Abstract: An extrusion head (1) for blow moulding of hollow bodies comprises: a body (2) and a force plug (3) set within the body so as to define a cylindrical gap (4), through which the molten plastic material fed by an extruder can flow; a die opening (6) set at the bottom end of the body (2); a bottom part (30) of the force plug (3), set within the die opening (6) so as to define an annular gap (10) communicating with the cylindrical gap (4) for exit of the tubular parison; and a plunger (20) supporting at the bottom an ovalizing insert (40), slidably mounted within a chamber (32) formed in the bottom part (30) of the force plug. The plunger can pass from a retracted, resting, position, in which the bottom edge (48) of the ovalizing insert is located within the chamber (32), to an extracted, working, position, in which the bottom edge (48) of the ovalizing insert projects at the bottom with respect to the bottom edge (38) of the bottom part of the force plug.

Abstract: The blow molding machine is characterized in that that the preferably two closing units can be reciprocated along a first guide path extending in a direction transverse to a second guide path which extends from a central removal position of the first guide path to the insertion device, the lower closing plates with the lower mold halves of the two closing units being alternately movable on the second guide path from the removal position to the insertion device and back. The blow molding machine is characterized by an improved mode of operation.

Abstract: A metal mold for blow molding which may prevent a mold biting while maintaining a blowing performance and may mold a thermoplastic-elastomer article having a stable shape. In a blow molding metal mold provided with an annular loosely surrounding part for loosely surrounding an end part of a parison, a clearance between an outer peripheral surface of the end part and an inner peripheral surface of the loosely surrounding part at a parting line of the metal mold is larger than a clearance at the other parts than the parting line.

Abstract: An extrusion blow molded container is provided comprising a closed base, a body portion extending from the closed base having a surface finish that is substantially free of striations, and an open neck portion extending from the body portion. In an embodiment, the container is comprised of polyethylene terephthalate (PET); the base portion includes a support portion and a substantially elevated portion having a center and a major diameter; and the center is disposed an elevated distance above said surface that is less than about 0.05 the major diameter. A method and apparatus for extrusion blow molding an article is also disclosed.

Abstract: A container obtained from a compression-moulded preform (1; 31; 41; 51; 61; 71; 81; 91) comprises abase wall (203; 303) intended for being rested on a supporting surface and a side wall (202; 302) surrounding a main axis (X), the thickness (C4; P4) of said base wall (203; 303) measured near said main axis (X) being less than, or equal to 8.2 times the thickness (C1; P1) of said side wall (202; 302).

Abstract: The invention relates to a plastic metering system in a device for producing plastic articles, comprising a metering unit (1) forming a block (2) comprising a material feed duct (10), a metering cavity (4) which may communicate with the said material feed duct (10), a material outlet orifice (5) placed on a wall of the said metering cavity (4), and a valve (3) in the form of a cylindrical rod designed to slide through and close off the said material outlet orifice (5), characterized in that the metering unit (1) furthermore includes a piston (7) mounted so as to slide coaxially around the valve (3) so as to allow the volume of the metering cavity (4) to be varied and the material feed duct (10) to be momentarily closed off. The invention also relates to a method for using the said system.

Abstract: An extruder head for extrusion blow-molding plastic containers includes a ring gap nozzle with a mandrel and a ring-shaped nozzle body. An elastically deformable sleeve is arranged on an end of the nozzle outlet side and defines a gap width which can be varied by axial setting movements of the mandrel and/or the nozzle body. The geometry of the nozzle gap can be influenced by radially deforming the sleeve with setting devices during the extrusion of a hose-shaped preformed blank. The sleeve may be moved in a radial direction and is guided on sliding surfaces which support it in upward and downward directions. The sleeve may be in the form of a cylinder or tube. A lower edge of the sleeve shapes a cross-section of a melt stream exiting from the ring gap nozzle.

Abstract: An apparatus and method for producing plastic objects. The apparatus comprises an extruder disposed to extrude at least one parison, a parison coating system and a mold disposed to receive the extruded parison. The parison coating system comprises: a powdered material source; a fluid source interconnected with the powdered material source; and a nozzle connected to the interconnected fluid and powdered material sources. The nozzle is disposed such that the nozzle disperses the powdered material in a spray pattern which interacts with the extruded parison. The method comprises steps of extruding a plastic parison, applying a powdered material coating to the parison, enclosing the coated parison in a mold cavity and expanding the coated parison to the limits of the cavity.

