JPS597246Y2 - Synthetic resin bottle lid - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a soft synthetic or resin bottle lid for sealing the opening of a packaging container.

Conventionally, a cylindrical skirt part that fits around the outer periphery of the bottle mouth part is integrally connected to a stopper body or lid body that seals the opening of a packaging container, such as a bottle mouth part, and the skirt part is connected to the stopper body or lid body. A bottle lid made of soft synthetic resin that can be opened by separating it from the body is provided with a thin weakened line surrounding the circumference at the connecting part between the stopper or the lid and the skirt part. The seal is opened by tearing along this weakened line to separate the skirt from the plug or lid.

However, due to the stretchability of the soft synthetic resin itself, the cutting along the weakened line is heavy and the cutting quality is extremely poor. This makes the cap or lid extremely unsightly, and in order to make it easier to tear, making the thin wall at the weakened line even thinner will reduce the amount of molten resin when injection molding the bottle cap. Not only will the flow be significantly hindered by the shape of the weakened line, but there is also a risk that the weakened line will be torn and torn when cutting a certain shape. It was because it would be difficult.

In the present invention, the connecting part of the skirt part to the stopper body or the lid body is made into a thin weakened line as in the conventional method, and the skirt part is separated by tearing along the weakened line. A plurality of narrow connecting pieces extending in the axial direction are provided at appropriate intervals in the circumferential direction to connect the skirt portion to the stopper body or the lid body, and each of the narrow connecting pieces is directed inward with respect to the axis of the bottle lid. By slanting the narrow connecting piece and by forming the cross section perpendicular to the axis of the bottle cap into a substantially triangular or semicircular shape, the skirt can be separated without making it difficult to eject the bottle cap. It is designed to be very easy to cut, with good sharpness and without creating jagged edges.

Below, we will explain the drawings of an example in which the skirt part is integrally connected to the stopper body in a separable manner. The bottle cap 1 is made up of a stopper 3 with a flange 4 that is fitted into the inner surface of the bottle mouth 2, and a cylindrical skirt 5 that is fitted around the outer periphery of the bottle mouth 2. , the skirt portion 5 has its upper end connected to the plug body 3. The skirt portion 5 is integrally connected to the outer peripheral portion of the lower surface of the collar 4 via a separable connecting portion 6, which will be described in detail later.
An annular engagement protrusion 8 is formed on the inner circumferential surface of the bottle neck portion 2 to engage with an annular protrusion 7 protruding from the outer circumferential surface of the bottle mouth portion 2, and extends obliquely upward from the lower end of the skirt portion 5 toward the connecting portion 6. An incision groove 9 of an appropriate length is provided to form the gripping piece 10, and a thin weakening line 11 is provided between the upper end of the incision groove 9 and the connecting portion 6 to form the gripping piece 10. When the skirt portion 5 is held and pulled outward in the radial direction, the skirt portion 5 is cut along the cutting grooves 9 and the weakened lines 11.

The separable connection part 6 has slots 12 provided at appropriate intervals in the circumferential direction, and the skirt part 5 is integrally attached to the collar 4 via narrow connecting pieces 13 between the slots 12. In this structure, a stepped portion 14 having a diameter D4 appropriately smaller than the inner diameter D5 of the skirt portion 5 is provided on the outer periphery of the lower surface of the collar 4, and the upper end of each narrow width connecting piece 13 is integrally attached to the stepped portion 14. By locating the connection position of each narrow connecting piece 13 to the collar 4 on the inside of the inner surface of the skirt portion 5 in the radial direction, each narrow connecting piece 13 is connected to the axis 15 of the plug body 3. The cross-section of each narrow connecting piece 13 perpendicular to the axis 15 of the bottle lid 1 is approximately triangular or semicircular in shape and is inclined inward at an appropriate angle θ.

Note that 16 is a decorative cap made of a metal plate that is fitted onto the collar 4.

