A plural preform assembly having nested preforms with an inner preform and an outer preform. The preforms are sealably joined together, defining a volume between the preforms. Propellant is disposed in the volume between the preforms. The preforms are later blow molded to provide a bag in bottle, bottle in bottle or similar container. The propellant charge is already present when blow molded, preventing the need for a later propellant filling step.

A snorkeling tube structure with a tube body and a partition portion is provided. The tube body is formed along an axis and has an outer surface and an inner surface which encircles the axis to define an air passage; the axis includes a curved section. The partition portion is formed integrally with the tube body along the axis, and disposed on the inner surface of tube body to divide the air passage into an intake passage and an outtake passage. A method of manufacturing a snorkeling tube structure is also provided, including the following steps: forming a parison including a first passage and a second passage; placing the parison in a mold cavity; injecting air into the first and second passages to inflate the parison towards a wall of the mold cavity; and removing the inflated parison from the mold to get a snorkeling tube structure.

A blow molded structure and having ribs formed therein, the ribs defined by a recess in one wall of the blow molded structure that defines two sidewalls on either side of a joint, the joint being a weld between the two opposing walls of the blow molded structure. The ribs are arranged in intersecting paths and a passage is defined in the interior cavity of the blow molded structure at the intersection of two ribs such that fluid flows through the passage during molding.

A preform configured to be blow-molded into a plastic bottle includes a neck section defining an opening, the neck section including a threaded portion configured to engage a closure, and a neck ring, a transition section having a first end positioned adjacent to the neck ring and a second end opposite the first end, a cylindrical body section extending from the second end of the transition section to a base, and a longitudinal axis extending from the opening through the base. The neck section, transition section, and the body section define a hollow channel positioned between the opening and the base. The transition section defines a tapered sidewall relative to the longitudinal axis, the tapered sidewall decreases a cross-sectional diameter of the hollow channel. The tapered sidewall of the transition section contains 20% to 30% of a total weight of the preform.

A plural preform assembly having nested preforms with an inner preform and an outer preform. The preforms are sealably joined together, defining a volume between the preforms. Propellant is disposed in the volume between the preforms. The preforms are later blow molded to provide a bag in bottle, bottle in bottle or similar container. The propellant charge is already present when blow molded, preventing the need for a later propellant filling step.

A plural preform assembly having nested preforms. The preforms are held together by an interference fit. The interference fit is provided by the friction between the preforms which occurs when the inner preform is inserted into the outer preform. At least one preform may have ribs extending radially towards the other preform. The ribs provided concentricity and interference to hold the preforms together during subsequent operations. The preforms may later be blow molded to provide a bag in bottle or similar container.

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.