JP3771372B2 - Tube container manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a tube container having a mouth and neck portion of an arbitrary structure such as a hinge type or a pull top type using a thin tube of a thermoplastic synthetic resin as a raw material.
[0002]
[Prior art]
As a method for producing a tube container using a conventional thermoplastic synthetic resin, a blow molding method from Parison is known, but it is difficult to mold a small neck and neck, and due to restrictions imposed by a molding die, Not only is it possible to mold only those with a relatively simple mouth-and-neck part, and there is a problem such as a parting line entering the molded container, but the molding process of the mouth-and-neck part becomes complicated, resulting in production efficiency. Has a low problem.
[0003]
[Problems to be solved by the invention]
In view of the problems in the above-described conventional method for manufacturing a thin-walled tube container, the present invention uses a desired structure, a neck and neck portion, and a thin-walled tube made of a thermoplastic synthetic resin that has been previously molded into a required structure, and has high production efficiency. Thus, it is an object of the present invention to provide a method for producing a tube container that is rich in decorating properties and that has a high gas barrier property at the connection portion between the container body and the mouth and neck.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the first aspect of the present invention, as a first step, a mouth member composed of a mouth-neck portion and a shoulder portion, which are integrally molded in advance with a thermoplastic synthetic resin, is connected to a male member at the tip of the tube holder. As a second step, a thin tube made of thermoplastic synthetic resin is externally fitted to the tube holder, and the distal end of the tube extends beyond the male mold portion to a predetermined length. The tip of the thin-walled tube was placed in the heating / cooling zone of the inner and outer surfaces.
[0005]
Next, as the third step, while cooling the outer surface of the distal end portion of the thin tube, the inner surface was heated to cause the distal end portion to undergo axial contraction and radial deformation.
[0006]
Further, as the fourth step, the outer surface of the thin-walled tube that was externally fitted to the tube holder and heated through the third step was heated, and the tip portion was gradually deflated and deformed to reach the open end.
[0007]
Next, as a fifth step, the male part that externally fits and fixes the mouth member is advanced, the mouth neck of the mouth member protrudes from the opening end of the thin tube, and the wiping that continues to the opening end of the thin tube A manufacturing process in which a thin tube tip in a heated state, which is a heated portion, is clamped between a female mold portion for forming a shoulder portion of a tube container and the male mold portion, and the tip portion and a shoulder portion of a mouth member are welded. It was a method.
[0008]
In the invention of claim 2, in the invention of claim 1, the length of the shoulder portion of the mouth member is made shorter than the length of the shoulder portion of the tube container to be molded, and the shoulder portion having a predetermined length continuous to the mouth and neck portion. A process of adding only a double welded structure between the tip of the thin tube and the shoulder of the mouth member was added.
[0009]
In the invention of claim 3, in the invention of claim 1, the length of the shoulder portion of the mouth member is made equal to the length of the shoulder portion of the tube container to be molded, and the entire shoulder portion of the thin-walled tube and the mouth member are A process of making a double welded structure with the shoulder was added.
[0010]
In the invention of claim 4, a method of heating the inner surface and the outer surface of the distal end portion of the thin-walled tube by blowing heated air is added to the invention of any one of claims 1, 2, or 3.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, as shown in FIG. 1 as an example, the length A of the shoulder portion 2 of the mouth member 1 is shorter than the length B of the shoulder portion 4 of the tube container 3 and continues to the mouth-and-neck portion 5. In the illustrated example, only the shoulder portion 4 having a length A is a tube container 3 having a double welded structure with a shoulder portion 6 formed at the distal end portion of a thin tube to be described later and a shoulder portion 2 of the mouth member 1. 2, the length C of the shoulder portion 8 of the mouth member 7 is equal to the length C of the shoulder portion 10 of the tube container 9, and the entire shoulder portion 10 is formed by the distal end portion of the thin-walled tube. The present invention relates to a method of manufacturing a tube container having a structure such as a tube container 9 having a double welded structure of a shoulder portion 11 and a shoulder portion 8 of a mouth member 7.
[0012]
1 and 2, each of the mouth and neck portions 5 and 12 of the mouth members 1 and 7 that are molded in advance have a structure in which a cap is screwed. In the manufacturing method of the present invention, the mouth and neck portions 5, Since the member corresponding to 12 is pre-molded, the cap is hinged to the mouth and neck, or the mouth and neck opening is a pull-top type, and the cap is further joined. Any type of mouth-and-neck tube container can be molded.
