JPS6340744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a container made from a laminate having a base layer that is relatively hard and difficult to stretch, and is equipped with tear-off dotted holes that do not allow liquid to pass through. There is. At least one side of the base layer, that is, the side that will become the inside of the container, is provided with a liquid-impermeable and continuous plastic coating, and the above-mentioned tear-off dotted hole is completely cut through to the bottom of the base layer, or Although it penetrates most of the way, it does not penetrate the plastic layer inside the container. BACKGROUND OF THE INVENTION Disposable liquid containers in use today are often made from packaging laminates, which have a relatively stiff and inextensible base layer made of paper or the like. A homogeneous liquid-impermeable plastic layer is applied to both sides of the base layer. When containers are made from such packaging laminates, they are usually formed by folding the container material and heat-sealing opposite sides to create a sealed container with an internal, unbroken, liquid-tight plastic layer. Make it. Containers of this type can be made in various shapes, so on the market you will find containers in the shape of a tetrahedron or a parallelepiped. However, the common desire of both types is to have an opening that can be easily broken to allow easy access to the liquid inside the container, and various methods have been tried to date. For example, a container may have an opening with a cover on its wall that reveals an opening when the cover is torn off, or a container may have a dotted tear hole in the container that allows part of the container to be torn off. There is a type with holes that allow the contents to be taken out. (Problem to be solved by the invention) When the tear-off cover described above is attached, the container functions satisfactorily, but unfortunately, it is difficult to apply it to disposable containers containing frequently used foods such as milk. The disadvantage is that it is quite expensive to use. This is because creating such openings requires special materials and extra processing. However, openings based on the principle of making dotted holes in the container wall for tearing have the disadvantage that if the dotted hole is formed in the container material before the container is formed, the dotted hole becomes too weak. . This is because the material is exposed to significant tensile and pressure stresses associated with the folding during the container forming process. Therefore, a kind of cooperation is necessary. In other words, the dotted opening part should be set so that the dotted hole part can withstand the stress applied to the material during container molding, and can be easily torn off when the container is completed and the dotted hole part must be opened to take out the contents. Must be. It was inevitable that this compromise system would result in dotted hole sections of the type described above not being as easy to tear as desired and functionally quite unsatisfactory. The present invention solves the above problems and eliminates the drawbacks of the tear-off dotted hole portion. SUMMARY OF THE INVENTION The present invention provides a liquid-impermeable, tear-dotted hole container made from a laminate having a relatively hard and inextensible base layer, comprising: The inside surface of the container is provided with a liquid-impermeable, continuous plastic coating, and the tear-off dotted hole is completely or almost completely through to the bottom of the base layer. In a container that does not penetrate the inner plastic layer of the container, punch holes are provided in the tear-off dotted hole portions on portions of the container where strong stress is applied to the container material due to bending or other processing during container molding. is only slightly open or not punched, thereby weakening the container material to the extent that the tear-off dotted hole portion ruptures under the stress caused by the bending or other processing. The tear-off dotted hole portion on the surface of the container that has not been deformed by bending or other processing is not affected by the tear-off dotted hole portion on the container portion to which the stress is applied. It is characterized by being provided with dotted holes that have a smaller tearing resistance than the standard. (Function) The tearing dotted hole portion, which is located in the portion of the container where a large stress is applied during container molding, is made to have a large tearing resistance and is prevented from tearing due to the stress. In addition, the tearing resistance of the tearing dotted hole portion of the other portions is made small, so that tearing can be easily made. Embodiments Embodiments of the invention will now be described in detail with reference to the accompanying drawings. The container shown in FIG. 1 is a parallelepiped and consists of a side wall 1, a top wall 2 and a bottom wall not shown in this figure. As mentioned at the outset, the container is made from a material that is relatively stiff and difficult to stretch, but is bendable and belt-like. When making containers, it is a rational manufacturing method to form a belt of material into a tube and seal this tube laterally in the form of a narrow zone by pressing flat or sealing diagonally. It's a method. When the contents are filled in the tube in advance, the contents are sealed inside the seal-molded container, and the container is bent into the desired parallelepiped shape. By repeating pressing and sealing along each spaced zone on the tube, a sealing fin 3 is formed, which is folded towards the top wall 2 of the container in the subsequent forming process. It will be done. In the forming process required to make the parallelepiped shown here, an additional 4
A corner flap 4 is formed with two triangular overlapping walls, which are the corner portions that overlap the edge portions of the container. Figure 1 shows one corner flap 4 on the upper left side of the four corner flaps mentioned above.
