JP4209304B2 - Label-in-mold forming method of wide-mouth container and pseudo core for label adsorption holding - Google Patents

Description

  The present invention relates to a biaxial stretch blow molding method for a wide-mouth container for forming a wide-mouth container used as a container for ice cream, milk beverages, and the like. More specifically, the present invention relates to a label-in-mold molding method for a wide-mouth container in which biaxial stretch blow molding is performed with a label attached to the outer peripheral surface of the wide-mouth container, and a pseudo core for label adsorption holding used in the method.

  Plastic containers for ice cream and dairy drinks generally have a truncated cone shape or a truncated pyramid shape, and are generally shaped with a thin mouth flange formed at the opening edge. . Conventionally, such a wide-mouth container is molded from a polyolefin-based plastic sheet such as polyethylene, polystyrene, or HIPS by a pressure forming method or a vacuum forming method. In many cases, a wide-mouthed container is used with a label attached to the outer peripheral surface thereof. The label is generally attached after the wide-mouth container is formed.

  Here, in order to enable efficient and continuous production of a wide-mouthed container, the applicant of the present invention disclosed, for example, in Taiwan Patent Publication No. 531488 (Taiwan Patent Application No. 91115877) and biaxial stretch blow molding. Proposes a method and apparatus for manufacturing.

  An object of the present invention is to propose a label-in-mold forming method for a wide-mouth container that can efficiently attach a label to the outer peripheral surface of the wide-mouth container when bi-axial stretch blow molding of the wide-mouth container.

  Another object of the present invention is to propose a pseudo core for adsorbing and holding a label, which is suitable for use in such a wide-mouth container label-in-mold forming method.

The label-in-mold forming method of the wide-mouth container of the present invention is
Wrap the label around the outer peripheral surface of the pseudo core with the outer peripheral shape corresponding to the wide-mouthed container,
Vacuum adsorbing the label on the outer peripheral surface of the pseudo core,
Put the pseudo core in the cavity for blow molding while the label is adsorbed on the outer peripheral surface,
Release the vacuum suction of the label to the outer peripheral surface of the pseudo core, to adsorb the label on the inner peripheral surface side of the cavity,
Removing the pseudo core from the cavity;
Biaxial stretch blow molding is performed by placing a preform in a temperature state suitable for blow molding into the cavity.

In order to vacuum suck the label on the outer peripheral surface of the pseudo core, the suction hole formed in the outer peripheral surface of the pseudo core is evacuated through the suction port formed in the bottom surface portion of the pseudo core, and the label Is vacuum-adsorbed on the outer peripheral surface .

In addition, in order to maintain the state in which the label is vacuum-adsorbed on the outer peripheral surface of the pseudo core, the suction hole is sealed with a spring force after the suction port is evacuated, so that the suction hole has a predetermined negative pressure. It is characterized by being held in a state .

Further, in order to deliver the label from the outer peripheral surface of the pseudo core to the inner peripheral surface of the cavity, the pseudo core is sealed in the air opening for releasing the suction hole to the atmosphere by a spring force and placed in the cavity. The air opening is opened using an eject pin for ejecting a molded product from the cavity to release the vacuum suction of the label to the outer peripheral surface of the pseudo core.

Next, the present invention is a pseudo core for label adsorption holding used in the above method,
A core body having an outer peripheral shape corresponding to the wide-mouth container;
A vacuum chamber formed inside the core body;
A plurality of suction holes formed in the outer peripheral surface of the core body and communicating with the vacuum chamber;
A suction port for evacuating the vacuum chamber;
An air opening for opening the vacuum chamber to the atmosphere;
An opening / closing mechanism for opening / closing the suction port and the atmosphere opening port is provided.

The opening / closing mechanism includes
A valve rod;
A first valve body for opening and closing the air opening formed at the first end of the valve rod;
A second valve body for opening and closing the suction port, which is coaxially attached to the rod portion on the second end side of the valve rod so as to be slidable in the axial direction of the valve rod;
An urging member that urges the first valve body to a valve seat formed in the atmosphere opening port and urges the second valve body to a valve seat formed in the suction port; ,
When a predetermined negative pressure is applied to the suction port from the outside of the second valve body, the second valve body separates from the valve seat against the biasing force of the biasing member, and the suction port is Opening and pushing the second end of the valve rod against the biasing force causes the first valve body to move away from the valve seat and open the atmosphere opening .

  In addition, it is desirable that the suction port is formed in the bottom surface portion of the core body so that the second end of the valve rod can be pushed from the outside through the suction port.