[0013]
FIGS. 3 to 13 show an embodiment in which the inventions of claim 1, claim 2 and claim 4 are combined to show a process for manufacturing the tube container 3 shown in FIG. 1 and a manufacturing apparatus. In the first step, as shown in FIG. 3, a tube holder 14 serving as a core metal for slidingly fitting the thin tube 13 made of thermoplastic synthetic resin shown in FIGS. 4 and 6 slidably. A mouth portion 1 made of a thermoplastic synthetic resin, which has been molded in a separate process in advance, is externally fitted and fixed to a male mold portion 17 which is arranged at the tip 15 so as to be movable up and down by a shaft 16.
[0014]
The mouth member 1 is formed of a shoulder portion 2 that forms a part of the shoulder portion 4 of the tube container 3 and a mouth and neck portion 5 that becomes the mouth and neck portion of the container 3. A head portion 18 that is press-fitted into the mouth-and-neck portion 5 and fixes the mouth member 1, a truncated cone portion 19 that forms the shoulder inner surface of the tube container 3, and a guide cylinder portion 19 </ b> A having an outer diameter equal to the inner diameter of the thin-walled tube 13 , 19B.
[0015]
4 and 5 show the manufacturing process performed in the second process and the third process, and the manufacturing apparatus used. The manufacturing apparatus heats the inner surface 21 of the distal end portion 20 of the thin tube 13 with heated air. The internal heater 22 is heated by spraying, and the cooling unit 24 is in close contact with the outer surface 23 of the tip 20 to cool the outer surface 23.
[0016]
The internal heater 22 and the cooling part 24 are disposed in the outer body 25, and the cooling part 24 has an inner hole 26 in which the thin tube 13 is smoothly fitted and lightly abutted on the outer surface 23 at the center. A circulation path 27 for a cooling medium such as water is formed in the interior adjacent to the inner hole 26.
[0017]
The internal heater 22 has a small-diameter cylindrical portion 30 disposed in an inner hole 26 of the cooling portion 24 with an annular gap 28, and the small-diameter cylindrical portion 30 is a large number of heating media on the peripheral wall immediately below the closed top portion. A heated air outlet 29 and an inner cavity 31 communicating with a heated air pressure source are formed, and the annular gap 28 is formed between the outer body 25 and the outer peripheral wall of the inner heater 22. The suction passage 32 communicates with the suction passage 32.
[0018]
In the second step according to the present invention, as shown in FIG. 4, the thin tube 13 is externally fitted to the tube holder 14, and its distal end portion 20 extends beyond the male portion 17 by a predetermined length H. Subsequently, as a third step, the tube holder 14 is lowered, and as shown in FIG. 5, a predetermined height portion L from the distal end edge of the distal end portion 20 is moved inside and outside the distal end portion 20 by the blowout port 29 and the inner hole 26. It arrange | positions in the heating and cooling area | region of a surrounding surface, and performs heating and cooling for predetermined time as a 3rd process.
[0019]
The length of the predetermined height L, the opening area of the air outlet 29, the heating air temperature and pressure, the heating and cooling time are the material of the thin tube 13, the thickness, and the shape of the container shoulder and mouth neck to be molded. In accordance with the above, it is experimentally measured and selected in advance. After the heating and cooling in the third step, the tube holder 14 is raised from the heating and cooling zone while the thin tube 13 is fitted, and is placed outside the manufacturing apparatus.
[0020]
When the third step is completed, the portion of the predetermined height L from the distal end of the distal end portion 20 of the thin tube 13 shown in FIG. 4 is slightly expanded outward as shown in FIG. 6A. The predetermined height portion L is slightly contracted in the axial direction. This deformation is considered to be due to the instantaneous restoring action due to the memory phenomenon during heating at a temperature higher than the glass transition point due to the material of the thin tube 13, especially the laminated tube. The state appears as shown in Fig. 6-B, Fig. 6-C or Fig. 6-D in addition to Fig. 6-A, depending on the heating temperature and material, and in the case of Fig. 6-A, Fig. 6-B, Fig. 6-C The bulging part is sent to the next process in a shape pressed inward by the surface of the inner hole 26, and the degree of deformation is experimentally confirmed for each material.
