material; and a core layer of a second polymeric material disposed between the inner exterior layer and the outer exterior layer. A radial thickness or a material of the core layer is selectively varied to govern non-uniform blow molding of the molded article into the final-shaped container.

A method of injection molding a test tube-shaped preform for biaxial stretch blow molding includes supplying a major material resin from outer and inner flow paths to a combined flow path for a predetermined time and rate. For a period of time within a range of the predetermined time period during which the major material resin is supplied, the intermediate layer resin is simultaneously supplied from the middle flow path to the combined flow path at a second predetermined supplying rate. A columnar laminated molten resin is injected into a cavity of a metal mold connected to a tip of the nozzle through a gate to fill the cavity, the columnar laminated molten resin being composed of the major material resin and the intermediate layer resin formed in the major material resin in a laminated manner that are combined into a columnar shape at the combined flow path.