JP2006264746A - Packaging bag with zipper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily open in the case of opening a packaging bag without opening of a zipper due to an inner pressure rise or the like in sealing of the packaging bag in the packaging bag with the zipper which has a bag body and the zipper opening/closing the opening part of the bag body, and of which opening end above the zipper is closed. <P>SOLUTION: The packaging bag 101 with the zipper has a bag body 20 formed by opposing heat-welded layers 33, 34 of the surface of laminated films 31, 32 and heat welding, and the zipper 1 opening/closing the opening part of the bag body 20, and the opening end 21 of the bag body positioned above the zipper 1 is closed. The packaging bag has a welding part 23 dividing the inside of the bag body into a zipper side and a content storage part side at the inner side of the zipper 1, and the separation surface 37 for opening of the welding part is formed in one side of the laminated film 32, and vulnerable parts 24a, 24b are formed in the vicinity of an upper end part 23a of the welding part and at the heat-welded layer 34 of the lower side than the welding part 23 in the area from the upper end part of at least welding part 23 to the lower side than the welding part 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a packaging bag having a zipper that opens and closes an opening after opening a seal.

  The zippered bag is widely used in daily life because it can be repeatedly sealed and opened. However, as shown in FIG. 8A, the bag body 20 is filled with the contents A and then opened above the zipper 1. The zippered packaging bag 100 sealed by forming the heat-sealed sealing portion 22 by heat-sealing the end 21 is often used as a packaging bag for products such as foods and daily necessities. The packaging bag 100 with a zipper is filled with a food material, sealed, boiled or retorted, and shipped as a product. When the end user uses the contents packaged in such a zippered packaging bag 100, the packaging bag 100 is first opened by removing the heat-sealed sealing portion 22, and the zipper 1 opens the bag body 20 or Reseal.

  However, as shown in FIG. 8B, since the zipper 1 creates a sealed state simply by meshing the male mold 1a and the female mold 1b, internal pressure is applied to the bag body 20 by boil processing, retort processing or loading during transportation. As shown in FIG. 8C, the zipper 1 can be easily disengaged, the contents can be caught in the engaging portion, and it becomes difficult to reseal during use, the confidentiality at the time of resealing is impaired, There are drawbacks such as reduced strength and impaired appearance.

  For this, there are methods such as increasing the biting strength of the zipper or providing double zippers, but for those with weak power such as the elderly and disabled people, opening and resealing are not possible. It is difficult and expensive.

  In addition, a tape-shaped delamination material is interposed outside the bag body to form a heat-sealing portion above the zipper, or a tape-shaped delamination material is interposed under the zipper to form a heat-sealing portion. By doing this, while maintaining the opening from the opening end side of the bag body, the packaging bag with a zipper (Patent Document 1) that has improved peel strength from the inside of the bag, or the opening end of the bag body located above the zipper A packaging bag with a zipper (Patent Document 2) that has been heat-sealed and heat-sealed to such an extent that the lower part of the zipper can be peeled by hand has also been proposed.

JP-A-5-246442 JP 2004-168420 A

  However, since the packaging bag with a zipper described in Patent Document 1 uses a tape-like delamination material to provide a heat sealing part only above or below the zipper, an excessive internal pressure of the bag body 20 It is desired to further increase the seal strength of the heat seal part against the rise. For this, it is conceivable to form a heat sealing portion both above and below the zipper using a tape-like delamination material, but the upper and lower sides of the zipper are sealed using a tape-like delamination material. As long as there is a limit to improving the seal strength.

  Furthermore, in the packaging bag with a zipper described in Patent Document 1, since the tape-like delamination material is provided so as to protrude into the bag body, the contents accumulate between the protruding tape and the inner surface of the bag body. When the bag body is tilted and the contents are taken out, there is a problem that the contents get caught in the protruding portion.

  Moreover, in the packaging bag with a zipper described in Patent Document 2, since the heat seal below the zipper is performed by a hot melt adhesive provided on the surface of the zipper tape forming the zipper, the heat seal portion is the opening of the bag body. The peel strength when opened from the end side is the same as the peel strength when opened from the inside of the bag, and the peel strength when the heat seal part is opened from the inside of the bag is It cannot be sufficiently increased compared to the peel strength. Therefore, if the peel strength is given so that the heat seal part does not peel against the increase in internal pressure when bottle processing or retort processing is performed, or the load or the swinging of the contents during transportation, packaging is performed when the contents are used. There arises a problem that it is difficult to open the bag.

  With respect to such conventional problems, the present invention provides a zippered packaging bag with the open end of the bag body positioned above the zipper, and when the packaging bag is sealed, the internal pressure of the bag body is obtained by boil processing or retort processing. To provide a packaging bag with a zipper that can be opened easily from the opening end side when the packaging bag is opened, and when the packaging bag is opened, even if the zipper does not open due to rising, loading during transportation or swing of contents It is an object.

  In the packaging bag with a zipper that closed the upper open end of the zipper, the inventor provided a welded portion that protects the zipper on the inside of the zipper, and in the region extending from the upper end portion of the welded portion to below the welded portion, In the case of opening the bag body from the opening end side of the bag body by forming a release surface for opening in one film of the opposite laminated film and forming a site to be the opening start point at a specific position, The welded part is easily peeled off at the peeling surface, but when the force for opening the welded part is applied from the inside of the bag body, the welded part becomes difficult to peel off, and it has been found that the above object can be achieved.

