JP2005144757A - Bag made of widely heat-sealed straight chain low density polyethylene resin laminated film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bag made of a wide heat-sealed straight chain low density polyethylene resin laminated film having a heat-sealing width of 5-20 mm. <P>SOLUTION: The bag made of the widely heat-sealed straight chain low density polyethylene resin film is constituted by heat-sealing a laminated film constituted of a laminated film, which is obtained by laminating an outer layer (A) comprising a straight chain low density polyethylene resin film with a density of 0.929 g/cm<SP>3</SP>or above and an inner layer (B) comprising an ultralow density straight chain low density polyethylene resin film with a density of 0.907 g/cm<SP>3</SP>or below and characterized in that the temperature difference between the melting point of the resin of the outer layer (A) and that of the resin of the inner layer (B) is 30-50°C, so that a heat-sealing width is 3.5 mm or above and forming the same into a bag shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a linear low density polyethylene resin laminated film bag heat-sealed with a wide width of a heat seal width of 3.5 mm or more. More specifically, the heat seal temperature can be easily adjusted even when heat-sealing with a wide width, and the film surface at the seal edge portion does not leave a melt mark (resin thinning) due to heat, and a beautiful seal finish is obtained. The present invention relates to a linear low-density polyethylene resin laminated film bag heat-sealed with a wide width of 3.5 mm or more.

  Conventionally, bags made of a low density polyethylene resin film (LDPE) have been widely used in packaging of various lightweight foods such as bread and confectionery because they are excellent in transparency, soft in touch and easy to heat seal. .

  However, such low-density polyethylene resin film (LDPE) bags have been used in the packaging of heavy items such as heavy rice bags and cement bags, although their tensile strength is weak.

  In addition, when heat-sealing a linear low-density polyethylene resin film (LLDPE), a bag with moderate heat-sealing strength can be obtained with ambiguous heat-sealing temperature adjustment compared to low-density polyethylene resin (LDPE). It was difficult.

  In addition, regarding the co-extruded film obtained by multilayering, if the difference between the fusion temperature of the sealing surface and the melting temperature of the film surface is less than 10 ° C., the sealing portion is sealed before the sealing portion reaches a sufficient adhesion temperature. Since the part melts, the adjustment of the heat seal temperature control becomes more difficult as the heat seal width is increased, and it is often impossible to perform heat seal due to edge breakage at the time of heat seal.

  Therefore, in a normal heat seal, the heat seal width is 1.5 to 2.5 mm, and even if the heat seal width is widened to the maximum, the limit is about 3 mm. It was extremely difficult to increase the breaking strength of the part.

  Therefore, although the linear low density polyethylene resin film (LLDPE) itself has a high tensile strength and the like, in the case of forming a bag by heat sealing, the width of the heat sealed joint portion is narrow, so the heat sealing Since it lacks reliability, it was difficult to obtain a bag with sufficient adhesive strength.

  In addition, it is possible to maintain the shape stability of the bag in a bag that is bent at the bottom and heat-sealed on both sides and the bottom with a wide width. There was a problem that it could not be kept.

  On the other hand, bags using nylon / LLDPE laminated film in which nylon film and linear low density polyethylene resin film (LLDPE) are laminated have high tensile strength, sufficient sealing strength, and easy temperature control for wide heat sealing. Therefore, it is the mainstream as this type of bag and is widely used (for example, see Non-Patent Document 1).

  However, the bag using the nylon / LLDPE laminated film is expensive because the nylon film is expensive, and the laminated film is also expensive.

  In addition, bags made of nylon / LLDPE laminated film in which this nylon film and linear low-density polyethylene resin film (LLDPE) are laminated defrosted frozen cocoons because the nylon film is gas barrier. In this case, the red color of the salmon is difficult to develop, so that it was not sufficient as a bag for freezing storage of the salmon for Negitro.

