JP7426069B2 - Packaging materials and packaging using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to packaging materials, particularly to easily tearable packaging materials and packaging bodies using the same.

Although various materials are used as packaging materials, nonwoven fabrics are sometimes used to accommodate changes in the shape of packaged articles and to allow the contents to be seen through. Nonwoven fabrics are suitable for encapsulating soft articles because they can be heat-sealed and hermetically packaged. However, nonwoven fabrics have the disadvantage that they are difficult to tear when opened. Furthermore, since the nonwoven fabric is made of fibers, it is difficult to achieve uniform heat-sealing.

JP 2016-203594A (Patent Document 1) discloses a stretched laminate having an unstretched layer made of a resin composition containing a polyolefin resin and a polyolefin/polystyrene elastomer on one side of a polyolefin nonwoven fabric. A composite sheet is disclosed. This composite sheet is also difficult to unwrap as it is difficult to tear the non-woven fabric.

Japanese Patent Application Publication No. 2016-203594

The present invention provides a packaging material that can be easily torn when opened, and a packaging body using the same.

That is, the present invention provides the following aspects:
[1]
A polyolefin resin is coated on one side of a spunbond nonwoven fabric made of a core-sheath composite filament whose sheath is a polyolefin polymer and whose core is a thermoplastic polymer with a melting point higher than that of the polyolefin polymer in the sheath. The spunbond nonwoven fabric is made up of laminated layers and has a thermocompression bonded part, and the thermocompression bonding part changes the fiber form by melting or softening the polyolefin polymer in the sheath of the core-sheath composite filament. A packaging material in which maintained core parts are adhered to each other, and a continuous concave thermocompression bonded part surrounds a non-thermocompression bonded part.
[2]
The packaging material according to [1], wherein the thermoplastic polymer of the core is a polyester polymer, and the melting point of the core is 30° C. or more higher than the melting point of the polyolefin polymer constituting the sheath.
[3]
The packaging material according to [1] or [2], wherein the melting point of the polyolefin resin layer is approximately the same as the melting point of the polyolefin constituting the sheath component.
[4]
The packaging material according to any one of [1] to [3], wherein the spunbond nonwoven fabric has a basis weight of 20 to 40 g/m ² .
[5]
The packaging material according to any one of [1] to [4], wherein the core-sheath type composite long fiber has a single fiber fineness of 1 to 10 decitex.
[6]
A package obtained by stacking the packaging material according to claim 1 so that the polyolefin resin layer sides face each other and heat-sealing at least the machine direction of the spunbond nonwoven fabric, wherein a cut is made in the machine direction near the heat-sealed part. A packaging body with a rounded notch.
[7]
The package according to [6], wherein the spunbond nonwoven fabric is heat-sealed not only in the machine direction but also in the transverse direction.
[8]
The package according to [6] or [7], which includes an article to be packaged.

The packaging material of the present invention is a spun core-sheath type composite continuous fiber whose sheath is made of a polyolefin polymer and whose core is made of a thermoplastic polymer having a melting point higher than that of the polyolefin polymer of the sheath. A bonded nonwoven fabric with a polyolefin resin layer laminated on one side is used, and the spunbond nonwoven fabric has a thermocompression bonding section, and the thermocompression bonding section is formed by melting the polyolefin polymer in the sheath section of the core-sheath composite filament. Alternatively, core portions that maintain their fiber form are bonded to each other by re-solidification after softening, and a continuous concave thermocompression bonded portion surrounds a non-thermocompression bonded portion. When a cut is made in the machine direction at the end of the packaging material of the present invention, it can be easily torn in the machine direction from the cut point, and it is easy to open even though the packaging material uses nonwoven fabric. . Furthermore, although the package is easy to open, it does not cause damage to the packaged item due to unnecessary tearing.

The packaging material of the present invention can be stacked so that the polyolefin resin layers face each other, an article to be packaged is inserted therein, and all openings are heat-sealed to enclose the article. Heat sealing is performed in the machine direction (MD direction) of the spunbond nonwoven fabric and in the transverse direction (CD direction) perpendicular to the machine direction (MD direction). It can be cut with just the right amount of force at the starting point. In the present invention, the packaging material refers to a material in which a spunbond nonwoven fabric and a polyolefin resin layer are laminated, and the packaging material is used to package an article, the open end is heat-sealed, and the opening is cut in the MD direction. A package with a notch is called a package.

