JPWO2018047711A1 - Resin cap - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a resin cap which is excellent in moldability and can improve sealing performance. The present invention comprises a ceiling wall and a skirt wall extending downward from an outer peripheral portion of the ceiling wall and having an internal thread screwed to an external thread of the container port, and the container port is provided on the lower surface of the ceiling wall. A resin cap in which an annular middle foot in close contact with the inner peripheral surface of the part and an annular outer foot in close contact with the outer peripheral surface of the container opening are integrally formed, the inner periphery of the outer foot The diameter of the surface is expanded downward, the diameter of the outer peripheral surface is reduced downward, and the taper angle of the outer peripheral surface is made larger than the taper angle of the inner peripheral surface.

Description

  The present invention relates to, for example, a resin cap attached to the mouth of a container for containing contents such as beverages.

  As the conventional resin cap, a ring-like inner seal projection fitted into the container opening on the inner surface of the top plate of the cap body provided with the top plate and the cylindrical portion suspended from the periphery thereof, and the opening of the container opening An annular open end seal projection is formed in contact with the end, and the open end seal projection is known to be bent and deformed in the radial direction until it abuts on the cap body by the container opening when the cap is attached. (Patent Document 1).

  In such a resin cap, the open end seal is formed even when the container opening portion is easily bent and deformed in the diameter reducing direction due to the bulging deformation of the top plate portion as the pressure in the container increases. It is said that the projection can seal the open end reliably and maintain high sealing performance.

Japanese Patent Laid-Open No. 2002-68236

  However, the above-mentioned conventional resin-made caps have room for improving formability and sealing performance.

  The present invention has been made in consideration of the above-mentioned matters, and an object thereof is to provide a resin cap which is excellent in moldability and hence can improve sealing performance.

  In order to achieve the above object, a resin cap according to the present invention comprises: a ceiling wall; and a skirt wall having an internal thread which extends downward from the outer peripheral portion of the ceiling wall and is screwed to an external thread of a container port. In the lower surface of the ceiling wall, an annular middle foot in close contact with the inner peripheral surface of the container opening and an annular outer foot in close contact with the outer peripheral surface of the container opening are integrally formed. It is a resin cap, and the inner peripheral surface of the outer foot is expanded downward, the outer peripheral surface is reduced downward, and the taper angle of the outer peripheral surface is larger than the taper angle of the inner peripheral surface. (Claim 1).

  In the resin cap, the taper angle of the inner circumferential surface may be 5 ° or more, and the taper angle of the outer circumferential surface may be 20 ° or less (claim 2).

  In the present invention, it is possible to obtain a resin cap which is excellent in moldability and can improve sealing performance.

  That is, in the resin cap of the invention according to each claim of the present application, since the location where the forced removal is necessary is not formed in the outer foot, the die-cutting property (moldability) can be improved. The taper angle of the side is larger than the taper angle of the inner side, so that the outer foot is less likely to be elastically deformed in the diameter expansion direction, the adhesion of the outer foot to the container opening is increased, and the sealing performance can be improved.

It is a bottom view which shows roughly composition of a cap made of resin concerning a 1 embodiment of the present invention. It is the sectional view on the AA line of FIG. It is the BB sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  A resin cap (hereinafter referred to as a cap) 1 shown in FIGS. 1 to 3 is used by being attached to an opening M (see FIG. 3) of a container such as a plastic bottle, for example, and compression molding or injection molding Are integrally molded of polyethylene. In addition, the raw material which forms the cap 1 is not specifically limited, In addition to the polyethylene used by this embodiment, a polypropylene etc. are used suitably.

  Further, as shown in FIGS. 1 and 2, the cap 1 has a top wall 2 which is substantially circular in a plan view, and a substantially cylindrical skirt wall 3 which extends downward from the outer peripheral portion of the top wall 2 There is. Here, a knurled groove 4 is provided on the outer peripheral surface of the skirt wall 3 and an internal thread 5 is provided on the inner peripheral surface, and the internal thread 5 is coupled to an external thread M1 (see FIG. 3) formed on the outer periphery of the container opening. It is possible.