In order to improve curl resistance, rigidity, low-temperature heat sealability, water vapor barrier properties, fragrance retention, hygiene, heat resistance, heat seal strength, and puncture strength, a straight chain having a density of 0.94 g / cm ³ or less. Low density polyethylene resin film (LLDPE) layer (I), a polyolefin-based resin material layer (II) having a flexural modulus of 2,500 kgf / cm ² or more, and a linear shape having a density of 0.94 g / cm ³ or less A laminate having at least a three-layer structure with a low density polyethylene resin film (LLDPE) layer (III) has been proposed (see, for example, Patent Document 1).

However, the laminate having such a three-layer structure uses a linear low-density polyethylene resin film (LLDPE) in which the outer layer (I) and the inner layer (III) have the same density in the examples. It is difficult to increase the heat seal strength, and furthermore, since heat sealing is performed using a heat seal tester with a seal bar width of 1 mm, a wide-width heat-sealed linear low-density polyethylene resin laminate Film bags were never made.
JP 2002-52669 A “Latest Functional Packaging Encyclopedia”, pp. 571-577, Publisher: Keisuke Ono, Publisher: Fuji Techno System Co., Ltd., Date of issue: August 1, 1994

  As described above, in the present invention, the joint portion heat-sealed with a wide width has high heat-sealing reliability and sufficient adhesive strength, and the heat-sealing temperature can be easily adjusted even when heat-sealing. In addition, the film surface of the seal edge portion of the heat-sealed linear low-density polyethylene resin film bag does not leave a melt mark (resin thinning) due to heat, and can have a beautiful seal finish. In order to obtain a bag made of a linear low density polyethylene resin film.

As a result of intensive research in view of the above problems, the present inventor has produced a linear low-density polyethylene resin film (LLDPE) by heat-sealing with a wide width of a heat seal width of 3.5 mm or more. In the density polyethylene resin laminated film bag making, since the width of the heat-sealed joint portion is wide, in order to obtain a bag having high heat-sealing reliability and sufficient adhesive strength, a density of 0.929 g / and cm ³ or more linear outer layer of low density polyethylene resin film (LLDPE) (a), an inner layer of a density 0.907 g / cm ³ or less of ultra low density linear low density polyethylene resin film (LLDPE) (B ) And a melting point of the resin used for the outer layer (A) using a linear low density polyethylene resin laminated film (LLDPE) having at least a two-layer structure. In which the temperature difference between the melting point of the resin used in the inner layer (B) has completed the present invention based on the finding that can be achieved by a range of 30 to 50 ° C..

That is, the wide-width heat-sealed linear low-density polyethylene resin film bag of the present invention has an outer layer (A) composed of a linear low-density polyethylene resin film having a density of 0.929 g / cm ³ or more, a density The outer layer (A) is composed of a laminated film of at least two layers formed by laminating an inner layer (B) made of an ultra-low density linear low density polyethylene resin film of 0.907 g / cm ³ or less. The linear low-density polyethylene resin laminated film having a temperature difference between the melting point of the resin used for the inner layer (B) and the melting point of the resin used for the inner layer (B) in the range of 30 to 50 ° C. is widened to a heat seal width of 3.5 mm or more. It is heat-sealed and formed into a bag shape.

  Since the linear low-density polyethylene resin laminated film bag heat-sealed with such a wide width is made of a linear low-density polyethylene resin laminated film, it is inexpensive and wide with a heat seal width of 3.5 mm or more. The heat sealing temperature can be easily adjusted during heat sealing at the same time, and the melt surface (resin thinning) due to heat is applied to the film surface at the sealing edge of the heat sealed linear low density polyethylene resin laminated film bag. ) And a beautiful seal finish.

  In addition, the linear low-density polyethylene resin laminated film bag that is bent at the bottom and heat-sealed on both sides and the bottom with a wide width has ribs formed on the three sides of the bag, and has shape stability. Therefore, it is ideal as a liquid container for refilling, because the contents of liquid etc. are put in, so it is most suitable as a liquid container for refilling. Since it is easy to grasp the side portion and the suitability for automatic filling is improved, it is optimal as a bag for automatic filling, and since it is oxygen permeable, it can also be used as a bag for freezing storage for Negitro.

