A manufacturing method of a resin container includes: a first injection molding process for injection-molding a first layer of a preform by using a first resin material, the preform having a bottomed cylindrical shape and including a groove that extends in an axis direction; a second injection molding process for injecting a second resin material into the groove of the first layer, the second resin material having a color that is different from a color of the first resin material, and laminating a second layer on an outer peripheral side or an inner peripheral side of the first layer; and a blow-molding process for blow-molding a preform that includes multiple layers and has been obtained in the second injection molding process in a state where residual heat at a time of injection molding is contained, and manufacturing the resin container having a vertical-striped color pattern formed by using the second layer.

A delaminated container has a main body portion and an opening portion. An accommodation space of the delaminated container is formed by a body inner surface of the main body portion and an opening inner surface of the opening portion. The delaminated container includes a first layer and a second layer. The first layer includes a first tightly-attached section. At the main body portion, the first layer is located closer to the body inner surface than the second layer located thereto and is exposed on the body inner surface. The second layer includes a second tightly-attached section. The first tightly-attached section and the second tightly-attached section are tightly attached to each other. The first tightly-attached section and the second tightly-attached section are both located at the opening portion of the delaminated container.

A preform, a synthetic resin container, and a method for manufacturing a synthetic resin container in which an air passage leading from an ambient air introduction hole to a trunk can be easily preserved. In the mouth, the inner body includes a large-diameter portion provided at an upper end thereof, and a small-diameter portion continuously extending below the large-diameter portion via a connecting portion. In the mouth, the outer body is provided with an ambient air introduction hole passing through the outer body, and a neck ring positioned within a height range of the small-diameter portion. The inner body is made of a crystalline resin, and a crystallized region is formed in part of the inner body, the crystallized region having a higher degree of crystallization than other regions.

A liquid blow-molding method for molding a delamination container from a resin container material. The resin container material includes an outer layer, an inner layer, and an ambient air introduction hole. The delamination container includes an outer layer body and an inner layer body, which is laminated on the inner side of the outer layer body in a manner such that the inner layer body is separatable from the outer layer body. The liquid blow-molding method includes the container molding step of molding the container material into the delamination container by supplying a pressurized liquid into the container material; and the inner layer body separation step of separating the inner layer body from the outer layer body by sucking the liquid out of the delamination container.

The present invention is a double-walled container manufacturing method in which when a pair of partial molds is brought towards each other to be assembled to form a split mold, at least a portion of the mating surfaces of the pair of partial molds clamp a parison at two side portions that are at horizontal positions facing each other. The method is able to manufacture the container easily with a molding device that does not differ significantly from the past and, in a double-walled container obtained from a relatively rigid outer container and a flexible inner container the volume of which can change according to the amount of contents filled inside said outer container, an opening for introducing outside air can be formed very easily and reliably at a lower cost than the processing cost of prior art.

A method of manufacturing containers consisting of a substantially stiff outer container and a readily deformable inner bag of first and second thermoplastic plastic materials, where the inner bag is detached from the wall of the outer container, includes the step of the excess material is supplied again to the first screw conveyor, which mixes the excess material with the first thermoplastic plastic material and supplies it to the extruder nozzle, wherein the first thermoplastic plastic material has a lower viscosity in the molten state than the excess material so that the outer layer of the extruded tube consists only of the first thermoplastic plastic material.

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 delaminated container has a main body portion and an opening portion. An accommodation space of the delaminated container is formed by a body inner surface of the main body portion and an opening inner surface of the opening portion. The delaminated container includes a first layer and a second layer. The first layer includes a first tightly-attached section. At the main body portion, the first layer is located closer to the body inner surface than the second layer located thereto and is exposed on the body inner surface. The second layer includes a second tightly-attached section. The first tightly-attached section and the second tightly-attached section are tightly attached to each other. The first tightly-attached section and the second tightly-attached section are both located at the opening portion of the delaminated container.

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 liquid blow-molding method for molding a delamination container from a resin container material. The resin container material includes an outer layer, an inner layer, and an ambient air introduction hole. The delamination container includes an outer layer body and an inner layer body, which is laminated on the inner side of the outer layer body in a manner such that the inner layer body is separatable from the outer layer body. The liquid blow-molding method includes the container molding step of molding the container material into the delamination container by supplying a pressurized liquid into the container material; and the inner layer body separation step of separating the inner layer body from the outer layer body by sucking the liquid out of the delamination container.