Abstract: An extrusion blow molded container is provided comprising a closed base, a body portion extending from the closed base having a surface finish that is substantially free of striations, and an open neck portion extending from the body portion. In an embodiment, the container is comprised of polyethylene terephthalate (PET); the base portion includes a support portion and a substantially elevated portion having a center and a major diameter; and the center is disposed an elevated distance above said surface that is less than about 0.05 the major diameter. A method and apparatus for extrusion blow molding an article is also disclosed.

Abstract: In a method for the production and filling of containers (12), at least one tube (3) of plasticized plastic material is extruded into an open mold (6). The tube (3) is bonded at its advancing end on closing the mold (6) to form the container base. The tube (3) is severed above the mold, by a separating element (21) to form a filling opening. The mold (6) having the tube (3) with a filling opening is moved to a filling position in which the container is filled after the tube (3) formed in the mold by generating an expanding pressure gradient acting on the tube (3). During the movement of the mold (6) into the filling position, the filling opening of the tube (3) is covered by a sterile barrier (23).

Abstract: A mold insert set is provided for use with a mold system having first and second mold bodies, the first and second mold bodies aligning opposite each other during a molding process. Each of the mold bodies has at least one insert receiving region for replaceably receiving an insert of the mold insert set. Each of the inserts has an insert body, a mold cavity formed in the insert body, the mold cavity being for forming an object, and an opening in the mold cavity for aligning with a gas injection region of the mold body in which the insert is received. The gas injection region is where blow gas is introduced to the mold cavity for forming the object.

Abstract: In a blow molding machine comprising a preform station having arranged thereon at least one extruder including at least one downstream parison head, comprising at least one blowing station on which a blowing device is arranged with at least one blowing and calibrating mandrel, and at least one mold system having a blow mold arranged underneath the at least one parison head to accommodate the thermally plasticated parison extruded out of the at least one parison head between the opened mold halves, the blow mold being moved into the blowing station after the mold halves have been closed, wherein the blowing station is arranged in front of the preform station and in parallel with the mold system.

Abstract: A process and device for extrusion/molding of thermoplastic hollow bodies using at least one extruder and at least two molds and including the extrusion of a flow of material, its cutting into parisons, and the molding of the parisons to produce the hollow body, alternately in the first mold and then in the second mold. The process may work in parallel for certain of its operations. The process and the device are well suited for producing hollow bodies of complex three-dimensional geometry with a high productivity.

Abstract: A system for forming a hollow body may include at least one closing unit positioned beneath the die of a tube extrusion device. The closing unit may include a first vertical closing plate and second vertical closing plate. Specifically, an upper horizontal closing plate is cantilevered to the first vertical closing plate carrying an upper mold half, while a lower horizontal supporting plate is cantilevered to the second vertical closing plate carrying a lower mold half. At least one hydraulic cylinder may connect to the horizontal supporting plate and be adapted to vertically displace the lower horizontal closing plate. The closing unit is configured in such a way that when the vertical closing plates are moved toward each other, the upper horizontal closing plate and the lower horizontal supporting plate interlock. The system can be configured to produce oblong hollow bodies requiring a horizontal mold parting plane.

Abstract: An extruder head for extrusion blow-molding plastic containers includes a ring gap nozzle with a mandrel and a ring-shaped nozzle body. An elastically deformable sleeve is arranged on an end of the nozzle outlet side and defines a gap width which can be varied by axial setting movements of the mandrel and/or the nozzle body. The geometry of the nozzle gap can be influenced by radially deforming the sleeve with setting devices during the extrusion of a hose-shaped preformed blank. The sleeve may be moved in a radial direction and is guided on sliding surfaces which support it in upward and downward directions. The sleeve may be in the form of a cylinder or tube. A lower edge of the sleeve shapes a cross-section of a melt stream exiting from the ring gap nozzle.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.

Abstract: A mold assembly for blow molding plastic articles is provided having an upper mold member, a lower mold member and a lower support member. The lower mold member is preferably a relatively lightweight plate having a generally centrally located molding cavity matingly matched with an upper molding cavity in the upper mold member. The lower mold member is moved horizontally and optionally vertically beneath an extrusion head as a molten parison is extruded. The lower mold member is then transported to, and positioned within, the lower support member. The upper mold member is then closed over the lower mold member and lower support to close the mold assembly. The molten parison is then expanded in the mold cavity. After the molding operation, the plastic part may be removed and the lower mold member may be cooled by immersion in a cooling fluid. The apparatus to move the lower mold member during extrusion of the parison and to the molding station may be a robotic arm.