That is, the present invention has a bag body formed by heat-welding the heat-sealable layer of the laminated film having the heat-weldable layer on the surface, and a zipper that opens and closes the opening of the bag body. And
A zippered packaging bag in which the open end of the bag body located above the zipper is closed,
On the inner side of the zipper, it has a welded part that divides the inside of the bag body into a zipper side and a content container side,
At least in the region from the upper end of the welded part to the lower part of the welded part, a release surface for opening the welded part is formed in one laminated film, and the thermal welding on the peeled surface is performed in the vicinity of the upper end of the welded part. The fragile part is formed in the adhesive layer, or the upper end part of the peeling surface is located in the vicinity of the upper end part of the welded part, and the fragile part is formed in the heat-weldable layer on the peeled surface below the welded part. Or a zippered packaging bag in which the lower end portion of the peeling surface is located below the welded portion.

  The packaging bag with a zipper of the present invention has a welded portion that divides the inside of the bag main body into a zipper side and a content accommodating portion side inside the zipper, and at least the welded inside is provided in one of the opposed laminated films A peeling surface is formed in a region extending from the upper end of the weld to the lower part of the weld, and a weak part is formed in the heat-weldable layer near the upper end of the weld, or the upper end of the peel The part is located in the vicinity of the upper end of the welded part. The weakened portion formed at such a position and the upper end portion of the peeling surface serve as an opening start point when the welded portion is opened from the opening side of the packaging bag. Therefore, the packaging bag with a zipper of the present invention can be easily opened from the opening end side of the bag body.

  On the other hand, the weak part of heat-weldability and the lower end part of a peeling surface are not formed in the lower end part of a welding part, but the lower end part of a weak part and a peeling surface is formed in the downward direction. Thus, the weak part formed away from the lower end part of the welded part and the lower end part of the peeling surface are unlikely to become the opening start point even if force is applied to the welded part due to an increase in internal pressure of the bag body.

  Therefore, according to the packaging bag with a zipper of the present invention, even if the internal pressure of the bag body rises due to the boil processing or retort processing of the contents, and the force is applied to the welded portion due to loading during transportation or the swing of the contents. Even if it is applied, the welded portion remains closed. Therefore, the zipper is not opened, and the contents are prevented from being stained and the resealability of the zipper being impaired.

In general, forming the welded surface in a peelable manner is likely to lead to a decrease in the sealing strength, but according to the packaging bag with a zipper of the present invention, the welded surfaces of the laminated films facing each other at the welded portion are heat-weldable layers. Since it is welded firmly, high sealing performance is maintained.
Therefore, according to the packaging bag with a zipper of the present invention, it becomes possible to fill and seal the contents while maintaining airtightness, the zipper does not get dirty with the contents, and the resealability is good, and the contents After opening the packaging bag when using an object, the bag body can be easily opened.

  Therefore, this packaging bag with a zipper is also suitable as a packaging bag for large packaging or retort processed foods that require a sealing strength at the welded portion.

  Furthermore, according to the packaging bag with a zipper of the present invention, the shape of the bag body is not restricted by the inner welded portion of the zipper, and can be formed in various designs.

  Moreover, it becomes possible to manufacture at a low cost as compared with the case where double zippers are provided. Particularly, one of the laminated films facing each other in the bag body is composed of a laminated film of a base film and an exfoliation type heat-welding film, and the delamination-type heat-welding film has a fragile part near and below the upper end of the welding part. According to the embodiment, since it is not necessary to use a separate film tape for forming the inner welded portion of the zipper, the number of necessary members can be reduced and the manufacturing process is simplified. Can be manufactured at a lower cost.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In each figure, the same numerals indicate the same or equivalent components.

  1A is a perspective view of a packaging bag 101 with a zipper according to an embodiment of the present invention when sealed, FIG. 1B is a sectional view when sealed, and FIG. 1C is a sectional view when opened. 2A is an enlarged cross-sectional view when sealing the vicinity of the welded portion, FIG. 2B is an enlarged cross-sectional view when the internal pressure is increased, and FIG. 2C is an enlarged cross-sectional view when opening.

  The bag body 20 of the packaging bag with zipper 101 is formed by facing and thermally welding the two heat-bondable layers 33 and 34 of the laminated films 31 and 32. The heat-weldable layers 33 and 34 are formed by laminating an adhesive 36 on the base material layer 35, respectively. The heat-weldable layer 33 of one of the two laminated films 31 and 32 facing each other is formed of various heat-weldable resin films in the same manner as known heat-welded bags. The heat-weldable layer 34 of the laminated film 32 is formed from a delamination-type heat-weldable film. These heat-weldable layers 33 and 34 are preferably excellent in content resistance, low odor, and heat resistance as well as heat-weldability so that the contents A can be heated while filling the bag body 20.

  The delamination-type heat-weldable film forming the heat-weldable layer 34 of the laminated film 32 has a peel strength of the peel surface 37 between the first layer 34a and the second layer 34b constituting the heat-weldable layer 34. It is preferable that it is not more than one half of the delamination strength between the heat-weldable layer 34 and the base material layer 35, for example, 0.2 to 1.5 kg / 15 mm width. If this value is greatly exceeded, it may be difficult for an elderly person or a handicapped person to open the bag, and the bag shape may be damaged when the bag is opened, which may make it difficult to re-seal.

