JPH08324563A - Paper container for liquid - Google Patents

Abstract

PURPOSE: To easily and cleanly open a discharge port on a gable type roof part using only a sheet paper on both surfaces of which are coated with a thermoplastic resin, being used for a gable top carton. CONSTITUTION: For a gable top carton 20, a recessed part treated pattern is formed on the internal surface of both or either one of a rib 1T at the upper end of an upper folded-in side wall 1G on an opening side and a rib which is confronted with the rib 1T, and an area where the ribs are not bonded with each other is partially provided. By doing so, an easy openability is imparted by attaching a pull tab PU on the top of the upper folded-in side wall 1G by a half cut method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily openable Gobeltop liquid paper container for milk, fruit juice and the like.

[0002]

2. Description of the Related Art In order to make it easy to open the spout of a Gobel top carton (gable roof carton) that has been established as a liquid paper container for milk, fruit juice drinks, dairy drinks, soft drinks, mineral water, etc. An anti-heat sealing agent is partially coated on the inner surface of a top panel (hereinafter referred to as a rib) that constitutes a spout to weaken the heat sealing strength of the rib portion, so that a Gobel top carton that is easy to open is used. In addition, a method has also been proposed in which a plastic spout prepared separately from the carton is pierced and fixed to the roof portion from the outside, and the liquid content is poured out from the spout. Furthermore, a plastic spout with a cap is attached by heat sealing so as to cover the opening provided in the roof part.
In -1380, there is also proposed an economical type in which the spout is a one-piece plastic molded product, and when the integrally formed pull tab is pulled to the front, the molded product is ruptured from the weakening line to open.

[0003]

However, when the anti-heat-sealing agent is provided on the rib portion, it takes time and effort to partially coat the rib on the inner surface of the carton with the anti-heat-sealing agent, and the anti-heat-sealing agent itself. Need
There is a problem that not only the cost is increased by that amount, but also liquid leakage is caused when the coating is not accurately applied at a predetermined position. In addition, the method of sticking the spout prepared separately from the carton from the outside will reduce the total cost if the spout is used repeatedly, but there is the inconvenience that the spout must be present at the time of using the product containing the liquid paper container. , If you continue to use the same spout for different liquid drinks as it is, there is a problem that the liquid of the contents mixes,
Moreover, the repeated use without cleaning has a sanitary problem. In addition, the plastic spout attached to the roof of each Goebel top carton has the problem of increasing costs even if it is an economy type, and it is difficult to separate and dispose of paper and plastic. There is also the problem of doing. Today, the retail industry tends to increase the pressure during heat-sealing in a molding and filling machine in order to reduce the liquid leakage at the distribution stage of the liquid carton. It is becoming difficult for users to open. On the one hand, the end users' demand for liquid paper containers that are clean and easy to open is only increasing. The industry has such a trade-off. The present invention has been made in view of such a problem, and an object thereof is to provide a liquid paper container which is provided with a double-sided thermoplastic resin coat and has an easy opening property, which is used for a Gobel top carton.

[0004]

The gist of the present invention made to solve the above problems is as follows. (1) Using a paperboard coated on both sides with a thermoplastic resin or a laminate centered on the paperboard, a gabled body connected to the upper end of a quadrangular prism-shaped body composed of four body side wall panels via a fold line. The shaped roof part folds the opposite upper folded side walls inward along the diagonal fold lines, folds the remaining opposite upper folded side walls inward, and overlaps the upper folded ribs of the upper folded side wall with the upper folded ribs so that they overlap. In the paper container formed by heat-sealing this overlapped portion, both of the ribs at the upper end of the upper folding side wall on the opening side and the ribs facing the ribs, or either one of them has a concave portion according to a predetermined pattern on the inner surface. A liquid paper container characterized by being formed. (2) A pull tab region having a shape in which the lower portion is closed and the upper portion is opened is defined on the upper folded side wall on the opening side or across the uppermost portion of the body side wall panel which is connected to the upper folded side wall via a folding line. Then, a half cut is formed from the front side of the paper container laminate, and a pull tab that can be peeled from the lower portion of the pull tab region is formed.

