A double walled container has a container bottom that is blow molded after an intermediate portion of a parison in the vertical direction is sandwiched by a split mold from the horizontal direction; at least a portion of the container bottom is sandwiched by the split mold; the container bottom has a bottom projection on the underside of the container bottom made of the outer layer of a rigid outer layer container and the outer layer of a flexible inner layer container; in the bottom projection, an extended portion of the rigid outer layer container and an extended portion of the flexible inner layer container have protrusions and recesses of different heights in the horizontal direction; and the protrusions and recesses are combined so that the extended portions of the rigid outer layer container and the flexible inner layer container do not shift vertically with respect to each other.

A resin fuel tank includes a peripheral wall portion that is configured to structure a portion of a fuel tank main body portion that is made of resin and in which fuel is stored, the peripheral wall portion having a parting line portion that is visible from an outer side of the fuel tank main body portion, and a projecting portion that is solid, is disposed along the parting line portion, and is configured to project outward, integrally with the peripheral wall portion, from the peripheral wall portion toward the outer side of the fuel tank main body portion.

A manufacturing method of double walled container comprises preparing a parison having a rigid outer layer and a flexible inner layer, enclosing the parison within a mold including split mold halves, thereby forming a molded parison including a pre-blow cylindrical section, a pre-blow conical bottom section, a pre-blow bottom projection, and a lower parison excessive burr, blowing gas into an inside of the molded parison, thereby forming a blown parison including a cylindrical section and a bottom section, the bottom section including a bottom projection, and removing the lower parison excessive burr from the blown parison, wherein the flexible inner layer is fixed to the rigid outer layer in the bottom projection.

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.

An extrusion blow mold machine forming hollow containers. The machine has at least one pair of opposing half molds that combine to form a mold and define a mold cavity. Each of the half molds is positioned on a carrier plate and includes first, second, and third mold segments. The first and third mold segments can move with respect to each other and with respect to the second, fixed mold segment. A mechanical structure creates vertical movement of the first and third mold segments relative to the second mold segment as the mold opens horizontally, without the aid of any electrical, hydraulic, or pneumatic device. A closing unit engages the carrier plate to move the carrier plate and its respective half mold toward and away from the opposing half mold and its respective carrier plate, thereby closing and opening the mold.

A process of producing a hollow resin-molded article includes: arranging covers on inner walls of mold halves, the covers having shapes corresponding to the inner walls; introducing a pair of sheets of thermoplastic resin each facing the cover arranged on the inner wall of a corresponding mold half; blowing air into a space between the sheets to cause the sheets to respectively contact the covers arranged on the inner walls, and thereby fusion-welding the sheets to the covers; and closing the mold halves; and cooling down the covers and the sheets in a state where the mold halves are closed. In the step of arranging, there are uncovered portions of the inner walls that are not covered by the cover. In the step of closing, there are mold contact portions of the sheets that respectively contact the uncovered portions directly and the mold contact portions are fusion-welded to each other in an overlapping manner.

Provided is a manufacturing method for a double container that allows easy manufacturing with a molding device not significantly different from conventional devices and that can, at a lower cost than the processing cost of conventional technology, very easily and reliably form, in a comparatively rigid outer container and in a double container that allows, inside the outer container, capacity to be varied with respect to the amount of content, an opening for allowing external air to enter. When a pair of partial molds are brought near each other in order to form a split mold, at least part of the mating faces of the pair of partial molds forms a projection by sandwiching a small outer diameter portion of a parison, a gap that passes between the double container is created by cutting off the projection, and the gap is opened and expanded by screwing on a cap.

A blow-molding plastic bubble-generating device is provided, including a board-like shell body. The board-like shell body is formed through blowing a hollow embryo placed in a mold, the hollow embryo is blown and expanded, the hollow embryo is penetrated through by a plurality of needle posts on an inner wall of the mold to form the board-like shell body, the board-like shell body is integrally formed and hollow and has a shell wall which completely and continuously surrounds the board-like shell body, and the shell wall has a plurality of through holes.

The method comprises the step of forming pipes (12) by clamping a bag between shells (13, 14) and by injecting an inflating agent via an inflating connector. The circuit comprises a bag (126) and a press (10) comprising two shells (13, 14) clamping said bag in a state in which pipes (12) are formed between the films (25, 26) of the bag.

Apparatus for forming hollow containers (110), suitable to contain in particular one or more liquid or semi-liquid food products, starting from parisons (F) made of thermoplastic material. The apparatus comprises a matrix (11) defined by a pair of molds (12) cooperating with each other to define a cavity (13) shaped like the container (110) to be formed, and to define a support channel (14), configured to define an additional portion (112) of said container (110). The apparatus also comprises a forming punch (17), operatively mobile through said support channel (14) to enter into/exit from said cavity (13) so as to thrust and blow one of said parisons (F) against the walls of said cavity (13) to form at least said container (110).