JPH0885546A - Plastic container with metal lid - Google Patents

Abstract

PURPOSE: To obtain good sealability similar to that of a metal can by limiting a clamping thickness and a clamping width within a specific range when a plastic container and a metal lid without compound applied are double-clamped. CONSTITUTION: A plastic container 1 molded by pressure-forming a sheet made of a material such as polyethylene comprises a housing 11 for holding contents and a metal lid clamping flange 2 provided on an upper end of a peripheral wall of the housing 11. The clamping flange 2 has a width WF of 2.0 to 2.5mm and a thickness TF of 0.4 to 0.7mm, wherein a metal lid 5 without sealing compound applied is used to double-clamp from an outer peripheral direction, thereby providing a container whose clamping thickness T is in a range of 1.95 to 2.05mm and clamping width is in a range of 2.40 to 2.80mm. Thus a double-clamped state having good and sufficient sealability similar to that of a metal can may be obtained without a clamping machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combination of a metal lid not coated with a sealing compound and a plastic container, which is as good as a metal can in spite of having no sealing compound. The present invention relates to a plastic container with a metal lid, which has a sufficient sealing property and is double-wound.

[0002]

2. Description of the Related Art Conventionally, tin or aluminum metal cans have been used as containers for food cans, but in recent years, plastic molding containers have been increasingly used due to their lighter weight and preference for fashionability. In this case, as a method of constructing the lid, there is a case where a flexible sheet or film made of plastic is heat-sealed, but in order to emphasize the image of the conventional metal can or to improve retort resistance and unsealing property. A method in which a metal lid made of tin or aluminum and provided with an easy-open property is fastened around a plastic container may be used.

This method has a peripheral portion for forming a winding tightening portion with the flange portion as in the conventional image, and a sealing compound is applied to the inner surface of the peripheral portion. It was a method of winding the metal lid as it was and tightening it in a plastic container.

As a method of winding the metal lid around the plastic container, a method of double winding with a winding roll of a winding machine can be applied as in the case of the conventional metal can. In this case,
Since the flange portion on the container side is plastic, rigidity and elastic modulus are factors, and as shown in the front sectional view of the conventional double winding portion and the conventional second winding roll in FIG. Occasionally, a clearance occurs in the flange portion 2 of the container 1, or the peripheral edge of the metal lid 5 bends to return to a portion (hereinafter referred to as a cover hook CH) that bites into the container flange, and as a result, an appropriate overlap OL cannot be obtained. Occasionally, problems such as leakage of items occurred.

In addition, the conventional sealing compound 41
With the metal lid 5 to which is applied, the flange portion 2
Since the compound is scraped off, the compound 41 is deposited on the lower clearance LC between the tip of the compound and the cover hook CH as shown in FIG. 5, and the flange portion 2 is pressed by the deposited compound 41 because it is less rigid than metal. However, it has been difficult to obtain an overlapping OL that is larger than a metal can.

[0006]

Various proposals have heretofore been made to improve the sealing performance of a plastic container with a metal lid which is double-wound by using a metal lid for the plastic container as described above. However, the conventional improvement plan requires a plastic container having a special flange shape and a special winding device, which causes a problem in cost.

Further, none of the conventional techniques has achieved double winding tightening having a good and sufficient sealing property equivalent to that of a metal can.

[0008]

The present invention has been invented in order to solve the above-mentioned problems and does not require the use of a special plastic container or a winding machine as described above. The purpose is to obtain a plastic container with a metal lid that is double wound and has a good and sufficient sealing property equivalent to a metal can. The gist of the container is a plastic container that has a flange portion for winding the metal lid in the container opening. And a metal lid that has a peripheral edge portion for forming a winding fastening portion between the flange portion and the sealing compound and is not double-wound from the outer circumferential direction. : T is 1.9
5 to 2.05 mm, and winding width: W is 2.40 to
It relates to a plastic container with a metal lid in the range of 2.80 mm. Hereinafter, the present invention will be described with reference to the drawings.

