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.

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.

A production apparatus of a two-layer preform including an inner layer preform and an outer layer preform includes: an outer layer cavity mold for injection-molding the outer layer preform. A bottom surface of the outer layer cavity mold is provided with a protrusion for separating the inner layer preform disposed in the outer layer cavity mold from the bottom surface.

There is provided a system, a method and preform suitable for executing liquid forming of the preform into a final-shaped container. The present technology includes various improvements to methods, apparatuses, and systems for forming final-shaped containers from preforms using a liquid destined to be contained in the final-shaped container.

In a manufacturing method for a delamination container, in a first injection molding, a first recess portion is formed by a first protrusion portion in at least part of a first layer. In a second injection molding, a second recess portion which penetrates the first layer and through which a surface of a second layer is exposed is formed in a preform by inserting a second protrusion portion into the first recess portion. During a blow molding, the second recess portion is stretched to form an air introduction hole in an outer layer of the delamination container.

In a manufacturing method for a delamination method, in a second injection molding including forming a second layer on an inner peripheral side of a first layer of a preform having a bottomed cylindrical shape, a second resin material is guided from an opening portion formed in the first layer toward the inner peripheral side of the first layer, and a locking portion protruding from the opening portion toward an outer peripheral side of the first layer is integrally formed with the second layer.

A delamination container includes a neck portion having an opening communicating with an inside of the inner layer, a shoulder portion continuously extending in the radial direction from the neck portion, a body portion having a bottomed cylindrical shape, and a constricted portion interconnecting the shoulder portion and the body portion. The diameter of the outer peripheral edge of the shoulder portion is 40 mm or more and 55 mm or less, the axial length from the outer peripheral edge of the shoulder portion to a constricted bottom portion which has the smallest diameter in the constricted portion is 12 mm or more and 25 mm or less, and a ratio of the diameter of the constricted bottom portion to the diameter of the outer peripheral edge of the shoulder portion is 0.80 or more and 0.93 or less.

There is provided a system, a method and preform suitable for executing liquid forming of the preform into a final-shaped container. The present technology includes various improvements to methods, apparatuses, and systems for forming final-shaped containers from preforms using a liquid destined to be contained in the final-shaped container.

A preform including: an opening portion; a body portion; and a bottom portion, the preform having a two-layer structure in which the body portion and the bottom portion include an inner layer made of a virgin material and an outer layer made of a recycled material, in which a weight ratio of the recycled material to a total weight of the preform is 50% by weight or more, a ratio of a thickness of the outer layer to a thickness of the inner layer in the body portion is 1.5 or more, and a haze of a body portion of a container molded from the preform is 1.8% or less.

A method for injection molding a preform includes: a) loading a barrier membrane into a first mold cavity; b) injecting melt into the first mold cavity to undermold the barrier membrane and form a preform inner layer on an inside of the barrier membrane; c) moving the preform inner layer and the barrier membrane from the first mold cavity into a second mold cavity; and d) injecting melt into the second mold cavity to overmold the barrier membrane and form a preform outer layer on an outside of the barrier membrane. Preforms formed by the method and an injection molding machine to carry out the method are also disclosed.