It is not known why the tearability has improved, but when a polyolefin resin layer is laminated on a nonwoven fabric, the sheath component of the core-sheath type composite long fibers that make up the nonwoven fabric is composed of a polyolefin polymer, so the lamination At times, the polyolefins are melted and integrated, but the core portion of the core-sheath composite filaments remains in the form of fibers, and the fibers are oriented in the machine direction, making it easier to tear in that direction. In addition, the packaging material of the present invention is a spunbond nonwoven fabric, and a part of it is heat-compressed so that the polyolefin polymer in the sheath part of the core-sheath composite filament melts or softens, and the core part changes into a fiber form. It is believed that the fibers were oriented in the machine direction, making tearing easier. However, this theory alone is not sufficient to explain why, when a notch is made in the MD direction, it can be torn in the MD direction with just the right amount of force starting from the notch. Therefore, it is not limited to this theory, and it is necessary to consider other theories as well.

FIG. 1 is a diagram schematically showing a non-thermo-compression bonded portion and a thermo-compression bonded portion of a spunbond nonwoven fabric used in the packaging material of the present invention. FIG. 2 is a diagram schematically showing another embodiment of the non-thermo-compression bonded portion and the thermo-compression bonded portion of the spunbond nonwoven fabric used in the packaging material of the present invention. FIG. 3 is a schematic diagram showing the packaging material of the present invention in a bag shape.

The packaging material of the present invention is a spun core-sheath composite continuous fiber whose sheath is made of a polyolefin polymer and whose core is made of a thermoplastic polymer having a melting point higher than that of the polyolefin polymer of the sheath. This is a bonded nonwoven fabric laminated with a polyolefin resin layer.

Combinations of the polyolefin polymer in the sheath and the thermoplastic polymer with a high melting point in the core include polyolefin polymer (sheath)/polyester polymer (core), polyolefin polymer (sheath)/polyamide Examples include polyethylene polymer (core), polyethylene polymer (sheath)/polypropylene polymer (core). If a polyester polymer is selected as the core, it will have high mechanical strength. Further, the combination of polyethylene polymer (sheath)/polypropylene polymer is preferable because it has high compatibility with each other and is easy to handle. In the present invention, a core-sheath type composite long fiber composed of a polyolefin polymer (sheath)/polyester polymer (core) can be preferably used.

In the following, a spunbond nonwoven fabric consisting of a core-sheath type composite filament composed of a polyolefin polymer (sheath)/a polyester polymer (core) will be explained.

<Spunbond nonwoven fabric>
The polyester polymer constituting the core may be an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6 dicarboxylic acid, or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid. There are homopolyesters or copolyesters synthesized from these esters and diol compounds such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and cyclohexane-1,4-dimethanol as alcohol components. , paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol, bisphenol A, etc. may be added or copolymerized with the above polyester.

Examples of the polyolefin polymer constituting the sheath include aliphatic α-monoolefins having 2 to 16 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, and 1-hexene. , 1-octene, 1-dodecene, and 1-octadecene homopolyolefins or copolymer polyolefins. The aliphatic α-monoolefins may contain other olefins and/or small amounts (up to about 10% by weight of the polymer weight) of other ethylenically unsaturated monomers, such as butadiene, isoprene, pentadiene-1,3, styrene, α- It may also be copolymerized with similar ethylenically unsaturated monomers such as methylstyrene. In particular, polyethylene is preferably copolymerized with propylene, butene-1, hexene-1, octene-1, or similar higher α-olefins in an amount of up to about 10% by weight of the polymer weight.

The polyester polymer and polyolefin polymer may contain matting agents, pigments, flame retardants, deodorants, antistatic agents, antioxidants, ultraviolet absorbers, Optional additives such as antibacterial agents may be added.