[0021]
4 and 5, the heated air, which is a heating medium, is heated to a predetermined height at the distal end portion 20 of the thin tube 13 from the blowout port 29 as indicated by the arrow A in FIG. After being sprayed on the inner surface 21 of the portion L, the suction negative pressure acting on the suction path 32 of the heated air is recovered by the pumping source through the annular gap 28 and the suction path 32 as shown by the arrow B.
The thin-walled tube 13 in which the heated air is blown to the inner surface from the blowout port 29 is cooled by the outer surface of the blowing portion coming into contact with the inner hole 26 of the cooling unit 24, so that it does not cause irregular deformation. A controlled deformation is produced in the shape shown in FIG.
[0022]
7 to 10 show the fourth step of the present invention, the device used, and the shape of the thin tube 13 that has undergone the fourth step. The device used for carrying out the fourth step is shown in FIG. As shown in FIG. 7, in the third step, as shown in FIG. 6A, an external heating device 33 that heats the zone of height K at the lower end of the thin tube 13 that has been subjected to heating and cooling processing from the outer surface. 6-A has an annular hole 34 into which the distal end portion of the thin-walled tube 13 that is still fitted on the tube holder 14 shown in FIG. 6A can be fitted, and the heated air over the entire circumference of the inner peripheral surface of the annular hole 34. An air outlet 35 is opened, and a heated air passage 36 is formed close to the inner peripheral surface of the external heating device 33. In addition, illustration of the supply path of heated air is abbreviate | omitted. The heated air blown from the blower outlet 35 is sucked and collected by the heated air supply source as indicated by the arrow C by the suction passage 37 below the external heating device 33.
[0023]
The thin-walled tube 13 shown in FIG. 6-A that has undergone the third step is disposed immediately above the external heating device 33 as shown in FIG. 7, and is lowered in the direction of arrow D while being externally fitted to the tube holder 14. The heated air, which is inserted into the annular hole 34 and pumped to the heated air passage 36, is blown from the blower outlet 29 until the zone of the predetermined height K of the tip 20 faces the blower outlet 29 of the heated air. It is done.
The heated air blown flows toward the suction path 37 as indicated by an arrow C along the band of the predetermined height K of the distal end portion 20 of the thin tube 13.
[0024]
As shown in FIGS. 9 and 10, the band of the height K of the distal end portion 20 of the thin-walled tube blown with the heated air from the air outlet 29 is gradually deflated from the upper part toward the lower end toward the center, and is generally reversed. It deforms irregularly close to a frustoconical shape, and is deflated until the open end 38 is concentric with the mouth neck 5 of the mouth member 1 fixed to the tube holder 14 and has a slightly larger diameter.
[0025]
The deformation of the distal end portion 20 of the thin-walled tube 13 into the shape shown in FIGS. 9 and 10 depends on the material, diameter, thickness, and height K of the thin-walled tube 13. Is experimentally measured in advance, and the temperature and time for obtaining a predetermined shape are selected.
[0026]
The thin tube 13 having the shape shown in FIGS. 9 and 10 in the fourth step is bonded to the mouth member 1 and the thin tube 13 in the fifth step while being fitted to the tube holder 14. 11, 12 and 13 show the fifth step, the apparatus used in this step, and the main part of the molded tube container.
[0027]
As shown in FIG. 11, the apparatus used in the fifth step includes a female mold portion 39 corresponding to the male mold portion 17, an opening portion 41 at the bottom of the cavity 40 of the female mold portion 39, and a lower portion of the opening portion 41. And a female member 39 is provided with a heating member (not shown). The hollow frame 42 has a discharge port on the top surface 43 of the mouth neck of the mouth member 1. It is a space for arranging the punching device when it is necessary to punch and the like.
[0028]
The thin-walled tube 13 having the shape shown in FIG. 9 that has undergone the fourth step is fitted into the tube holder 14 and guided directly above the female mold portion 39 in a heated state, and is then moved in the direction of arrow E by the tube holder 14. The tip 20 that has been lowered and deflated is inserted into the cavity 40.
