JP2005313906A - Resin cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin cap which can be opened by lifting with the fingers, is superior in plugging, sealing, and unsealing, and has a practical resealing function. <P>SOLUTION: The resin cap has locking projection 21, and expanding/contracting curved parts 23, each having a plan section of almost curved shape and curving outwardly of a skirt 20, are formed on a part of the locking projection 21. The resin cap has a uniform wall thickness in the part ranging from the skirt 20 to the expanding/contracting curved parts 23. Each expanding/contracting curved part 23 is of an almost triangular shape in a front view, and has a curved part that becomes wider as the curved part 23 gets closer to the lower end of the skirt 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly relates to a resin cap suitable for covering a wide-mouth bottle such as a milk bottle, and more particularly to a resin cap excellent in stoppering performance, sealing performance, opening performance, and resealability.

  A resin cap described in Patent Document 1 is known as a synthetic resin lid for covering a milk bottle or the like. The cap has a sealing engagement portion that fits into the inner wall of the container mouth portion, and an annular engagement portion that is provided so as to protrude downward from the peripheral edge of the top plate portion. Further, a protrusion that engages with the outside of the container mouth portion, and a thin-walled portion that can be broken on both sides of the opening tab are provided. And it is a resin-made cap of the structure which pulls up the tab for opening and removes a cap by fracture | rupturing a thin part.

  A resin cap described in Patent Document 2 has been proposed as a resin cap improved from Patent Document 1. This resin cap is provided so that the thin-walled portion can be opened by simply lifting the cap with a finger without breaking the thin-walled portion. That is, in order to improve the adhesion between the cap and the container mouth portion, an annular engagement portion that engages with the outer peripheral portion of the container mouth portion is provided, and in addition, in order to provide flexibility to the annular engagement portion, the container mouth A thin portion that is formed thinner than the upper thick portion and the lower thick portion provided along the outer periphery of the portion is provided. The thin portion is formed by forming a plurality of window-shaped concave portions in the circumferential direction on the outer surface of the annular engagement portion, or by providing a vertical slit shape extending upward from the lower end portion of the annular engagement portion.

  Further, similarly to Patent Document 2, Patent Documents 3 and 4 describe resin caps that can be opened simply by lifting the cap with a finger. In the cap described in Patent Document 3, a plurality of thin portions are spaced to form a recess on the inner surface of the outer peripheral wall. Moreover, the cap described in Patent Document 4 has a thin portion provided on the top wall of the base portion of the inner ring.

These conventional resin caps are all created to improve the ease of opening, sealing and plugging of caps that cover wide-mouth bottles such as milk bottles.
Japanese Utility Model Publication No. 47-13109 JP 2002-179107 A JP 2001-240091 A JP 2003-231537 A

  In contrast to Patent Document 1 in which the thin cap is cut and the resin cap is opened, Patent Documents 2 to 4 all utilize the elastic deformation of the thin portion and can be opened simply by lifting the cap with a finger. It has become. However, since the ease of opening and the sealing performance are contradictory to each other, the resin caps of Patent Documents 2 to 4 have different contrivances for improving the sealing performance.

  That is, in patent document 2, in order to improve sealing performance, the annular engaging part engaged with the outer peripheral part of a container opening part is provided. Further, in order to facilitate the opening operation, a thin portion that provides flexibility to the annular engagement portion is provided. Therefore, the annular engaging portion keeps the sealing property until the cap is opened, but when the cap is opened, the thin portion is forcibly opened until the deformation occurs. The shape is deformed to such an extent that it does not recover, and the sealing property of the annular engagement portion is lost. As a result, the ring-shaped engagement portion once opened can no longer maintain the sealing performance at the time of stoppering, and it is impossible to reseal the opened cap to the container opening.

  Such a problem is the same in Patent Document 3, and a plurality of thin wall portions formed on the outer peripheral wall described in Patent Document 3 can be easily opened by being deformed. It does not have a re-seal function. Moreover, in Patent Document 3, the means for improving the sealing performance depends on the configuration of the heat-shrinkable film cover that covers the bottle mouth part and the lid together, so that the heat-shrinkable film cover is removed. After that, the sealing performance could not be maintained.