The hollow mold for forming the above-mentioned bottle cap 1 by injection molding is composed of an upper mold 20, a lower mold 30, and a core mold 40 that is slidably fitted into the lower mold 30. The lower surface of the mold 20 is formed with a recess 21 corresponding to the plug 3 having a diameter D1, and a protrusion 22 with a diameter D2 directed downward at an appropriate height in the center thereof. a vertical fitting hole 31 corresponding to the outer periphery of the skirt portion 5, and an annular protrusion 32 with an inner diameter D4 for forming the stepped portion 15 of the collar 4 on the upper inner periphery of the fitting hole 31; The lower surface of the annular protrusion 32 is shaped into a tapered surface 33 at an appropriate angle θ with respect to the axis.

The core mold 40 has a cylindrical shape that fits vertically and slidably into the fitting hole 31 of the lower mold 30, and its upper outer periphery corresponds to the inner periphery of the skirt portion 5 and corresponds to the inner diameter of the annular protrusion 32. D4
It is shaped into a stepped cylindrical surface 44 having a larger diameter D5, and an annular groove 41 corresponding to the annular protrusion 8 is carved at a mid-height position in the vertical direction of this stepped cylindrical surface 44.

The upper end surface 42 of the core mold 40 has a recess 43 having a diameter D6 that faces the protrusion 22 at the center of the lower surface of the upper mold 20 with an appropriate gap when the core mold 40 approaches the upper mold 20. While drilling, a tapered surface 45 is formed so that the intersection corner of the upper end surface 42 of the core mold 40 and the stepped cylindrical surface 44 comes into contact with the tapered surface 33 of the lower surface of the annular protrusion 32 of the lower mold 30. to take shape.

Further, in the tapered surface 45 of the core mold 40, communication grooves 46 having a substantially triangular cross section are formed at appropriate pitches along the circumferential direction, each one end of which communicates with the stepped cylindrical surface 44, and each other end of which communicates with the upper end surface. 42 so as to communicate with each other.

At this time, the groove depth of the communication groove 46 is shaped so that it becomes gradually shallower as it approaches the upper end surface 42 of the core mold 40, and the upper end surface side edges of the adjacent communication grooves 46 The shape is such that the distance P1 is larger than the distance P2 at the upper edge of the stepped cylindrical surface.

With this configuration, the lower surface of the upper mold 20 and the upper surface of the lower mold 30 are aligned,
The core mold 40 that fits into the fitting hole 31 of the lower mold 20 is brought close to the lower surface of the upper mold 20, and the tapered surface 45 of the core mold 40 is aligned with the lower mold 30.
When brought into contact with the tapered surface 33 on the lower surface of the annular protrusion 32, the recess 21 of the upper mold 20, the protrusion 22, the annular protrusion 32 of the lower mold 30 and the upper surface separated by the upper end surface 42 of the core mold 40, The cavity A formed by the recess 43 of the core mold 40 corresponds to the contour of the stopper 3, and is formed by the inner peripheral surface of the fitting hole 31 of the lower mold 30, the lower surface of the annular protrusion 32, and the outer surface. The cavity B formed by the stepped cylindrical surface 44 of the child die 40 corresponds to the shape or contour of the cylindrical skirt portion 5.

Both cavities A and B are the substantially triangular communication grooves 4 provided at appropriate pitches in the core mold 40.
6 and the tapered surface 33 on the lower surface of the annular protrusion 42 of the lower mold 30 communicate through the gap formed by the mold. The liquid flows from A to the other cavity B through the substantially triangular communication groove 46 and is completely filled.

When this injection or shaping is completed, the bottle cap 1 can be removed from the preform mold by first retracting the core mold 40 downward and then separating the lower mold 30 downward from the upper mold 20. In this case, a lower mold 30 is used to form each narrow connecting piece 13 in the bottle lid 1 and the opening 12 between each connecting piece 13.
The annular protrusion 32 and the upper part of the core mold 40 form a tapered surface 33 that widens toward the end by making each narrow connecting piece 13 inwardly inclined, so that when the lower mold 30 is separated from the upper mold 20 The annular protrusion 32 allows the skirt portion 5 of the bottle cap 1 to be easily cut out of the mold while shrinking, and therefore, no unreasonable force is applied to each narrow width connecting piece 13 during the die cutting process, so that each narrow width connecting piece 13 is easily removed from the mold. 13 can be cut out without tearing into pieces.

