JP5806929B2 - Blow molding device and blow molding container manufacturing method - Google Patents

Description

  The present invention relates to a blow molding apparatus and a blow molding container manufacturing method for manufacturing a blow molding container by blow molding a preform formed in a bottomed cylindrical shape, and in particular, deformation of a mouth portion of the preform at the time of blow molding. About things to try to prevent.

  A blow molded container obtained by preforming a bottomed cylindrical preform using a thermoplastic resin material and then blow molding the preform has a high degree of freedom in shape, is inexpensive and lightweight, Because of its excellent recyclability, it is widely used as a container for filling cosmetics, pharmaceuticals, beverages, and the like.

  Normally, when a preform is blow-molded in a blow mold, the preform body is blow-molded while the opening serving as the opening end of the preform is held from the inner wall side or the outer wall side by a holding jig. Blow air is blown in through a holding jig that is housed in a mold, and a seal is formed between the preform mouth and the holding jig to prevent blow air leakage. However, in order to allow the preform or the container after blow molding to be attached to or detached from the holding jig, the mouth portion of the preform is loosely fitted to the holding jig (see Patent Document 1 below). For this reason, there is a possibility that the mouth part is expanded in diameter due to a pressure difference generated inside and outside the mouth part when blowing blow air, because of the play between the mouth part of the preform and the holding jig.

JP 2003-251685 A

  Therefore, an object of the present invention is to propose a blow molding apparatus and a method for manufacturing a blow molded container that can prevent deformation of the mouth portion of the preform during blow molding.

The blow molding apparatus of the present invention has been made to solve the above-described problems. The blow molding apparatus of the present invention has a cavity that is partitioned on the inside and preformed into a bottomed cylinder in the cavity. A blow mold for storing the reform leaving a mouth serving as an opening end thereof, a blow nozzle for supplying pressurized fluid into the preform through the mouth of the preform, and an outer wall surface of the mouth of the preform And a partition member that tightly surrounds the space while forming a space therebetween, and pressurized fluid supply means for supplying a pressurized fluid into the space during blow molding. .
Furthermore, in the blow molding apparatus according to the first aspect of the present invention, the blow nozzle has a guide tube that is inserted into the mouth portion and whose tip is reduced in diameter.
In the blow molding apparatus according to a second aspect of the present invention, the pressurized fluid supplied from the blow nozzle is a liquid, and the fluid supplied by the pressurized fluid supply means is a gas.

  In the blow molding apparatus according to the present invention, it is preferable that the blow nozzle and the partition wall member are each provided with a drive mechanism that moves the blow nozzle toward and away from the blow mold.

Further, in the blow molding apparatus of the present invention, the blow nozzle has a flat surface opposed to the upper end of the mouth portion, and the interior of the preform between the upper end and the flat surface of the mouth portion It is preferable that a sealing element for sealing the space is provided.

Furthermore, in the blow molding apparatus of the present invention, the preform are those having a neck ring at the lower end of the mouth portion, the partition member, so that its lower end is tightly abuts the neck ring of the preform Preferably, it is configured.

Furthermore, in the blow molding apparatus of the present invention, the pressurized fluid supply means, at substantially equal pressure as the pressurized fluid supplied to the flop within preform, it is preferable to supply pressurized fluid to said space.

Further, in order to solve the above-mentioned problem, the method for producing a blow molded container of the present invention is to store the preform in a blow mold, leaving the mouth of the preform preformed in a bottomed cylindrical shape, a method for producing a blow-molded container by supplying pressurized fluid from said inlet portion performs blow molding of the preform, through the opening, at the same time to supply pressurized fluid to the flop within preform, the mouth portion to the outer wall surface of the is characterized in pressurizing the outer wall by supplying pressurized fluid.
Further, in the blow molded container manufacturing method of the invention according to claim 7, the pressurized fluid supplied into the preform is a liquid, and the pressurized fluid supplied to the outer wall surface side of the mouth is a gas. It is.

Further, the method for producing the blow-molded container of the invention, approximately equal pressure as the pressurized fluid supplied to the flop within preform, it is preferable to supply pressurized fluid to the outer wall surface side of the mouth.