Abstract: A mold system for blow molding hollow plastic containers includes an extruder for providing a hollow tube of plastic material having a longitudinal axis. Three mold segments include at least two mold segments that are movable against the third mold segment, in directions perpendicular to the tube axis, between a closed position in which the mold segments form a hollow mold cavity in which the tube is captured and an open position spaced from the tube axis. A blow pin is disposed on one of the mold segments to pierce the tube in the closed position of the mold segments. One of the mold segments may be a mold core movably mounted on a second of the mold segments, and cylinders are mounted on the second mold segment for moving the mold core between an extended position and a retracted position with respect to the second mold segment. The blow pin may be movably mounted on the mold core.

Abstract: The invention provides a blow mold parison closing apparatus having actuators which are interchangeable. The closing apparatus includes an attachment block having a cylinder body mount and holder/guide support, a pinch bar spaced apart from the attachment block, the pinch bar having a cylinder piston mount and holder/guide mount. The closing apparatus also includes a holder/guide slidingly supported by the attachment block and coupled to the pinch bar. The holder/guide is configured to hold a spring between the pinch bar and attachment block and guide the motion of the pinch bar relative to the attachment block. In operation relative motion between said attachment block and pinch bar may be controlled by either a spring or a cylinder each being easily interchangeable.

Abstract: A blow molding apparatus comprises a base, a blow molding extruder, a carriage, and first and second molding stations. The carriage is movably mounted to the base in a manner such that the carriage is movable along a non-linear path between first and second positions relative to the extruder and in a manner such that the carriage maintains a constant rotational orientation relative to the base as the carriage moves along the non-linear path. Each of the first and second molding stations is mounted to the carriage in a manner such that the first and second molding stations move with the carriage relative to the base as the carriage moves along the non-linear path.

Abstract: An apparatus for blow-molding a parison, the apparatus comprising a mold defining a cavity into which a parison may be introduced for blow-molding, a die for extruding the parison into said cavity, and means for blowing a gas around the outside of the parison in said cavity, the means for blowing a gas around the parison comprising (a) a distributor located at the entrance of the mold cavity for emitting gas around the circumference of the parison and (b) means for injecting gas directly into said distributor, wherein during use the die is separated from the distributor by unenclosed space.

Abstract: A vertical rotary blow molding machine with dual cavity molds includes two coextrusion flow heads for extruding multi-layer parisons for capture and blowing in the dual cavity molds.

Abstract: An exemplary extrusion head for producing a plastic strand in the form of a flexible or rigid tube can be made to communicate with the outlet of an extruder and has a nozzle tool, which includes a mandrel, or core, and a nozzle ring. The mandrel and the nozzle ring define an opening gap, whose opening width is variable by means of an axial relative motion (A, B) between the core and the nozzle ring that can be controlled via an electric or hydraulic actuating drive. The extrusion head includes a suspension element and an extrusion element, detachably connected to it, which has all the connections and flow channels for the composition to be extruded and is equipped with the nozzle tool. The actuating drive is disposed on the suspension element and can be connected detachably to the mandrel or to the nozzle ring.

Abstract: An apparatus for producing plastic hollow bodies using an extrusion blow molding process has an extrusion unit, which is mounted in a housing, and at least one blow molding station. The extrusion unit has an extruder and an extruder head, connected to the extruder, with at least one extrusion nozzle. The longitudinal extent of the extruder defines a longitudinal direction of the apparatus. The blow molding station has a blow molding table with at least one molding tool, which is provided with an opening disposed on the side of the molding tool toward the extrusion nozzle. The blow molding table is movable on a lateral path, extending essentially perpendicular to the longitudinal direction, from a terminal position laterally of the extruder head into a position beneath the extruder head and back again, in order to make the extrusion nozzle and the opening of the molding tool coincide vertically with one another.

