JP2004001308A - Molding method and molding of glass bottle-like vial - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the molding of a glass bottle-like vial made of a resin by a method wherein the molding of the vial through the air blowing of an injection-molded preform is performed independently through the adoption of a fixing rod. <P>SOLUTION: The lustrous resin is injectingly filled in an injection cavity around an injection core so as to mold the preform, the inner diameter of the mouth part of which is small and its height is nearly equal to that of the vial and the side wall thickness of which is two to three times as thick as the wall thickness of the vial. After that, the preform is released from a mold and transferred to a cavity mold for molding the vial. Then, through the insertion of the fixing rod for compressing the bottom of the vial, the preform is fixed to the bottom surface of a cavity. Finally, by pressingly spreading the side wall of the preform to the surface of the cavity, the glass bottle-like vial is molded. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for molding a glass bottle-shaped small container using a resin and a molded product thereof.
[0002]
[Problems to be solved by the invention]
The small container to which the present invention is applied is a thick-walled bottle having a small body diameter of about 25 mm or less in body height and about 25 mm in width, and a small capacity for perfume, pills, eye drops, etc., and most of them are made of glass. . Since glass has a large mass, it is desired to reduce the weight of a small container for portable use. In addition, since the impact strength is weak, it is dropped and damaged at the time of use, so that not only the contents cannot be used but also wasteful.
[0003]
Under these circumstances, small containers made of resin are demanded. In the injection blow molding used for molding bottles and containers, the inside of the mouth of the preform, which is the mouth of the container after molding, is injected. The preform formed around the outside of the blow core and formed around the injection blow core is expanded by the pressure of air blown into the inside from the tip of the injection blow core to form a thin-walled container such as a bottle.
[0004]
For this reason, since the injection blow core has both the core cooling water passage and the blow air circuit inside, there is a limit to the minimum outer diameter of the core, and it is not possible to design the core smaller than that, and it is smaller than the minimum outer diameter. It is considered difficult to mold small-diameter containers. In the case of air blow from the injection blow core, the preform is held in the core, so that the thicker the wall, the more difficult it is to blow the air evenly and the more uneven the thickness. It has not been possible to form a small container having a textured shape.
[0005]
The present invention has been conceived in order to solve the above-mentioned problem, and an object thereof is to form a preform by injection molding with a small-diameter injection core having only a core cooling water passage, and to form a small container by air blow using a fixed rod. It is an object of the present invention to provide a new molding method and a molded article that can be formed separately by adopting them so as to form a small container having a thick side wall and a glass bottle-like texture.
[0006]
[Means for Solving the Problems]
In the molding method of the present invention according to the above object, a glossy resin is injected and filled into an injection cavity around an injection core, the inner diameter of the mouth is small, the height is substantially equal to the height of the container, and the side wall thickness is the thickness of the side wall of the container. A preform having a thickness of 2 to 3 times is molded, the preform is released, transferred to a cavity mold for container molding, and the bottom is compressed by inserting a fixing rod to fix the preform to the bottom surface of the cavity. Then, the side wall of the preform is compressed and expanded to the cavity surface by air blow, and the side wall is formed into a small container that has a thick-walled see-through due to light refraction and internal reflection, and exhibits a glass bottle-like texture in combination with the surface reflection. It becomes.
[0007]
Further, the glass bottle-shaped small container of the present invention is a small container made of a resin molded by the above-mentioned molding method, wherein the thickness of the side wall is thickly seen by refraction of light and internal reflection, and is combined with surface reflection. The resin is made of a resin having a glass bottle-like texture, and the resin is made of a glossy resin such as an acrylic resin, a polycarbonate resin, and a polyester resin.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In the drawing, reference numeral 1 denotes a preform, and 2 denotes a small container having a glass bottle-like texture formed by air blowing the preform.
[0009]
The preform 1 is formed of a block having a horizontally long rectangular cross section obtained by integrally molding a threaded mouth 11 serving as a mouth 21 of the small container 2 and four thick side walls 12. The sprue 14 is formed to protrude. The side wall 12 of the preform 1 has a height of about 20 mm, a thickness of about 5.0 mm, a thickness of the bottom part of about 2.0 mm, and an inner diameter of the mouth part 5.4 of about 5.4 mm. Note that the sprue 14 is cut in some cases.
[0010]
The small container 2 has a rectangular cross-section in which a mouth 21 having the same dimensions as the mouth 21 of the preform 1 and four side walls 22 are integrally formed, and has a horizontally long quadrilateral shape, and a front surface spreading downward. It consists of a corner and a bottom corner formed on a cut surface. The side wall 22 of the small container 2 has a height of about 20 mm, a thickness of about 2.5 mm, a thickness of the bottom 23 of about 1.5 mm, and an inner diameter of the mouth 21 of about 5.4 mm.
[0011]
The preform 1 and the small container 2 can be formed by the steps shown in FIG. The resin is preferably an acrylic resin having a glassy texture, a polycarbonate resin, a polyester resin such as polyethylene terephthalate, or the like, and particularly preferably an acrylic resin, in view of transparency, gloss and hardness.
[0012]