The combination of the core and sheath is selected from the above-mentioned polymers with a melting point difference of 30°C or more, preferably 50°C or more. That is, a polyolefin polymer constituting the sheath portion is selected to have a melting point lower than the melting point of the polyester polymer constituting the core portion by 30° C. or more, preferably by 50° C. or more. The long fibers constituting the nonwoven fabric are integrated with each other by having thermocompression bonded parts and maintain their shape as a nonwoven fabric. The thermocompression bonding part is formed by heat embossing. In the thermocompression bonding part, the sheath part melts or softens and then re-solidifies, contributing to adhesion, but the core part is not affected by heat. It maintains its fiber form rather than melting. In this way, in the thermocompression bonded part, in order for the sheath part to melt or soften while the core part maintains its fiber form, by providing a difference in melting point between the two of 30°C or more, more preferably 50°C or more, During hot embossing, the core part is not affected by heat, and the sheath part can be reliably melted or softened and fixed by heat bonding at the thermocompression bonding part.

The core-sheath composite ratio (mass ratio) in the core-sheath type composite long fiber is preferably core/sheath = 80/20 to 50/50. By making the ratio of the core part equal to or higher than that of the sheath part, excellent mechanical properties and practical strength can be maintained. In addition, when the ratio of the core exceeds 80% by mass, the ratio of the sheath, which is an adhesive component, decreases, so the adhesive strength at the thermocompression bonding part tends to decrease, and furthermore, it tends to be easy to tear in the MD direction. Therefore, the upper limit of the ratio of the core portion is preferably 80% by mass.

The single fiber fineness of the core-sheath type composite filament is preferably 1 to 10 dtex, and the basis weight of the nonwoven fabric is preferably 20 to 40 g/m ² . By setting the single fiber fineness to 1 decitex or more, the strength of the nonwoven fabric can be maintained and the nonwoven fabric can effectively play a role of protecting the packaged articles. On the other hand, by setting the nonwoven fabric to 10 decitex or less, unevenness in the nonwoven fabric is less likely to occur, and uniform strength can be maintained. By setting the basis weight to 20 g/m ² or more, practical strength can be ensured, while by setting it to 40 g/m ² or less, it can be made to have a slightly transparent feel, so it cannot be wrapped. When an article is printed, it can be seen from the outside, making it possible to perform confirmation work on the article.

The nonwoven fabric is a spunbond nonwoven fabric and is manufactured by a spunbond method. For example, a long fiber bundle is drawn using air pressure, electrostatically opened using a method such as corona discharge, deposited on a moving collection surface to form a web, and then the fibers are integrated. to obtain a nonwoven fabric. Spunbond nonwoven fabrics are easily torn in the MD direction because many fibers (core-sheath composite filaments) in the nonwoven fabric are oriented mainly in the machine direction (MD direction). In the present invention, the spunbond nonwoven fabric has a tendency to be easily torn in the MD direction, and the nonwoven web formed into a web by being piled up is passed through a hot embossing device to perform hot embossing to create a nonwoven fabric. However, it is believed that forming a specific thermocompression bonded portion makes it more likely to be torn.

The nonwoven fabric is thermally embossed using a hot embossing roll to form a thermocompression bonded portion. is preferably formed. Although FIG. 1 shows an example in which the non-thermo-compression-bonded part has an elliptical shape and is surrounded by continuous thermo-compression-bond parts, the shape is not limited to this. For example, as shown in FIG. 2, the non-thermo-compression bonding portion may have a square shape, which may be surrounded by cross-shaped thermocompression bonding portions. The thermocompression bonding part is a state in which the polyolefin polymer in the sheath part of the core-sheath composite filament is melted or softened and then re-solidified, and the core parts that maintain the fiber form without being affected by heat are adhered to each other. In the non-thermocompression bonded part, both the core part and the sheath part are substantially unaffected by heat and maintain the form of a core-sheath composite filament. Continuous thermocompression bonded areas also improves the morphological stability of the obtained nonwoven fabric, and if the non-thermocompression bonded areas are surrounded by continuous thermocompression bonded areas, the morphological stability is good and tearing is easy. A nonwoven fabric can be obtained.