Of the three corner flaps not shown, the upper one is
It is folded over the area close to the edge on the right side of the top wall 2 of the invisible side wall on the right side of the figure, and the two flaps on the left and right sides of the bottom wall are folded in, respectively, on the left and right sides of the bottom wall. It is folded toward the right and left so that it overlaps the area near the right edge. This corner flap 4 is folded in with a straight side wall edge 6 and is fixed to the side wall 1 belonging to the side wall edge 6 by means of an easily tearable connection. Seal fin 3 is
It extends above the corner flap 4 and the top wall 2, and further extends above the folded corner flap, which is not visible in this figure, on the opposite side of the top wall 2. Also, the illustrated container has a fold line 5.
, which emerges from the distal end of the side wall edge 6 and runs over the top wall and intersects the base line 7 of the seal fin 3. To provide the opening, the container is provided with a tearable part surrounded by straight or arcuate dotted holes 8 and 8' which penetrate only partially through the material of the container. Dotted hole 8
and 8' start from a common point a on the lower wall of the flap 4, which is a little distance from the base line 7 of the seal fin 3, and point b and 8' are located at symmetrical positions.
b' passes through points d and d' and ends at the common point c . The common point a is two dotted line holes 8 passing through both sides of the seal fin 3.
and 8' intersect at the lower surface of the lower wall of the corner flap 4 constituted by a double wall. Points b and b' are the points where the two dotted holes 8 and 8' pass through the edge of the folded corner flap 4; points d and d' are the points where the two dotted holes 8 and 8' pass through the edge of the folded corner flap 4; Point c is the point where the dotted holes 8 and 8' extending from the upper surface to the upper surface of the top wall 2 pass through the upper side wall edge 6 of the side wall of the container, and point c is the point where the two dotted holes 8 and 8' extend into the sealing fin 3. inner base line 7
This is the point where they intersect at the top. Prior to molding the container, it is preferred to pre-drill dotted holes in the container material to provide the desired tear-off holes in the container shown in FIG. FIG. 5 shows a portion of a belt of container material with a dotted line pattern.
In the example taken here, this pattern consists of a rather wide V-shaped dotted hole 8;
is set in the form of a belt of container material so that it lies at a predetermined location on the container during container molding. 1st
The figure shows a parallelepiped, closed container with a tearing device according to the invention,
Further, FIG. 4 shows a state in which the container shown in FIG. 1 has been opened to form a pouring hole. 2 and 3 respectively show states intermediate between the state of FIG. 1 and the state of FIG. 4. Hereinafter, the operations for opening the container will be explained in order with respect to each of the above figures. (a) First, in the container shown in Figure 1, a triangular corner
The flap 4, together with the sealing fin 3 located above it, is pivoted around the upper side wall edge 6 of the side wall 1 and raised until it is located in the plane containing the top wall 2, as shown in FIG. (b) Next, in the container that is in the state shown in Figure 2,
Starting from point a , points b and b' , point d and
d' and ending at point c , cut and remove the part of the upper wall of the corner flap 4 which is surrounded by these dotted holes. . At this time, the portion of the seal fin 3 that overlaps the portion surrounded by the dotted line holes 8, 8', and the portion of the top wall 2 that is connected to this portion are further removed to the right of the figure. is located near the side wall edge 6 of the extending seal fin 3 and the upper and lower sides of the corner flap 4 which is to the left in the figure of the line connecting points a and b and points a and b' . When the wall portion (the tip of the corner flap 4) is removed, a spout hole 9, which is the opening of the container, is created as shown in FIG. Note that due to the force acting when removing the seal fin 3, the portion of the seal fin that was not removed, which is on the right side in the figure, assumes an upright position as shown in the figure. (c) Finally, when the front side wall in the figure and the opposing rear side wall (not visible) of the container in the state shown in Figure 3 are pressed from the front and back so that both walls approach each other, the container The opening rises together with the top wall 2, resulting in the state shown in FIG. As shown in Figure 5, the dotted hole 8 for tearing
There are parts b and d consisting of many small broken points, and considerable stress is applied to these parts above the dotted hole during forming. However, if the dotted holes existing in these parts are so weak that they break easily when subjected to the above stress, there is a risk of liquid leakage. In order to make the dotted hole not tear resistant and to eliminate the drawbacks mentioned above, the dotted hole shown in FIG. 5 has a diversified tear resistance. The dotted hole in Figure 5 consists of two straight lines placed at an angle to each other; however, if you want the dotted hole on the container to have a different shape, the dotted hole drawn on the container can be Change the
Needless to say, it is molded to match the appearance of the tear-off dotted hole portion of the completed container. Therefore, the shape of the tear-off dotted line hole portion can be a single straight line or arched line, or it can be made up of a number of interdigitated straight lines or arched lines. In this embodiment, the tear-off dotted hole 8 is made of the material of the container.