In addition, since the cross-sectional shape of each narrow connecting piece 13 perpendicular to the axis 15 of the bottle cap 1 is approximately triangular or approximately semicircular, the cross section of each communication groove 46 forming this is also approximately triangular or approximately semicircular. The flow of the molten melt or resin through the communication groove 46 is significantly better than when the circumference of the connecting portion between the skirt portion 5 and the collar 4 is made extremely thin. The molten metal or resin can be quickly and reliably filled into each communication groove 46.

In the bottle cap 1 thus shaped, the bottom outer circumference of the collar 4 of the stopper 3 and the upper end of the cylindrical skirt portion 5 have a substantially triangular or semicircular cross section at appropriate intervals along the circumferential direction. They are connected by narrow connecting pieces 13, and the connecting pieces 13 correspond to the locations where the tapered surface 33 on the lower surface of the annular protrusion 31 of the lower mold 30 and the tapered surface 45 on the core mold 40 come into contact, as described above. , the resin will not flow into that part and the window 12 will be formed (in this case, the lower mold 30 and the Okiko mold 4
The tapered surface 3 of the annular protrusion 32 in the lower mold 30 due to an error in the manufacturing of the mold or due to the filling pressure of the molten resin.
3 and the tapered surface 45 of the core mold 40 may not be in perfect contact with each other, resulting in a slight gap, and a very thin resin film may be formed in the area where the window 12 is to be formed. (This resin film is extremely easy to break, so it does not interfere with the present invention in any way.)

Therefore, the connecting part 6 between the stopper 3 and the skirt part 5 in the bottle lid 1 has a narrow connecting piece 13 and a slotted window 1 along the circumferential direction.
2 are lined up alternately, and after pulling the scar 1/part 5 by the gripping piece 10 to make an incision along the weakened line 11, and then pulling it further radially outward, each opening is made. The connecting pieces 13 between the 12 are cut sequentially from the base of the flange 4, and the skirt part 5 can be separated from the stopper 3. In this case, each narrow connecting piece 13 is aligned with the axis 15 of the bottle lid 1. the cross section perpendicular to is approximately triangular or approximately semicircular, and
It is connected to the flange 4 which has a relatively thick wall, and if an external force acts on this connecting piece 13 to cut it, the external force will be applied to the connecting piece 13.
Each connecting piece 13 is cut at the base of the flange 4 because stress is concentrated at the corner of the approximately triangular or semicircular cross section. As a result, the cut area will not be jagged and will be beautiful, and the cut will not be heavy.
It can be easily done with light force.

Therefore, according to the present invention, it is possible to easily separate the skirt portion from the stopper or lid without making injection molding of the resin bottle lid difficult.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is a partially cutaway vertical front view of the bottle cap, Fig. 2 is a partially cutaway longitudinal front view with the skirt section removed, and Fig. 3 is a cross-sectional view of the bottle lid. Figure 4 is an enlarged view of the main parts of Figure 3, Figure 5 is a longitudinal sectional front view of the mold, Figure 6 is an enlarged view of the main parts of Figure 5, and Figure 7 is a middle view of the main parts. FIG. 8 is an enlarged front view of the tip of the child mold, FIG. 8 is a plan view of FIG. 7, and FIG. 9 is an enlarged perspective view of the tip of the core mold. 1... Bottle lid, 3... Stopper, 4...
...Brim, 5...Skirt part, 6...Connection part, 12...Window, 13...Connection piece.

Claims (1)

[Scope of utility model registration request] A bottle lid made of a soft resin, in which a cylindrical skirt part that fits around the outer periphery of the bottle mouth part is integrally connected to the stopper for the bottle mouth part or the lid body through a detachable connecting part. A plurality of narrow connecting pieces extending in the axial direction of the bottle cap are provided at appropriate intervals in the circumferential direction in the connecting part, and the connection position of each connecting piece to the stopper or lid is set in a radial direction from the inner surface of the skirt part. A case in which each connecting piece is located on the inside and is inclined inward with respect to the axis of the bottle cap, and the cross section of each connecting piece perpendicular to the axis of the bottle cap is shaped into a substantially triangular or semicircular shape. Bottle lid made of resin.