  According to the method of the present invention, the label can be attached to the outer peripheral surface simultaneously with the molding of the wide-mouth container. Therefore, unlike the case of pasting a label on the outer peripheral surface of a wide-mouth container as in the past, there is no need for an independent label pasting process, so the work process can be shortened and a wide-mouth container with a label can be efficiently produced. Can be manufactured.

  Moreover, if the pseudo core of this invention is used, the label attachment operation | work with respect to the cavity internal peripheral surface for blow molding can be performed efficiently.

  A biaxial stretch blow molding apparatus for a wide-mouth container to which the method of the present invention is applied will be described below with reference to the drawings.

(Example of wide-mouth container and preform)
First, FIG. 1 shows a wide-mouth container with a label manufactured by the biaxial stretch blow molding apparatus of this example and the shape of a preform for molding the wide-mouth container. As shown in FIG. 1 (a), the wide-mouthed container 1 has a shape in which a mouth flange 5 that spreads outward is formed along the opening edge 4 of a cylindrical container body 3 with a bottom 2. . The container body 3 includes a truncated cone-shaped body portion 3a that is tapered toward the opening edge 4 from the bottom 2 side, and a cylindrical neck portion 3b that is continuous with the upper end, and the neck portion 3b. The outer diameter of the opening edge 4 which is the upper end edge of is the largest. A label L is attached to the truncated cone-shaped body 3a by in-mold molding as will be described later.

  As shown in FIG. 1 (b), the preform 6 used to form the wide-mouthed container 1 having this shape by a biaxial stretch blow molding method is a shallow bowl-shaped stretch that becomes a container body 3 by biaxial stretch blow molding. It has a shape including a molded part 7 and a mouth flange 9 which is formed along the opening edge 8 of the stretch-molded part 7 and remains as the mouth flange 5 of the wide-mouth container without being stretch-molded. The stretch-molded portion 7 is stretched in the mold as shown by an imaginary line in FIG. 1A to form the container body 3 of the wide-mouthed container 1.

(Overall configuration of biaxial stretch blow molding equipment)
FIG. 2 is a schematic partial plan view showing the biaxial stretch blow molding apparatus of this example. The biaxial stretch blow molding apparatus 10 of this example heats the preform 6 in an inverted state while heating the preform 6 to a temperature suitable for stretch molding while transporting on the same plane, In addition, they are transported on the same plane, placed in a stretch blow mold assembly and biaxial stretch blow molding, and a wide-mouth container molded from the stretch blow mold assembly is taken out and collected. Also, a pseudo core having a shape corresponding to the outer peripheral surface shape of the wide-mouthed container 1 is prepared, and a label L is wound around the outer peripheral surface of the pseudo core, vacuum sucked and held on the outer peripheral surface, and the pseudo core is stretched and blown. Place the label L in the mold assembly and deliver it to the inner peripheral surface of the cavity, and then place the preform 6 heated to a temperature suitable for molding into the stretch blow mold assembly and perform biaxial stretch blow molding Thus, the label L is attached to the outer peripheral surface of the wide-mouth container 1 by in-mold molding.

  The biaxial stretch blow molding apparatus 10 of this example includes a preform supply station 20 for supplying a preform 6 and a preform 6 supplied in an inverted state from the preform supply station 20 in a loop-shaped carrier circulation path 30. Suitable for biaxial stretch blow molding of a preform transport mechanism 50 having a plurality of preform carriers 40 circulated along the preform and a preform 6 disposed along the carrier circulation path 30 and transported by the preform carrier 40 A heating station 60 for heating to a different temperature. Furthermore, a blow molding station 70 for biaxially stretching blow-molding the heated preform 6 and a delivery station 80 for delivering the heated preform 6 from the carrier circulation path 30 side to the blow molding station 70 are molded. And a recovery station 90 that recovers the wide-mouthed container from the blow molding station 70. Further, a vacuum is applied to the label supply station 12 having a labeler for winding the label L around the outer peripheral surface of the pseudo core conveyed along the circular circulation path 11 and the pseudo core around which the label L is wound around the outer peripheral surface. The pseudo core supply unit 14 that is handed over to the blow mold 72A after the molded wide-mouthed container 1 is taken out while maintaining the suction state, and the stage before the heated preform 6 is supplied to the blow mold 72 And a pseudo core recovery unit 15 that recovers the pseudo core after the label L has been delivered to the blow molding die 72 from the blow molding die 72B and delivers it to the label supply station 12.

  Here, as the preform supply station 20, the blow molding station 70, the heating station 60, the delivery station 80, and the recovery station 90, those disclosed in the aforementioned Taiwanese Patent Publication can be adopted.

