JP4609792B2 - Method for producing a synthetic resin double structure container - Google Patents

Description

  The present invention relates to a method for producing a synthetic resin double structure container mainly used as a container for cosmetic liquid or the like.

  Conventionally, glass bottles are generally used as containers for cosmetic liquids, but in recent years, instead of glass bottles, synthetic resin containers with excellent productivity and a wide selection range of shapes and the like are used. In particular, with the upscaling of cosmetics and the like, a double-structured container in which two containers are integrated is used.

  In this synthetic resin double structure container, the inner container and the outer container are molded in different colors, and the colors of both are changed, or a display body for displaying products is arranged between the inner and outer containers. Various added values that are not available in single-layer containers can be obtained.

  The synthetic resin double structure container is manufactured by sandwiching the lower end portion of the synthetic resin material 2 suspended in a cylindrical shape from the ring-shaped nozzle 1 by the bottom portions of the half molds 3 and 4 for the outer container. After the portion protruding from the upper end surface of the cylindrical synthetic resin material 2 on the opening of the container molds 3 and 4 is cut to form the outer container rough body 5, A driving pin 6 having a length reaching the bottom of the outer container formed in the outer container rough shape body 5 is inserted, and air is pressed into the outer container rough shape body 5 to expand it into a wide-mouthed bottle shape. The outer container 7 is molded by pressing the bottom part of the mold toward the bottom of the mold at the lower end of the driving pin 6, and the inner container 8 separately molded by injection molding is fitted into the outer container 7. (See Patent Document 1).

Further, in this double structure container, the convex portion 9a protruding from the bottom surface of the inner container 8 is fitted into the concave portion 7a formed by pressing the tip of the driving pin against the inner bottom portion of the outer container. It has become.
Japanese Patent Laid-Open No. 8-198256

  However, the conventional techniques as described above have a problem in that it is expensive to manufacture an injection mold for molding the inner container, and the cost is inevitably high.

  Further, in blow molding, when forming a long and narrow container, that is, a container having a shape in which the outer diameter of the container is not so wide with respect to the outer diameter of the coarsely shaped body (parison), the container is formed at the tip of the driving pin. The area of the portion that presses the inner bottom cannot be sufficiently ensured, and it has been difficult to form the concave and convex portions that fit the inner bottom of the outer container and the bottom of the inner container.

  SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, an object of the present invention is to provide a method for producing a synthetic resin-made double structure container that can be suitably molded even in a small-diameter and slender shape.

In order to solve the conventional problems as described above and achieve the intended purpose, the invention according to claim 1 is characterized in that the lower end portion of the synthetic resin material that is hung in a cylindrical shape from the ring-shaped nozzle is divided into half of the inner container. While sandwiched between both bottoms of the mold, the upper portion of the cylindrical synthetic resin material is cut on the opening of the mold to form a hollow inner container rough shape body having one end opened, the contents dexterity mold molding pins are protruded from the inner bottom surface of, after inflating the bottle shape was pressed air into the inner container crude shape body in this state, the molding pin withdrawal from the mold, the bottom An inner container molding step for molding a bottle-shaped inner container having a locking recess ;
The lower end portion of the synthetic resin material that is hung in a cylindrical shape from the ring-shaped nozzle is sandwiched between the bottom portions of the half mold for the outer container, and the cylindrical synthetic resin material is placed on the opening of the outer container mold. A hollow outer container rough shape body having one end opened is formed by cutting the upper portion of the outer container, and a molding pin protrudes from the inner bottom surface of the outer container mold. after inflated by press-fitting the air bottomed cylinder in the body, closed to the forming pin withdrawal from the mold, it has a locking protrusion which protrudes from the inner bottom surface fitting together with the locking recess An outer container molding process for molding a bottom cylindrical outer container;
The body portion of the inner container is fitted into the outer container, and the position of the recess for locking is fitted to each other according to the position of the protrusion for locking , so that the inner container and the outer container are integrated. It is a manufacturing method of the synthetic resin-made double structure container which consists of an assembly process to be made.

  The invention according to claim 2 is characterized in that, in addition to the configuration of claim 1, the synthetic resin material is PET.