[I] Wide, heat-sealed linear low-density polyethylene resin laminated film bag
(1) Structure The wide-width heat-sealed linear low-density polyethylene resin laminated film bag of the present invention comprises an outer layer (A) made of linear low-density polyethylene resin laminated film (LLDPE) having different densities. It consists of a film having at least a two-layer structure formed by laminating the inner layer (B), and the temperature difference between the melting point of the outer layer (A) resin and the melting point of the inner layer (B) resin is in the range of 30 to 50 ° C. is there.

(A) Outer layer (A)
The linear low density polyethylene resin film (LLDPE) used for the outer layer (A) has a density of 0.929 g / cm ³ or more, preferably 0.930 to 0.945 g / cm ³ , particularly preferably 0.935. It is necessary to use a relatively high-density linear low-density polyethylene resin film (LLDPE) of ˜0.945 g / cm ³ .

  If the density of the linear low-density polyethylene resin film (LLDPE) is less than the above range, the heat resistance is inferior, making it difficult to adjust the heat seal temperature, and the heat received from the seal bar causes melting and fusion problems. . Moreover, when the thing exceeding the said range is used, there exists a tendency for the problem on a shaping | molding process to arise easily.

However, as the density used in the outer layer (A) is 0.929 g / cm ³ or more linear low density polyethylene resin film (LLDPE), density of 0.929 g / cm ³ or more linear low density polyethylene Although the resin (LLDPE) may be a single film, the low density polyethylene resin (LDPE) is contained in an amount of 20% by weight or less, preferably 5 to 5% for the purpose of improving physical properties such as molding processability and optical properties. It is preferable to use those added in the range of 15% by weight, particularly preferably 8 to 12% by weight.

(B) Inner layer (B)
The linear low density polyethylene resin film (LLDPE) used for the inner layer (B) has a density of 0.907 g / cm ³ or less, preferably 0.907 to 0.898 g / cm ³ , particularly preferably 0.903. It is necessary to use an ultra low density linear low density polyethylene resin film (LLDPE) of ˜0.901 g / cm ³ .

  When the ultra low density linear low density polyethylene resin film (LLDPE) used here has a density exceeding the above range, a problem arises in the low temperature seal initiation performance. Further, if a material less than the above range is used, there is a tendency that a problem is likely to occur in molding stability.

However, the density used in the outer layer (B) is 0.903 g / cm ³ or less of ultra low density linear low density polyethylene resin film (LLDPE) has a density of 0.903 g / cm ³ or less of very low density A straight-line low-density polyethylene resin (LLDPE) alone film may be used, but for the purpose of improving physical properties such as molding processability and blocking resistance, 20 low-density polyethylene resin (LDPE) is used. It is preferable to use those added in an amount of not more than wt%, preferably 5 to 15 wt%, particularly preferably 8 to 12 wt%.

(C) Middle layer (C)
An intermediate layer (C) made of various materials is required between the outer layer (A) and the inner layer (B) for the purpose of increasing impact resistance and improving stiffness, transparency, economy, etc. Can be used.

The film used for the intermediate layer (C), for example, density of 0.907 g / cm ³ exceeded ~0.929g / cm less than ^3, preferably 0.910~0.927g / cm ^3, particularly preferably 0. List 912 to 0.925 g / cm ³ linear low density polyethylene resin (LLDPE) film, low density polyethylene resin film (LDPE), ethylene / vinyl acetate copolymer resin (EVA) film, etc. Can do. These particular the density among films it is desirable to use a 0.907 g / cm ³ exceeded ~0.929g / cm ³ less than the linear low density polyethylene resin film (LLDPE).
These intermediate layers (C) do not need to be a single layer, and may be a laminate of various materials. However, preferably the density in was used alone layer of 0.907 g / cm ³ exceeded ~0.929g / cm ³ less than the linear low density polyethylene resin film (LLDPE) as the intermediate layer (C) an outer layer (A) It is desirable to have a three-layer structure of / intermediate layer (C) / inner layer (B).