  Furthermore, in the blow molded container manufacturing method of the present invention, it is preferable that the pressurized fluid supplied into the preform is a liquid, and the pressurized fluid supplied to the outer wall surface side of the mouth is a gas. .

  According to this invention, since the sealed space is formed outside the mouth portion of the preform and the pressurized fluid is also supplied to the space during blow molding, the inner wall surface side and the outer wall surface side of the mouth portion Can be reduced, and the mouth portion can be prevented from expanding and deforming due to such a pressure difference.

It is sectional drawing which shows the principal part of the blow molding apparatus of one Embodiment according to this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of a blow molding apparatus according to an embodiment of the present invention. The blow molding apparatus 1 blows a preform 3 preformed into a bottomed cylindrical shape and molds it into a predetermined container shape. In the illustrated example, the preform 3 has a mouth 3a serving as an opening end, A shape having a neck ring 3c projecting annularly between the mouth portion 3a and a body portion 3b that closes the lower end is shown, but the shape of the preform 3 is not limited to this. Moreover, although the screw is formed in the outer wall of the opening part 3a, it is good also as the preform 3 which replaces with a screw and has an engaging part like an undercut.

  As shown in FIG. 1, a blow molding apparatus 1 includes a blow mold 8 of a matching mold type in which a cavity 7 is defined inside by a mold surface 5 corresponding to the final shape of a blow molding container such as a bottle, and a preform. And a blow nozzle 10 for supplying a pressurized fluid into the preform 3 through the three mouth portions 3a. In the figure, reference numeral 12 denotes a support block that supports the blow nozzle 10.

The blow nozzle 10 is connected to a pressure source 14 and has a passage 16 that defines an inlet for receiving pressurized fluid from the pressure source 14 and an outlet for delivering the pressurized fluid into the preform 3. The blow nozzle 10 has a guide tube 10a that is inserted into the mouth portion 3a of the preform 3 and whose tip is reduced in diameter. The outer diameter of the guide tube 10a of the blow nozzle 10 is preferably smaller than the inner diameter of the mouth portion 3a (that is, a gap is formed between the outer wall surface of the guide tube 10a and the inner wall surface of the mouth portion 3a). According to this, when the guide tube 10a is inserted into the mouth portion 3a of the preform 3, the guide tube 10a and the inner wall surface of the mouth portion 3a are rubbed to prevent the inner wall surface of the mouth portion 3a from being damaged. In addition, the same blow nozzle 10 can be used to cope with the preforms 3 having various diameters, and the apparatus can be simplified. By the way, the pressurized fluid supplied from the pressure source 14 is a liquid in this example.
The content filled in the blow molded container as a product is a pressurized fluid. A gas (for example, air) may be used as the pressurized fluid. In the illustrated example, the stretching rod 18 is disposed in the passage 16 of the blow nozzle 10. However, the stretching rod 18 may not be provided, and when the stretching rod 18 is not used, the effective opening area (additional pressure) of the passage 16 is not necessary. The opening area through which the pressurized fluid can pass is increased, and the pressurizing speed can be increased. Therefore, the molding time can be shortened.

  Here, the blow molding apparatus 1 includes a partition wall member 22 that surrounds the outer wall surface of the mouth portion 3a of the preform 3 so as to form a space 20 therebetween and tightly (airtight or liquid tight), and at the time of blow molding. And a pressurized fluid supply means 24 for supplying pressurized fluid into the space 20.

  The partition member 22 is supported by the support block 12 together with the blow nozzle 10. Inside the partition member 22, a passage 22 a that is connected to the pressurized fluid supply means 24 and opens into the space 20 is formed. In addition, an annular rib 22b is formed at the lower end of the partition wall member 22 so as to closely contact the upper surface of the neck ring 3c of the preform 3 supported on the upper surface of the blow mold 8. Although not shown, the lower end of the partition wall member 22 is brought into close contact with the upper surface of the blow mold 8, and the gap between the outer wall surface of the mouth portion 3 a of the preform 3, the upper surface of the blow mold 8 and the partition wall member 22. A sealed space 20 may be formed.