The drawings show an embodiment of the present invention, FIG. 1 is a front sectional view showing an example of a plastic container with a metal lid according to the present invention, and FIG. 2 is a front sectional view showing an example of a metal lid according to the present invention. FIG. 3 is a front cross-sectional view of a first winding roll and a winding state for double-wrapping a plastic container with a metal lid according to the present invention, and FIG. 4 is a front sectional view of a second winding roll and the winding state. It is a figure and Drawing 5 is a front sectional view of the conventional double winding part and the conventional second winding roll.

In the present invention, as shown in FIGS. 1 to 4, a plastic container 1 having a flange portion 2 for winding a metal lid in an opening portion of the container 1 and a winding portion 3 are formed between the flange portion 2 and the plastic container 1. A metal lid 5 having a peripheral edge portion 4 for applying a sealing compound and a metal lid 5 to which the sealing compound is not applied are double-wound from the outer peripheral direction, and the winding thickness: T is 1.95 to 2.05 m.
m and winding width: W is a plastic container with a metal lid having a range of 2.40 to 2.80 mm.

Winding thickness of plastic container with metal lid: T is 1.95 to 2.05 mm, winding width: W is 2.
It was found that the use of a metal lid in the range of 40 to 2.80 mm and not coated with a sealing compound provides a double winding state having a good sealing property which is as good as or better than a metal can. It was

[0012] The reason for this is that when the winding thickness of the winding container with a metal lid: T is thicker than 2.05 mm, a void occurs inside the winding, and when it is thinner than 1.90 mm, the inside of the winding is excessively compressed. It is considered that a problem such as deformation of the inside of the winding tightening occurs and a good winding tightening state cannot be obtained. Further, if the winding tightening width W is smaller than 2.40 mm, a problem such as cutting the flange portion of the container 1 at the tip of the cover hook CH occurs, and if it is larger than 2.80 mm, the cover hook CH is largely returned and a stable overlap. It is considered that the OL cannot be obtained.

The plastic container 1 used in the present invention may be made of a thermoplastic resin material such as polyethylene, polypropylene, nylon, polyester, polyvinyl chloride, or polyvinylidene chloride.
A laminated material containing an oxygen barrier resin such as vinyl acetate OH may be used. A plastic container 1 obtained by forming a sheet made of the above material by pressure forming, vacuum forming, or the like.
Includes a storage portion 11 for storing the contents, and a metal lid winding flange portion 2 provided on the upper end of the peripheral wall of the storage portion 11.

The metal lid winding flange portion 2 is preferably mechanically press-molded to have a highly accurate shape. The width: WF is 2.0 to 2.5 mm, and the thickness: TF is 0.4 to 0.7 mm to obtain a double-wrapped plastic container with a metal lid, which has the hermeticity of the present invention. It is convenient for

The metal lid 5 used in the present invention is also used.
The shape, the material, etc. are not limited as long as they can be wound and tightened, but a counter sink CS is formed as shown in FIG. 2, and it is preferable that the peripheral portion 4 is curled in advance. In the case of aluminum lid, thickness: TC
Is 0.28-0.30 mm, thickness for steel lid:
A TC of about 0.23 mm can usually be used.

Next, according to the present invention, when the double tightening is performed from the outer peripheral direction, the tightening thickness: T is 1.95 to 2.05 mm, and the tightening width: W is 2.40 to 2.80 mm. A method for producing a plastic container with a metal lid as in range is described.

As shown in FIGS. 2 to 4, the metal lid 5 is placed on the metal lid winding flange portion 2, and while the chucking roll 8 supports the counter sink CS of the metal lid 5 from the inside, The curling peripheral edge portion 4 of the metal lid 5 is further sharply bent from the outside by the one-tightening roll 6 to form a cover hook CH, and the metal lid winding flange portion 2 is wound so as to be tied together.

Next, the second winding roll 7 further presses the peripheral portion 4 of the metal lid 5 from the outside to bring the flange portion 2 for winding the metal lid into close contact with the peripheral portion 4 of the metal lid 5, Get the double winding state.

The first winding roll 6 and the second winding roll 7 are, as shown in FIGS. 3 and 4, a plastic container 1 having a flange portion 2 for winding a metal lid at the container opening, and the flange. Plastic container 1 having part 2
Roll grooves 61 and 71 for tightening the metal lid 5 having the peripheral edge portion 4 for forming a tightening portion with the flange portion 2 from the outer peripheral direction are formed.