  Then, when the cap 1 is rotated and attached to the container opening M so that the female screw 5 of the skirt wall 3 is coupled to the external screw M1 of the container opening M, an annular shape continuously provided on the inner surface (lower surface) of the ceiling wall 2 The middle foot (inner ring) 6, the annular rib 7, and the annular outer foot (outer ring) 8 are in close contact with the container opening M, whereby the container opening is sealed (see FIG. 3). That is, as shown by imaginary lines in FIG. 3, when the cap 1 is attached to the container opening M, the middle foot 6 is inserted into the container opening M and closely attached to the inner circumferential surface of the container opening M The annular rib 7 is in close contact with the annular upper end surface of the container opening M, and the outer foot 8 is in close contact with the outer peripheral surface of the container opening M.

  In addition, the cap 1 is a pill fur proof cap having a function of proving unopened (the fact that the opening has never been made), and at the time of opening the unopened cap 1 attached to the container opening M (first When the cap 1 is turned so that the connection between the male screw M1 and the female screw 5 is released at the time of opening the cap, the cap 1 is detached from the container opening M, but the tamper evidence connected to the lower part of the skirt wall 3 A band (hereinafter simply referred to as a "band") 9 is configured to remain at the container opening M.

  That is, the band 9 is connected to the lower portion of the skirt wall 3 via the annular weakening portion 10 extending all around the skirt wall 3 (see FIG. 3). The annular weakening portion 10 includes the skirt wall 3 and the band 9. And a plurality of bridges 10a existing on the inner peripheral side of the boundary between them and the slits 10b extending in the circumferential direction of the band 9 and the skirt wall 3 so as to define the skirt wall 3 and the band 9 up and down. A part (peripheral part) of bridge 10a is also cut by slit 10b so that it will break if it is pulled by predetermined power.

  Further, on the inner peripheral side of the band 9, a plurality (eight in this example) of locking pieces (flaps) projecting inward are provided at intervals in the circumferential direction (see FIGS. 1 to 3). ). Each locking piece 11 is positioned substantially below the annular protrusion (bead portion) M2 formed on the outer periphery of the container opening M below the male screw M1 in a state where the cap 1 is attached to the container opening M. And lock it on the annular projection M2 by an opening operation (see FIG. 3). That is, the locking piece 11 is configured to be able to be locked to the annular projection M2 from below, and the cap body (the skirt wall 3 and the top wall 2) above the annular weakening portion 10 is a container opening when opening. The band 9 which is separated from M and lower than the annular weakening portion 10 remains at the container mouth M, and the annular weakening portion 10 is broken accordingly.

  Here, the band 9 is integrally formed with the cap body (the skirt wall 3 and the top wall 2), and the locking pieces 11 provided on the band 9 protrude downward as shown in FIG. 2 when the cap 1 is formed. However, when the cap 1 is attached to the container opening M, the annular projection M2 is pushed up and turned upside down to project upward as shown by imaginary lines in FIG.

  And in this embodiment, as shown in FIG. 3, the outer foot 8 is extended by 1.35 mm or more below the lower surface 2a located in the outer peripheral side of the outer foot 8 in the top wall 2. That is, the length of the outer foot 8 (protruding length from the lower surface 2a of the top wall 2) L is set to 1.35 mm or more, which is longer than a general one. Thereby, the area | region which can contact | adhere the outer leg | foot 8 with respect to the outer peripheral surface of the container opening part M increases, and it can aim at the sealing improvement. Specifically, the length L of the outer foot 8 can be 1.58 mm, 1.78 mm or the like.

  Here, the outer diameter of the midfoot 6 is largest at the largest outer diameter portion 6 a formed between the proximal end and the distal end of the midfoot 6, and the outer foot 8 is exposed from the proximal end of the midfoot 6. It extends to a position corresponding to the maximum diameter portion 6a.