The shape of the thermocompression bonding part may be appropriately designed, and various shapes such as a circle, an ellipse, and a polygon such as a triangle or a square can be cited. Further, the area of each thermocompression bonded part is preferably about 0.2 to 2 ^mm2 , and the density of the non-thermocompression bonded part is about 15 to 70 pieces/ ^cm2 . The shape of the convex portion of the embossing roll becomes the shape of the thermocompression bonded portion formed on the nonwoven fabric, and the shape of the concave portion of the embossing roll becomes the shape of the nonthermocompression bonding portion formed on the nonwoven fabric. The ratio of the area occupied by the convex parts to the entire surface of the embossing roll (area ratio of the convex parts) is determined by the thermocompression bonded areas and non-thermocompression bonded areas (areas where fibers are simply deposited) formed on the resulting nonwoven fabric. Considering the balance, 25 to 50% is good. It is believed that by setting the amount to 25% or more, a continuous thermocompression bonded area of a certain amount or more can be formed, making it easier to tear. In addition, by setting the upper limit to 50%, the area other than the thermocompression bonded area (area where fibers are deposited) is secured in the resulting nonwoven fabric, thereby providing the nonwoven fabric with flexibility and practical mechanical strength. be able to.

As the embossing device used for hot embossing, it is preferable to use a device consisting of an embossing roll having the above-mentioned uneven engraving pattern and a flat roll.

Any agent such as an antistatic agent may be attached to the heat-embossed nonwoven fabric by coating, etc., as long as it does not impede the object of the present invention.

<Polyolefin resin layer>
A polyolefin resin layer is laminated on one side of the spunbond nonwoven fabric. Since the sheath component of the fibers constituting the spunbond nonwoven fabric is a polyolefin polymer, the resin layer to be laminated is made of a polyolefin that is highly compatible with this.

The polyolefin resin layer basically uses the same type of polyolefin as the sheath component of the core-sheath composite filament, so it will not be described again here. The polyolefins used are preferably of the same type from the standpoint of compatibility with the sheath component of the core-sheath composite filament, but different polyolefins may be used.

<Lamination method>
The spunbond nonwoven fabric and the polyolefin resin layer are created separately (for example, a polyolefin film is prepared as the polyolefin resin layer), and one side of the spunbond nonwoven fabric is heated to a temperature at which only the sheath part melts, that is, the melting point of the core part. Although lamination can be achieved by heating the resin to a temperature lower than the melting point of the sheath and pressing the two together, it is possible to extrude the polyolefin resin in a molten state onto the spunbond nonwoven fabric being conveyed from a melting die and cool it. The method of bonding and integrating by pressing between rolls is preferable because the polyolefin resin penetrates into the spunbond nonwoven fabric more and is integrated. Since the polyolefin resin layer is laminated in a molten state, the polyolefin in the sheath of the spunbond nonwoven fabric also easily softens, and the polyolefin resin layer and the spunbond nonwoven fabric adhere more tightly and become integrated, making it easy to tear. Becomes good. In addition, the polyolefin resin layer is preferably joined and integrated so that the side in contact with the flat roll becomes the side facing the polyolefin resin layer in the heat embossing process when the spunbond nonwoven fabric forms the thermocompression bonded part. In particular, when forming a polyolefin resin layer by the above-mentioned melt extrusion, the polyolefin resin easily penetrates into the spunbond nonwoven fabric, allowing for better integration and formation of a uniform layer.

<Packaging material>
As mentioned above, the packaging material of the present invention is made by laminating a polyolefin resin layer on a spunbond nonwoven fabric made of a core-sheath composite filament whose core portion is a polyester polymer and sheath portion is a polyolefin polymer. The spunbond nonwoven fabric has a thermocompression bonded portion of a specific shape (that is, a shape in which the thermocompression bonded portion surrounds the non-thermocompression bonded portion).