(2) Temperature difference of melting point The melting point of a relatively high-density linear low-density polyethylene resin having a density of 0.929 g / cm ³ or more used for the outer layer (A) and the density used for the inner layer (B) A low-temperature linear low-density polyethylene resin having an extremely low density of 0.903 g / cm ³ or less having a melting point temperature difference of 30 to 50 ° C., preferably 35 to 49 ° C., particularly preferably 40 to 48 ° C. It is necessary to use it.

  If the temperature difference between the melting points of the linear low-density polyethylene resin used for the outer layer (A) and the inner layer (B) is less than the above range, the low temperature sealing start temperature and the heat-related thermal condition are not satisfied, There arises a problem that the surface layer is melted and fused by the seal bar. Further, if the temperature exceeds the above range, a problem in molding processing occurs.

(3) Layer structure A linear low-density polyethylene resin laminated film bag made of a laminated film having at least a two-layer structure of the outer layer (A) and the inner layer (B) has an outer layer (A) as a layer structure of the bag. The thickness is 15 to 100 μm, preferably 20 to 50 μm, particularly preferably 25 to 40 μm, and the inner layer (B) is 5 to 50 μm, preferably 8 to 40 μm, particularly preferably 10 to 30 μm.

  When the layer structure is less than the above range or exceeds the above range, a wide heat seal tends to be difficult to perform.

  Moreover, as an intermediate | middle layer (C) used as needed, generally 1-150 micrometers, Preferably it is 10-100 micrometers, Most preferably, the thing of 20-50 micrometers is used.

  Therefore, such a linear low density polyethylene resin laminated film is a laminated film having a thickness of generally 20 to 300 μm, preferably 30 to 200 μm, particularly preferably 40 to 120 μm.

(4) Shape The linear low-density polyethylene resin laminated film bag made by heat-sealing according to the present invention is a rectangular bag in which one end side of a tubular film obtained by inflation molding is heat-sealed, or T A square bag that is heat-sealed on three sides by overlapping films formed by die molding or the like, or a square bag that is heat-sealed on two sides by folding a film molded by T-die molding, etc. In addition, a so-called stand pouch-type bag or the like in which three sides of the bottom are heat-sealed with a wide width can be given.

  Of these, bags that are folded at the bottom and heat-sealed on both sides and the bottom are wide, so that the wide heat-sealed part has ribs formed on the three sides of the film-like container, so that the shape is stable. Since the self-supporting property is increased even when contents such as liquid are added, it is optimal as a liquid container for refilling.

(5) Wide heat seal
(A) Heat-seal width The heat-sealed joint portion of the linear low-density polyethylene resin laminated film bag formed by heat-sealing with the above wide width has a heat-seal width of 3.5 mm or more, preferably 4 to 50 mm, particularly A heat seal of 5 to 30 mm is preferable.

(B) Shape The shape of the heat-sealed part that has been heat-sealed in the above-mentioned width has a beautiful sealing finish without leaving any melt marks (resin thinning) due to heat on the film surface of the seal edge part.

(6) Physical properties Since the wide and heat-sealed linear low density polyethylene resin laminated film bag of the present invention is basically composed of a linear low density polyethylene resin laminated film, It is gas permeable and can permeate oxygen.

  Therefore, it is oxygen permeable compared to a bag using a nylon / LLDPE laminate film in which a nylon film and a linear low density polyethylene resin film (LLDPE) are laminated. In addition, the red color of salmon tends to appear, so it is excellent as a bag for frozen storage of salmon for Negitro.

In order to be used as a bag for freezing storage of such Negitro bags, oxygen gas permeability is generally 500 to 40,000 cc / m ² · day, preferably 1,000 to 20,000 cc / m ² · day, especially Those having 1,500 to 10,000 cc / m ² · day are preferred.

