JP2005119170A - Method for producing connection container of synthetic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing a connection container in which adjacent containers are firmly integrated with the expanded barrel parts welded to each other, the welding surface is formed in a desired shape, and each container keeps its shape. <P>SOLUTION: Bottomed cylindrical bodies in the shape of a test tube are made by injection molding, the openings of the cylindrical bodies are grasped, the barrel parts are melted, and cylindrical bodies are placed in one blow molding mold. A positioning plate is inserted between the cylindrical bodies, and gas is supplied from the opening of each cylindrical body to expand the barrel part of each cylindrical body. The positioning plate is moved immediately before the expanded barrel parts are contacted with each other to be removed from the cavity of the blow molding mold. After that, the gas is supplied into each cylindrical body, and the barrel parts are welded to each other to obtain the connection container. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a synthetic resin connection container. In particular, the present invention is a method for efficiently producing a connection container in which each container is firmly integrated by welding a plurality of synthetic resin containers each having an opening to each other over almost the entire body. It is about.

  Synthetic resin connection containers are known. The simplest method for manufacturing a connecting container is to form individual synthetic resin containers each having an opening and a swelled body part, and a plurality of these parts are arranged and bonded to each other with an adhesive. Alternatively, the body is surrounded by a shrinkable film and integrated. However, in order to make a connection container by such a method, it is necessary to make the surface of the body part which adheres or abuts each container an accurate plane, and a special technique is required for molding each container. This is not practical due to the inconvenience of having to enclose each container later with an adhesive or shrinkable film.

  Utility Model Registration No. 2568993 discloses that a synthetic resin-made connecting container is manufactured by injection blow. That is, in this publication, when a bottomed tubular body having a test tube shape is formed by an injection molding method, the openings of the two tubular bodies are provided with a connecting piece, and the two tubular bodies are formed by the connecting pieces. It needs to be united from the beginning. And this gazette performs blow molding to the two cylindrical bodies united by the connection piece, and makes each the container the connection container couple | bonded by the connection piece. Therefore, this publication does not describe that the body portions of two containers are welded together to form a connected container.

  There is a reason why the above-mentioned utility model registration No. 2568993 does not lead the container body parts to weld each other. The reason for this is that if the body parts are to be welded together, the welded surface does not become a flat surface but becomes a curved surface whose shape is not fixed, and the shape of the container is destroyed. In other words, when trying to weld the body parts of the container, the body part must be kept in a molten state at a high temperature and inflated at the same time, but in this way, it supports the welding surfaces. This is because the welding surface does not become a flat flat surface and is curved into various shapes depending on the case and the case, and the shape of each container is destroyed.

  The above publication describes that a partition member is inserted between cylindrical bodies when blow molding is performed. However, this partition member should be left between the cylindrical bodies until the end of the blow molding, and is therefore only for forming partial irregularities on the body of the container.

As the above publication teaches, when each container is integrated with a connecting piece, the connecting piece is provided in the middle of the cylinder forming the opening of the container. A piece can get in the way and the lid cannot be covered to a sufficient depth. In order to cover the lid to a sufficient depth, the length of the tube from the opening to the connecting piece must be increased. However, when the length of such a cylinder is increased, the cylinder part occupies a larger volume than the essential trunk part, and not only the use effect of the raw material resin is reduced but also the shape of the container is deteriorated. Furthermore, if the connecting pieces are only integrated, there is a problem that the whole connecting container is weakly coupled and easily separated.
Utility Model Registration No. 2568993

  The present invention is intended to solve the above-mentioned problems and to provide a method of manufacturing a connection container that is firmly united by welding the barrels in which a plurality of adjacent containers are swollen together. . In this case, the present invention also provides a method for efficiently producing a connection container in which the welded body portion of the connection container has a desired shape, particularly a flat surface, and the shape of each container is not collapsed. It is something to try.