  Furthermore, in the present embodiment, as shown in FIG. 3, the diameter of the inner peripheral surface of the outer foot 8 is reduced downward, and the diameter of the outer peripheral surface is decreased downward. The taper angle β of the surface is increased. Specifically, it is conceivable to set the taper angle α of the inner peripheral surface to 5 ° or more and the taper angle β of the outer peripheral surface to 20 ° or less. With such a configuration, no part requiring forced removal is formed in the outer foot 8, so that it is possible to improve the moldability (moldability), and the taper angle β of the outer face of the outer foot 8 is on the inner face The outer foot 8 is difficult to be elastically deformed in the diameter expansion direction because it is larger than the taper angle α, so the adhesion of the outer foot 8 to the container opening M is increased, and the sealing performance can be improved. The latter effect is further enhanced by forming the lower surface 2b located on the inner peripheral side of the outer leg 8 in the top wall 2 above the lower surface 2a located on the outer peripheral side. Specifically, the taper angle α of the inner peripheral surface is 10 °, the taper angle β of the outer peripheral surface is 15 °, the taper angle α of the inner peripheral surface is 5 °, and the taper angle β of the outer peripheral surface is 10 ° It is preferable to set the difference between the taper angles α and β to 3 to 10 °, and more preferably 5 ° or 5 ° (4 ° to 6 °).

  The present invention is not limited to the above embodiment, and it is needless to say that the present invention can be modified in various ways without departing from the scope of the present invention. For example, the following modifications can be mentioned.

  In the above embodiment, the lower surface 2b located on the inner peripheral side of the outer foot 8 in the ceiling wall 2 is formed above the lower surface 2a located on the outer peripheral side, but the present invention is not limited thereto. Even if it forms in the same height, you may form the lower surface 2a above the lower surface 2b.

  As shown in FIG. 2 and FIG. 3, the middle foot 6 projects downward below the outer foot 8, and the container mouth M contacts the middle foot 6 earlier than the outer foot 8 at the time of capping, so it is shown in FIG. In the example, the thickness (the width in the radial direction) of the base end of the outer foot 8 is made larger than the thickness (the width in the radial direction) of the base end of the middle foot 6 By making it relatively easy to deform, the initial resistance at the time of capping is kept relatively small, and the outer foot 8 adheres to the container opening M at the time of completion of capping, so that sufficient sealing performance can be obtained. Not limited to this, the thickness of the base end of the middle foot 6 may be equal to or greater than the thickness of the base end of the outer foot 8.

  Moreover, in the said embodiment, although the length L of the outer leg | foot 8 is 1.35 mm or more, you may make it shorter than this.

  Needless to say, the above-described modifications may be combined as appropriate.

  The resin cap according to the present invention can be used as a container for containing various beverages, in addition to fruit juice beverages and carbonated beverages, and further, liquids, powders and the like other than beverages.

Reference Signs List 1 cap 2 ceiling wall 2a lower surface located on the outer peripheral side of the outer foot 2b lower surface located on the inner peripheral side of the outer foot 3 skirt wall 4 knurl groove 5 female screw 6 middle foot 6a maximum outer diameter 7 annular rib 8 outer foot 9 tamper Evidence band 10 Annular weakening portion 10a Bridge 10b Slit 11 Locking piece L Outer leg length M Container mouth M1 Male thread M2 Annular projection α Taper angle of inner peripheral surface of outer leg β Taper angle of outer peripheral surface of outer leg

Claims (2)

The ceiling wall and a skirt wall extending downward from the outer periphery of the ceiling wall and having a female screw screwed to the external thread of the container mouth, the lower surface of the ceiling being the inner periphery of the container mouth A resin cap in which an annular middle foot in close contact with a surface and an annular outer foot in close contact with the outer peripheral surface of the container opening are integrally formed,
The inner peripheral surface of the outer foot is expanded downward, the outer peripheral surface is reduced downward, and the taper angle of the outer peripheral surface is made larger than the taper angle of the inner peripheral surface. Plastic cap.   The resin cap according to claim 1, wherein a taper angle of the inner peripheral surface is 5 ° or more, and a taper angle of the outer peripheral surface is 20 ° or less.

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