[0005]

According to the present invention, it is possible to provide a spout that can be opened easily and cleanly by processing only the base material of the Gobel top carton, and it is possible to reduce the material cost and the manufacturing cost. Is. Further, the factor of liquid leakage can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the drawings. FIG. 1 is a development view of a carton blank 10 for a liquid paper container according to the present invention. As shown in FIG. 1, first, in the body of the liquid paper container, the side wall panels 1 to 4 and the glue allowance 5 are broken lines 15
Roof parts 2G and 3G which are connected to each other through ~ 17 and form a gable roof on the upper part, and upper folding side walls 1G and 4G corresponding to gables (the portions of the mountain-shaped walls at both ends of the gable roof) are folded lines 1
Ribs 2T and 3T that are connected to each other via a folding line 14 and that fold the folding ribs 1T and 4T to seal and seal the palm are provided via a folding line 14. Also, the upper folded side wall 1
G and 4G are provided with fold lines 12 and 18 for obliquely folding the side wall. The top sealing after filling the liquid paper container according to the present invention is all performed by heat sealing of ribs. Particularly, an important part in the present invention is that the upper rib 1T of the upper folded side wall 1G and the rib 1T which are folded and face each other
The T and 3T parts. The bottom portion B is composed of a portion that is connected to the lower side of the body portion D via a fold line 19, and these are heat-sealed to form a flat bottom portion without liquid leakage.

From the above blank 10 to this liquid paper container 20
In order to mold the blank, first, the blank is vertically folded in three by the folding line 15 (right) and the folding line 17, and the glue allowance panel 5 and the body portion 4,
The upper folding side wall 4G and the rib 4T are heat-sealed and attached to a tube to form a flat folding carton. This is supplied to a molding and filling machine, raised in a prismatic shape, the bottom is molded first, the contents are filled, then a gable roof is molded, and finally the top rib is sealed by heat sealing. In this top seal, first, when the upper folded side walls 1G, 4G are folded inward along the diagonal folding lines 12, 18, and the folding line 11, the ribs 1T, 4T on the upper side are folded at the central folding lines 27, 2.
Folds in two at 8, and in conjunction with that, the remaining ribs 2T, 3T
Ribs that collapsed inward at the same time and double folded 1
Sealed together with T and 4T sandwiched between them, the top seal is completed and finished in a Gobel top carton. In this case, the thermoplastic resin layer welds between the four ribs to be polymerized.

FIG. 2 is an explanatory view of opening the Gobel top carton. FIG. 2A is a perspective view showing a state before opening. When the folded roof portions of the upper folded side walls 1G and 2G, 1G and 3G are opened to the left and right with both hands and peeled from the middle of the ribs that are heat-sealed in a quadruple manner and overlapped with each other.
As shown in (b), the rib is T-shaped. If you pull it toward you while pressing the left and right with your fingers as shown by the arrow, the rib 1T
Peeling starts from the point where the five broken lines intersect with each other, and the peeling spreads upward, leftward, and rightward, and finally the spout M can be opened as shown in FIG. 2C. Hereinafter, this point at which peeling starts will be referred to as point K. From the state shown in FIG. 2 (b), the pull tab PU for pulling provided beforehand on the upper folding side wall 1G is peeled off as shown in FIG. 2 (b) or FIG. 5, and is pulled out straight to the front. By doing so, it may be opened as shown in FIG. Further, if the opening method described above is combined and opened, the pouring opening can be formed more easily without touching the inside of the rib. The pull tab PU is formed by half-cutting a carton base material, and a peeling stop means is provided above the pull tab PU to prevent excessive peeling. It can therefore be used again when the reclosed roof is reopened.

It takes a little force to reach the state shown in FIG. 2B, but anyone can easily open it. How to easily perform the opening from the state of FIG. 2B without forming an additional coating agent such as an anti-heat sealing agent or a pull tab member separately prepared and attached to form the spout , Is the subject of the present invention. The explanation will be given below, but before that, the conventional anti-heat sealant method will be explained. The conventional anti-heat seal agent is spot-coated at three locations almost the same as the pattern shown in FIG. The rib 1T is folded in the center and thermocompression-bonded by the inner surfaces of the opposing 2T and 3T, but it does not adhere when the anti-heat seal agent is interposed, and even if it adheres, it maintains a weakly adhered state. Therefore, the peel strength of this portion is small, and peeling is easily performed at the interface of the anti-heat seal agent layer.

