A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

A co-injection nozzle for an injection moulding device for producing multi-layered injection-moulded products. The nozzle includes: a central bore; a valve needle for opening and closing a nozzle opening; an annular inner melt channel for the first melt; an annular central melt channel for a second melt; and an annular outer melt channel for the first melt. The inner, central and outer melt channels are fluidically combined in the region of the nozzle tip to form a concentrically-layered melt stream. The co-injection nozzle has a back-flow barrier, integrated into the central bore, for the second melt, this barrier formed by a cut-out in the valve needle and by a melt channel for the second melt, the channel penetrating the central bore. In the open position of the back-flow barrier, the cut-out is located such that the second melt can flow through the melt channel, whilst flowing in the central bore past the valve needle.

A preform configured to form a container. The preform includes a finish defining an opening and a top sealing surface configured to contact a closure to seal the opening closed. A body portion extends from the finish. A bottom portion is at an end of the preform opposite to the finish. A longitudinal axis of the preform extends through an axial center of the bottom portion. An oxygen barrier layer extends along the body portion to the bottom portion and across the bottom portion. A base layer includes an outer portion and an inner portion. The oxygen barrier layer is between the outer portion and the inner portion. The oxygen barrier layer extends along the body portion and the bottom portion.

A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

A method for manufacturing a container including: forming a preform by injection molding, the preform having a bottom portion, a body portion, and a finish portion including a top sealing surface, threads, and a support flange; forming the preform such that the top sealing surface is made of a base layer, and such that the body portion and the bottom portion are both made of the base layer and an oxygen barrier layer; and forming the container from the preform by blow molding. The top sealing surface includes only the base layer. The body portion and the bottom portion both include an inner portion made of the base layer, an outer portion made of the base layer, and an oxygen barrier layer between the inner portion and the outer portion.

A multilayered preform including inner and outer layers of an ethylene terephthalate type polyester resin, and at least one intermediate layer of at least a lowly crystalline ethylene terephthalate type polyester resin and a gas-barrier aromatic polyamide resin, wherein the lowly crystalline ethylene terephthalate type polyester resin contains, as a copolymerizable component, a cyclohexanedimethanol in an amount of 15 to 20 mol % or an isophthalic acid in an amount of 7.5 to 15 mol %, a weight ratio of the lowly crystalline ethylene terephthalate type polyester resin and the gas-barrier aromatic polyamide resin is in a range of 50:50 to 75:25, a weight ratio of the intermediate layer is not less than 1% by weight but is less than 10% by weight per the whole preform, and a haze is not less than 5% in a portion where a multilayered structure has been formed.

A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

A process includes: supplying a main resin from outer and inner flow channel, to a joined flow channel at a predetermined supply velocity for a predetermined time; supplying a second resin from a middle flow channel to the joined flow channel simultaneously with the main resin at a predetermined supply velocity for a certain time within the predetermined time; and sliding a shut-off pin to bring the pin forefront to a predetermined position near an outlet of the inner flow channel, open to the joined flow channel, before the second resin is supplied, or during a time starting after a time from the start of the second resin supply and ending with the termination of the supply, so that the velocity of main resin supply from the inner flow channel to the joined flow channel is reduced to a predetermined level by adjusting the degree of aperture for the outlet.

A method for manufacturing a container includes injecting a first material into a first mold to form a top portion of a preform. The first material and a second material are injected into the first mold to form a bottom portion of the preform. The preform is disposed in a second mold. The preform is blow molded into a finished container.