[0029]
Subsequently, the male mold part 17 press-molds the distally deformed tip part 20 of the thin-walled tube 13 with the cavity 40 of the female mold part 39 by the downward movement of the shaft 16 coupled to an appropriate driving device. At the same time, the tip 20 and the shoulder 2 of the mouth member 1 are welded together, and the shoulder 4 of the tube container 3 is formed by the cavity 40.
[0030]
After the shoulder portion 4 is formed and required cooling is performed, the shaft 16 is moved upward, and then the tube holder 14 is moved upward to release the tube container 3 from the female mold portion 39 shown in FIG. Next, the tube container 3 is removed from the tube holder 14 to complete the molding of the shoulder portion and the mouth / neck portion of the tube container 3.
[0031]
In the above process, since the bottom of the tube container 3 (not shown) is left open, the tube container 9 having the mouth member 7 shown in FIG. It is molded by the same method and equipment.
[0032]
In the embodiment described above, heated air is used as a heating source for the thin-walled tube 13, but other heating sources and heating media can be used as long as the temperature condition and heating mode can be the same as the heating air. Of course.
[0033]
【Example】
As a thin-walled tube, an adhesive polyethylene is used as an inner layer and an outer layer, and a three-layered tube with an ethylene / vinyl copolymer resin as an intermediate layer and a gas barrier property with a thickness of 0.5 mm is used. It was.
Internal heating of the thin tube in the third step: heating air temperature: 375 ° C, air flow rate: 400 l / min. (Atmospheric pressure conversion), heated air suction: 300 l / min. (Atmospheric pressure conversion), cooling Water volume 2.2 l / min., Inner surface heating time 1 second, outer surface heating in the 4th step: heated air temperature: 400 ° C., heated air flow rate 380 l / min. (Atmospheric pressure conversion), heated air suction power: 370 l / min. (atmospheric pressure conversion), outer surface heating time was 3 seconds.
In the fifth process, the male mold part 17 is pressurized with a molding pressure of about 750 kg / cm ² against the female mold part 39 whose outside is cooled to about 18 ° C., and after pressurizing for 3 seconds, the pressurization is released. Thus, the mouth member 1 and the thin tube 13 are bonded.
[0034]
【The invention's effect】
According to the first aspect of the present invention, the mouth member pre-molded with the thermoplastic synthetic resin is externally fitted and fixed to the male part at the tip of the tube holder, and this mouth member is externally fitted to the tube holder. Since the thin tube made of thermoplastic synthetic resin is welded by pressurization under heating by the male part and the female part, the thin tube and the mouth member can be welded by the male part and the female part. Any shape and structure of the mouth member can be employed, and there is an effect of expanding the types of tube containers that can be manufactured.
[0035]
The shoulder of the molded tube container has a double welded structure starting from the base of the mouth and neck, with the continuous shoulder of the mouth and neck of the mouth member and the tip of the thin tube, and the gas barrier properties of the shoulder of the tube container The effect which can improve is produced.
[0036]
Furthermore, the tip of the thin-walled tube has a thickness required for forming a shoulder as a tube container by a process of heating from the inner surface while cooling the outer surface, and subsequent heating from the outer surface to the tip. It can be formed at the tip while using the tube as a raw material, and the strength of the container shoulder can be increased.
[0037]
As described above, in addition to being able to adopt any shape and structure as the mouth member, means for changing the color, color tone, means for changing the color, color tone of any of the films, etc. The effect that the decoration property of a tube container can be enlarged by adoption is exhibited.
[0038]
The mouth member and the distal end portion of the thin tube can be welded only by pressurization under heating by the male mold portion and the female mold portion, and only by heating the distal end portion of the thin tube. The molding time required is about 3 to 5 seconds. Compared to the molding time of about 10 seconds when compression molding the neck and shoulder of the tube container and the molding time of about 20 seconds when injection molding, The effect which can improve productivity remarkably is also show | played.
[0039]
According to the invention of claim 2, because the shoulder portion of the tube container is composed of two parts, a part formed only by the material of the thin-walled tube and a part where the material and the shoulder part of the mouth member overlap, The effect which can express the design effect by the difference in color tone is produced.
[0040]
According to invention of Claim 3, there exists an effect which can make the mechanical gas barrier property of the connection part of the mouth neck part of a tube container and a shoulder part perfect.