  In addition to the structure of claim 1 or 2, the invention described in claim 3 is formed with a locking groove continuous in the circumferential direction at the upper end of the body portion of the inner container, and the locking groove is formed in the opening inner edge of the outer container. A locking flange to be locked is formed.

  According to a fourth aspect of the present invention, in addition to the configuration of the third aspect, a locking protrusion is formed along the longitudinal direction at the upper end of the body portion of the inner container, and the locking flange is formed on the locking flange of the outer container. It is characterized by forming a recessed part into which the protruding line fits.

The method for producing a synthetic resin dual structure container according to the present invention includes sandwiching the lower end portion of a synthetic resin material suspended in a cylindrical shape from a ring-shaped nozzle between both bottom portions of an inner container half mold, The upper portion of the cylindrical synthetic resin material is cut on the opening of the inner cylindrical portion to form a hollow inner container rough shape body having one end opened, and a molding pin is inserted from the inner bottom surface of the inner container mold. is projected, after being expanded in the bottle shape was pressed air into the inner container crude shape body in this state, the molding pin withdrawal from the mold, the bottle-shaped inner container having a locking recess in the bottom An inner container molding process for molding;
The lower end portion of the synthetic resin material that is hung in a cylindrical shape from the ring-shaped nozzle is sandwiched between the bottom portions of the half mold for the outer container, and the cylindrical synthetic resin material is placed on the opening of the outer container mold. A hollow outer container rough shape body having one end opened is formed by cutting the upper portion of the outer container, and a molding pin protrudes from the inner bottom surface of the outer container mold. after inflated by press-fitting the air bottomed cylinder in the body, closed to the forming pin withdrawal from the mold, it has a locking protrusion which protrudes from the inner bottom surface fitting together with the locking recess An outer container molding process for molding a bottom cylindrical outer container;
The body portion of the inner container is fitted into the outer container, and the position of the recess for locking is fitted to each other according to the position of the protrusion for locking , so that the inner container and the outer container are integrated. Manufacturing process can be reduced because an expensive injection mold is not used, and even in the case of an elongated container, a locking recess is formed at the bottom of both the inner and outer containers. And the convex part for latching can be formed.

  Since the synthetic resin material is PET, a highly transparent container can be formed.

  A circumferentially continuous locking groove is formed at the upper end of the body portion of the inner container, and a locking flange locked to the locking groove is formed at the opening inner edge of the outer container so that the inner and outer containers are connected to each other. It can be prevented from coming off.

  By forming a locking ridge along the longitudinal direction at the upper end of the body portion of the inner container, and forming a recessed portion into which the locking ridge fits in the locking flange of the outer container, both the inner and outer containers It is possible to prevent a shift in the rotation direction.

  Next, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows an example of a synthetic resin double structure container 10 manufactured by the method of the present invention. In the figure, reference numeral 11 denotes an inner container, and reference numeral 12 denotes an outer container.

  The synthetic resin double structure container 10 includes a bottle-shaped inner container 11 and a bottomed cylindrical outer container 12, and the body portion 13 of the inner container 11 is fitted into the outer container 12 to be double. It is designed to form a structure.

  As shown in FIG. 2, the inner container 11 includes a cylindrical body portion 13 and a bottle mouth portion 15 that communicates with the inside of the body portion 13 through a flange portion 14 that constitutes the upper surface of the body portion 13. The bottle is formed of a synthetic resin material such as PET (polyethylene terephthalate).

  The body portion 13 is formed with a bulging portion 16 bulging outwardly at the upper end portion, and is continuous in the circumferential direction between the bulging portion 16 and the flange portion 14, that is, at the upper end of the body portion 13. A locking groove 17 is formed.

  Further, a locking projection 18 that is long in the longitudinal direction is formed on the upper end of the body portion 13 across the locking groove 17.

  On the other hand, on the bottom of the inner container 11, that is, the bottom of the body portion 13, locking recesses 19 and 19 that are recessed inward are formed side by side in the diameter direction.

  The bottle mouth portion 15 is formed in a cylindrical shape, and a screw portion 15a is formed on the outer periphery thereof so that a cap-shaped lid is screwed together.