The first point of the present invention is to form the recess processing pattern P at predetermined positions as shown in FIG. 3 on the inner surfaces of the ribs 1 to 3T, instead of the anti-heat sealing agent. In the case of FIGS. 3 (a) and 3 (b), a method of providing a rectangular pattern F on either one of the inner surfaces of the ribs facing each other is used. However, as shown in FIG. You may provide in both. The pattern shape does not necessarily have to be rectangular. If only the opening trigger is provided, a spot-like recess SP may be provided in the central portion of the rib 1T as shown in FIG. As described above, since the thickness of the paperboard in the recesses formed according to the predetermined pattern is smaller than the normal thickness, even if heat sealing is performed by the opposing ribs 1T and 2T, 1T and 3T, the recesses of the recesses are not formed. Since the thermoplastic resin layers are not in contact with each other, heat sealing is not performed. However, except for the recesses, heat sealing is performed as usual, and the thermoplastic resin layer is welded and integrated. By performing the recess processing as described above, the ribs 1T and 2T, 1T and 3T facing each other can be easily separated to open the spout similarly to the case where the conventional anti-heat sealing agent is applied. The peeling mechanism is the same as the conventional one, and the concave portion is peeled off as it is.However, except for the concave portion, since the thermoplastic resins are completely welded and integrated, it is possible to peel the interlayer between the paper layers on either side of the facing ribs. There is no choice but to peel it off. The delamination that has once occurred propagates to the periphery and stops at the broken line 15. Although it is the same as the conventional one, at the stage where the peeling shifts from the concave portion to the non-concave portion, it is necessary to break the thermoplastic resin layer of any of the facing ribs, which causes peeling resistance.

The recesses can be formed in the ribs on the opening side in the present invention at the same time when the blanks are stamped. That is, when the male mold is set on the upper basin according to a predetermined pattern and the blank is strongly pressed, the paperboard of the pressing portion is compressed to form the concave portion. When the carton is formed, the recesses of the ribs or the recesses face each other, but if the pressure applied to the non-recesses during heat sealing is too high, compression will occur.
Since heat sealing is performed also in the concave portion, there is no meaning to process the concave portion. Normally, the pressure applied during heat sealing reaches approximately 1.2 ton / cm ² , so in order to make it as small as possible, preheat the ribs with hot air immediately before heat sealing and then lighten the pressure before heat sealing. Is desirable. Further, as shown in FIG. 3, the concave portion pressurizing treatment is performed with a space of 1 to 2 mm provided between the bent line 14 of each rib lower portion and the concave portion processing pattern edge, and during this period, heat sealing is completely performed and liquid It is desirable to completely prevent leaks. Since the recess processing is performed at the same time as the pressing rule as described above, the positional accuracy of the obtained recess with respect to the folding line is extremely excellent.

When the rib 1T which is further heat-sealed by the above-mentioned opening operation is to be pulled away from the semi-opened state shown in FIG. 2B, the shear stress concentrates at the point K due to the structure of the container. Therefore, it is important to provide a point where peeling easily occurs at least near the point K. FIG. 4 is FIG.
It is a cross-sectional schematic diagram which shows the peeling condition from the vicinity of K point when the recessed part processing pattern P shown to (a) is given. In FIG. 4, the diagonal lines indicate the paperboard layer or the laminate layer 21 having the paperboard layer inside, and the transparent portion indicates the thermoplastic resin layer 22.
FIG. 4A shows that, before the peeling, the concave portions prevent the ribs facing each other from adhering to each other near the point K. Next, as shown in FIG. 4B, the force in the direction of the arrow acting on the point K easily separates the rib 1T from the inner surface of the facing rib in the presence of the recess processing pattern P, but when it enters the non-processing surface portion, the paper The delamination propagates in the horizontal direction instead of the delamination. FIG.
Although not shown in (b), the peeling propagates in the vertical direction,
Finally, the ribs 1T, 2T and 1T, 3T are separated from each other, and the spout is fully opened as shown in FIG. 2 (c).

The second point of the present invention is to provide a clean opening means which facilitates not only the first opening of the Gobel top carton but also the second and subsequent reopening of the opening, as shown in FIG.
(C) is to provide a pull tab PU as shown in FIG. The pull tab PU is preferably provided so as to pull outward near the point K or over the central portion of the upper folded side wall 1G or over the upper folded side wall 1G and the upper end of the body portion 1. In this pull tab PU, the pull tab area is divided into a shape in which the lower portion is closed and the upper portion is opened.
As shown in FIG. 5, a half cut 24 is added from the surface of the paper container laminated material, and at the time of the first opening, the thin film made of the paper and the thermoplastic resin which is easily delaminated from the lower end thereof is peeled off. You just have to pull it towards you. As a stopper means for stopping the peeling at the upper portion of the pull tab PU, a poly tape 25 is attached, and a peeling stop portion 26 having a rounded shape is provided at the upper portion of the half cut 24. The half cut 24 of the pull tab PU may have a depth enough to separate the paperboard from the intermediate layer. The processing of the half cut 24 can be performed at the same time when the carton blank is punched. Further, a half cut device may be attached to the molding and filling machine, and the half cut 24 may be processed for each of the liquid paper containers.