  When the inventor performs blow molding by arranging two test tubular bottomed cylindrical bodies made by injection molding in the method of manufacturing a connection container by injection blow taught by the above-mentioned utility model registration No. 2568993, 2 A plate that determines the position of the welding surface is interposed between the individual cylindrical bodies so as to avoid the damaging deformation of the cylindrical body that is swollen, and the positioning plate just before the cylindrical parts are welded together. It was found that when the molding was moved to the outside of the blow molding die and further blow molding was performed, the body portions were welded in a desired shape and welded together, and a connection container in which the welded surface did not collapse was obtained.

  At that time, if the positioning plate is removed from the blow mold, a gap will be formed later in the blow mold, and it has been found that this gap may be filled by inserting another refill mold. Furthermore, the inventor has found that, depending on the shape of the container, it is not necessary to use a replenishing mold if the positioning plate is merely moved and left in the blow mold so that no gap is generated. The present invention has been completed based on such knowledge.

  This invention forms a test tubular bottomed tubular body with a thermoplastic resin, grasps the opening of the tubular body, suspends the tubular body and heats and melts the portions other than the opening, Place in a blow mold and place at least two melted cylindrical bodies suspended in one mold cavity and line up close to each other, and insert a positioning plate on the welding surface between each cylindrical body In addition, each cylinder is inflated into a container by press-fitting gas from the opening of each cylinder, and the positioning plate is moved and blow-molded immediately before the swelled barrels try to contact each other. A connecting container manufacturing method is provided, in which a gas is pressed into each cylindrical body after that and the body portions facing each other are welded to each other.

  According to the present invention, since the bottomed cylindrical body is a test tube, the core mold can be easily removed, and therefore the bottomed cylindrical body can be easily molded. In addition, since it was decided to hold the opening of the obtained cylindrical body, suspend the cylindrical body and move to the next step, the outside of the mouth required to form the opening at the time of forming the cylindrical body The mold can be left as it is and used as a support, and therefore it is easy to move to the next heating process and blow molding process. In addition, in the blow molding process, gas is separately injected into each cylindrical body, inflated into a container shape, and the inflated body portions are welded together as they are. , Can make the connection container efficiently.

  Further, in the present invention, at the time of blow molding, a positioning plate is inserted between the cylindrical bodies to determine the position and shape of the welding surface, and the swelled body portions of the cylindrical bodies try to contact each other. Immediately before, the positioning plate is moved and removed from the mold cavity of the blow molding die, and after removing the positioning plate, the gas is injected into each cylindrical body to perform the blow molding. A shape body will form the welding surface as the shape of a positioning plate in the position where the positioning plate existed. In this way, it is possible to easily obtain a connection container in which a container having a desired shape is welded at the body portion and is firmly integrated. The present invention provides such an effect.

  An embodiment of the present invention will be described below with reference to the drawings. 1 to 7 sequentially explain an example of a method for manufacturing a connection container according to the present invention. That is, FIG. 1 is a cross-sectional view showing a process of forming two cylindrical bodies by injection molding. FIG. 2 is a cross-sectional view showing a state in which the openings of the two cylindrical bodies obtained in the process of FIG. 1 are grasped and moved to the next process. FIG. 3 is a cross-sectional view showing a process of heating two cylindrical bodies in a heating tool. FIG. 4 is a cross-sectional view showing a state where two heated cylindrical bodies are put into a blow molding die, a positioning plate is inserted, and blow molding is started. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view showing a state in the middle of blow molding performed by press-fitting gas into two cylindrical bodies. FIG. 7 is a cross-sectional view showing a process in which a refilling mold is inserted instead of the positioning plate moving and blow molding is performed. FIG. 8 shows a connection container made by the method for manufacturing a connection container according to the present invention.

  FIG. 9 is a cross-sectional view showing another embodiment of the method for manufacturing a connection container according to the present invention.

  10 and 11 show another connecting container that can be made by the method of the present invention.

  In the present invention, a bottomed tubular body having a test tube shape is first molded from a thermoplastic resin. An injection molding method is suitable as the molding method. The reason why the bottomed cylindrical body is made into a test tube is that if it is not a test tube but a cylindrical body with a swelled bottom, the core mold cannot be pulled out. Because it takes time to inflate the bottom later.