  On the other hand, the cap of Patent Document 4 is different from the thin parts of Patent Document 2 and Patent Document 3 by providing a thin portion on the top wall of the base portion of the inner ring in order to facilitate opening. Has an effect. However, in order to improve the sealing performance of the cap, since it is provided with a locking projection that presses against the outer surface of the bottle mouth portion and engages with the engagement recess of the bottle mouth portion, the device makes it easy to remove the locking projection. Is needed. For this reason, for example, the locking projection is not provided on the portion corresponding to the knob that is lifted when the cap is opened, and the locking projection in the vicinity of the knob is a small projection. Therefore, the structure is easy to open. As a result, the engaging force of the locking projection that enhances the sealing performance of the cap is reduced and biased, leaving a problem in the sealing performance of the locking projection.

  Further, in Patent Document 4, in order to enable plugging without increasing the plugging strength, it is also planned to dispose small projection-like locking projections at equal intervals in the circumferential direction of the skirt. However, in order to facilitate the opening with the locking projections arranged at equal intervals, it is necessary to provide the skirt with a vertical score (groove) that facilitates deformation of the skirt. Since such a vertical score (groove) has the same structure as the thin wall portion in Patent Document 2 and Patent Document 3, when the cap is opened, the vertical score (groove) is forcibly opened, and the skirt is original. Since the cap is deformed until it does not return to its shape, the cap once opened cannot be resealed to the container.

  As described above, in the conventional resin cap that lifts and opens the cap with a finger, the conflicting configurations adapted to the ease of opening and the sealing, respectively, are adopted. The caps that had been opened once could not be resealed.

  In this way, practical resealing is still difficult in conventional resin caps that cover milk bottles, etc., but with paper milk packs, practical use of the folding structure of the opening is practical. Sealing is possible. Moreover, since the cap used for a PET bottle etc. is a screw structure, practical resealing can be performed very easily. Under such circumstances, it is strongly desired to provide a cap capable of practical resealing even in a resin cap that covers a wide-mouth bottle such as a milk bottle.

  Therefore, the present invention was created to solve the above-mentioned problems. In a resin cap that can be opened simply by lifting it with a finger, it is excellent in stoppering performance, sealing performance, and opening performance. The object is to provide a resin cap having a sealing function.

  The first means of the present invention includes a top plate 10 that is press-contacted to the upper end surface of the bottle mouth portion P, an inner ring 11 that is provided on the lower surface of the top plate 10 and is fitted to the inner peripheral surface of the bottle mouth portion P, A skirt 20 that extends from the top plate 10 and is crimped to the outer surface of the bottle mouth portion P, and an engagement recess provided on the inner surface of the lower end portion of the skirt 20 and provided on the outer surface of the bottle mouth portion P. In a resin cap having a locking projection 21 to be locked and a locking piece 22 protruding from the outer surface of the skirt 20 and locking a finger when the plug is opened, a part of the locking projection 21 is The flat cross section has a substantially curved shape and extends out toward the outside of the skirt 20, the curved portion is forcibly expanded when the cap is plugged and opened, and the curved portion contracts when the cap is covered, and the locking projection 21 Has a stretchable bay portion 23 provided so as to be locked in the engagement recess. .

  In the second means, the thickness from the skirt 20 to the stretchable bay portion 23 is formed to a substantially uniform thickness.

  In the third means, the stretchable bay portion 23 has a substantially triangular shape in front, and is formed such that the curved portion is widened toward the lower end portion of the skirt 20.

  A 4th means forms the said expansion-contraction bay part 23 in the right-and-left object position of this center line X when the imaginary line X from the center of the said locking piece 22 to the center part of a cap is made into a center line.

  In order to solve the problem, the fifth means is that when the position where the locking piece 22 is provided is a front part a and the counter electrode is a rear part b, the stretchable bay part 23 is arranged in the front part a. This means.

  According to the first aspect of the present invention, a part of the locking projection 21 has a substantially curved shape in cross section and protrudes toward the outside of the skirt 20, and the curved portion is forcibly expanded when the cap is plugged and opened. In addition, since it has the expansion / contraction bay portion 23 provided so that the curved portion contracts when the cap is applied and the locking projection 21 is locked to the engagement recess, the resin cap can be opened simply by lifting it with a finger. Are excellent in plugging performance, sealing performance, and opening performance, and in particular, practical re-sealing is possible. In addition, the resin cap can be provided with a practical reseal function that has been possible with a paper pack, which makes it extremely suitable for the cover of milk bottles. Moreover, since it is extremely simple and versatile, it is not limited to the use of milk bottles and can be applied to all wide-mouth bottles.