In the figure, 3 is an injection mold for the preform 1, 4 is a container molding mold, 5 is an upper holding mold also serving as a mold for the mouth portion 11, which is attached to the guide member 6 so as to be openable and closable, and is attached to the lower surface of the transfer member 7. It consists of a pair of split types provided. 8 is an injection nozzle.
[0013]
The injection mold 1 includes an injection cavity 33, an injection core 33 (base outer diameter 5.4 mm) inside a core cooling water channel inserted into the injection cavity die 31 through the upper holding die 5, and the injection core. An injection cavity 8 is formed around the periphery of the injection cavity 33, and the injection nozzle 8 is nozzle-touched to the bottom surface of the injection cavity 32 through a base 34. A molten resin (for example, acrylic resin) is injected and filled into the injection cavity 32 from the injection nozzle 8 to form the preform 1.
[0014]
As shown in FIG. 4, the container forming die 4 has a cavity 42 that forms a container over the closed surfaces of the pair of split dies 41. The upper portion of the cavity 42 is formed by the lower surface of the holding die 5, and the blow core 44 is received in the holding die 5 from above, and has a diameter smaller than the inner diameter of the preform inserted into the center of the blow core 44 so as to be able to advance and retreat. A fixed rod 43 having a blow passage 45 in the portion is inserted from the mouth 11 to the bottom 13 of the preform 1. A bottom mold 46 is provided at the bottom of the cavity 42 so as to be able to move up and down through the machine base 9.
[0015]
In order to form the preform 1 into a glass bottle-shaped small container 2 in such a container molding die 4, as shown in FIG. Also, a small diameter fixed rod 43 is inserted. Simultaneously or thereafter, the bottom mold 46 is raised to compress the bottom 13 together with the sprue 14 and to form the bottom 13 into the thin bottom 23 of the small container 2. Then, the preform 1 is fixed to the bottom surface of the cavity while keeping both the positions.
[0016]
After the preform 1 is fixed, compressed air of about 30 kgf is blown from the upper blow core 44 into the gap around the fixing rod 43. As a result, the wall portion 12 of the preform 1 is compressed and expanded to the cavity surface to form the small container 2. In addition, the preform 1 is fixed above and below the cavity by the mouth 11 and the bottom 13, and the air expands in the gap around the fixed rod and presses and expands the side wall 12. Is applied uniformly to the entire side wall, and uneven thickness, which tends to occur on the thick side wall 12, is prevented.
[0017]
Further, the inner surface of the side wall and the thickness distribution are adjusted by performing air blowing to secure the inner capacity. As a result of this air blowing, the preform 1 becomes a small-sized container 2 whose wall 22 is seen through the refraction of light and internal reflection, except for the bottom 23, as shown in FIG. In this case, if there is a vertical difference in the distance between the preform 1 and the cavity surface due to the inclination of the cavity surface, the thickness of the lower wall having a larger distance tends to be formed thinner than that of the upper wall. Since the side wall is seen through by refraction and internal reflection, the glass bottle-shaped impression is not lost.
[0018]
In the illustrated example, the fixing of the bottom portion 13 is performed by the fixing rod 43 and the bottom mold 46. However, depending on the cavity structure, the fixing and fixing can be performed only by the fixing rod 43 alone.
[Brief description of the drawings]
FIG. 1 is a view showing a half vertical section front view (A) and a half transverse plane (B) of a preform of a glass bottle-shaped resin small container according to the present invention.
FIG. 2 is a view showing a half vertical section front view (A) and a half cross section plane (B) of the glass bottle-shaped resin small container according to the present invention.
FIG. 3 is a longitudinal sectional front view of an injection mold showing a molding state of a preform.
FIG. 4 is a longitudinal sectional front view of a cavity mold for container molding showing a state in which a blow core mold is inserted into a preform.
FIG. 5 is a longitudinal sectional front view of a cavity mold for forming a container, showing a state in which the bottom of the preform is compressed and fixed.
FIG. 6 is a longitudinal sectional front view of a cavity mold for molding a container showing a molded state of a glass bottle-shaped small container.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Preform 11 mouth part 12 side wall 13 bottom part 14 sprue 2 glass bottle-shaped small container 21 mouth part 22 side wall 23 bottom part 3 injection mold 31 injection cavity mold 32 injection cavity 33 injection core 4 container molding mold 41 cavity mold 42 cavity 43 fixing Rod 44 Blow core 46 Bottom type

Claims (3)

A preform in which a glossy resin is injected into an injection cavity around the injection core, the inner diameter of the mouth is small, the height is substantially equal to the height of the container, and the thickness of the side wall is two to three times the thickness of the side wall of the container. Molded,
After releasing the preform and transferring it to the cavity mold for container molding, inserting the fixing rod, compressing the bottom and fixing the preform to the bottom of the cavity,
By compressing and expanding the preform side wall to the cavity surface by air blow, the side wall is molded into a small container that has a thick-walled see-through due to light refraction and internal reflection, and has a glass bottle-like texture combined with surface reflection. A method for forming a glass bottle-shaped small container. A small container made of a resin molded by the molding method according to claim 1, wherein a thickness of a side wall is thickly seen by refraction of light and internal reflection, and a glass bottle-like texture is obtained in combination with surface reflection. A glass bottle-shaped small container characterized by being made of a resin to be exhibited. 3. The glass bottle-shaped small container according to claim 2, wherein the resin is made of a resin having gloss such as an acrylic resin, a polycarbonate resin, and a polyester resin.

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