  FIG. 1 shows a process of forming two bottomed cylindrical bodies by an injection molding method. In FIG. 1, 1 is a core mold, 2 is an outer mold, and 3 is a mouth outer mold. The core mold 1 is inserted into the outer mold 2 and the mouth outer mold 3 to form two bottomed cylindrical mold pits therebetween. The solution resin from the hot runner portion 4 connected to the injection molding machine is injected into the mold cavity to form two cylindrical bodies A and B.

  In FIG. 1, the mouth outer die 3 is separated from the outer die 2 because it is convenient for locking the two formed cylindrical bodies to the mouth outer die 3 and moving to the subsequent steps. That's why. In the cylindrical bodies A and B, the portion in contact with the mouth part outer die 3 is thinned, and the portion near the bottom is thickened. Thus, the thinned portion is quickly cooled and solidified in the mold, but the thick portion is still at a high temperature, which is convenient for continuing to expand the thick portion. Thus, the cylindrical bodies A and B are removed from the core mold 1 and the outer mold 2 and moved to the next step while being locked by the mouth outer mold 3 as shown in FIG. .

  As described above, the cylindrical body taken out of the core mold 1 and the outer mold 2 has a low temperature due to solidification of the opening, but the remaining portion is still at a high temperature. In order to keep the high temperature at an optimum temperature for blow molding, the cylindrical bodies A and B taken out from the injection mold are once put in a heating tool and the portions other than the opening are heated. FIG. 3 shows the heating process.

  In FIG. 3, the cylindrical bodies A and B are locked to the outer mouth mold 3, suspended in the air, and inserted into the outer heating tool 5. Further, the inner heating tool 6 is inserted into the cylindrical bodies A and B, respectively, and the intermediate heating tool 7 is inserted between the cylindrical bodies A and B. Thus, the cylindrical bodies A and B are maintained in a molten state by heating the portions other than the opening from the inside and the outside.

  Thereafter, the heating elements 5 to 7 are removed from the cylindrical bodies A and B, suspended in the air by the mouth outer mold 3 and placed in the blow mold 8. As shown in FIG. 4, the blow mold 8 has one mold cavity 9 that accommodates the cylindrical bodies A and B. The blow mold 8 is provided with a gap 11 for inserting and retracting the positioning plate 10. Next, the air blowing tool 12 is inserted into the openings of the cylindrical bodies A and B. The air blowing tool 12 is configured to blow air separately into the cylindrical bodies A and B.

  The state shown in FIG. 4 is the state shown in FIG. As shown in FIG. 5, the positioning plate 10 is inserted into a position where the entire mold cavity 9 of the blow mold 8 is divided into two parts, and is moved in the direction of arrow P to be extracted from the blow mold 8. Have been able to. For this purpose, the blow mold 8 is provided with a gap for inserting and removing the positioning plate 10.

  Air can be separately press-fitted from the air blowing tool 12 into the cylindrical bodies A and B placed in the blow mold 8. Thus, the cylindrical bodies A and B are separately inflated as shown in FIG. As the air press-fitting of the cylindrical bodies A and B proceeds, a part of the swelled barrel portion is likely to come into contact with the positioning plate 10. In this way, the positioning plate 10 is moved in the direction of the arrow P and removed from the blow molding die 8 immediately before the swelled barrels try to contact each other.

  When the positioning plate 10 is removed from the blow mold 8 in this way, the blow mold creates a gap 11 where the positioning plate 10 was present. The gap 11 is filled with the replenishment die 13 as the replenishment die 13 shown in FIG. The tip surface 14 of the replenishment mold 13 is shaped to be flush with the wall surface that just defines the mold cavity 9.

  When the wall surface of the mold cavity 9 is completed by the replenishment mold 13, the blow mold 8 is in a state as shown in FIG. In this state, air is further pressed into the cylindrical bodies A and B to swell the body, and the swelled body is pressed against the surface of the mold cavity 9, and the body portions facing each other form the positioning plate 10. They will be welded to each other where they existed. Thus, the two containers are welded to each other along the shape of the positioning plate at the position where the positioning plate is present. As a result, as shown in FIG. 8, a container having a desired shape that is not deformed is welded together in one plane, thereby obtaining a connection container that is firmly integrated.