  According to claim 2, by forming the wall thickness from the skirt 20 to the stretchable bay portion 23 to a uniform thickness, even if the stretchable bay portion 23 is expanded at the time of opening, the stretchable bay portion 23 is restored to the original. Return to shape. Therefore, the sealing performance by the locking projection 21 is ensured, enabling practical resealing, and there is no possibility that the cap will come off even if the internal pressure of the bottle changes.

  As in claim 3, the stretchable bay portion 23 is formed in a substantially triangular shape on the front side, and the curved portion is widened toward the lower end of the skirt 20, thereby facilitating operability at the time of opening. it can. As a result, the risk of spilling the contents excessively at the time of opening was eliminated. In addition, manufacturing using the current production line is possible, the basis weight is reduced, the thickness is substantially uniform, the moldability is good, and a good product can be provided.

  By disposing the stretchable bay portion 23 as described in claim 4 or claim 5, the opening operability can be further improved.

  As described above, according to the present invention, a resin cap that can be opened simply by lifting with a finger is excellent in plugging performance, sealing performance, and opening performance, and particularly has a practical reseal function. There are various effects.

  In the best mode of the present invention, a part of the locking projection 21 has a substantially curved shape in cross section and extends toward the outside of the skirt 20, and the curved portion is forcibly expanded when the cap is plugged and opened. And has a stretchable bay portion 23 provided so that the curved portion contracts when the cap is applied and the locking projection 21 is locked to the engagement recess, and the wall thickness extends from the skirt 20 to the stretchable bay portion 23. Is formed to have a uniform thickness, thereby achieving the original purpose.

  The resin cap of the present invention has a top plate 10, a skirt 20, and a locking piece 22 that protrudes from the outer surface of the skirt 20 and locks a finger so that it can be opened simply by lifting the finger. This is a resin cap provided (see FIGS. 8 and 9).

  The top plate 10 is in pressure contact with the upper end surface of the bottle mouth portion P when the cap is covered, and an inner ring 11 that fits to the inner peripheral surface of the bottle mouth portion P projects from the lower surface of the top plate 10 (FIG. 5). reference).

  The skirt 20 is a member that extends from the top plate 10 and is crimped to the outer surface of the bottle mouth portion P. The skirt 20 is further provided with a locking projection 21, a locking piece 22, and a telescopic bay portion 23. (See FIGS. 2 and 3).

  The locking projection 21 is provided on the inner surface of the lower end portion of the skirt 20 and is locked to an engaging recess provided on the outer surface of the bottle mouth portion P (see FIG. 5). The illustrated locking protrusion 21 has a substantially triangular cross section. As described above, the locking piece 22 is a projection for locking a finger, and the cap can be opened simply by lifting the locking piece 22 with a finger (see FIG. 9).

  The stretchable bay portion 23 has a substantially curved shape in cross section and protrudes toward the outside of the skirt 20 and is continuously formed on a part of the locking projection 21 (see FIG. 1). The thickness of the stretchable bay portion 23 is formed to be substantially equal to the thickness of the skirt 20, that is, the thickness of the upper portion of the locking projection 21 (see FIG. 7).

  That is, the stretchable bay portion 23 is formed to have substantially the same thickness as the portion other than the locking protrusion 21 of the skirt 20, and only the locking protrusion 21 is thick. As a result, even when the skirt 20 is expanded when the cap is plugged and opened, the curved portion having the same thickness as the skirt 20 absorbs deformation at the time of expansion, so that the locking force of the locking protrusion 21 is extremely high. No longer drops.

  In addition, the stretchable bay portion 23 has a substantially triangular shape in the front, and is formed such that the curved portion expands toward the lower end of the skirt 20 (see FIG. 4). Then, when the virtual line X from the center of the locking piece 22 to the center of the cap is taken as the center line, the stretchable bay part 23 is formed at the left and right target positions of the center line X, so (See FIG. 10). In addition, when the position where the locking piece 22 is provided is the front part a and the counter electrode is the rear part b, by disposing a large number of the stretchable bay parts 23 in the front part a, particularly the initial operation at the time of opening the plug Can be made easier.