(Pseudo core)
FIG. 3 is a longitudinal sectional view showing the pseudo core 100 of this example. The pseudo core 100 has a shape corresponding to the outer peripheral surface shape of the wide-mouthed container 1, and thus has a shape corresponding to the cavity inner peripheral surface shape of the blow molding die 72. The pseudo core 100 includes a core body 101 having a truncated cone shape and an end plate 102 fixed to the end on the large diameter side of the core body 101, and extends in the direction of the central axis 101a inside the core body 101. A vacuum chamber 103 having a circular cross section is formed. A plurality of suction passages 103 a communicate with one end (upper end in the drawing) of the vacuum chamber 102, and the end of the suction passage 103 a is formed at the center of the bottom surface portion 104 that is the end on the small diameter side of the core body 101. It communicates with the suction port 105. A plurality of suction holes 101 c are formed in the conical outer peripheral surface 101 b of the core body 101, and each suction hole 101 c communicates with the vacuum chamber 103. A plurality of atmosphere release passages 106 are formed at the other end (lower end in the drawing) of the vacuum chamber 102, and the ends of the atmosphere release passages 106 are formed at the center of the outer end face of the end plate 102. It communicates with the atmosphere opening 107.

  Here, the valve body 110 passes through the core body 101 and the end plate 102 in a coaxial state with the central axis 101a. A portion on one end side of the valve rod 110 extends to the suction port 105, and a large-diameter piston head 111 is fixed to the end of the valve rod 110 in a coaxial state. A valve body 113 for opening and closing the suction port is attached to the rod portion 112 of the valve rod 110 extending through the suction port 105 in a slidable state. A coil spring 114 is inserted in a compressed state between the valve body 113 and the piston head 111, and the valve body 113 always blocks the suction port 105 by a spring force. On the other hand, the other end of the valve rod 110 passes through the end plate 102 and protrudes toward the atmosphere opening port 107, and a large-diameter opening member 115 for opening and closing the atmosphere opening port is fixed to the protruding end. . In this example, the valve rod 110 is always pushed upward by the coil spring 114, so that the valve body 115 is in a state of blocking the atmosphere opening 107.

  On the other hand, the label supply station 12 and the pseudo core supply unit 14 are provided with a vacuum evacuation mechanism for evacuating the pseudo core 100 having this configuration. The vacuum evacuation mechanism is attached to the bottom surface portion 104 of the pseudo core 100. A possible vacuuming pad 120 is provided.

(Label supply operation)
Next, an operation of supplying the label L into the cavity of the blow mold 72 using the pseudo core 100 will be described. First, before the label L is wound around the outer peripheral surface 101b of the pseudo core 100 by a labeler (not shown) at the label supply station 12, the pad 120 is brought into close contact with the bottom surface portion 104 of the pseudo core 100 as shown in FIG. I do. When a predetermined negative pressure is applied to the suction port 105, the valve body 113 is sucked against the spring force of the coil spring 114, the suction port 105 is opened, and evacuation of the vacuum chamber 103 is started via the suction passage 103 a. As a result, the suction by the suction hole 101c of the pseudo core outer peripheral surface 101b is started. In this state, when the label L is wound around the outer peripheral surface 101b by the labeler, the wound label L is vacuum-sucked to the outer peripheral surface 101b and the adsorbed state is maintained.

  As shown in FIG. 4, when the vacuum suction is stopped and the pad 120 is removed through the pad 120 after the label L is sucked and held on the outer peripheral surface 101 b, the valve body 113 reopens the suction port 105 by the spring force of the coil spring 114. Blockade. As a result, the vacuum chamber 103 is held in a predetermined negative pressure state, and the label L remains in a state of being sucked and held on the outer peripheral surface 101b by a predetermined suction force acting on the suction hole 101c.

  Thereafter, as shown in FIG. 5, the pseudo core 100 in which the label L is adsorbed and held on the outer peripheral surface is placed in the blow mold 72. After that, the piston head 111 exposed from the bottom surface portion 104 of the pseudo core 100 is pushed down by using the eject pin 73 of the blow molding die 72. As a result, the valve rod 110 as a whole is pushed down against the spring force, and the valve body 115 fixed to the end moves to open the atmosphere opening 107. Thereby, the vacuum chamber 103 is opened to the atmosphere via the atmosphere opening passage 106, and the suction force of the label L is released.