  As shown in FIG. 3, the outer container 12 is formed in a bottomed cylindrical shape with a synthetic resin material such as PET.

  A locking flange 20 projecting inward is integrally formed on the inner edge of the opening of the outer container 12, and the locking flange 20 is formed in a locking groove formed on the outer periphery of the upper end of the inner container 11. 17 and fits each other.

  The locking flange portion 20 is formed with a recessed portion 21 into which the locking ridge 18 is fitted.

  Further, on the bottom portion of the outer container 12, locking convex portions 22, 22 projecting from the inner bottom surface in accordance with the positions of the locking concave portions 19, 19 are formed.

  The manufacturing method of the synthetic resin double structure container 10 is configured such that the inner container 11 and the outer container 12 are separately molded and combined, and includes an inner container molding process, an outer container molding process, and an assembly process. Has been.

  The inner container 11 is molded by so-called blow molding using half molds 30 and 31 for the inner container.

  First, as shown in FIG. 4 (a), a synthetic resin material 32 such as PET in a molten state is extruded into a cylindrical shape from a ring-shaped nozzle 33 and suspended to a certain length. As shown in the figure, the left and right half-shaped molds 30 and 31 are closed, the lower end portion of the cylindrical synthetic resin material 32 is sandwiched between the bottoms of both molds, and the upper end surface of the mold is cylindrical by the hot cutter 34. The upper part of the synthetic resin material is cut to form a hollow inner container rough body (parison) 35 having one end opened in the mold.

  Next, as shown in FIG. 4C, the molding pins 36, 36 are projected from the inner bottom surfaces of the molds 30, 31, and the air supply nozzle 37 is inserted into the opening of the inner container rough shape 35. In the drawing, reference numeral 38 denotes a cylinder for projecting the molding pin 36 from the inner bottom surfaces of the molds 30 and 31.

  The air supply nozzle 37 includes a molding portion 39 that molds the bottle mouth portion 15, and the molding portion 39 defines a portion corresponding to the bottle mouth portion 15 of the surrounding synthetic resin material, that is, the inner container rough shape body 35, as the inner surface of the mold. Is pressed into a shape having a screw portion 15a on the outer periphery.

  In this state, air is injected into the inner container rough shape body 35 so that the inner container rough shape body 35 is shaped like a bottle in accordance with the shapes of the molds 30 and 31 as shown in FIG. The bottle-shaped inner container 11 which expand | swells and has the recessed parts 19 and 19 for latching in the bottom part is shape | molded.

  Finally, after cooling for a certain time and the synthetic resin material is solidified, the cylinders 38 and 38 are operated, the molding pins 36 and 36 are pulled out from the molds 30 and 31, the molds 30 and 31 are opened, and the inner container 11 is opened. To complete the process.

  The outer container 12 is molded by so-called blow molding using half molds 40 and 41 for the outer container 12.

  First, as shown in FIG. 5 (a), a synthetic resin material 42 such as PET in a molten state is extruded into a cylindrical shape from a ring-shaped nozzle 43 and suspended to a certain length. As shown, the left and right halves of the molds 40 and 41 are closed, the lower end of the cylindrical synthetic resin material 42 is sandwiched between the bottoms of both molds, and the upper end surface of the mold is cylindrical by the hot cutter 44. The upper portion of the synthetic resin material is cut to form a hollow outer container rough body (parison) 45 having one end opened in the molds 40 and 41.

  Next, as shown in FIG. 5C, the molding pins 46 and 46 are projected from the inner bottom surfaces of the molds 40 and 41, and the air supply nozzle 47 is inserted into the mold opening. In the figure, reference numeral 48 denotes a cylinder for projecting the molding pin from the inner bottom surface of the mold.

  In this state, air is press-fitted into the outer container rough body 45 so that the outer container rough body 45 conforms to the shape of the molds 40 and 41 as shown in FIG. The bottomed cylindrical outer container 12 in which the locking convex portions 22 and 22 protrude from the inner bottom portion is molded.