  Any pressurized fluid supply means 24 may be used as long as the pressurized fluid can be supplied to the space 20 between the outer wall surface of the mouth portion 3a and the partition wall member 22, and an example thereof is a conventionally known one. A pressure pump and a compressor can be mentioned. As the pressurized fluid, it is preferable to use a gas such as air adjusted to a constant pressure, and it is more preferable to use a gas having substantially the same pressure as the pressurized fluid supplied into the preform 3. Here, “substantially equal” refers not only to the case where the pressure of the pressurized fluid supplied to the space 20 is completely equal to the pressure of the pressurized fluid supplied into the preform 3, but also to the space 20. This includes the case where there is a pressure difference between the pressure of the pressurized fluid and the pressure of the pressurized fluid supplied into the preform 3 so that the mouth 3a of the preform 3 is not deformed during blow molding. .

  Further, in this embodiment, the blow nozzle 10 has a flat surface 10b that extends radially outward from the base end of the guide tube 10a and faces the upper end of the mouth portion 3a, and the upper end and the flat surface of the mouth portion 3a. A sealing element 26 such as an O-ring for sealing between the inside of the preform 3 and the space 20 is provided between the space 10b and the space 10b.

  Further, in this embodiment, the blow molding apparatus 1 includes a drive mechanism (not shown) that moves both the blow nozzle 10 and the partition member 22 close to and away from the blow mold 8 in the axial direction. As the drive mechanism, a known mechanism using an actuator such as an electric motor or a hydraulic cylinder can be used.

  Next, a method for producing a blow-molded container using the blow-molding apparatus 1 having such a configuration will be described. First, the preform 3 softened by heating is left in the blow mold 8 while leaving its mouth 3a. Place and clamp. Next, the blow nozzle 10 and the partition wall member 22 are both moved close to the blow molding die 8 by the operation of the drive mechanism, and the guide tube 10 a of the blow nozzle 10 is inserted into the mouth portion 3 a of the preform 3. Thereby, a sealed space 20 is formed between the outer wall surface of the mouth portion 3 a of the preform 3 and the partition wall member 22. In this state, the blow nozzle 10 supplies the pressurized liquid (contents) into the preform 3 through the mouth 3a to perform blow molding, and at the same time pressurizes the space 20 by the pressurized fluid supply means 24. Supply the gas (air). Then, after the blow molding is completed, the supply of air to the space 20 is stopped, the blow nozzle 10 and the partition member 22 are raised by the drive mechanism, and the blow nozzle 10 and the partition member 22 are molded. Remove from mouth. The combinations of the pressurized fluid supplied into the preform 3 and the pressurized fluid supplied into the space 20 are “liquid” and “gas”, “liquid” and “liquid”, “gas” and “liquid”. Or “gas” and “gas”.

  Thus, according to the blow molding apparatus 1 of this embodiment, the sealed space 20 is formed outside the mouth portion 3a of the preform 3, and the pressurized fluid is also supplied to the space 20 during blow molding. Therefore, the pressure difference between the inner wall surface side and the outer wall surface side of the mouth portion 3a can be reduced or zero, and the mouth portion 3a can be prevented from being deformed to expand by such a pressure difference. it can. Also, in the conventional method of holding a preform with a holding jig, a holding jig must be prepared separately according to the diameter of the mouth part of the preform and the outer wall fitting shape of the mouth part. According to the apparatus 1, since the blow nozzle 10 and the partition wall member 22 are not fitted into the mouth 3a of the preform 3, a common blow is applied to the preforms 3 having different mouth diameters and outer wall fitting shapes of the mouth 3a. The nozzle 10 and the partition member 22 can be used, and the inexpensive blow molding apparatus 1 can be provided.

  Further, according to the blow molding apparatus 1 of this embodiment, the blow nozzle 10 is provided with the flat surface 10b facing the upper end of the mouth portion 3a, and the preform 3 is provided between the upper end of the mouth portion 3a and the flat surface 10b. Since the seal element 26 that seals between the interior of the interior and the space 20 is disposed, the interior of the preform 3 and the space 20 on the outer wall surface side of the mouth portion 3a can be sealed with the common seal element 26. The structure of the blow molding device 1 can be simplified.

  Furthermore, according to the blow molding apparatus 1 of this embodiment, since the blow nozzle 10 is provided with the guide cylinder 10a that is inserted into the mouth portion 3a and whose tip is reduced in diameter, the blow nozzle 10 and the partition member 22 are provided. It can be easily and reliably set to the mouth 3a of the preform 3.