(7) Applications The wide and heat-sealed linear low-density polyethylene resin laminated film bags of the present invention can be formed as bags of various shapes and used as various containers, but as described above, A linear low-density polyethylene resin film bag with at least three sides heat-sealed is wide, and the wide heat-sealed part looks like ribs are formed on the three sides of the film-like container. The so-called stand pouch-type bag, which is improved and is heat-sealed in the three sides of the side and bottom, is highly self-supporting even when contents such as liquid are put in it. Can be used as optimal.

  By using it as a bag for frozen storage of salmon, when the frozen salmon is thawed, the red color of the salmon tends to appear, so it is most suitable as a bag for frozen storage of Negitro.

[II] Production of linear low density polyethylene resin laminated film bags
(1) Production of a film having at least a two-layer structure In order to produce a wide, heat-sealed linear low-density polyethylene resin laminated film bag according to the present invention, a linear film having a density of 0.929 g / cm ³ or more. A low-density polyethylene resin film (LLDPE) and an ultra-low-density linear low-density polyethylene resin film (LLDPE) having a density of 0.907 g / cm ³ or less have a density used as an intermediate layer (C) of 0 if necessary. laminate film of at least two-layer structure .907g / cm ³ exceeded ~0.929g / cm ³ less than the linear low density polyethylene resin film (LLDPE) are laminated is used.

  It is important that these at least two-layered films have a temperature difference between the melting points of the two resins of 30 to 50 ° C.

(2) Film lamination To produce a wide-width heat-sealed linear low-density polyethylene resin film bag, a cylindrical film obtained by inflation molding is sandwiched between rolls and the laminated body is cut. The laminated body obtained by the above, or the laminated body obtained by superposing the film formed by T-die molding or the like and cutting the three sides, or the film molded by T-die molding or the like is bent and both ends are heat-sealed. A laminated body etc. can be mentioned.

  The linear low density polyethylene resin laminated film laminated in this manner is a laminated film having a thickness of generally 20 to 300 μm, preferably 30 to 200 μm, particularly preferably 40 to 120 μm.

(3) Wide and heat-sealing In the present invention, it is important to heat-seal with a wide width.

(A) Heat seal condition The heat seal with a wide width in the present invention is a heat seal having a heat seal width of 3.5 mm or more, preferably 4 to 50 mm, particularly preferably 5 to 30 mm.

  By heat-sealing with such a wide width, the width of the heat-sealed joint is widened, and a bag with sufficient strength can be obtained.

  When the heat seal width is less than the above range, a problem of bag shape stability occurs. Moreover, when the said range is exceeded, the problem that a uniform heat seal will become difficult arises.

(B) Wide-width heat-sealing device As the wide-width heat-sealing device for performing heat-sealing at a wide width, for example, a product name “BH-” manufactured by Totani Giken Kogyo Co., Ltd. having a heat-sealing bar width of 5 to 50 mm. The apparatus for wide heat sealing of “60HVL bag making machine” is used.

  The present invention will be described more specifically with reference to the following examples and comparative examples.

[I] Evaluation method
(1) Resin density The density of the resin in the present invention is a value measured by the method of JIS K6760.

(2) Melting | fusing point of resin The measurement of melting | fusing point of resin in this invention is a value measured by the method of JISK7121.

(3) MFR
The measurement of the melt flow rate (MFR) of the resin in the present invention is a value measured by the method of JIS K6760.

(4) Heat seal strength The measurement of the heat seal strength in the present invention was carried out by using a test piece obtained by making a sample using HEAT-SEAL TESTER (TP-701-13) manufactured by Tester Sangyo Co., Ltd. according to JIS Z1711. The value measured by the method.

(5) Evaluating the ease of adjusting the heat seal temperature For the ease of adjusting the heat seal temperature, the seal measurement results when making a bag with the product name “FP35V2 bag making machine” manufactured by Totani Giken Kogyo Co., Ltd. The ease of the set temperature adjusted below was evaluated.

