JP2005193915A - Load push-pull cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load push-pull cap with an improved ESCR strength and without generating liquid leakage by ensuring a moldability by a cold runner with inexpensive mold for molding and cost for installation, preventing a weld line during molding from decreasing in strength, and improving roundness of the load push-pull cap part. <P>SOLUTION: Five to eight openings for passing a content liquid through are provided around a plug body projected vertically on a cap main body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a push-pull cap that is attached to the top of a container, and particularly to a push-pull cap that has good moldability and a high roundness of the inner diameter of a fitting portion.

Generally, a container for filling a liquid containing a surfactant such as a liquid detergent is provided with a liquid dispensing cap at the top. The cap is formed with a small-diameter spout for pouring liquid at the top, and the spout is closed with a plug from the outside or the inside. Among these, a so-called push-pull cap having a vertical slide type overcap has been used as a type that closes the spout from the inside. Various ideas have been added to the push-pull cap.
For example, it has been proposed that a liquid-permeable film is attached to the pouring hole so that there is little change in the outflow of the content liquid due to changes in air temperature, and it can also be used for an inverted container (for example, see Patent Document 1). .
Or the thing provided with the guide which causes the liquid which remained in the cap at the time of pouring of a content liquid to rapidly flow down in a container main body is proposed (for example, refer patent document 2).
Alternatively, there has been proposed a solution in which the diameter of the spout is changed to prevent the foam from blowing out for a solution that easily foams (see, for example, Patent Document 3).
JP 2000-255212 A JP 2001-151260 A JP 2001-130616 A

  FIG. 3 is a sectional view showing an example of a conventional push-pull cap of this type. As shown in FIG. 3, the normal push-pull cap 100 includes a cap body 110 and an overcap 120 that are attached to the top of a container 1 filled with, for example, a liquid detergent. A pouring outlet 121 for pouring is formed, and the slide part 111 can move up and down while being liquid-tightly attached to the cap body 110.

The cap body 110 has a protruding plug body 112 that closes the spout 121 from the inside when the overcap 120 is pushed down by hand, and the plug body 112 is supported by a support plate 113 extending from the cap body. . The support plate 113 is a disc in which a plurality of openings 114 are formed around the base of the plug 112, and the liquid in the container can freely flow through the openings 114.
A cylindrical portion 115 is provided around the disc in which the opening 114 is formed so as to surround the plug body 112, and the tip of the cylindrical portion 115 has a hook shape, and the tip of the cylindrical portion 122 of the overcap 120 has a flange. It meshes with the portion to serve as a stopper for the overcap 120 and prevents leakage of the content liquid to the outside.

  The overcap 120 has a cylindrical portion 122 that surrounds the spout 121 and hangs down on the container 1 side. This cylindrical portion 122 prevents liquid from flowing around the slide portion 111 and leaking out when the liquid is discharged. Yes. A gap 123 is formed between the cylindrical portion 122 and the plug body 112. Further, on the outer side of the spout 121, an annular protrusion 124 for preventing dripping is formed extending gradually.

  The push-pull cap 100 is opened by separating the spout 121 from the plug 112 when the overcap 120 is pinched with a finger and pulled up until stopped by the stopper of the slide portion 111 prior to the liquid pouring. . When the container 1 is tilted and the body part is pushed in this state, the content liquid is poured out through the opening 114, the gap 123 and the spout 121. When the container is erected, the dispensing stops, and the liquid remaining after adhering to the annular protrusion 124 for preventing dripping flows backward from the spout 121 and returns to the container. Next, when the overcap 120 is pushed down, the spout 121 is closed by the plug 112. In this state, the content liquid does not leak even if the container is turned over.

