A manufacturing method includes an injection molding process of injection-molding a preform, a temperature adjustment process of temperature-adjusting the preform while cooling the preform, and a blow molding process of blow-molding the temperature-adjusted preform to manufacture a resin container. In the injection molding process, a step portion thicker than at least an engagement groove of a neck portion is formed between the neck portion and a body portion of the preform.

There is provided a mold unit for cooling a preform that has been injection-molded, the preform having a bottomed shape and made of a resin, the mold unit including a core mold having an outer shape corresponding to an inner shape of the preform, and being insertable into the preform, in which a flow path for a temperature adjustment medium extending in an axial direction of the core mold is formed inside the core mold, the flow path is formed at a position displaced in a circumferential direction of the core mold, and a position of the flow path is adjustable in the circumferential direction.

A blow molding apparatus includes a machine bed, an upper base disposed at intervals in a vertical direction from the machine bed, a transport plate configured to rotate at a height position of the upper base to convey the preform between an injection molding part and a blow molding part, and an elevation mechanism configured to move the transport plate or the upper base up and down in the vertical direction with respect to a mold disposed on the machine bed. A support pillar includes a height adjusting part configured to adjust a stroke of the transport plate or the upper base in the vertical direction with respect to the machine bed.

In a manufacturing apparatus for manufacturing a resin container which includes an injection molding part configured to injection-mold a preform, a temperature adjustment part configured to adjust a temperature of the preform molded in the injection molding part, and a blow molding part configured to blow-mold the preform whose temperature has been adjusted in the temperature adjustment part, the preform is carried into the temperature adjustment part before an outer surface temperature of the preform molded in the injection molding part becomes higher than an inner surface temperature of the preform molded in the injection molding part, and the preform is cooled to be lowered within a range equal to or higher than 10° C. and equal to or lower than 50° C. in the temperature adjustment part.

An object is to provide an injection stretch blow molding machine and a method for molding a polyethylene container capable of molding a favorable hollow container even if its preform is released from an injection mold early. The injection stretch blow molding machine and the method for molding a polyethylene container molds a preform by injecting and filling a molten polyethylene resin into an injection mold, which includes a cavity mold and a core mold both cooled to a temperature range of 5° C. to 25° C., transfers the molded preform to a blow molding mold, and molds a hollow container by blowing the preform within a time range of ±2 sec from a point in time when a temperature of the preform reaches a first minimum point after a point in time when the injection mold completes being opened.

Provided is a blow molding machine including an injection molding unit and a blow molding unit, wherein the injection molding unit includes a preform mold and an injection device configured to supply resin to the preform mold, wherein the injection device is fixed to a support plate, and wherein the support plate includes a position adjustment mechanism capable of adjusting a position of the injection device in an upper and lower direction with respect to the preform mold.

A blow molding mold in which a holding mechanism is independently provided to a bottom mold and is configured to be capable of gripping a protruding portion provided to a bottom portion of a preform independently of a gate portion, and a rotation mechanism is configured to be capable of rotating the bottom mold, relative to a neck portion of the preform which is in a stationary state held by neck molds, in a state where the protruding portion is gripped by the holding mechanism.

When an injection stretch blow molding machine in which the molding cycle is tried to be shortened manufactures hollow molded bodies, blow molding in which shaping and cooling are simultaneously performed by blowing compressed air from a single compressed air supply source while discharging compressed air is performed to achieve energy saving for manufacturing hollow molded bodies.

A blowing apparatus 10 of a stretch blow molding apparatus 11 includes a compressed air supply source 32 configured to send out compressed air adjusted to have an air pressure at which an object to be shaped e is inflated to be shaped into a hollow molded body, an inflow passage 33 through which the compressed air from the compressed air supply source 32 flows to the internal space of the object to be shaped e disposed in a blow mold 8, and a non-closed outflow passage 34 through which the compressed air flows out from the internal space of the object to be shaped e to a discharging space outside the blow mold. In the entire process of the blowing operation by the blowing apparatus 10, a compressed air flow passage 36 is formed through which the compressed air from the compressed air supply source 32 flows through the inflow passage 33 and the internal space of the object to be shaped e and through the outflow passage 34 into the discharging space. Shaping and cooling are simultaneously performed by blowing the compressed air adjusted to have an air pressure at which the object to be shaped e being in the form of a preform is inflated to be shaped into the hollow molded body throughout the entire process of the blowing operation.

A blow molding apparatus comprises: a continuous transport section provided with a loop-shaped transport path for continuously transporting a preform; an intermittent transport section for intermittently transporting the preform to a blow molding section; and a delivery section for holding the preform being transported on the transport path, and delivering it to the intermittent transport section. The delivery section is equipped with a cooling means for jetting a cooling fluid from a first nozzle member onto an outer surface of the preform to cool the preform locally.

Fixation of a container shape of a hollow molded body is not completed during a blow molding process but is completed during an ejection process of an ejection section, thereby shortening an operation time in a stretch blow molding section, and improving the production efficiency of hollow molded bodies by shortening the time required for the blow molding process during a molding cycle. Cooling air is blown into the inside of the hollow molded body disposed in the ejection section in the ejection process C during the blow molding process B in the next molding cycle to cool the hollow molded body disposed in the ejection section to solidify the container shape.