Abstract: An extruder head for extrusion blow-molding plastic containers includes a ring gap nozzle with a mandrel and a ring-shaped nozzle body. An elastically deformable sleeve is arranged on an end of the nozzle outlet side and defines a gap width which can be varied by axial setting movements of the mandrel and/or the nozzle body. The geometry of the nozzle gap can be influenced by radially deforming the sleeve with setting devices during the extrusion of a hose-shaped preformed blank. The sleeve may be moved in a radial direction and is guided on sliding surfaces which support it in upward and downward directions. The sleeve may be in the form of a cylinder or tube. A lower edge of the sleeve shapes a cross-section of a melt stream exiting from the ring gap nozzle.

Abstract: Disclosed is a mold for forming molded products including a guide mechanism for guiding at least one movable mold part into and out of the closed mold forming position with another mold part. In a preferred embodiment, the guide mechanism includes a mount for guiding the movable part of a mold into and out of the mold forming position with extreme precision. The guide mechanism in a preferred embodiment can be constructed of a structure fixed to a fixed mold part and a second structure sandwiching the fixed structure and movable in conjunction with the movable mold part. Bearings separate the fixed structure from the movable structure and permit movement of the mold mount into and out of the molding forming position. These bearings are preloaded by the compression of the fixed structure by two portions of the movable structure interconnected by a bolt and a preload spring.

Abstract: Each of the clamping plates of the closing unit of the blow molding machine has secured thereto a pivotable locking means which in the calibration position in the swung-up state comes into engagement with a plate which is part of the calibration device. A short friction-type connection which is symmetrical relative to the mold parting plane is thereby established between the blow mold and the calibration cylinder during calibration so that the calibration forces are transmitted in an exact manner. The locking means swing downwards when the blow mold is opened and/or the closing unit returns to the head station. Collisions with other machine parts are thereby ruled out.

Abstract: Process and device for the extrusion-moulding of hollow bodies made of a thermoplastic, comprising the extrusion of a tubular parison, its deposition via the use of a robot arm in a preforming device which takes it into a lower part of a mold in which the parison is blow-molded in order to produce the hollow body. Certain steps of the process may be carried out in parallel. This process and this device are very suitable for producing hollow bodies of complex three-dimensional geometry with a high productivity.

Abstract: A method of extrusion blow molding is disclosed; the method allows the finished part to have consistent and even wall thickness within a broad range of local mold radii. This result is achieved without resorting to injection blow molding or other common techniques of deforming the parison.

Abstract: Shuttle blow molding apparatus having an extruder for substantially continuously extruding a thermoplastic material in tubular form at a moldable temperature downwardly along a vertical axis. A first finite length of the thermoplastic material is grasped by a first mold set, which then moves outwardly and downwardly with respect to the extruder to provide clearance for a second mold set to move to a position to grasp a second finite length of the extruded thermoplastic tube. The first mold set is then moved horizontally away to permit the finite length of thermoplastic tube therein to be blown into a hollow article, and thereafter removed from the first mold set at a second position of the first mold set.

Abstract: A plastic hollow preform is drawn through a mold passage formed in a closed mold by applying a generally constant suction to a downstream end of a conduit having an upstream end connected to an output end of the mold passage. A flow cross section of the conduit is varied between its upstream and downstream ends so as to vary a rate at which the preform is drawn through the passage by the suction. The flow cross section is varied by displacing a valve element in the conduit between positions in which it differently blocks flow through the conduit.

Abstract: A mold assembly for blow molding plastic articles is provided having an upper mold member, a lower mold member and a lower support member. The lower mold member is preferably a relatively lightweight plate having a generally centrally located molding cavity matingly matched with an upper molding cavity in the upper mold member. The lower mold member is moved horizontally and optionally vertically beneath an extrusion head as a molten parison is extruded. The lower mold member is then transported to, and positioned within, the lower support member. The upper mold member is then closed over the lower mold member and lower support to close the mold assembly. The molten parison is then expanded in the mold cavity. After the molding operation, the plastic part may be removed and the lower mold member may be cooled by immersion in a cooling fluid. The apparatus to move the lower mold member during extrusion of the parison and to the molding station may be a robotic arm.

Abstract: A blow molding mold has first and second fixtures. The first fixture includes drive means, typically in the form of pins, while the second mold fixture has drive receiving means, typically in the form of holes. When the second mold fixture is in registration with the first mold fixture, the drive means are extended to lock and locate the two fixtures together to enable blow molding without a blow molding press. The method of blow molding uses a robotic arm to move a lightweight second mold fixture to accept a parison as it is extruded. After extrusion the arm moves the second fixture toward the first fixture so that the fixtures can be located and locked together. A single robot using a single extrusion head can serve several mold stations depending upon cycle times.