In the push-pull cap configured as described above used for household detergents and the like, generally, three openings are usually formed.
FIG. 4 shows a cross-sectional view along the line BB ′ of the push-pull cap shown in FIG. As shown in FIGS. 3 and 4, a cap body 112 is provided at the center of the top of the cap body 110, and three openings 114 are arranged at equal intervals around the stopper body 112. Between the openings 114 is a support plate 113 that connects the cap body 110 and the plug body 112. When the container 1 is tilted and the body part is pushed, the content liquid moves to the gap 123 through the opening 114 and is poured out through the spout 121.

  The push-pull cap having the above structure is usually manufactured by injection molding low density polyethylene (LD-PE). A cold runner or a hot runner is used as the injection molding machine. In the former, since the mold at the molding site is low in temperature, a heating equipment for the mold is unnecessary, and the equipment cost is low. The latter preheats the mold at the molding site to a temperature higher than the melting point of the raw resin, so that a mold heating facility is required and the facility cost is high. However, since the raw material resin has good fluidity and can be easily filled into a narrow gap of a mold, it has good moldability and is widely used because it has the advantage of reducing molding defects.

When the push-pull cap having the above structure is injection-molded using a cold runner, the molten resin wraps around from the back side of the mold for forming the opening and is joined. If the wraparound of the resin is insufficient or the temperature is too low, the integral molding becomes incomplete, and a wrinkle-like seam called a weld line 130 as shown in FIG. 4 is often generated outside the opening.
When the weld line is generated and the strength of the seam is lowered, a crack is generated from the weld line, which causes liquid leakage.

  Further, in FIG. 4, it is ideal that an arc shape is formed between the opening 114 and the opening 114 as shown in the figure. However, when the resin is not sufficiently wrapped or the temperature is too low, the arc shape is formed. Instead of being pulled, it becomes a straight line as shown by the chain line in the figure. Accordingly, the top surface of the cap body has a mussel shape in a planar manner. If it becomes like this, the roundness of a push pull cap part will worsen, and the sealing property of a push pull cap will become bad.

  In addition, in order to improve the opening and closing of the push-pull cap, about 0.001 to 0.025% of a slipping agent such as oleic acid amide is mixed in the material of the push-pull cap. Since the cap body and the overcap are easily attached and detached even in the mated state, the cost of the raw material is also increased.

  The present invention has been made to solve these drawbacks, and it ensures moldability with a cold runner with low molding costs and equipment costs, prevents weld lines during molding, and push-pull caps. The purpose is to provide a push-pull cap that improves the ESCR strength (Environment Stress Cracking) and does not cause liquid leakage by improving the roundness of the part.

In order to solve the above problems, the present invention is a push-pull cap that is attached to the top of a container, comprising a cap body and an overcap that is liquid-tightly attached to the cap body and is movable up and down. A plug body for sealing the outlet of the overcap is provided in the center of the top of the cap body in a vertical convex shape, and the contents liquid passes around the plug body on a concentric circle at the center of the plug body. 5 to 8 apertures are provided, and a cylindrical protrusion that fits the overcap is provided on the outer periphery of the aperture in a vertically convex shape. The top has a spout for pouring out the liquid, and has a first cylindrical portion that hangs down on the container side surrounding the spout, and further slides on the outside of the tubular portion also on the container side Push with part It was Le cap.
In the push-pull cap of the present invention, it is preferable that the apertures are provided at regular intervals on the circumference.
Moreover, it is preferable that the distance which the said opening adjoins is 1.2 mm or more. The size of the opening is preferably 6 mm × 4 mm or less.

If the push-pull cap as described above is used, it is possible to secure good moldability even if it is formed using a cold runner with low molding die costs and equipment costs. It becomes possible to provide. Further, the generation of weld lines during molding is eliminated, and as a result, the ESCR strength is improved, the roundness of the push-pull cap portion is improved, and it is possible to provide a push-pull cap that does not cause liquid leakage. .
It is intended.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. FIG. 1 shows an embodiment of a push-pull cap according to the present invention. The push-pull cap 30 of this embodiment includes a cap body 10 that is screwed onto the top of the container 1 and an overcap 20 that is liquid-tightly attached to the cap body 10 and can be moved up and down. . The container 1 is filled with, for example, an easily foamable liquid detergent.