  In this invention, it is a great feature that the positioning plate is attached in the blow mold so as to be inserted and withdrawn. As the positioning plate, a plate as thin as possible is used as long as the necessary strength can be maintained. For this purpose, the positioning plate is preferably made of metal, in particular steel. The positioning plate is preferably covered with a fluorine resin, particularly polytetrafluoroethylene, so that the thermoplastic resin constituting the container is not strongly bonded.

  In the present invention, the time when the positioning plate is moved out of the blow mold is important. The moving time is immediately before the barrels inflated with the cylindrical body try to contact each other. This time is when each cylindrical body fills the space of the mold cavity partitioned by the positioning plate approximately 70% to 90%. At this time, a part of the swelled body of the cylindrical body may be in contact with the positioning plate. In such a case, the positioning plate is moved to escape from the blow mold while being carefully pulled away so as not to deform the contacting body.

  The time when each cylindrical body mentioned above fills the space of the mold cavity approximately 70% to 90% can be known from the amount of air press-fitted into each cylindrical body. Specifically, the air amount is 70% by creating a graph showing the relationship between the ejection time and the ejection amount in advance by ejecting air at a constant pressure from an air ejection port of a certain size. Furthermore, it is determined based on the time required to flow the air amount necessary to inflate 90%.

  According to the method described above based on FIGS. 1 to 7, the connection container as shown in FIG. 8 can be produced. In FIG. 8, (a) shows a side view of the connection container, (b) shows the same plan view, and (c) shows a cross-sectional view taken along line CC in (b). In the connecting container shown in FIG. 8, two containers X and Y made of two cylindrical bodies A and B are welded together at the welding surface M, and are firmly integrated, and the welding surface M Is in the position where the positioning plate 10 was present, and is a flat surface as the shape of the positioning plate 10.

  1 to 7 exemplify a blow mold having a structure in which the positioning plate 10 is removed from the blow mold 8 and the replenishment mold 13 is inserted later. However, it is not always necessary to remove the positioning plate from the blow mold, and it is not always necessary to use a refill mold. For example, when making a container in which two semi-cylindrical containers are connected as shown in FIG. 9, the positioning plate 15 is made of two flat plates, and the tip surfaces 16 that are in contact with each other are made flat. The two positioning plates 15 are first brought into contact with each other, then moved in the direction of the arrow R, and the wall surface of the mold cavity 9 is simply moved until the distal end surface 16 is flush with the wall surface of the mold cavity 9. Finalize. Therefore, in this case, a replenishment type is not required.

  In this invention, after the cylindrical body is placed in the blow mold and maintained in a molten state, the stretching rod is inserted from the opening of the cylindrical body, the stretching rod is pushed down to extend the cylindrical body, and the bottom of the cylindrical body is Is preferably brought into contact with the bottom of the blow mold. If it does in this way, a cylindrical body tends to become a shape along the wall surface of a mold cavity in the early stage of blow molding. The movement of the stretching rod may be performed before or after the blowing of air, but is preferably performed simultaneously with the blowing of air.

  4 to 7, since the purpose is to obtain a connecting container having a flat welding surface M as shown in FIG. 8, a flat plate is used as the positioning plate 10. In this invention, the positioning plate is waved in one direction, so that a connection container having a welding surface waved in the horizontal direction as shown in FIG. 10 can be produced. In this way, the welded surface can be made into a connecting container having a wave in the vertical direction.

  4 to 8, the case where two containers are connected has been described as an example. However, according to the present invention, a structure in which three or more containers are connected can be manufactured in the same manner. it can. A connected container in which three or more containers are connected is not limited to one in which the containers are arranged in a straight line, and a zigzag or polygonal array can be produced in the same manner.