  The thickness of each layer constituting the heat-weldable layer 34 is not particularly limited. However, the first layer 34a is usually used because it easily causes delamination between the first layer 34a and the second layer 34b. Is preferably 0.5 to 30 μm, the second layer 34 b is preferably 10 to 200 μm, and the second layer 34 b is more preferably 10 to 50 μm.

  As such a heat-weldable layer 34, for example, an easy-open packaging composite film in which a first layer and a second layer are laminated by coextrusion, and the first layer 34a serving as a release layer is made of polypropylene or propylene. The second layer 34b is made of a copolymer with other α-olefin, and the second layer 34b may be made of a resin component containing a mixture of polypropylene and a high-density polyethylene having a melting point of 120 ° C. or higher or a linear low-density polyethylene. it can.

  Further, in order to make the packaging bag 101 transparent and resistant to retort processing, when the heat-weldable layer 34 is formed from a polypropylene-based heat-weldable resin excellent in transparency, heat resistance, etc., a first layer that becomes a release layer A multilayer film in which a blend resin layer of polypropylene and polyethylene is provided as a peel strength adjusting layer between the polyethylene as 34a and the polypropylene layer as the second layer 34b which becomes the surface after the first layer 34a is peeled off. Can be used.

  As the delamination-type heat-weldable film for forming the heat-weldable layer 34, a commercially available delamination-type sealant film may be used. Examples of such a film include Tosero CPMS (manufactured by Tosero Corporation), Sholex Aroma TP (manufactured by Showa Denko KK), Trephalon CF (manufactured by Toray Synthetic Co., Ltd.), VMX (manufactured by J-Film Corporation), and the like. .

  On the other hand, as a preferable example of the other heat-weldable layer 33, any one of low density polyethylene (LD), linear low density polyethylene (L LDPE), unstretched polypropylene (CCP), or a combination thereof can be used. The formed layer can be mentioned. In particular, when the zippered packaging bag 101 is used for food, unstretched polypropylene is excellent in heat resistance, low odor, and content resistance, and the contents can be packaged and distributed more safely. It is preferable from the viewpoint of food hygiene without causing a resin odor or the like to be transferred to the contents and losing the flavor. The heat-weldable layer 33 may have a single layer structure or a multilayer structure.

  However, the heat-weldable layer 33 is preferably the same type or similar resin excellent in thermal adhesion with the first layer 34a of the above-described delamination-type heat-welded film. More specifically, for example, the first layer 34a is made of a propylene-ethylene random copolymer so that the heat sealing strength of both the heat-weldable layers 33, 34 is usually 3.0 kg / 25 mm width or more. In this case, the heat-weldable layer 33 is preferably formed from a propylene-ethylene random copolymer having the same amount of ethylene component, polyethylene, or the like, and the first layer 34a is made from syndiotactic polypropylene. In this case, the heat-weldable layer 33 is preferably formed from the same kind of syndiotactic polypropylene, and when the first layer 34a is polyethylene or the like, the heat-weldable layer 33 is preferably formed from polyethylene.

  Examples of the base material layer 35 include layers formed from polyester, stretched nylon, polypropylene, and the like. More specifically, biaxially stretched nylon (ON), biaxially stretched polypropylene (OPP), and biaxially stretched polyethylene. Terephthalate (PET), linear low density polyethylene (L LDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), unstretched polypropylene (CPP), saponified ethylene-vinyl acetate copolymer (EVOH), etc. Films formed from can be used.

  Among these, by using an ON film or a PET film as the outermost layer of the laminated films 31 and 32, mechanical strength, heat resistance, and printability can be imparted to the packaging bag 101, and by using these as an intermediate layer. , Mechanical strength can be reinforced. Further, by using an OPP film for the intermediate layer, it is possible to increase the thickness and increase the rigidity, and at the same time to improve the water vapor transmission rate, and it is possible to improve the gas barrier property by using the EVOH film.

  As the adhesive 36, generally, an adhesive for dry lamination or wet lamination used for bonding films can be used. More specifically, the material of the film to be bonded, use such as boil or retort, etc. Depending on the case, an adhesive such as a polyester resin or a urethane resin can be used.

  For the laminated films 31 and 32, as necessary, aluminum foil, alumina vapor-deposited layer, silica vapor-deposited layer, iron foil, polyacrylonitrile as functional layers such as an oxygen barrier layer and a water vapor barrier layer from the viewpoint of preventing deterioration of the contents. A barrier layer such as a film or a coating film of polyvinylidene chloride may be laminated. In particular, in this case, it is preferable to use an alumina vapor-deposited layer, a silica vapor-deposited layer, or the like when imparting transparency.

The specific layer configuration of the laminated films 31 and 32 can be determined as appropriate according to the contents and applications. For example, the following are preferable layer configurations of the laminated film 31 that does not have a release surface inside. Can do. In the following layer structure, the left side is the outside of the bag body and the right side is the inside of the bag body. Further, the layer configuration of the laminated film 32 having the release surface 37 is that the innermost layer is replaced with the aforementioned delamination-type heat-weldable film 34 in the layer configuration of the laminate film 31 having no release surface 37. Good.
(1) ON film / adhesive / L LDPE film
(2) ON film / adhesive / EVOH film / adhesive / L LDPE film
(3) ON film / adhesive / PET film / adhesive / CPP film
(4) ON film / adhesive / OPP film / adhesive / L LDPE film
(5) PET film / adhesive / L LDPE film
(6) PET film (silica or alumina deposited layer) / adhesive / L LDPE film
(7) PET film (silica or alumina deposited layer) / adhesive / ON film / adhesive / CCP film
(8) PET film / adhesive / aluminum foil / adhesive / L LDPE film
(9) PET film / adhesive / aluminum foil / adhesive / CCP film

  Such laminated films 31 and 32 can be obtained by coextrusion or lamination. In the case of co-extrusion, for example, the material of each layer is melt-extruded using different extruders, and this is laminated by a feed block and formed into a film by a flat die, or produced in a die using a multilayer die. A method of forming a film is mentioned. As the laminating process, for example, methods such as extrusion lamination, hot melt lamination, dry lamination, and wet lamination can be used.