The second winding roll 7 in the present invention
As shown in FIG. 4, the shape of the roll groove 71 is particularly characteristic, and since the receiving portion 72 extending below the roll groove 71 is provided, a recess 73 for preventing the cover hook CH from escaping is formed. ing.

Therefore, when the second winding roll 7 according to the present invention is wound using the conventional second winding roll 7 having no lateral receiving portion under the roll groove 71 as shown in FIG. The structure is such as to effectively prevent the decrease of the overlap OL due to the return of the cover hook CH to the lower side, which has been a problem.

Further, since no sealing compound is used, there is no accumulation of the compound 41 as shown in FIG.
As shown in FIG. 4, the lower clearance LC is minimized, and it is possible to secure sufficient winding of the flange 2.

Then, the receiving portion 7 of the second winding roll 7
For the depth d2 of 2, if winding is performed with a roll having a value equal to or less than twice the metal lid thickness and the total thickness of the plastic container flange thickness, the winding portion can be sufficiently compressed during the second winding. As a result, a good winding internal shape can be obtained without generating voids inside the winding tightening portion.

The degree of bending of the cover hook CH in the middle of winding and the final winding width W of the winding portion 34 are determined by the groove height h1 of the first winding roll 6 and the groove of the second winding roll 7. It is defined by the height h2. Therefore, by changing the groove heights h1 and h2 of the roll, it is possible to freely set the bending degree and the winding tightening width of the cover hook CH.

As a result of various studies on a plastic container with a metal lid, in which the first and second winding rolls as described above are used and which has good sealing performance, the groove height of the first winding roll 6 is determined. : For h1, 2.25-2.
65 mm, groove height of the second winding roll 7: 2.40 to 2.80 mm for h2, depth of the receiving portion of the second winding roll 7: 2 times the metal lid thickness and plastic container flange portion for d2 If the roll having a value not more than the total thickness is wound, the winding thickness of the plastic container with the metal lid, which is wound by the first and second winding rolls, is 1.95. ˜2.05 mm, winding width: W can be easily accommodated in the range of 2.40 to 2.80 mm, and the obtained plastic container with a metal lid has good and sufficient sealing property equivalent to a metal can. It was found that a double winding tightened state was obtained.

As shown in FIG. 3, the second winding roll 7 according to the present invention has a hollow shape so as to prevent the cover hook CH from escaping, and the depth of the receiving portion below the hollow shape is the thickness of the metal lid. Is less than the total of the thickness of the plastic container and the flange thickness of the plastic container, and is less than the total thickness of the flanges.
Since 2 is provided, it is possible to effectively prevent the return of the cover hook CH, which is a problem when the second second tightening roll 7 having no receiving portion at the lower part of the roll groove as shown in FIG. It has a simple structure.

[0027]

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

In this embodiment, the following plastic container 1, a metal lid 5 not coated with a sealing compound, a first winding roll 6 and a second winding roll 7 were used.

The plastic container is made of a laminated material containing an oxygen barrier resin and has a flange 4
Thickness: TF 0.50 mm, width: WF 2.30 m
m, and the inner diameter of the opening was 74.0 mm.

As the metal lid 5 not coated with the sealing compound, an aluminum product having a thickness of 0.28 mm and having the peripheral edge portion 4 curled in advance was used. Then, double winding was performed so that (roll groove height h1 of first winding roll 6) <(groove height h2 of second winding roll 7) was obtained to obtain a plastic container with a metal lid. .

With respect to the plastic container with a metal lid thus obtained, the quality of winding was evaluated by the following method. Roll groove height: h1 of the first winding roll 6 was 2.05.
2.25, 2.45, 2.65, 2.85 mm, and the roll groove height: h2 of the second winding roll 7 is 2.20,
Table 1 shows the evaluation of the sealing property and the winding tightening when the products having the sizes of 2.40, 2.60, 2.80 and 3.00 mm are used, separately for the case without the sealing compound and the case with the sealing compound. The winding width W corresponds to the roll groove height h2 of the second winding roll 7.