Certain portions b and d in FIG. 5 correspond to the portions shown in FIG. 1 that are to be bent. The dotted holes 8 shown in FIG. 5 consist of a series of cuts or punches in the belt of container material. These cut or punched holes 11 are separated from each other by an uninterrupted continuous section 12.
Conveniently, the uninterrupted continuous section 12 is of the same length throughout the dotted hole section. The length of the cut or punched hole 13 in the area of parts b and d is much shorter than the length of the cut or punched hole 11 in the other parts of the dotted hole. This makes the dotted line hole part more difficult to tear off, increasing the strength of the areas b and d, but the other parts of the dotted line hole are made easier to tear off. In the completed container, the tearing start point is point c.
Or point a. That is, start from the point on the dotted line that is easy to tear. Since the tearing process starts easily in this way, the tearing resistance of the parts b and d, which are slightly more difficult to tear, on the tearing dotted hole area becomes smaller, and in most cases, it becomes imperceptible. It is shown in FIG. 5 that the tearing resistance of each part of the dotted hole 8 is varied as described above. In this figure, in the tear-off parts b and d, the holes 13 made with a cut or punch in these parts are torn-off holes 8 marked with dotted lines.
hole 1 made with a cut or punch in another part of
It is gradually becoming shorter than 1. In the tear-dotted hole container 1 shown in FIG. 1, the double triangular corner flaps 4 of the wall are clearly visible, as mentioned above. In this case, the aforementioned dotted line is set at one of these corner flaps 4. The dotted hole 8 is actually mostly hidden in FIG. The reason is that the dotted line hole is point b
past the edge of the triangular corner flap 4 at It reappears on the upper side of the corner flap 4 in the part where it is not covered. Most of the dotted holes 8 in the corner flaps 4 and top wall 2 of the container 1 on the side where the sealing fins 3 are folded are hidden by the sealing fins 3. To show that some parts of the dotted holes are hidden by the overlying layer or sealing fin 3, the hidden parts are shown in this figure with thinner lines than the visible parts. As already mentioned, in order to make the tearing resistance as average as possible when opening the container, and at the same time shorten the holes 13 made with the cut or punch one by one to increase the tearing resistance of the bent part, it is necessary to use a cut or punch. It is convenient to provide an uninterrupted continuous section 12 of the same length between the holes 11 and 13 drilled. However, of course, in addition to changing the overall length of the holes 11 and 13 made by cutting or punching, it is also possible to change the length of the unbroken continuous part between them, or by changing the length of the holes 11 and 13 made by cutting or punching. It is also possible to change the length of 13 itself and the top length of the uninterrupted continuous portion 12, and these are consistent with the spirit of the present invention. As mentioned above, it is possible to vary the tear resistance by varying the depth of the cut into the base layer of the container, but the tear-off dotted hole portion created in this way has Experience has shown that it is difficult to obtain sufficient precision for a given purpose and that it does not make it easy to tear. The material of the container is a thin polyethylene surface treated paper base layer, and the base layer is completely penetrated by dotted holes. Tear-off tests using this material surprisingly showed that the unbroken continuum between the dotted holes was much wider than the unbroken continuation between the dotted holes. It was found that the strength of the dotted hole portion was greater when the portion was made shorter. however,
It is assumed that the ratio of the length of the part punched completely to the bottom and the length of the unbroken part is then the same. Of course, this is not a principle that is generally applicable, but the tear-off dotted line shows the relationship between the tear-off resistance and the length (expressed in %) that is completely punched to the bottom for a given unit length of the hole section. According to the graph of FIG. 9, it can be seen that this principle is valid for cut lengths of 0.5 mm to 1 mm. The graph in FIG. 6 does not indicate tearing resistance in absolute values. This is because the absolute value is not very important in this case and will vary depending on the quality of the paper, its thickness, the quality of the plastic coating, etc. This graph reveals the interrelationship of tear strengths of various dotted hole sections, ie, sections cut with cutting knives having "teeth" of various sizes. Also shown in FIG. 6 is a cross-section of the cutting knife, where A is the width of the knife blades and B is the spacing between the blades. As mentioned above, the horizontal axis of the graph is in percentage units, and it shows at a glance how much of the tear-off dotted hole has been punched completely to the bottom. That is, the scale is
This corresponds to 100A/A+B, which is hereinafter referred to as the perfect punch ratio. The vertical axis of the graph is not scaled for the reason mentioned above, and shows that the tearing resistance increases as it goes up, and is 0 at the origin. This graph includes hatched areas that indicate areas that are easily torn. This area is the part of the tear-off dotted hole area that does not receive stress.