  In the packaging bag 101 with a zipper of the present invention, the shape of the bag body 20 is not limited to the illustrated shape. Various shapes such as a four-side seal, a three-side seal bag, a gusset bag, a barracuda bag, a pillow bag, and a stand pack can be taken.

  The zipper 1 that opens and closes the opening of the bag body when in use is provided at the portion that becomes the opening of the bag body 20, and the opening end 21 of the bag body 20 located above the zipper 1 is sealed by a heat welding sealing portion 22. ing. The heat-sealed sealing portion 22 has a notch 25 for the convenience of opening it.

  As the zipper 1, it is preferable to use one formed from a general-purpose resin that can be molded and used as a zipper such as polypropylene or methylpentene polymer.

  The zipper 1 may be formed of these single resins, but may have a multilayer structure. In order to improve the adhesion between the zipper 1 and the innermost layers of the multilayer films 31 and 32 forming the bag body 20, for example, a multilayer adhesive layer is provided on the back of the male or female ridges of the zipper 1 You may form by coextrusion etc.

  As shown in FIG. 1A and FIG. 1B, a zipper protection weld 23 is formed on the inside of the zipper 1 to divide the bag body 20 into a zipper 1 side and a content A container side. . And in this invention, the peeling surface 37 for opening for opening the welding part 23 is provided in one laminated film 32 of the laminated | multilayer film 31 and 32 which opposes by the welding part 23, and the upper end part vicinity of the welding part 23 is provided. Is provided with a fragile portion 24a in the heat-weldable layer (delamination-type heat-weldable film) 34 as an opening start point, and a fragile portion 24b in the heat-weldable layer 34 also below the welded portion 23. It is characterized by.

  Here, the preferable width L1 of the welding part 23 is 2-30 mm, More preferably, it is 3-10 mm. If it is less than 2 mm, when the internal pressure rises in the sealed state of the main body bag 20, the surface pressure of the welded portion 23 increases, and the laminated films 31 and 32 may be damaged. On the other hand, it is not necessary to provide a wide welded portion exceeding 50 mm.

  Moreover, although it is preferable to provide the welding part 23 in parallel with the zipper 1, it does not need to be provided in the vicinity of the zipper 1. When the inner volume of the bag body 20 is 50 to 500 mL, the distance L2 between the zipper 1 and the welded portion 23 is preferably 5 to 30 mm from the viewpoint of operability when opening the bag body 20. .

  The weakened portion 24a in the vicinity of the upper end portion of the welded portion 23 is preferably provided within 8 mm upward from the upper end portion 23a of the welded portion, more preferably within 2 mm above and below the upper end portion 23a.

  Moreover, the weak part 24b below the weld part 23 is preferably provided 3 to 20 mm below the lower end part 23b of the weld part, more preferably 3 to 6 mm.

  The depths of the fragile portions 24a and 24b are preferably set so that the fragile portion 24a acts as an opening start point and the strength of the second layer 34b of the heat-weldable layer 34 is not impaired, as will be described later. Considering the processing accuracy, it is usually preferable to set the depth to 50 to 200% of the first layer 34 a of the heat-weldable layer 34.

  As a method for forming the fragile portions 24a and 24b, there are cutting with a cutter, partial thinning by hot plate pressurization, half-cut lines by laser light irradiation, etc., and these can be used alone or in combination. .

  In particular, with respect to the fragile portion 24a in the vicinity of the upper end portion of the welded portion 23, when the welded portion 23 is thermally welded, the fragile portion 24a is used by using a heat sealing machine having an annular protrusion on the seal surface inner edge portion of the heat seal bar. It is preferable to form the thinned portion simultaneously with the heat welding of the welded portion 23. Such a method for forming the fragile portion 24a can be used for small weight applications such as a thin-walled bag, thereby reducing the production cost of the packaging bag. In FIG. 2A, the fragile portion 24a in the vicinity of the upper end portion of the welded portion 23 indicates that it has been formed by such partial thinning, and the fragile portion 24b below the welded portion 23 is a half by laser light irradiation or the like. It shows that it was formed by cutting.

  According to this packaging bag 101 with a zipper, as shown in FIG. 2B, even when a force is applied to the welded portion 23 due to an increase in the internal pressure of the bag body 20 during sealing, the bonding of the welded portion 23 on the content accommodating portion side Since the lower end 23b which is an end is firmly welded by the heat-weldable layer 33 of the laminated film 31 and the heat-weldable layer 34 of the laminated film 32 opposed thereto, the welded portion 23 is not easily opened.

  On the other hand, when the contents sealed in the packaging bag 101 are used, the heat-sealed sealing portion 22 is removed from the notch 25 and the bag body 20 is opened from the opening end 21 side. At this time, first, the zipper 1 is opened, and the force for opening the bag body 20 is concentrated on the upper end portion 23a of the welded portion. A fragile portion 24a is provided in the vicinity of the upper end portion 23a.