Further, the winding tightening thickness T thus obtained is
Is 1.90, 1.95, 2.00, 2.05, 2.10
With respect to the evaluation of the sealing property and the winding tightening of the plastic container with a metal lid having a diameter of mm, the results are shown in Table 2 according to whether there is a sealing compound or not.

1) Sealability evaluation: A container container 11 is filled with an aqueous starch solution and wound, and a plastic container with a metal lid is wound.
Treated in a heat sterilizer prepared to allow bacteria to invade 1 and then left for 2 weeks in a constant temperature bath at 35 ° C. to conduct a bacteria test in the container storage 11 and determine negative and positive. The presence or absence of expansion of the plastic container 1 due to rotting gas or the like was visually determined.

2) Evaluation of winding appearance: The entire circumference of the winding portion of the obtained plastic container with a metal lid was visually inspected, and those having no abnormality (○), those having irregularities (△), If the tip of the container flange 2 or the tip of the cover hook CH of the metal lid can be seen even slightly, it is defective (×).
It was determined.

3) Evaluation of internal shape of winding: The obtained plastic container with a metal lid is axially cut, and an enlarged photograph of the cross section is photographed by a real microscope, and there is almost no void and the overlap OL is 1.2 mm or more. (⊚), those with almost no voids and an overlap OL of 1.0 mm or more and less than 1.2 mm (○), those with few voids and an overlap OL of 0.5 mm to 1.0 mm (△) , There are gaps and overlap OL
The value of 0.5 mm or less was judged as (x).

[0036]

[Table 1] As shown in Table 1, in the case where the metal lid coated with the sealing compound is used, the groove height of the first winding roll 6: h1 is 2.25 to within a range in which there is no problem in sealing property and winding tightening. 2.65 mm, groove height of the second winding roll 7: h2, that is, winding width: W is 2.40 to 2.80 m
Whereas, in the range of m, the metal lid not coated with the sealing compound of the present invention is more excellent in the internal tightening evaluation in the above range with the overlap OL being 1.2 mm or more and the sealing property. Has a W of 2.20 to 3.
00 over the entire range.

[0037]

[Table 2] As shown in Table 2, the one using the metal lid coated with the sealing compound has a winding thickness: T of 1.95 to 2.05 m as a range in which there is no problem in sealing property and winding.
Whereas, in the range of m, the metal lid not coated with the sealing compound of the present invention is more excellent in the internal tightening evaluation in the above range with the overlap OL being 1.2 mm or more and the sealing property. Has a T of 1.90 to 2.
Excellent over the entire range of 10.

[0038]

As described above, according to the present invention, the plastic container having the metal lid winding flange portion at the container opening, and the peripheral portion for forming the winding portion between the flange portion and the plastic container are provided. A metal lid having a metal lid not having a sealing compound applied thereto is double-wound from the outer peripheral direction, the winding thickness: T is 1.95 to 2.05 mm, and the winding width: W is Since it is a plastic container with a metal lid in the range of 2.40 to 2.80 mm, the groove height of the first winding roll 6 and the second winding roll 7: h
By simply defining 1 and h2, without using a special plastic container or a winding machine as conventionally proposed, a double winding state having a good and sufficient sealing property equivalent to a metal can can be obtained. It is possible to obtain a plastic container with a metal lid.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an example of a plastic container with a metal lid according to the present invention.

FIG. 2 is a front sectional view showing an example of a metal lid according to the present invention.

FIG. 3 is a front cross-sectional view of a first winding roll for double-winding a plastic container with a metal lid according to the present invention and a winding state.

FIG. 4 is a front sectional view showing a second winding roll and a winding state.

FIG. 5 is a front sectional view of a conventional double winding portion and a conventional second winding roll.

[Explanation of symbols]

 1 plastic container body 2 flange part 3 winding part 4 peripheral part 5 metal lid

Claims (1)

[Claims] 1. A plastic container having a flange portion for winding a metal lid in an opening portion of the container, and a peripheral portion for forming a winding portion between the flange portion and a sealing compound applied thereto. A metal lid and a metal lid which are not double-tightened from the outer peripheral direction have a thickness T of 1.95 to 2.
05 mm, and winding width: W is 2.40 to 2.80 m
A plastic container with a metal lid in the range of m.