The laminated constitution of the base material of the liquid paper container of the present invention is preferably a paperboard layer which has been conventionally used, coated on both sides with a polyolefin-based resin, and the polyolefin-based resin may be low-density polyethylene or wire. Low density polyethylene, medium density polyethylene, polypropylene, ionomer, ethylene vinyl acetate copolymer, ethylene
Acrylic acid copolymer, ethylene / acrylic acid ester,
It may be selected from ethylene / vinyl alcohol copolymers and the like. Further, instead of the paperboard alone, a laminate of paper / polyethylene / aluminum foil, paper / ethylene / acrylic acid copolymer / aluminum foil, paper / polyethylene / aluminum foil / biaxially stretched polyester, etc. may be used.

(Example) A liquid paper container according to the present invention was applied to milk to prepare a carton blank having an inner volume of 1000 ml. As the carton base material, the one having the following laminated structure manufactured by Weyerhaeuser Co., which is currently used for milk, was used as it was. That is, it has a layer structure of polyethylene 16 g / m ² / bleached kraft paper 313 g / m ² / polyethylene 27 g / m ² in order from the surface, and the total basis weight is 356 g / m ² . The rib 1T of the carton blank made of this laminated material was pressure-molded so as to form a concave portion treatment pattern P as shown in FIG. After the blank 10 according to the present invention obtained by performing the above-mentioned processing is tube-adhered by the same tube-adhering machine as the conventional one, it is molded, filled and sealed under the same conditions as the conventional one by the same molding and filling machine for milk as the conventional one. went. Twenty samples were randomly selected from the products obtained in this way, and the opening test was conducted by five panelists. It was uncomfortable with the products using conventional anti-heat sealant. It turned out to be easy to open. Further, a peeling resistance value at the time of opening was tested with a push-pull scale (made by Imada Seisakusho Co., Ltd.) by adding a comparative example sample in which no rib portion was processed, and the following results were obtained. Carton using anti-heat sealing agent 1.7 Kg Carton with recess processing 2.0 Kg Comparative example (carton without processing) 3.0 Kg Depending on the position of another frame processing pattern F shown in FIG. , There was some difference in the initial resistance value and the resistance value in the middle, but it was possible to open the bag with almost the same force.

The liquid paper container according to the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention. For example, the blank of the Gobel top carton of this embodiment is drawn in a pure pack type, but it is also effective for other types of Gobel top carton. The liquid paper container according to the present invention has a square horizontal cross section, but may have a rectangular cross section.

[0017]

According to the present invention, a double-sided thermoplastic resin-coated paperboard, which is the base material of a Gobel top carton, or a laminated body centering on the paperboard alone can be processed to cleanly and easily open the spout. As compared with the conventional anti-heat sealant method, the risk of liquid leakage can be reduced, and the material cost and the manufacturing cost can be reduced. Further, the base material coated with polyethylene on both sides of the paperboard can be incinerated and discarded as burning dust even after use, and can be recycled, so that the environmental load can be reduced.

[Brief description of drawings]

[Figure 1] Carton blank development view

[Fig.2] Illustration of opening procedure of spout

FIG. 3 is an explanatory view of a recess processing pattern.

FIG. 4 is a schematic cross-sectional view near a peeling start point (point K).

FIG. 5 is an explanatory diagram of a pull tab.

[Explanation of reference signs] 1-4 carton body side wall 5 gluing allowance for tube attachment 1G, 4G upper folded side wall 2G, 3G roof part 1T-4T rib (top panel) 11 fold line 12, 13 diagonal fold line 14-17 fold line 18 diagonal Folded line 19 Folded line 20 Liquid paper container according to the present invention 21 Paper layer 22 Thermoplastic resin layer 23 Recessed surface 24 Half cut 25 Poly tape 26 Peeling stop part 27, 28 Folded line 29 Delamination part in paper layer B Bottom molding part K Peeling start point M opening P recessed pattern PU pull tab SP spotted recess

[Procedure amendment]