(6) Shape stability The shape stability in the present invention was evaluated based on whether or not the opening was twisted when the ear portion of the three-side sealed bag was grasped and the contents were filled in the bag.

  It was evaluated as good that there was no twist in the opening.

(7) Evaluation about heat-sealed state after heat-sealing About the heat-sealed state after heat-sealing, the presence or absence of the melt mark (resin thinning) by heat was evaluated visually.

(8) Evaluation of automatic filling suitability The automatic filling suitability was evaluated by the workability of automatic filling using a vacuum automatic filling machine (FVF-8-260N) manufactured by Furukawa Seisakusho.

  It was considered good that it could be filled without any work defects.

[II] Examples and Comparative Examples
Example 1
(1) Production of a linear low density polyethylene resin (LLDPE) film having a three-layer structure A linear low density having a density of 0.935 g / cm ³ , a melt flow rate (MFR) of 3.5, and a melting point of 126 ° C. Biaxially, 90 parts by weight of a density polyethylene resin (LLDPE) and 10 parts by weight of a low density polyethylene resin (LDPE) having a density of 0.927 g / cm ³ , a melt flow rate (MFR) of 1.0 and a melting point of 117 ° C. A molten resin composition (A) melt-kneaded by an extruder, a linear low-density polyethylene resin (LLDPE) 100 having a density of 0.925 g / cm ³ , a melt flow rate (MFR) of 1.7, and a melting point of 123 ° C. A molten resin composition (C) obtained by melting and kneading parts by weight with an extruder, and a straight chain having a density of 0.903 g / cm ³ , a melt flow rate (MFR) of 2.0, and a melting point of 85 ° C. A molten resin composition (B) obtained by melt-kneading 10,000 ppm of AB agent and 2,000 ppm of SL agent with a twin-screw extruder to 100 parts by weight of a low-density polyethylene resin (LLDPE) is supplied to the die, and the outer layer A linear low density polyethylene resin (LLDPE) laminated film having a three-layer structure of (A): 30 μm / intermediate layer (C): 40 μm / inner layer (B): 20 μm was molded.

(2) Production of a linear low density polyethylene resin laminated film bag by heat sealing in a wide width Next, the inner layers (B) of the linear low density polyethylene resin (LLDPE) laminated film having this three-layer structure are joined together. Overlaid and heat-sealed with a wide width under the following conditions, a wide-width heat-sealed linear low density polyethylene resin laminated film bag was produced.

(3) 設定温度とシール強力との測定結果
上記広幅でのヒートシールによる上シールバーの設定温度とシール強力との関係を測定した結果を表２に示す。

表２の結果から図１を作成し、図１に示す安定したシール強力を発現開始する温度３とシールバーの熱によって溶融開始する温度４との間隔が広いことから、ヒートシール温度の調整が容易であることが確認できた。 Heat seal pressure: 0.2 MPa,
Heat sealing time: 2.0 seconds,
Heat seal bar width: 15mm
Set temperature of upper seal bar: Temperature shown in Table 2 (° C)
Lower seal bar set temperature: 80 ° C

(3) Measurement results of set temperature and seal strength Table 2 shows the results of measuring the relationship between the set temperature of the upper seal bar and the seal strength by heat sealing with the above wide width.

FIG. 1 is created from the results in Table 2, and since the interval between the temperature 3 at which the stable sealing strength shown in FIG. 1 starts to develop and the temperature 4 at which the melting starts by the heat of the seal bar is wide, adjustment of the heat seal temperature is possible. It was confirmed that it was easy.

  Moreover, the bag was excellent in shape stability because both sides and the bottom were heat-sealed with a wide width. Further, Table 2 shows the results of visual evaluation of the state of the heat seal portion of the bag after heat sealing.

  When the bag made of the linear low-density polyethylene resin laminated film heat-sealed with the above-mentioned wide width was evaluated with an automatic filling machine, it was easy to grasp the side-surface portion of the bag because the side-surface portion was heat-sealed with a wide width. Therefore, it was a bag excellent in automatic filling suitability.