  Finally, after cooling for a certain time and the synthetic resin material is solidified, the cylinders 48 and 48 are operated, the molding pins 46 and 46 are pulled out from the molds 40 and 41, the molds 40 and 41 are opened, and the outer container 12 is opened. To complete the process.

  Then, the inner container 11 is inserted and fitted into the molded outer container 12, and the locking recesses 19, 19 are aligned with the locking projections 22, 22 to lock the locking recess 19. , 19 and the locking projections 22 and 22 are fitted to each other and the inner and outer containers 11 and 12 are integrated to form the synthetic resin double structure container 10.

Note that Te assembly process smell, may be to insert a label for displaying the product in the gap between the two containers.

  Moreover, in the above-mentioned Example, although the example which uses PET (polyethylene terephthalate) as a synthetic resin material was demonstrated, you may use other synthetic resin materials, such as another polypropylene.

It is sectional drawing which shows an example of the synthetic resin double structure container manufactured by the method of this invention. (A) is the perspective view seen from the front side diagonal direction which shows the inner container in FIG. 2, (b) is the bottom view. (A) is a front view which shows an outer container same as the above, (b) is the top view. (A)-(d) is sectional drawing which shows the state of an inner container formation process. (A)-(d) is sectional drawing which shows the state of an outer container shaping | molding process. (A)-(e) is sectional drawing which shows the state of the conventional outer container shaping | molding process.

DESCRIPTION OF SYMBOLS 10 Synthetic resin double structure container 11 Inner container 12 Outer container 13 Body part 14 Flange part 15 Bottle part 15a Screw part 16 Bulging part 17 Locking groove 18 Locking protrusion 19 Locking recess 20 Locking Flange part 21 Recessed part 22 Locking convex part 30, 31 Half mold 32 Synthetic resin material 33 Nozzle 34 Hot cutter 35 Inner container rough shape body (Parison)
36 Molding Pin 37 Air Supply Nozzle 38 Cylinder 39 Molding Parts 40, 41 Half Container Mold for Outer Container 42 Synthetic Resin Material 43 Nozzle 44 Hot Cutter 45 Outer Container Rough Shape (Parison)
46 Molding pin 47 Air supply nozzle 48 Cylinder

Claims (4)

The lower end portion of the synthetic resin material that is hung in a cylindrical shape from the ring-shaped nozzle is sandwiched between the bottom portions of the half mold for the inner container, and the upper side portion of the cylindrical synthetic resin material is placed on the opening portion of the mold. Cut into a hollow inner container shape with one end open, and mold pins project from the inner bottom surface of the inner container mold. In that state, air is injected into the inner container shape. after inflating the bottle shape, and the molded pin withdrawal from the mold, the inner container forming step of forming a bottle-shaped inner container having a recess for engaging the bottom,
The lower end portion of the synthetic resin material that is hung in a cylindrical shape from the ring-shaped nozzle is sandwiched between the bottom portions of the half mold for the outer container, and the cylindrical synthetic resin material is placed on the opening of the outer container mold. A hollow outer container rough shape body having one end opened is formed by cutting the upper portion of the outer container, and a molding pin protrudes from the inner bottom surface of the outer container mold. after inflated by press-fitting the air bottomed cylinder in the body, closed to the forming pin withdrawal from the mold, it has a locking protrusion which protrudes from the inner bottom surface fitting together with the locking recess An outer container molding process for molding a bottom cylindrical outer container;
The body portion of the inner container is fitted into the outer container, and the position of the recess for locking is fitted to each other according to the position of the protrusion for locking , so that the inner container and the outer container are integrated. The manufacturing method of the synthetic resin-made double structure container characterized by comprising the assembly process to make.   The method for producing a synthetic resin double structure container according to claim 1, wherein the synthetic resin material is PET.   3. A locking groove that is continuous in the circumferential direction is formed at the upper end of the body portion of the inner container, and a locking flange that is locked to the locking groove is formed at the inner edge of the opening of the outer container. A method for producing a synthetic resin double structure container.   The locking protrusion is formed along the longitudinal direction at the upper end of the body portion of the inner container, and a recess portion into which the locking protrusion is fitted is formed in the locking flange of the outer container. A method for producing a synthetic resin double structure container.

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