  Therefore, as shown in FIG. 2C, the fragile portion 24a becomes the opening start point, and the release layer 34a of the heat-weldable layer 34 peels along the peel surface 37 immediately below the fragile portion 24a. This peeling continues to the fragile portion 24b below the lower end portion 23b of the welded portion. Therefore, according to this packaging bag 101 with a zipper, the peeling surface 37 from the weak part 24a in the vicinity of the upper end part 23a of the weld part to the weak part 24b below the weld part 23 serves as an opening peel surface of the weld part 23. Will function.

  Although the manufacturing method of this packaging bag 101 with a zipper is not specified, for example, when making the bag main body 20 into a flat bag, first, the zipper 1 is attached to the laminated films 31 and 32, and the weak parts 24a and 24b are respectively attached. Then, the flat bag 110 is formed as shown in FIG. 3 by heat-welding the heat-welded portion 23 and the heat-welded sealing portion 22 and heat-welding the side edges of the bag body 20. Next, the contents A are filled into the bag from the opening 26 on the bottom side of the bag body 20, and the bottom side of the bag body 20 is sealed.

  If the contents cannot be filled from the bottom side of the bag body 20 such as a stand pouch, etc., after the side edge and bottom of the bag body 20 are thermally welded and the contents A are filled from the opening end 21 side, The zipper 1 is engaged, and the welding part 23 and the heat welding sealing part 22 are heat-welded.

  The heat welding conditions are not particularly limited, but heat sealing is preferably performed under conditions of a pressure of 0.1 to 4 MPa, a temperature of 120 to 250 ° C., and a time of 0.2 to 5 seconds.

  The contents A to be filled in the packaging bag 101 with the zipper are not particularly limited, but the contents include heavy, liquid, sticky, heat sterilized foods that perform boil processing, retort processing, and the like. By doing so, the effect of the present invention can be remarkably enjoyed.

  4A is a cross-sectional view of a packaging bag 102 with a zipper according to another embodiment at the time of sealing, FIG. 4B is a cross-sectional view of the vicinity of the welded portion when the internal pressure is increased, and FIG. 4C is a cross-sectional view at the time of opening. .

  In the zippered packaging bag 102, the laminated films 31a and 31b facing the bag body 20 with respect to the zippered packaging bag 101 in FIGS. 1A and 1B are both thermally weldable layers 33 on the base layer 35. However, the surface of one laminated film 31a has a delamination-type heat in a region extending from the upper end 23a of the welded portion to a position below the welded portion 23. The welding film tape 38 is welded to a solid, and the laminated film 31a, 31b facing each other through the delamination type heat welding film tape 38 is welded at the welding portion 23.

  The delamination-type heat-weldable film tape 38 has the same layer structure as the delamination-type heat-weldable film of the heat-weldable layer 34 that forms the laminated film 32 of the zippered packaging bag 101 of FIGS. 1A and 1B described above. The delamination strength between the heat-weldable first layer 38a and the second layer 38b constituting the delamination-type heat-weldable film tape 38 is 0.2 to 1.5 kg / width 15 mm. More preferably, the first layer 38a has a layer thickness of 0.5 to 30 [mu] m, the second layer 38b has a layer thickness of 10 to 200 [mu] m, particularly 10 to 50 [mu] m, and the first layer and the second layer easily peel off.

  In the packaging bag 102 with a zipper, the delamination-type heat-weldable film tape 38 has an upper end portion 38c exposed in the vicinity of the upper end portion 23a of the weld portion, and a lower end portion 38d from the lower end portion 23b of the weld portion. Exposed and exposed. The upper end portion 38c of the delamination-type heat-weldable film tape is preferably provided within 15 mm upward from the upper end portion 23a of the weld portion, more preferably within a portion within 2 mm from the upper end portion 23a, and the lower end portion 38d is preferably Is provided 3 to 30 mm, more preferably 3 to 6 mm downward from the lower end 23 b of the welded portion.

  By providing the upper end portion 38c and the lower end portion 38d of the delamination-type heat-weldable film tape at such positions, the upper-end portion 38c of the delamination-type heat-weldable film tape allows the welded portion 23 to be connected to the opening end side of the bag body 20. However, the lower end portion 38d of the delamination-type heat-weldable film tape does not act as an opening start point when the welded portion 23 is opened from the inside of the bag.

  Therefore, as shown in FIG. 4B, even if a force is applied to the welded part 23 due to an increase in the internal pressure of the bag body 20 during sealing, the lower end part 23b, which is the joint end of the welded part 23 on the content accommodating part side, Since it is firmly welded by the heat-weldable layer 33 of the laminated film 31 and the delamination-type heat-weldable film tape 38 opposed thereto, the welded portion 23 does not easily open.

  On the other hand, when the bag body 20 is opened from the zipper side when the contents sealed in the packaging bag 102 are used, as shown in FIG. 4C, the force to open the bag body 20 is increased by the upper end 23a of the welded portion. In the vicinity of the upper end 23a of the welded portion, there is an upper end portion 38c of the delamination-type heat-weldable film tape, and the easily peelable interface between the first layer 38a and the second layer 38b is exposed. Yes. Therefore, the easily peelable interface end exposed at the upper end portion 38c of the delamination-type heat-weldable film tape becomes the opening start point, and the first layer 38a is delaminated, and this delamination is the delamination-type heat-weldable film. It reaches the lower end 38d of the tape, and the weld 23 is opened.