Example 2
It implemented similarly to Example 1 except having changed into resin shown in Table 1. FIG.

  The results are shown in Table 2.

Comparative Example 1
It implemented similarly to Example 1 except having changed into resin shown in Table 1. FIG.

  The results are shown in Table 2.

  Since the linear low-density polyethylene resin film bag heat-sealed with a wide width of the present invention is made of a linear low-density polyethylene resin film, it is inexpensive and has a wide width of a heat seal width of 3.5 mm or more. It is easy to adjust the heat sealing temperature during heat sealing, and heat melt marks (resin thinning) are left on the film surface at the sealing edge of the heat sealed linear low density polyethylene resin film bag. It is possible to achieve a beautiful seal finish.

  In addition, the linear low-density polyethylene resin film bag that is bent at the bottom and heat-sealed on both sides and the bottom with a wide width is shaped like a rib on the three sides of a film-like container. As stability increases, it becomes highly self-supporting even when contents such as liquid are put in. Therefore, it is ideal as a liquid container for refilling and useful as a bag for freezing storage of bag for Negitro. Therefore, it is extremely useful industrially.

FIG. 1 is a diagram illustrating the relationship between the set temperature of the upper seal bar of Table 2 of Example 1 and the seal strength. FIG. 2 is a diagram illustrating the relationship between the set temperature of the upper seal bar of Table 2 in Example 2 and the seal strength. FIG. 3 is a diagram showing the relationship between the set temperature of the upper seal bar of Table 2 in Example 3 and the seal strength. FIG. 4 is a diagram illustrating the relationship between the set temperature of the upper seal bar of Table 2 in Example 4 and the seal strength. FIG. 5 is a diagram illustrating the relationship between the set temperature of the upper seal bar of Table 2 of Comparative Example 1 and the seal strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer surface layer 2 Inner surface layer 3 Temperature which starts expression of stable seal strength 4 Temperature which starts melting by heat of seal bar 5 Temperature which linear low density polyethylene resin of general-purpose density starts expression of seal strength stably

Claims (7)

Density 0.929 g / cm ³ or more linear low density of polyethylene resin film layer (A), density 0.907 g / cm ³ or less of ultra low density linear low density of polyethylene resin film inner layer ( And a temperature difference between the melting point of the resin used in the outer layer (A) and the melting point of the resin used in the inner layer (B) is 30 to 50. It is heat-sealed in a wide width, characterized by being formed into a bag shape by heat-sealing a linear low density polyethylene resin laminated film that is in the range of ° C. with a wide width of a heat seal width of 3.5 mm or more. A linear low density polyethylene resin laminated film bag. Was formed as the outer layer linear low density polyethylene resin (LLDPE) intermediate layer a film density of less than 0.907 g / cm ³ exceeded ~0.929g / cm ³ to between (A) and inner layer (B) (C) A wide, heat-sealed linear low-density polyethylene resin laminated film bag according to claim 1.   The wide-width heat-sealed linear low-density polyethylene resin laminated film bag according to claim 1 or 2, wherein the heat-sealing width is in the range of 4 to 50 mm.   The wide and heat-sealed linear low-density polyethylene resin laminated film bag according to any one of claims 1 to 3, wherein the bottom portion and both end portions are heat-sealed to increase the shape stability.   The wide-width heat-sealed linear low-density polyethylene resin laminated film bag according to any one of claims 1 to 4, wherein the thickness of the resin laminated film is 20 to 300 µm.   The outer layer (A) is a linear low density polyethylene resin (LLDPE) containing a low density polyethylene resin (LDPE) in a proportion of 5 to 15% by weight. Heat-sealed linear low density polyethylene resin laminated film bag.   A wide, heat-sealed linear low-density polyethylene resin laminated film bag according to any one of claims 1 to 6, which is a bag for frozen storage.

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