Abstract: A method is provided for forming a parison for use with a blow mold machine for producing blow molded containers. The method includes supplying exclusively a first material from a first extruder to an extrusion head, the first material being for forming a portion of the parison, and supplying a second material from a second extruder to the extrusion head, the second material being for forming a portion of the parison. The method also includes forming the parison in the extrusion head, the parison having a tubular shape with an outer layer of the first material, a middle layer of the second material and an inner layer of the first material. The first material has a lower tendency to adhere to parts of the blow mold machine than does the second material.

Abstract: An extrusion blow-molding machine, including several molding units borne by a carrousel rotating about a substantially vertical axis (A1), wherein each molding unit is mounted on the carrousel such that it can be tilted about a substantially horizontal axis (An).

Abstract: An apparatus for manufacture of a hollow article having a configuration in which the wall thickness of each of both end portions changes multidirectionally with extremely high accuracy. The apparatus includes an annular orifice nozzle including a nozzle core and a nozzle mouthpiece. The nozzle mouthpiece is multi-divided vertically and laterally, and the divided part is disposed so as to be able to reciprocate laterally. A part of the upper portion of the nozzle mouthpiece is replaced with a blow mold and a lower portion can be moved laterally upon taking out a product.

Abstract: The invention relates to a method for producing a large-volume cup-shaped or tub-shaped container made of a synthetic thermoplastic material, whereby a compact plastic, flexible hose-type preform (6) is extruded to obtain a given length and the container (1) is subsequently shaped. In order to carry out said operations with the aid of extremely simple extrusion devices and moulds, thc extruded preform (6) is expanded to a given size and a core (2) is moved upwards into the expanded preform (6). The lower, open end of the expanded preform (6) is then clamped against the core (2) to provide a seal and the preform is shaped by air in order to form a container.

Abstract: Shuttle blow molding apparatus having an extruder for substantially continuously extruding a thermoplastic material in tubular form at a moldable temperature downwardly along a vertical axis. A first finite length of the thermoplastic material is grasped by a first mold set, which then moves outwardly and downwardly with respect to the extruder to provide clearance for a second mold set to move to a position to grasp a second finite length of the extruded thermoplastic tube. The first mold set is then moved horizontally away to permit the finite length of thermoplastic tube therein to be blown into a hollow article, and thereafter removed from the first mold set at a second position of the first mold set.

Abstract: A blow molding apparatus comprising a wheel mounted rotationally on a base for rotating a plurality of molds past an extrusion die. The wheel is comprised of a hub mounted to a rotational shaft and a plurality of disk segments mounted about the hub to carry the plurality of molds. The disk segments may be individually selectively secured to the hub to facilitate simple replacement of disk segments.

Abstract: A method for continuously forming molded parts includes providing an extruder; directing a hollow column of plastic material from the extruder; providing a plurality of die blocks each including planar end segments having differing geometry and joined by the intermediate convoluted segments; continuously moving such die blocks for receiving and forming the hollow column into strut boots with planar end segments and intermediate convoluted segments and advancing the shaped column of plastic material from the continuously moving die blocks and providing a cutter synchronized to the movement of the shaped column for separating the planar end segments to form one or more parts having planar end segments of the same or differing geometry in each part or with differing geometry from part to part.

Abstract: Blow-molding molds 10 and 20 having parison shutters 31 and 32 for preventing an inflation of the parison 3 toward the outside of the molds 10 and 20 are used in a blow-molding method of the present invention. In other words, a closed space for preventing the parison 3 from inflating out of the molds 10 and 20 are formed by the parison shutters 31 and 32 and a predetermined air is secured in the parison 3 in a frame clamping step (B). In the subsequent mold clamping step (C), the pressure inside the parison 3 starts to be increased when the molds 10 and 20 press the parison 3, so that the parison 3 can be continuously in contact with the die design surface 11. Accordingly, since the parison 3 can be uniformly contracted by cooling, molding failure such as streaks and uneven pattern transfer can be avoided, thus obtaining a blow-molded product having good appearance.