  Therefore, according to this packaging bag 102, the easily peelable interface in the delamination-type heat-weldable film tape 38 adhered to the laminated film 31a functions as an unsealing release surface of the welded portion 23.

  Further, according to the packaging bag 102, the delamination-type heat-weldable film tape 38 is solidly welded to the surface of the laminated film 31a and does not protrude into the bag body, so that the film tape 38 and the bag body are formed. The contents do not collect or get caught between the laminated films 31a and 31b.

  FIG. 5A is a cross-sectional view of the zippered packaging bag 103 of still another embodiment at the time of sealing, FIG. 5B is a cross-sectional view of the vicinity of the welded portion when the internal pressure is increased, and FIG. 5C is a cross-sectional view at the time of opening. .

  The zippered packaging bag 103 is formed by replacing the delamination-type heat-weldable film tape 38 on one laminated film 31a in the zippered packaging bag 102 shown in FIGS. 4A to 4C. The peelable surface 40 of the heat-weldable film tape 39 having an adhesive surface 40 is attached to a solid surface with the release surface 40 facing the laminated film 31a. The heat-welding film tape 39 is formed by changing the coating amount, resin concentration, etc. of the adhesive resin on both surfaces of a base film such as polypropylene and polyethylene by a known processing technique such as adhesive resin surface coating. This is a difference in adhesion. In this case, the adhesive strength between the peeling surface 40 of the heat-weldable film tape 39 and the laminated film 31a is 0.2 to 1.5 kg / width 15 mm, and the other surface of the heat-weldable film tape 39 is bonded to the laminated film 31b. It is preferable to adjust the adhesiveness on both sides so that the strength is 1.5 kg / width 15 m or more and the adhesive strength between the peeling surface 40 and the laminated film 31a is twice or more.

  Here, as the adhesive resin, when the content A in the bag body 20 is a liquid or high-temperature heat treatment, a heat-adhesive resin having heat resistance is preferable, and an ethylene / ethyl acrylate copolymer ( EEA), ethylene / acrylic acid copolymer (EAA), α-olefin copolymer, ionomer (IO) and the like. Commercially available products can be used as the adhesive resin. For example, as an ethylene / ethyl acrylate copolymer (EEA), Nippon Unicar Co., Ltd. “NUC EEA Copolymer”, Mitsui DuPont Polychemical Co., Ltd. “Evaflex EEA”, ethylene / acrylic acid copolymer (EAA) is Dow Chemical Japan Co., Ltd. “Primacoll”, Mitsui DuPont Polychemical Co., Ltd. “Nucrel”, ethylene / vinyl acetate copolymer Examples of hot melt agents mainly composed of Toyo Ink Co., Ltd. “Topco” and ionomers (IO) include Mitsui DuPont Polychemical Co., Ltd. “High Milan”.

  In the zippered packaging bag 103, the upper end portion 39a of the heat-welding film tape acts as an opening start point when the welding portion 23 is opened from the opening end side of the bag body 20, but the lower end portion of the heat-welding film tape. 39b does not act as an opening start point when the welding part 23 is opened from the inside of the bag. Therefore, as shown in FIG. 5B, even if a force is applied to the welded portion 23 due to an increase in the internal pressure of the bag body 20 during sealing, the welded portion 23 does not open easily.

  On the other hand, when the bag body 20 is opened from the opening end 21 side when the contents sealed in the packaging bag 103 are used, as shown in FIG. 5C, the force to open the bag body 20 is the upper end of the welded portion. The heat-weldable film tape 39 is peeled off at the peeling start surface 40 of the upper end portion 39a of the heat-weldable film tape that is concentrated in the portion 23a and exposed in the vicinity of the upper end portion 23a of the weld portion, This peeling reaches the lower end 39b of the heat-weldable film tape.

  Therefore, according to this packaging bag 103, the release surface 40 of the heat-weldable film tape adhered to the laminated film 31 functions as an opening release surface of the weld portion 23.

  Also in this packaging bag 103, the heat-weldable film tape 39 is solidly stuck to the laminated film 31a, so that the contents accumulate between the film tape 39 and the laminated films 31a and 31b forming the bag body. Or get caught.

  In addition, the present invention can take various modes in which an opening peeling surface is formed inside one of the opposed laminated films in a region extending from the upper end of the welded portion 23 to below the welded portion 23. .

  For example, the packaging bag 104 with a zipper in FIG. 6A has a welded portion on the surface of one laminated film 31a of the laminated films 31a and 31b facing each other in the bag body 20, in accordance with the packaging bag with a zipper 102 in FIGS. 4A to 4C. The delamination-type heat-weldable film tape 38 is welded in a region extending from above the welding portion 23 to below the welding portion 23, and delamination is performed in the vicinity of the upper end portion of the welding portion 23 as an opening start point of the welding portion 23. A fragile portion 24 a is provided on the first layer 38 a of the mold heat-weldable film tape 38.

  Therefore, in this packaging bag 104 with a zipper, when the bag main body 20 is opened from the opening end 21 side, as shown in FIG. 6B, on the delamination type heat welding film tape 38 located in the vicinity of the upper end portion of the welding portion 23. The fragile portion 24a becomes the opening start point, the first layer 38a of the delamination-type heat-weldable film tape 38 is delaminated, this delamination reaches the lower end 38d of the delamination-type heat-weldable film tape, and the welded portion 23 is opened. To do.