  After that, the eject pin 73 is returned and the label L is sucked and held on the cavity inner peripheral surface 72a of the blow mold 72. The blow molding die 72 of this example includes a fixed-side base plate and a raising / lowering die that moves up and down relative to the base plate, and a label L is held on the cavity inner peripheral surface 72a of the raising / lowering die.

  After the label L is held on the cavity inner peripheral surface 72a, the mold is opened (the elevating mold is raised), and the preform 6 heated to a temperature suitable for blow molding is placed in the blow mold 72 and the mold is opened. Tighten and perform biaxial stretch blow. As a result, the labeled wide-mouthed container 1 is formed.

It is explanatory drawing which shows the example of a wide-mouthed container with a label, and its preform. It is a schematic plan view which shows the biaxial stretch blow molding apparatus to which this invention is applied. It is a longitudinal cross-sectional view which shows a pseudo core. It is a longitudinal cross-sectional view which shows the pseudo core by which the label was adsorbed-held. It is a longitudinal cross-sectional view which shows the pseudo core from which the label adsorption | suction holding state was cancelled | released in the blow molding die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wide mouth container 2 with label 3 Bottom 3 Container body 3a Body part 3b Neck part 4 Opening edge 5 Opening flange 6 Preform 7 Stretching part 8 Opening edge 9 Opening flange 10 Biaxial stretch blow molding apparatus 12 Label supply station 14 Pseudo core Supply unit 15 Pseudo core recovery unit 20 Preform supply station 40 Preform carrier 60 Heating station 70 Molding station 80 Delivery station 90 Recovery station 100 Pseudo core 101 Core body 101a Center axis 101b Outer peripheral surface 101c Suction hole 102 End plate 103 Vacuum chamber 103a Suction passage 104 Bottom surface portion 105 Suction port 106 Air release passage 107 Air release port 110 Valve rod 111 Piston head 113 Valve body 114 Coil spring 115 Valve body L Label

Claims (3)

Wrap the label around the outer peripheral surface of the pseudo core with the outer peripheral shape corresponding to the wide-mouthed container,
Vacuum adsorbing the label on the outer peripheral surface of the pseudo core,
Put the pseudo core in the cavity for blow molding while the label is adsorbed on the outer peripheral surface,
Release the vacuum suction of the label to the outer peripheral surface of the pseudo core, to adsorb the label on the inner peripheral surface side of the cavity,
Removing the pseudo core from the cavity;
A label-in-mold molding method for a wide-mouth container in which a preform in a temperature state suitable for blow molding is placed in the cavity and biaxial stretch blow molding is performed ,
The suction hole formed in the outer peripheral surface of the pseudo core is evacuated through the suction port formed in the bottom surface portion of the pseudo core, and the label is vacuum-adsorbed on the outer peripheral surface,
Holding the suction hole in a predetermined negative pressure state by sealing the suction port with a spring force after evacuating the suction port,
The air opening for opening the suction hole to the atmosphere is sealed with a spring force,
The air opening of the pseudo core placed in the cavity is opened by using an eject pin for ejecting a molded product from the cavity to release the vacuum suction of the label to the outer peripheral surface of the pseudo core. A label-in-mold forming method for a wide-mouth container. A pseudo core for label adsorption holding used in the label-in-mold molding method of the wide-mouth container according to claim 1,
A core body having an outer peripheral shape corresponding to the wide-mouth container;
A vacuum chamber formed inside the core body;
A plurality of suction holes formed in the outer peripheral surface of the core body and communicating with the vacuum chamber;
A suction port for evacuating the vacuum chamber;
An air opening for opening the vacuum chamber to the atmosphere;
An opening and closing mechanism for opening and closing the suction port and the atmosphere opening port,
The opening and closing mechanism is
A valve rod;
A first valve body for opening and closing the air opening formed at the first end of the valve rod;
A second valve body for opening and closing the suction port, which is coaxially attached to the rod portion on the second end side of the valve rod so as to be slidable in the axial direction of the valve rod;
An urging member that urges the first valve body to a valve seat formed in the atmosphere opening port and urges the second valve body to a valve seat formed in the suction port; ,
When a predetermined negative pressure is applied to the suction port from the outside of the second valve body, the second valve body separates from the valve seat against the biasing force of the biasing member, and the suction port is Open,
A pseudo core for label adsorption holding in which when the second end of the valve rod is pushed against the urging force, the first valve body is separated from the valve seat and the air opening is opened. In the pseudo core for label adsorption holding according to claim 2,
The suction port is formed in the bottom portion of the core body,
A pseudo core for label suction and holding that allows the second end of the valve rod to be pushed from the outside through the suction port.

Images