  The overcap 20 is formed with a spout 21 for pouring liquid detergent at the top, has a cylindrical portion 22 that surrounds the spout 21 and hangs down on the container side, and further on the outside of the cylindrical portion 22. The slide part 25 is provided at a slight interval.

  The spout 21 and the inner wall of the cylindrical portion 22 are continuously formed. An annular groove 16 is formed between the cylindrical portion 22 and the slide portion 25 of the overcap 20 to receive the cylindrical protrusion 15 of the cap body 10 and to allow the overcap 20 to move up and down in a liquid-tight manner. Yes. At the tip of the annular groove 16 and the tip of the cylindrical protrusion 15, a hook-like stopper that engages with each other to prevent the overcap from falling off is provided.

  The cap body 10 has a protruding plug body 12 that closes the spout 21 from the inside while the overcap 20 is pushed down, and a gap 23 is formed between the plug body 12 and the tubular portion 22. Is formed.

The plug body 12 extends from the cap body 10 and is supported by a support plate 13 having an opening 14 through which liquid flows, and the bottom end of the tubular portion 22 and the support plate 13 are closed with the spout 21 closed. A space 17 is formed between them.
In the push-pull cap 30, since the spout 21 is closed from the inside by the plug body 12 when the overcap 20 is pushed down, the liquid content does not flow out of the spout 21 even if the container falls. . FIG. 1 shows a state where the overcap 20 is pushed down and the spout 21 is closed from the inside by the plug 12.
When the overcap 20 is pulled up by hand prior to the dispensing of the content liquid, the overcap 20 is pulled up until it is limited by the engagement of the stopper, and the spout 21 is opened from the plug body 12 so that the content liquid can be poured out. If the container is tilted or inverted in this state and the body of the container is pushed by hand if necessary, the liquid in the container passes through the opening 14 and the gap 23 of the support plate 13 and is poured out from the spout 21.
Further, when the overcap 20 is pushed in, the push-pull cap 30 closes the spout 21 with the plug 12 so that the liquid content does not leak from the spout 21 even if the container is overturned.

Next, the opening 14 which is a main part of the present invention will be described.
FIG. 2 is a cross-sectional view taken along line AA ′ of the push-pull cap 30 of the present invention shown in FIG. FIG. 2 is cut across the support plate 13 including the plug 12 and opening 14 of the push-pull cap 30 of the present invention. As shown in FIG. 2, the push-pull cap 30 of the present invention has a plug body 12 having a doughnut-shaped cross section at the center, and six openings 14 around the concentric circle having the same center as the center of the plug body 12. Has been placed. FIG. 2 shows an example in which six openings 14 are arranged. The angle (θ) formed by each straight line connecting the centers of the openings 14 is 60 degrees.
The number of the openings 14 is suitably 5 or more and 8 or less. If the number of openings is 4 or less, it will be difficult to fill the resin on the back side of the mold during injection molding. Therefore, a weld line will be generated, resulting in a decrease in manufacturing yield and a decrease in ESCR strength. This may cause leakage.
On the other hand, if the number of openings is too large, the raw material resin goes around the opening at the time of injection molding and a film sticks out to the opening, which makes it difficult for the content liquid to flow out. Moreover, there is no room for providing a large number of openings because of the size of the space, and it becomes difficult to manufacture a mold for injection molding.