  The types of NO.1 to NO.9 shown in FIG. 10 indicate the arrangement positions of the stretchable bay portions 23 in the cap of the present invention. The stretchable bay portion 23 is provided at the intersection of each type of locking projection 21 (circumference in the drawing) and the virtual line R. About these types, the removal torque required at the time of opening was measured, and also the sensory test which judges the actual feeling at the time of removing a cap with a plurality of panelists was done. In the sensory test, the sensation of removing the cap by placing the bottle on the table and the sensation of removing the cap by holding the bottle were evaluated.

  As a result, in the removal torque, if the locking piece 22 side from the imaginary line Y orthogonal to the imaginary line X is the front part a, as in the types of NO.3, NO.7, and NO.9, It turned out that what provided the expansion-contraction bay part 23 in the range of 20 degree | times to the front part a direction can be opened with little torque. On the other hand, in the sensory test, it is easy to open the ones with the stretchable bay portion 23 evenly in the front part a and the rear part b based on the imaginary line Y, such as the types of NO.5, NO.7, and NO.8. It was felt. The NO.3 type is evaluated as being able to open with confidence even if it is opened with the bottle held in hand. In addition, NO.7 and NO.9 both have low removal torque, and are highly evaluated in sensory tests.

  Based on these comprehensive judgments, NO.3, NO.7, and NO.9 are selected as types that are easier to open, and for these types, the cap pressing force required at the time of stoppering and the opening are also selected. About the removal torque required at the time of plugging, and these deterioration values, it compares with the comparative product which does not provide the expansion-and-contraction bay part 23 (refer Table 1, 2).

  The cap pressing force is based on the measurement method shown in FIG. This method measured the force (Kg) when the cap was fitted into the bottle. The measuring machine uses a load cell S (200 Kg), puts a cap on the mouth of the bottle placed on the pedestal T, pushes the bottle up on the pedestal T, and measures the value when the cap is fitted to the bottle mouth. did.

  The removal torque is based on the measurement method shown in FIG. In this method, the jig W was locked to the locking piece 22 and pulled up vertically, and the force (Kg) when the cap was removed from the bottle was measured. In these measurement methods, the comparative product compared with the type of the present invention is provided with the locking projection 21 on the inner periphery of the skirt 20, and the difference in configuration from the present invention is only the presence or absence of the stretchable bay portion 23. It is. In addition, due to the characteristics of the synthetic resin, cap caps and caps require a higher force for plugging and opening at lower temperatures than at room temperature. The temperature was set immediately after removal (10 degrees Celsius), and the measurement was performed at this temperature.

表１は、図１１に示す測定方法により、打栓時に必要なキャップ押圧力を測定した結果である。この表によると、伸縮湾部２３を設けていない比較品の１回目に12.50 Kgの押圧力が必要であったが、第３回目の押圧力は10.00 Kgとなり、押圧力が2.5 Kg下がっている。この値は、キャップの弾性変形を繰り返したことにより、収縮強度が落ちた値、すなわち劣化値（最初の値から最後の値を引いた値）となる。NO.3、NO.7、NO.9のタイプにおけるこの劣化値は、夫々1.5 Kg、1.0 Kg、0.17 Kgであり、いずれの劣化値も前記比較品の2.5 Kgよりも劣化が少ないことが分かる。

Table 1 shows the results of measuring the cap pressing force required at the time of stoppering by the measuring method shown in FIG. According to this table, a pressing force of 12.50 Kg was required for the first comparison product without the stretchable bay 23, but the third pressing force was 10.00 Kg, and the pressing force was reduced by 2.5 Kg. . This value is a value in which the shrinkage strength is reduced due to repeated elastic deformation of the cap, that is, a deterioration value (a value obtained by subtracting the last value from the first value). The deterioration values of the NO.3, NO.7, and NO.9 types are 1.5 kg, 1.0 kg, and 0.17 kg, respectively, and it can be seen that the deterioration values are less than 2.5 kg of the comparative product. .

  Since the comparative product has a locking projection 21 protruding from the entire inner periphery of the skirt 20, as in Patent Document 2 to Patent Document 4, the locking projection 21 is locked compared to a cap provided with a thin portion. The force is extremely high, but on the other hand, it does not deform so that it cannot be recovered at the time of forced expansion, so the deterioration value also decreases. As a result, in the present invention, the lid can be applied with less pressing force than the comparative product, and the deterioration value is smaller than that of the comparative product, and the type No. 3, NO. 7, NO of the present invention. The coverability and deterioration value in .9 are proven.