Abstract: A blow molding apparatus having a mold clamping apparatus of the clam shell type, and having a linkage controlling the opening and closing of the mold, the linkage being comprised of two links pivotally connected to each other and driven by a pneumatic or hydraulic cylinder. The links are configured to provide the cylinder with mechanical advantage so that little mold separation force is recognized at the cylinder.

Abstract: An exemplary extrusion head for producing a plastic strand in the form of a flexible or rigid tube can be made to communicate with the outlet of an extruder and has a nozzle tool, which includes a mandrel, or core, and a nozzle ring. The mandrel and the nozzle ring define an opening gap, whose opening width is variable by means of an axial relative motion (A, B) between the core and the nozzle ring that can be controlled via an electric or hydraulic actuating drive. The extrusion head includes a suspension element and an extrusion element, detachably connected to it, which has all the connections and flow channels for the composition to be extruded and is equipped with the nozzle tool. The actuating drive is disposed on the suspension element and can be connected detachably to the mandrel or to the nozzle ring.

Abstract: A device produces containers having an inner space divided into separate container chambers by at least one separating wall. An extruder extrudes a tube of a plasticized synthetic material from an annular gap between an outer nozzle ring and an inner nozzle core. The nozzle core is provided with a guide for synthetic material that is branched off from the annular gap. At at least one outlet port at one nozzle end, the branched-off synthetic material is issued and forms a continuous separating wall that extends within the extruded tube. The guide for the branched-off synthetic material is positioned in a zone of the annular gap located upstream of and at a distance form the outlet end of the outlet port.

Abstract: Shuttle blow molding apparatus having an extruder for substantially continuously extruding a thermoplastic material in tubular form at a moldable temperature downwardly along a vertical axis. A first finite length of the thermoplastic material is grasped by a first mold set, which then moves outwardly and downwardly with respect to the extruder to provide clearance for a second mold set to move to a position to grasp a second finite length of the extruded thermoplastic tube. The first mold set is then moved horizontally away to permit the finite length of thermoplastic tube therein to be blown into a hollow article, and thereafter removed from the first mold set at a second position of the first mold set.

Abstract: Process and device for the extrusion-moulding of hollow bodies made of a thermoplastic, comprising the extrusion of a tubular parison, its deposition via the use of a robot arm in a preforming device which takes it into a lower part of a mould in which the parison is blow-moulded in order to produce the hollow body. Certain steps of the process may be carried out in parallel. This process and this device are very suitable for producing hollow bodies of complex three-dimensional geometry with a high productivity.

Abstract: In blow molding, each mold has two or more cavities, each respectively fed by two or more parisons. Each cavity fed by a separate parison may itself include two or more article cavities aligned with its parison.

Abstract: A ribbed pipe molding apparatus has a die with a plastic flow passage which carries molten plastic from an extruder to a mold for making the ribbed pipe. The plastic flow passage has a downstream flow region which exits at an acute angle through the external surface of the die. The inner wall of the end region which locates downstream of the outer wall of the flow passage in the downstream flow region of the passage has a transition wall part which is also inclined relative to the exterior surface of the die but which is sloped at a angle less than the main part of the downstream flow region of the passage. The transition wall part of the inner wall shapes the mouth of the passage so as to produce a wedging of the plastic flowing through the passage into the mold for extremely efficient production of the ribs on the pipe.

Abstract: A shuttle blow molding machine having two groups of mold units located on opposite sides of a series of workstations spaced along a horizontal workstation path. Each mold unit includes a mold that reciprocates in a direction transverse to the workstation path between a retracted position that is spaced from the workstation path and an extended position aligned with the workstation path. The mold units within each group are located in side-by-side relation adjacent each other and each group is indexed as a single unit along a path parallel to the workstation path. The transverse motion of the molds between their retracted and extended positions allows one group to be retracted out of the way while the other group advances through the workstations.

Abstract: A blow molding method includes steps of moving a split mold to a parison receiving position where a parison is supplied and receiving a parison, closing the split mold, performing blow molding at a blow molding position, and opening the split mold at a product discharge position and thereby discharging a product. The method further includes steps of: sequentially reciprocating each split mold in trains of split molds provided opposed to each other across the parison receiving position to and from a position opposed to the parison receiving position; and sequentially reciprocating the split mold disposed at the position where the split mold is opposed to the parsion receiving position to and from the parison receiving position for performing blow molding. There is also provided a blow molding apparatus for carrying out this molding method.