[Submission date] January 23, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The first point of the present invention is to form the recess processing pattern P at predetermined positions as shown in FIG. 3 on the inner surfaces of the ribs 1 to 3T, instead of the anti-heat sealing agent. In the case of FIGS. 3A and 3B, a rectangular pattern P is provided on one of the inner surfaces of the ribs facing each other, but as shown in FIG. You may provide in both. The pattern shape does not necessarily have to be rectangular. If only the opening trigger is provided, a spot-like recess SP may be provided in the central portion of the rib 1T as shown in FIG. As described above, since the thickness of the paperboard in the recesses formed according to the predetermined pattern is smaller than the normal thickness, even if heat sealing is performed by the opposing ribs 1T and 2T, 1T and 3T, the recesses of the recesses are not formed. Since the thermoplastic resin layers are not in contact with each other, heat sealing is not performed. However, except for the recesses, heat sealing is performed as usual, and the thermoplastic resin layer is welded and integrated. By performing the recess processing as described above, the ribs 1T and 2T, 1T and 3T facing each other can be easily separated to open the spout similarly to the case where the conventional anti-heat sealing agent is applied. The peeling mechanism is the same as the conventional one, and the concave portion is peeled off as it is.However, except for the concave portion, since the thermoplastic resins are completely welded and integrated, it is possible to peel the interlayer between the paper layers on either side of the facing ribs. There is no choice but to peel it off. The delamination that has once occurred propagates to the periphery and stops at the broken line 15. Although it is the same as the conventional one, at the stage where the peeling shifts from the concave portion to the non-concave portion, it is necessary to break the thermoplastic resin layer of any of the facing ribs, which causes peeling resistance.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

The recesses can be formed in the ribs on the opening side in the present invention at the same time when the blanks are stamped. That is, when the male mold is set on the upper basin according to a predetermined pattern and the blank is strongly pressed, the paperboard of the pressing portion is compressed to form the concave portion. When the carton is formed, the recesses of the ribs or the recesses face each other, but if the pressure applied to the non-recesses during heat sealing is too high, compression will occur.
Since heat sealing is performed also in the concave portion, there is no meaning to process the concave portion. The pressure exerted during normal heat sealing extends to about 1.2 ton / cm ^2, as small as possible, the heat sealing by lightly pressure from heated pre hot air rib portion immediately before the heat-sealing Is desirable. Further, as shown in FIG. 3, the concave portion pressurizing treatment is performed with a space of 1 to 2 mm provided between the bent line 14 of each rib lower portion and the concave portion processing pattern edge, and during this period, heat sealing is completely performed and liquid It is desirable to completely prevent leaks. As described above, since the recess processing is performed at the same time as the ruled line, the positional accuracy of the obtained recess with respect to the folding line is extremely excellent.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

(Example) A liquid paper container according to the present invention was applied to milk to prepare a carton blank having an inner volume of 1000 ml. As the carton base material, the one having the following laminated structure manufactured by Weyerhaeuser Co., which is currently used for milk, was used as it was. That is, it has a layer structure of polyethylene 16 g / m ² / bleached kraft paper 313 g / m ² / polyethylene 27 g / m ² in order from the surface, and the total basis weight is 356 g / m ² . The rib 1T of the carton blank made of this laminated material was pressure-molded so as to form a concave portion treatment pattern P as shown in FIG. After the blank 10 according to the present invention obtained by performing the above-mentioned processing is tube-adhered by the same tube-adhering machine as the conventional one, it is molded, filled and sealed under the same conditions as the conventional one by the same molding and filling machine for milk as the conventional one. went. Twenty samples were randomly selected from the products obtained in this way, and the opening test was conducted by five panelists. It was uncomfortable with the products using conventional anti-heat sealant. It turned out to be easy to open. Further, a peeling resistance value at the time of opening was tested with a push-pull scale (made by Imada Seisakusho Co., Ltd.) by adding a comparative example sample in which no rib portion was processed, and the following results were obtained. Carton using anti-heat sealing agent 1.7 Kg Carton with recess processing 2.0 Kg Comparative example (carton without processing) 3.0 Kg Depending on the position of the other recess processing pattern P shown in FIG. , There was some difference in the initial resistance value and the resistance value in the middle, but it was possible to open the bag with almost the same force.

Claims (2)

[Claims] 1. A board, which is coated on both sides with a thermoplastic resin, or a laminated body centered on the board, is connected to the upper end of a quadrangular prism-shaped body composed of four body side wall panels through fold lines. The gabled roof part folds the opposite upper folded side walls inward along each diagonal fold line, folds the remaining opposite upper folded side walls inward, and sandwiches the upper folded side ribs of the upper folded side wall by the upper end ribs. In a paper container formed by polymerizing and heat-sealing this polymerized portion, both of the ribs at the upper end of the upper folding side wall on the opening side and the ribs facing them, or either one of them, according to a predetermined pattern on the inner surface. A liquid paper container having a recess. 2. A pull tab region having a shape in which a lower part is closed and an upper part is opened is defined on the upper folded side wall on the opening side or across the uppermost part of the body side wall panel connected to the upper folded side wall via a fold line. The liquid paper container according to claim 1, wherein a half cut is formed from the front side of the paper container laminated material in this manner, and a pull tab that can be peeled from the lower portion of the pull tab region is formed.