Abstract: There is provided a parison guide which improves a flatness of parison with a simple configuration. A parison guide (1) guides a parison (P) which has an arc shape in horizontal cross section and is discharged from an extrusion apparatus (2). The parison guide is fixed to a discharge-side end portion of the extrusion apparatus (2). The parison guide includes a contact face (17) configured to come into contact with and guide an edge portion of the parison to flatten the parison. Preferably, the contact face (17) includes a curved surface, and the contact face (17) has a curvature of a horizontal cross section which gets smaller in a discharge direction.

Abstract: There is provided a parison guide which improves a flatness of parison with a simple configuration. A parison guide (1) guides a parison (P) which has an arc shape in horizontal cross section and is discharged from an extrusion apparatus (2). The parison guide is fixed to a discharge-side end portion of the extrusion apparatus (2). The parison guide includes a contact face (17) configured to come into contact with and guide an edge portion of the parison to flatten the parison. Preferably, the contact face (17) includes a curved surface, and the contact face (17) has a curvature of a horizontal cross section which gets smaller in a discharge direction.

Abstract: The object of the present invention is to cool forcibly the upper and the lower clamp portions of the parson using the upper and the lower blow holes of respective needle blow nozzle synchronously, the metallic mold is cooled by using the cooling apparatus inside the wall, thereby shorten molding cycle time and stabilize the quality. The blow molding method and apparatus, and metallic mold and needle blow nozzle of the present invention are constructed so that an upper and a lower needle blow nozzles (1a, 1) are inserted into said parison (59) to cool respective clamp portion (59c, 59d) forcibly, the discharge nozzle (1b) discharge air, and the molding parson (59) in the internal side of the metallic mold (40A) is cooled by the cooling apparatus (600) disposed inside of the metallic mold (40A), so as to shorten molding cycle time.

Abstract: The object of the present invention is to cool forcibly the upper and the lower clamp portions of the parson using the upper and the lower blow holes of respective needle blow nozzle synchronously, the metallic mold is cooled by using the cooling apparatus inside the wall, thereby shorten molding cycle time and stabilize the quality. The blow molding method and apparatus, and metallic mold and needle blow nozzle of the present invention are constructed so that an upper and a lower needle blow nozzles (1a, 1) are inserted into said parison (59) to cool respective clamp portion (59c, 59d) forcibly, the discharge nozzle (1b) discharge air, and the molding parson (59) in the internal side of the metallic mold (40A) is cooled by the cooling apparatus (600) disposed inside of the metallic mold (40A), so as to shorten molding cycle time.

Abstract: In a conventional multilayer crosshead, only one pressure sensor is disposed in the inlet of the annular passage, preventing monitoring of membrane discontinuities; parison thickness is not constant; as the crosshead body is not cooled and parison temperature is high, a long time is required for cooling during blow molding, preventing the reduction of the molding cycle. A multilayer crosshead according to the present invention includes pressure sensors disposed in at least two positions of the annular passage so that the flow rate is controlled and monitored so as to eliminate the pressure difference between the pressure sensors, and parison temperature is lowered to a greater degree by a cooling jacket with a built-in heater disposed in the crosshead body so that a blow molding cycle is shortened.

Abstract: In a conventional needle blow nozzle and blow molding apparatus, because a needle portion is formed to have a linear tip, resistance against insertion of the nozzle into a parison is large and only a small-diameter needle blow nozzle can be inserted into the parison. For this reason, it has been difficult to increase an amount of air supplied to the interior of the parison and to shorten the molding cycle. With a needle blow nozzle, an air cooling method and apparatus, a blow molding method and apparatus, and a blow molded product according to the present invention, since a needle portion of the needle blow nozzle is formed into an umbrella-like shape, the tip of the needle portion provides a pointed needle center so that resistance against insertion of the nozzle into a parison is reduced and a large-diameter needle blow nozzle can be employed.

Abstract: In a conventional multilayer crosshead, only one pressure sensor is disposed in the inlet of the annular passage, preventing monitoring of membrane discontinuities; parison thickness is not constant; as the crosshead body is not cooled and parison temperature is high, a long time is required for cooling during blow molding, preventing the reduction of the molding cycle. A multilayer crosshead according to the present invention includes pressure sensors disposed in at least two positions of the annular passage so that the flow rate is controlled and monitored so as to eliminate the pressure difference between the pressure sensors, and parison temperature is lowered to a greater degree by a cooling jacket with a built-in heater disposed in the crosshead body so that a blow molding cycle is shortened.

Abstract: Provided is a swing-driving device for driving two low molding units so as to swing around corresponding swinging fulcrums, each of the blow molding units having a carriage, one end portion of which is supported by the swinging fulcrum so as to swing, and a blow molding mold disposed on the carriage. The blow molding mold of one blow molding unit receives a parison on a common receiving position and is made to be an mold close state. The blow molding mold swings around a swinging fulcrum, and moves from the receiving position to a shunting position via a detaching position. Thereafter, the blow molding mold returns to the detaching position and is made to be a mold open state. A hollow article formed by blow-molding the parison in the blow molding mold is take out and moved to the receiving position kept in the mold open state.

Abstract: The present invention provides a laminated-parison extrusion-molding apparatus which includes a head body; a multi-ring structure having a spider provided in the head body; a head core provided inside the multi-ring structure; an outer cylinder member provided surrounding a lower outer periphery of the multi-ring structure, the outer cylinder member constituting a lower portion of the head body; and an annular member provided inside the outer cylinder member, wherein an outer main material is supplied to a flow passage provided between the outer cylinder member and the annular member so as to achieve an outer main material layer having a uniform thickness.

Abstract: An extrusion molding apparatus includes a die head with first, second, third and fourth annular nozzles. An adhesive extruder is connected to the first and third nozzles, a barrier extruder is connected to the second nozzle and a reclaimed material extruder is connected to the fourth nozzle. Inner and outer main material flow passages are connected to a main material extruder, as well. The annular nozzles and the main material flow passages are connected to an extrusion nozzle for forming a parison. The barrier material extruder has a cylinder which is connected to the second nozzle. A screw lies within the cylinder. The second nozzle has a ridge opposite an end of the screw, for dividing the extruded barrier flow material, mitigating stagnation of the barrier material as it passes through the second nozzle. A method of forming a parison is described, as well.

Abstract: A parison molding method and its apparatus in which at least two kinds of materials are used, and the layer formation and dispersion are uniform in the weld part and in the circumferential direction. In the parison molding method and its apparatus, molten resin at a weld part within a parison head is discharged out of the parison head by way of a flow control valve.

Abstract: A multilayer parison extruder includes a cylinder; an annular piston movably fitted in the cylinder; a material accumulation chamber in which the piston is moved; a material conduction chamber communicating with the accumulation chamber; an annular multilayer head provided in the conduction chamber; and a die slot provided under the conduction chamber. The extruder further includes a main material extruder for supplying a main material to the accumulation chamber; and auxiliary material extruders for supplying the auxiliary materials to the multilayer head. The extruder is characterized in that pairs of opposed feed ports are provided in the multilayer head and communicate with the auxiliary material extruders. At least one pair of the inlet ports is provided for each of a pair of arc-shaped passages which are for the auxiliary materials.

Abstract: An extruder for extruding a multilayer parison and a method for doing the same. The extruder includes a cylinder having a cylindrical hole and a die slit which extrudes a parison, a ring piston movably fitted in the cylindrical hole, a multilayer head provided between the die slit and the ring piston, and a plurality of annular nozzles concentrically provided in the multilayer head, the annular nozzles facing and being opened to the side of the die slit.