The tear-off dotted hole portion located where the bending deformation has occurred must not be included in this hatched portion. This is because the stress exerted by the bending deformation causes it to break. The graph in FIG. 6 shows three curves representing B=0.5 mm, B=0.7 mm, and B=1.0 mm. Here, B is
The spacing between the knife parts. perfect punch ratio
At 50% (i.e. A=B), the tearing resistance is
It can be seen that when B = 0.5 mm, it is slightly larger than B = 0.7 mm and B = 0.1 mm. However, the various B-value curves tend to converge as the full punch ratio increases. Therefore, the perfect punch ratio is 70~
It does not appear that the magnitude of coefficient B has any significant effect when reaching 75%. After various tests, a test was conducted to determine the optimum state of the tear-off dotted hole portion, and the results were as follows. (a) For the part of the dotted line hole that is easy to tear, that is, the part deformed by bending, B = 0.5 mm to 0.1 mm and A = 1.0 mm to 3.0 mm (b) For the part of the dotted line hole that should be bent and deformed. B = 0.3mm to 0.7mm and A = 0.3mm to 1.0mm As mentioned above, the size of the punch in the dotted hole area must be determined by carefully considering the type and quality of the base layer and the strength of the outer plastic layer. However, the above values are representative and serve as a guideline for appropriate specifications for the dotted hole portion. (Effects of the Invention) By setting the dotted hole portion that can be easily torn off according to the present invention, there is no danger that the hole portion will tear naturally and the contents will leak out during container molding. Also, when tearing off the container to make a pouring hole, it is easily torn open. The present invention can be applied to any container in which the tear-off dotted hole portion runs along any part of the edge that is subjected to strong stress during container molding. Therefore, the invention is applicable not only to containers of the structure and type shown here, but also to all types of containers with various technical problems, as mentioned at the outset.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a parallelepiped container with tear-off dotted hole portions according to the invention; FIG. 2 shows the corner flap of the container in the state shown in FIG. 1, including the top wall of the container; FIG. 3 is a perspective view showing a state in which the container has been lifted until it is on a flat surface, and shows the part surrounded by the torn-off dotted line hole and the part near it in the container in the state shown in FIG. 2. FIG. 4 is a perspective view showing the container in the state shown in FIG. 3 with its opening raised, and FIG. 5 is a perspective view showing the container shown in FIG. Figure 6, a schematic diagram showing a part of a flat material, shows the relationship between the tearing strength and the length of the hole cut or punched in the dotted hole area for various cut or punch hole lengths. This is a graph showing. 1...Side wall, 2...Top wall, 3...Seal fin,
4...Corner flap, 5...Fold line, 6...
... Side wall edge, 7 ... Base line, 8 ... Dotted line hole, 9 ... Spout hole, 12 ... Uninterrupted continuous part, 11, 13 ... Hole made with a cut or punch.

Claims (1)

[Scope of Claims] 1. A liquid-impervious container with tear-off dotted holes made from a laminate having a relatively hard and difficult-to-stretch base layer, wherein at least one of the base layers, that is, the surface that becomes the inside of the container. has a liquid-impermeable, continuous plastic coating, and the tear-dotted holes are completely or almost completely through to the bottom of the base layer, but do not penetrate the inside of the container. In a container that does not penetrate the plastic layer, a punch hole is slightly punched in the tear-off hole portion indicated by the dotted line on the portion of the container where strong stress is applied to the container material due to bending or other processing during container molding. Is it just?
or not punched, so that the tear-off dotted hole portion does not weaken the container material to the extent that it ruptures due to the stress caused by the bending or other processing; The tear-off dotted hole portion on the surface of the container that has not been deformed by bending or other processing has a dotted hole that has a lower tearing resistance than the tear-off dotted hole portion on the container portion to which the stress is applied. A container characterized by being provided with: 2. In the container according to claim 1,
The tear-off dotted hole portion consists of one or more straight or arcuate punch-hole lines that reduce the tear resistance of the container material, and the punch-hole line penetrates or substantially extends through the base layer of the material. It consists of holes that are repeatedly punched or cut at a certain distance on the container being pulled, and the tear resistance is increased by the punched holes or cut holes above the predetermined tear-off dotted holes. A container characterized by being diversified by varying the total length of the holes. 3. In the container according to claim 2,
The length of the uninterrupted continuous portion between the holes punched or cut one after another to form the tear-off dotted hole on the container is constant throughout the dotted hole portion. containers, characterized in that the lengths of the punched or cut holes are varied. 4. In the container according to claim 1,
This is a type of container in which corner flaps, which form triangular overlapping walls, are created at the corners of the container by bending during molding.
A tear-off dotted line hole extending above the line is formed to function as a dotted line hole for opening the container, and the tearing resistance of this tear-off dotted line hole causes the tear-off dotted line hole to A container characterized in that it is relatively large in the portion passing through the edge line, but is sufficiently diversified in other portions of the tear-off dotted hole.