  Further, in the present invention, the opening end of the bag body located above the zipper does not necessarily have to be closed by the heat-sealing sealing portion, and as shown in FIGS. 7A and 7B, by folding the single laminated film It may be closed.

  Hereinafter, the present invention will be described specifically by way of examples.

Example 1
The packaging bag with a zipper of FIG. 1A was manufactured as follows.

  First, a commercially available film was prepared as a material for forming the laminated films 31 and 32 constituting the bag body 20, and each film was laminated using an adhesive.

  That is, to produce one laminated film 31, an ON film (trade name: Emblem, manufactured by Unitika Co., Ltd.) having a substrate layer 35 of 15 μm thick and unstretched polypropylene (trade name, manufactured by Showa Denko KK) having a thickness of 50 μm. : Showrex Aroma U) was laminated using a two-component curable urethane-based dry laminate adhesive for retort.

  Further, in order to produce the other laminated film 32 as a pair, the base material layer 35 is an ON film (trade name: Emblem manufactured by Unitika Co., Ltd.) having a thickness of 15 μm, and an unstretched polypropylene of delamination type having a thickness of 50 μm ( Showa Denko Co., Ltd., trade name: Showrex Aroma TP11) was laminated using a two-component curable urethane dry laminate adhesive for retort.

  Moreover, in order to provide oxygen barrier properties to both laminated films 31 and 32, a polyester film (made by Toppan Printing Co., Ltd.) on which the inner surface is subjected to alumina deposition as the outermost layer on the outer side of the ON film as the base material layer 35. Trade name: GL-AEH) (thickness 15 μ).

  A flat bag 110 with a zipper as shown in FIG. 3 was manufactured using the above-described laminated films 31 and 32 by a four-side sealed bag making machine incorporating a zipper attachment device.

  The outer dimensions of the bag 110 were a width L3 of 130 mm, a length L4 of 180 mm, and a seal width L5 of each side of 7 mm. Moreover, the polypropylene zipper 1 was attached to the innermost layer surface at a position 2 cm from the opening end 21 in use by heat sealing.

  The welding of the peeling part 23 inside the zipper 1 was heat-sealed with a heat-seal bar having a width of 5 mm.

  Regarding the processing of the fragile portion 24a on the opening end 21 side of the welded portion 23, a protrusion is provided on the edge portion on the zipper side of the heat seal bar described above, and the original thickness of the first layer 34a of the delamination-type heat-weldable film. 50% thinner than 20 μm and processed to 10 μm to facilitate breakage.

  About the process of the weak part 24b below the welding part 23, it moves up and down with the above-mentioned bag making machine with an air cylinder so that it may be half-cut from the inner edge part of the bag of the 5 mm wide heat seal bar to 5 mm. A cutter blade was installed, the timing was controlled by electric control, and processing was carried out so that the depth was 20 μm and the length was 1.5 mm ± 0.5 mm before the side seal by the bag making machine.

  In the flat bag 110 with the zipper thus prepared, (1) tap water, (2) blended sauce (salad oil: vinegar: tomato ketchup = 1: 1: 1), (3) commercially available base sauce for cooking ( 4 types of doughgrass sauce and retort pouch), (4) Commercially boiled whole corn (canned) filled from the opening 26 at the bottom of the bag, sealed, and subjected to retort treatment at 120 ° C for 30 minutes Got a packaging bag.

For each of the obtained packaging bags, (a) the peel strength of the welded portion against the force applied from the inside of the bag, (b) the peel strength of the welded portion when opened from the opening end side, (c) the compression strength, d) Drop strength, (e) Zipper stain, (f) Appearance were tested and evaluated as follows. In addition, these tests tested 10 each about the same kind of packaging bags, and calculated | required the average value.
(a) Peel strength of welded part against force from inside of bag JIS-Z-0238 “Test method for sealed flexible packaging bag” was tested.

(b) Peel strength of welded part when opening from open end side JIS-Z-0238 “Test method for sealed soft packaging bags” was tested.

(c) Compressive strength The test was conducted according to JIS-Z-0238 “Test method for sealed soft packaging bags” and evaluated according to the following criteria.

○: 400N (40kg) or more ×: Less than 400N (40kg)

(d) Drop strength Tested according to JIS-Z-0238 “Test method for sealed soft packaging bags” and evaluated according to the following criteria.

○: No leakage at drop height of 50cm ×: Leakage at drop height of 50cm

(e) Dirt on the zipper part The following criteria are based on the presence or absence of dirt on the zipper part due to the contents penetrating the welded part inside the zipper in the above tests (c) and (d) and reaching the zipper. It was evaluated with.

○: No dirt ×: Dirt

(f) Appearance The appearance (wrinkle, deformation, etc.) of the packaging bag when the packaging bag filled with the contents was sterilized by retort (heat treatment 120 ° C., 30 minutes) was evaluated according to the following criteria.

○: Appearance is good enough not to hinder commercialization ×: Appearance is bad enough to hinder commercialization

The results are as shown in Table 1, and the packaging bag of this example has a peel strength at the welded portion that is remarkably large with respect to the force from the inside of the bag. The strength of the bag and the good opening of the bag body were both compatible. Neither spilled contents nor soiled hands when opening the bag body.