表２は、図１２に示す測定方法により、開栓時に必要なキャップの外しトルクを測定した結果である。この表によると、伸縮湾部２３を設けていない比較品の第１回目の外しトルクが2.85 Kg、第３回目の外しトルクが2.40 Kgとなり、劣化値は0.45 Kgであった。

Table 2 shows the results of measuring the cap removal torque necessary for opening the cap by the measurement method shown in FIG. According to this table, the first removal torque of the comparative product without the stretchable bay portion 23 was 2.85 kg, the third removal torque was 2.40 kg, and the deterioration value was 0.45 kg.

  On the other hand, the deterioration values of the types No. 3, NO. 7, and NO. 9 of the present invention are 0.15 Kg, 0.1 Kg, and 0.2 Kg, respectively, and the deterioration values of all types are smaller than those of the comparative products. As described above, the deterioration value of the comparative product is superior to that of Patent Document 2 to Patent Document 4 provided with a thin wall portion, so that the superiority of the present invention is proved even in the deterioration value at the time of opening.

  In addition, the removal torque of each type can be opened with less than 1 Kg compared to the comparative product, so how easy it is to open with the type No.3, NO.7, and NO.9 of the present invention. It is clear that In addition, the measurement at the time of plugging and the measurement at the time of opening are both performed three times each. For example, in order to perform three times of plugging measurement, it is necessary to open at least twice. Three times of plugging are required to measure the number of times of opening. Therefore, in the said measurement, it is a measured value which carried out attachment / detachment operation of this invention cap 6 times in total. Therefore, it can be said that the measured numerical values such as the pressing force at the time of plugging, the removal torque, and the deterioration value are extremely practical numerical values.

  In addition, each structure of the example of illustration in this invention is only one Example of this invention, the design change of the shape of this invention cap, a dimension, etc. other than the type shown to NO.1-NO.9, conversion of material It can be freely changed within a currently known technical range, such as a change of the form and the like.

It is a perspective view which shows one Example of the cap in this invention. It is a perspective view which shows one Example of the cap in this invention. It is a bottom view which shows one Example of the cap in this invention. It is a side view which shows one Example of the cap in this invention. It is a longitudinal cross-sectional view which shows one Example of the cap in this invention. It is a top view which shows one Example of the cap in this invention. It is a plane sectional view showing one example of a cap in the present invention. It is a perspective view which shows the mounting state of the cap in this invention. It is a perspective view which shows the partial opening state of the cap in this invention. It is a top view which shows the type which changed the arrangement position of the expansion-contraction bay part in this invention. It is the schematic which shows the apparatus which measures the cap pressing force at the time of stoppering in this invention. It is the schematic which shows the apparatus which measures the cap removal torque at the time of the opening in this invention.

Explanation of symbols

X, Y, R Virtual line a Front part b Rear part P Bottle mouth part
10 Top plate 11 Inner ring 20 Skirt 21 Locking protrusion 22 Locking piece 23 Stretching bay

Claims (5)

  A top plate that is in pressure contact with the upper end surface of the bottle mouth portion, an inner ring that is provided on the lower surface of the top plate and that fits on the inner peripheral surface of the bottle mouth portion, and is formed to extend from the top plate and is outside the bottle mouth portion. A skirt that is crimped to the skirt, a locking projection that is provided on the inner surface of the lower end of the skirt and that is engaged with an engagement recess provided on the outer surface of the bottle mouth, and is provided on the outer surface of the skirt, In a resin cap having a locking piece for locking a finger at the time of plugging, a part of the locking projection has a substantially curved shape in a plane cross section and protrudes toward the outside of the skirt. A resinous product characterized in that it has a stretchable bay portion provided so that the curved portion is forcibly expanded sometimes and the curved portion contracts when the cap is covered and the locking projection is locked to the engaging recess. cap.   The resin cap according to claim 1, wherein the thickness from the skirt to the stretchable bay portion is formed to be substantially uniform.   3. The resin cap according to claim 1, wherein the stretchable bay portion has a substantially triangular shape in front and is formed such that a curved portion spreads toward a lower end portion of the skirt.   The resin cap according to any one of claims 1 to 3, wherein the stretchable bay portion is formed at a left and right target position of the center line when a virtual line from the center of the locking piece to the center of the cap is used as a center line. . The resin cap according to any one of claims 1 to 4, wherein when the position where the locking piece is provided is a front part and the counter electrode is a rear part, a large number of the stretchable bay parts are arranged at the front part.

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