  In the method of the present invention, as shown in FIG. 1, when the test tubular bottomed tubular bodies A and B are made side by side, the above-mentioned utility model registration No. 2568993 teaches. A connecting piece for connecting the cylindrical bodies A and B may be provided. This is because when the connecting piece is provided, the shape of the cylindrical body is stabilized when the cylindrical body is suspended in the state shown in FIG. However, the connecting piece is preferably provided at a position as far as possible from the opening.

  A thermoplastic resin is used as the resin constituting the container. In principle, most thermoplastic resins can be used, but a connection container suitable for practical use can be obtained particularly when polyethylene terephthalate (PET), polyolefin, or polystyrene is used. Among them, the connection container using PET is tough, and it is awarded because it is transparent and beautiful.

  In order to carry out the method of the present invention, the bottomed cylindrical body injection molding step, the bottomed cylindrical body heating step, the bottomed cylindrical body blow molding step, and the connecting container take-out step are performed. It is preferable to implement these processes as a state in which they are arranged in a ring shape in this order. If it does in this way, since each process can be performed one after another in the place rotated only 90 degrees, a connection container can be made still more efficiently.

It is sectional drawing which showed the process of shape | molding two bottomed cylindrical bodies in this invention method. In this invention method, it is sectional drawing which showed the state which grasps and moves the opening part of two cylindrical bodies. In this invention method, it is sectional drawing which showed the process of putting two cylindrical bodies in a heating tool and heating. In this invention method, it is sectional drawing which showed the state which begins to blow-mold two cylindrical bodies. It is the VV sectional view taken on the line in FIG. In this invention method, it is sectional drawing which showed the state in which a positioning board is inserted and blow molding is performed. In this invention method, it is sectional drawing which showed the state in which a replenishment type | mold is inserted instead of removing a positioning plate and blow molding is performed. The connection container obtained by this invention is shown. It is sectional drawing which showed another embodiment of this invention method. The other connection container obtained by this invention method is shown. The further another connection container obtained by this invention method is shown.

Explanation of symbols

A, B Tubular body M Welding surface X, Y Container 1 Core type 2 Outer mold 3 Mouth outer mold 4 Hot runner part 5 Outer heating tool 6 Inner heating tool 7 Intermediate heating tool 8 Blow molding die 9 Mold cavity 10, 15 Positioning plate 11 Clearance 12 Air blowing tool 13 Replenishment type 14, 16 Tip surface

Claims (5)

  Mold the bottomed tubular body of the test tube with thermoplastic resin, grab the opening of the tubular body, suspend the tubular body and heat and melt the parts other than the opening, and use this as the blow mold And at least two melted cylindrical bodies are suspended in one mold cavity and arranged in close proximity to each other, and a positioning surface positioning plate is inserted between each cylindrical body, Each cylindrical body is inflated into a container shape by injecting gas from the openings of the cylindrical body, and the positioning plate is moved immediately before the inflated body parts come into contact with each other to move into the mold cavity of the blow mold The method for manufacturing a connected container is characterized in that after that, a gas is press-fitted into each cylindrical body, and the adjacent body parts of adjacent containers are welded to each other.   Out of the mold for molding the cylindrical body, the outer mold for the mouth for molding the opening of the cylindrical body is separated from the remaining part, and the cylindrical body and the outer mold for the mouth are locked. 2. The method for manufacturing a connection container according to claim 1, wherein the connection container is suspended in the air and transferred to the next step.   The method for producing a connection container according to claim 1 or 2, wherein a stretching rod is inserted into the cylindrical body in the blow mold, and the cylindrical body is stretched by lowering the stretching rod.   After the positioning plate is moved, another replenishment die is inserted into the gap formed after the positioning plate to complete the mold cavity surface of the blow molding die, and then gas is injected into the cylindrical body. The manufacturing method of the connection container as described in any one of Claims 1-3. The tip surface of the positioning plate was shaped to match the mold cavity surface of the blow mold, and the mold plate surface was completed by moving it until the tip surface of the positioning plate was flush with the mold cavity surface of the blow mold. After that, gas is press-fitted into the cylindrical body, The manufacturing method of the connection container according to any one of claims 1-3.

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