  Furthermore, according to the blow molding apparatus 1 of this embodiment, since the lower end of the partition wall member 22 is configured to come into close contact with the neck ring 3c of the preform 3, the posture of the preform 3 at the time of blow molding is stabilized. Higher quality blow molded containers can be manufactured.

  Furthermore, in the blow molding apparatus 1 of this embodiment, when the pressure of the pressurized fluid supplied to the space 20 is substantially equal to the pressurized fluid supplied into the preform 3, the mouth during blow molding The diameter expansion deformation of the portion 3a can be more reliably prevented.

  Moreover, when the fluid supplied by the pressurized fluid supply means 24 is a liquid, it is preferable to separately provide a means for collecting the liquid in the space 20 after completion of the blow molding. When the fluid to be used is a gas, it is not necessary to provide such means, and after the blow molding is completed, the gas in the space 20 is discharged to the outside by separating the blow nozzle 10 and the partition member 22 from the blow mold 8. What is necessary is that the device can be further simplified.

  According to the present invention, it is possible to prevent deformation of the mouth portion of the preform during blow molding.

DESCRIPTION OF SYMBOLS 1 Blow molding apparatus 3 Preform 3a Preform opening | mouth 3b Preform trunk | drum 3c Neck ring 7 Cavity 8 Blow molding die 10 Blow nozzle 10a Guide cylinder 10b Flat surface 14 Pressure source 18 Stretching rod 20 Space 22 Partition member 24 Addition Pressure fluid supply means 26 Sealing element

Claims (8)

A blow mold that divides a cavity inside and accommodates a preform preformed into a bottomed cylinder in the cavity, leaving a mouth serving as an opening end thereof;
A blow nozzle for supplying pressurized fluid into the preform through the mouth of the preform;
A partition member that tightly surrounds the outer wall surface of the mouth portion of the preform while forming a space between them,
A pressurized fluid supply means for supplying a pressurized fluid into the space at the time of blow molding ,
The blow molding device , wherein the blow nozzle has a guide tube inserted into the mouth and having a reduced diameter at the tip . A blow mold that divides a cavity inside and accommodates a preform preformed into a bottomed cylinder in the cavity, leaving a mouth serving as an opening end thereof;
A blow nozzle for supplying pressurized fluid into the preform through the mouth of the preform;
A partition member that tightly surrounds the outer wall surface of the mouth portion of the preform while forming a space between them,
A pressurized fluid supply means for supplying a pressurized fluid into the space at the time of blow molding,
The blow molding apparatus characterized in that the pressurized fluid supplied from the blow nozzle is a liquid, and the fluid supplied by the pressurized fluid supply means is a gas. The blow nozzle and both the partition member, proximate to the blow mold, comprising a driving mechanism for separating movement, the blow molding apparatus according to claim 1 or 2. The blow nozzle has a flat surface opposed to the upper end of the mouth portion, disposed a sealing element for sealing between the interior and the space of the preform between the upper end and the flat surface of the mouth portion The blow molding apparatus according to any one of claims 1 to 3 . The preform has a neck ring at the lower end of the mouth,
The partition member has its lower end configured to closely contact the neck ring of the preform, a blow molding apparatus according to any one of claims 1-4. The pressurized fluid supply means, at substantially equal pressure as the pressurized fluid supplied to the flop within preform, supplies pressurized fluid to the space, the blow molding apparatus according to any one of claims 1 to 5 . Leaving the mouth portion of the preformed preform into a closed-bottomed tubular shape, blow the preform housed within the blow mold, to supply pressurized fluid from they said inlet portion performs blow molding of the preform A method of manufacturing a molded container,
The pressurized fluid is supplied into the preform through the mouth, and at the same time the pressurized fluid is supplied to the outer wall surface of the mouth to pressurize the outer wall ,
It said pressurized fluid supplied into the preform is a liquid, method for producing a blow molded container, wherein the pressurized fluid supplied to the outer wall surface side of the opening portion is a gas. The method for manufacturing a blow molded container according to claim 7 , wherein the pressurized fluid is supplied to the outer wall surface side of the mouth portion at a pressure substantially equal to the pressurized fluid supplied into the preform.

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