[0041]
According to the invention of claim 4, not only is the handling of the heating medium easy, but even if the heating air temperature is constant, the softening degree of the thin-walled tube can be adjusted only by adjusting the heating air blowing time. There is an effect that process control and quality control become easy.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part of an example of a tube container manufactured according to the present invention.
FIG. 2 is a longitudinal sectional view of an essential part of another example of a tube container manufactured according to the present invention.
FIG. 3 is a side view of an essential part of an example of a tube holder used in the practice of the present invention and a male part assembled to the tube holder, showing only a mouth member as a cross section; The process is shown.
FIG. 4 is a schematic vertical sectional view showing a state immediately before the start of the second step in an example of the implementation of the apparatus used in the present invention.
FIG. 5 is a schematic longitudinal sectional view showing a third step of the present invention in the apparatus shown in FIG. 4;
FIG. 6A is a schematic longitudinal sectional view showing a deformed state of the thin tube upon completion of the third step of the present invention.
FIG. 6B is a schematic longitudinal sectional view showing different deformation states of the thin-walled tube.
FIG. 6C is a schematic longitudinal sectional view showing another deformed state of the thin tube.
FIG. 6D is a schematic longitudinal sectional view showing another deformation state of the thin-walled tube.
FIG. 7 is a schematic vertical sectional view showing a state immediately before the start of the fourth step in an example of the implementation of the apparatus used in the fourth step of the present invention.
8 is a schematic vertical sectional view showing a fourth step of the present invention in the apparatus shown in FIG. 7. FIG.
FIG. 9 is a schematic vertical sectional view showing a deformed state of the distal end portion of the thin-walled tube upon completion of the fourth step in the present invention.
10 is a bottom view of what is shown in FIG. 9. FIG.
FIG. 11 is a schematic vertical sectional view showing a state immediately before the start of the fifth step in an example of the implementation of the apparatus used in the fifth step of the present invention.
12 is a schematic vertical sectional view showing a fifth step of the present invention in the apparatus shown in FIG. 11. FIG.
FIG. 13 is a schematic vertical sectional view showing a demolded state after completion of the fifth step in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mouth member 2 Mouth member shoulder part 3 Tube container 4 Container shoulder part 5 Mouth member mouth neck part 13 Thin tube 14 Tube holder 17 Male part 20 Tip part 21 Inner surface 23 Outer surface 38 Open end 39 Female part H Predetermined length

Claims (4)

A first step of externally fitting and fixing a mouth member composed of a mouth neck portion and a shoulder portion integrally molded in advance with a thermoplastic synthetic resin to a male portion at the tip of the tube holder;
A thin tube made of thermoplastic synthetic resin is externally fitted to the tube holder, and the tip of the thin tube extends beyond the male mold part by a predetermined length. A second step of arranging in the heating and cooling zone of
A third step of heating the inner surface of the thin-walled tube while cooling the outer surface of the thin-walled tube, and causing the distal-end portion to undergo axial contraction and radial deformation;
A fourth step of heating the outer surface of the distal end portion of the thin tube that has been externally fitted to the tube holder that has undergone the third step, and gradually deforming the distal end portion so as to reach the open end;
The male part that externally fits and fixes the mouth member is advanced, the mouth neck of the mouth member protrudes from the opening end of the thin tube, and is in a heated state that is a deflated portion that continues to the opening end of the thin tube. The thin tube distal end is sandwiched between the male mold portion for forming the shoulder portion of the tube container and the male mold portion, and is composed of a fifth step of welding the distal end portion and the shoulder portion of the mouth member. A method for manufacturing a tube container. The length of the shoulder portion of the mouth member is shorter than the length of the shoulder portion of the tube container to be molded, and only the shoulder portion of a predetermined length continuous to the mouth and neck portion is connected to the distal end portion of the thin-walled tube and the shoulder portion of the mouth member. The manufacturing method of the tube container of Claim 1 made into a double welding structure. The length of the shoulder portion of the mouth member is made equal to the length of the shoulder portion of the tube container to be molded, and the entire shoulder portion has a double welded structure of the distal end portion of the thin tube and the shoulder portion of the mouth member. A method for producing a tube container according to 1. The manufacturing method of the tube container of Claim 1, Claim 2 or Claim 3 which heats the inner surface and outer surface of the front-end | tip part of a thin tube by spraying of heated air.

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