The openings 14 are preferably provided at regular intervals on a concentric circle around the plug body 12. This is because it is arranged in a narrow region between the plug body 12 and the cylindrical protrusion 15 and the sealing effect by the cylindrical portion 22 of the overcap 20 is ensured.
The size of the opening 14 is about 6 mm × 4 mm at the maximum. Taking a household detergent container as an example, the amount of detergent that flows out at one time is almost constant, although there are some differences in viscosity depending on the type of detergent. Therefore, even if the capacity of the container itself changes, the cross-sectional area of the outflow path is almost constant.
If the size of the opening is too small, the speed of the liquid passing through the opening increases, which may cause bubbles. Also, it is not a good idea to increase the area of the opening so much in terms of the strength of the cap body. Therefore, it is preferable that the size of the opening 14 is about 6 mm × 4 mm at the maximum, and the number of the openings 14 is 5 to 8 to ensure the entire cross-sectional area as much as necessary. Note that the size of the opening 14 is a rectangular horizontal (a) × vertical (b) dimension circumscribing the opening as shown in FIG.
The interval between adjacent openings 14 is also preferably set to 1.2 mm or more. If it is too narrow, it becomes difficult to produce a mold for molding, and burrs protrude from the opening, resulting in poor outflow of the internal solution.

Incidentally the total opening area and 48.3 mm ^2, the magnitude of the longitudinal opening (b) as a 3.5 mm, the push-pull cap using cold liner for the case of changing the number of openings from 3 to 8 The weld line strength and the pulling force of the fitting part were measured, and at the same time the occurrence of liquid leakage was examined. The openings were designed to have the same spacing as the width (a). These results are listed in Table 1.
In Table 1, in the ESCR test, after capping with a tightening torque of 30 kg-cm, the presence or absence of cracks after leaving at 50 ° C. for 120 hours was confirmed. F = 50 indicates that cracks occurred in 50% of the specimens.
The pulling force of the fitting part was measured when a slipping agent was used and when it was not used. The standard value of the lifting force is 1.5 to 5.0 kg, but about 1.5 to 3.0 kg is preferable because it is the easiest to use.

  From the results in Table 1, when the numerical aperture is set to 5 or more and 8 or less, the weld line strength is improved, the result of the ESCR test is good, and molding is easy even when a cold liner is used. It can be seen that a push-pull cap having a high-performance quality can be obtained by smoothly lifting the overcap without using an agent. Note that when the numerical aperture is 8, it tends to be difficult to make a molding die. Therefore, 6 or 7 is preferable.

According to the present invention, it is possible to obtain a push-pull cap with a good manufacturing yield by using inexpensive equipment and a molding die, and this contributes to cost reduction.
According to the present invention, it is possible to provide a push-pull cap having excellent sealing performance without causing cracks from the weld line and without worrying about liquid leakage, and thus can contribute to further popularization of small liquid containers. .

It is sectional drawing which shows the structure of the push pull cap of this invention. It is a figure which shows the cross section along line A-A 'of the push pull cap shown in FIG. It is sectional drawing which shows the structure of the conventional push pull cap. It is a figure which shows the cross section along line B-B 'of the push pull cap shown in FIG.

Explanation of symbols

1 ········································································································ ········································································································· ··································································································································· , 110... Cap body, 111... Slide part, 112... Plug body, 113. 115... Cylindrical part, 120... Overcap, 121... Spout, 122. ... gap, 130 ...... weld line

Claims (4)

  A push-pull cap attached to the top of the container, comprising a cap body and an overcap that is liquid-tightly attached to the cap body and is movable up and down, and an overcap spout at the center of the top of the cap body A plug body is provided in a vertically convex shape, and five to eight holes are provided around the plug body on a concentric circle at the center of the plug body. Further, a cylindrical protrusion that fits into the overcap is provided on the outer periphery of the opening in a vertical convex shape, and a spout for discharging liquid is provided at the top of the overcap. And has a cylindrical portion that hangs down on the container side surrounding the spout, and further has a slide portion that hangs down on the container side outside the cylindrical portion, and the cylindrical portion of the overcap, Between the slide part The push-pull cap characterized by comprising fitted cylindrical projection of the cap body.   The push-pull cap according to claim 1, wherein the openings are provided on the circumference at uniform intervals.   The push-pull cap according to claim 1 or 2, wherein a distance between adjacent openings is 1.2 mm or more.   The push-pull cap according to any one of claims 1 to 3, wherein the size of the opening is within 6 mm x 4 mm.

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