  The zippered packaging bag of the present invention can be used when the contents are boiled and retort processed, and also loaded and transported during distribution, and is widely used as a packaging bag for foods and daily necessities. can do.

  In particular, high sealing strength is required in terms of distribution due to the properties of the contents, retort processing conditions, bag size, etc., but this is suitable when easy-openability is required.

It is a perspective view at the time of sealing of the packaging bag with a zipper of an Example. It is sectional drawing at the time of sealing of the packaging bag with a zipper of FIG. 1A. It is sectional drawing at the time of opening of the packaging bag with a zipper of FIG. 1A. It is sectional drawing of the welding part vicinity of the packaging bag with a zipper of FIG. 1A. It is sectional drawing of the welding part vicinity at the time of the internal pressure rise of the packaging bag with a zipper of FIG. 1A. It is sectional drawing of the welding part vicinity at the time of opening of the packaging bag with a zipper of FIG. 1A. It is a top view of the flat bag produced in the Example. It is sectional drawing of the packaging bag with a zipper of another Example. It is sectional drawing of the welding part vicinity at the time of the internal pressure rise of the packaging bag with a zipper of FIG. 4A. It is sectional drawing of the welding part vicinity at the time of opening of the packaging bag with a zipper of FIG. 4A. It is sectional drawing at the time of sealing of the packaging bag with a zipper of another Example. It is sectional drawing of the welding part vicinity at the time of the internal pressure rise of the packaging bag with a zipper of FIG. 5A. It is sectional drawing of the welding part vicinity at the time of opening of the packaging bag with a zipper of FIG. 5A. It is sectional drawing of the packaging bag with a zipper of another Example. It is sectional drawing of the welding part vicinity at the time of opening of the packaging bag with a zipper of FIG. 6A. It is a perspective view at the time of sealing of the packaging bag with a zipper of another Example. It is sectional drawing at the time of sealing of the packaging bag with a zipper of FIG. 7A. It is a perspective view at the time of sealing of the conventional packaging bag with a zipper. It is sectional drawing of the opening part vicinity of the state which the zipper closed with the conventional packaging bag with a zipper. It is sectional drawing of the opening part vicinity of the state which the zipper opened with the conventional packaging bag with a zipper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Zipper 20 Bag main body 21 Open end 22 Heat welding sealing part 23 Welding part 23a Welding part upper end part 23b Welding part lower end part 24a Fragile part near the upper end part of welding part 24b Fragile part 31, 31a below the welding part, 31b Laminated film 32 Laminated film (having a peeling surface inside)
33 heat-weldable layer 34 heat-weldable layer (delamination-type heat-weldable film)
34a First layer (peeling layer)
34b Second layer (surface layer)
35 substrate layer 36 adhesive 37 release surface 38 delamination-type heat-weldable film tape 38a first layer of delamination-type heat-weldable film tape 38b second layer of delamination-type heat-weldable film tape 38c delamination-type heat Upper end portion of weldable film tape 38d Lower end portion of delamination type heat weldable film tape 39 Hot weldable film tape 39a Upper end portion of heat weldable film tape 39b Lower end portion of heat weldable film tape 40 Release surface 101 of film tape , 102, 103, 104, 105 Packaging bag with zipper of the present invention 110 Flat bag A Contents L1 Width of welded portion L2 Distance between zipper and welded portion L3 Bag width L4 Bag length L5 Seal width

Claims (7)

A bag body formed by facing and thermally welding the heat-weldable layer of the laminated film having a heat-weldable layer on the surface, and a zipper that opens and closes the opening of the bag body,
A zippered packaging bag in which the open end of the bag body located above the zipper is closed,
On the inner side of the zipper, it has a welding part that divides the inside of the bag body into a zipper side and a content storage part side,
At least in the region extending from the upper end of the welded portion to the lower portion of the welded portion, a release surface for opening the welded portion is formed in one laminated film, and the thermal welding on the peeled surface is near the upper end of the welded portion. The fragile part is formed in the adhesive layer, or the upper end part of the peeling surface is located in the vicinity of the upper end part of the welded part, and the fragile part is formed in the heat-weldable layer on the peeling surface below the welded part. Or a zippered packaging bag in which the lower end portion of the peeling surface is located below the welded portion.   One of the laminated films facing the bag body consists of a laminated film of a base film and a delamination-type heat-weldable film, and a fragile portion is formed near and below the upper end of the delamination-type heat-weldable film. The packaging bag with a zipper according to claim 1.   The packaging bag with a zipper according to claim 1 or 2, wherein the fragile portion is formed by cutting, half-cutting or thinning the heat-weldable layer.   The packaging bag with a zipper according to claim 1, wherein a delamination-type heat-weldable film tape is solidly welded to one surface of the opposite laminated film from the upper end portion of the welded portion to the lower side of the welded portion.   2. A film tape having a release surface on one surface of a facing laminated film from the upper end of the welded portion to the lower side of the welded portion is adhered to a solid surface with the peeled surface facing the laminated film. The packaging bag with a zipper as described.   The weak part formed in the upper end part vicinity of the welding part, or the upper end part of the peeling surface located in the upper end part vicinity of the welding part exists in the distance within 8 mm from the upper end part of a welding part. Packaging bag with zipper according to crab. The fragile part formed below the welded part, or the lower end part of the peeling surface located below the welded part is at a distance of 3 to 20 mm from the lower end part of the welded part. Packaging bag with zipper.

Images