The packaging material of the present invention will be explained based on FIG. 3. The packaging material of the present invention is used to package various articles (not shown), that is, articles to be packaged (hereinafter referred to as "packaged articles"). The packaging material 1 of the present invention consists of a nonwoven fabric layer 2 and a polyolefin resin layer 3 laminated on one side of the nonwoven fabric layer 2. The packaging material 1 is made by overlapping the polyolefin resin layers 3 so that they face each other and heat-sealing the necessary parts to form a bag-like or cylindrical shape with the heat-sealed portion 4 adhered. The article can be packaged by inserting it inside and then heat-sealing the opening 5. In FIG. 3, the packaging material 1 of the present invention is folded and stacked so that the polyolefin resin layers 3 face each other, and a heat-sealed portion 4 is formed at the end of the folded packaging material 1 by heat sealing. After the bag is formed into a bag having an opening 5 and a packaged article is inserted through the opening 5, a portion 6 to be heat-sealed near the opening 5 is heat-sealed to package the packaged article. Heat-sealing by placing the polyolefin resin layers facing each other and applying heat from the opposite side (non-woven fabric side) creates a strong seal by fusing all of the polyolefins that make up the polyolefin resin layer at least at the heat-sealed area. This is because it demonstrates. Further, since the spunbond nonwoven fabric side has high strength, by placing the spunbond nonwoven fabric side on the outside, it can effectively play the role of protecting the packaged article inside. In addition, at the heat-sealed portion, the sheath portion constituting the spunbond nonwoven fabric also melts or softens, contributing to adhesion.

Heat sealing is typically performed in the machine direction (MD direction) and the transverse direction (CD direction) of the packaging material. In FIG. 3, the MD direction 7 and the CD direction 8 are indicated by arrows, and since the MD direction 7 is the direction in which the fibers are mainly oriented, it is easy to tear, that is, open the package. In FIG. 3, when a packaged article is inserted through the opening 5 and its surroundings are heat-sealed, it becomes a package, but the edge of the intended heat-sealing section 6, which is not the heat-sealed section, is directed toward the article in the MD direction. By providing the notch 9 cut into the package, the package can be opened by easily tearing the notch 9 with fingers. The packaging material of the present invention has the advantage that it can be easily torn from the notch formed on the product side at the heat-sealed end. The size of the notch 9 is not particularly limited, but it is preferable to form a cut with a depth of 5 mm to 20 mm, which is easy to cut with a human finger. The shape of the notch 9 cut in the MD direction may be a simple cut or may be a cutout shape as shown in FIG. Although the notch is formed at only one location in FIG. 3, there is no problem even if the notch is formed at multiple locations.

<Package>
In the present invention, a package that is heat-sealed and has a notch formed therein is called a package. Therefore, the package has the packaged article inside and the opening is heat-sealed by heat-sealing, and a cut is made in the MD direction at the end where the heat-seal is to be torn. It has a notch. The package can be easily torn starting from the notch. However, the packaging body has the ability to sufficiently protect the items packaged inside. That is, the package has a toughness that does not tear easily, and since the nonwoven fabric is elastic, it can protect the article even from weak impacts. Furthermore, since the package is made of non-woven fabric, it is not possible to clearly see the goods, but since it is somewhat transparent, it is possible to see the goods inside, so there will be no mistakes in the goods during delivery or transportation.

[Example]
The present invention will be explained in more detail with reference to Examples. The present invention is not limited to these examples.

Example 1
<Spunbond nonwoven fabric>
Polyethylene terephthalate (melting point: 258° C., intrinsic viscosity: 0.70) was prepared as a polyester polymer disposed in the core. High-density polyethylene (melting point: 128° C., melt index value: 25 g/10 minutes) was prepared as the polyethylene to be placed in the sheath. After individually weighing so that sheath/core = 35/65 (mass ratio), they were melted using a separate extruder type extruder and melt-spun to have a core-sheath type composite cross section. After the spun yarn was cooled, it was taken up at high speed using an air sucker, opened using a known fiber opening device, and collected and deposited on a moving collection surface to form a nonwoven web consisting of continuous fibers. The single fiber fineness of the obtained core-sheath type composite continuous fiber was 3 dtex. Furthermore, this nonwoven web was passed through a heat embossing device consisting of an embossing roll and a flat roll to form a thermocompression bonded portion. The engraving pattern of the embossing roll is an engraving pattern in which convex parts are continuous and surround concave parts, each concave part is elliptical, and the long axes of the ellipses are arranged alternately (as shown in Figure 1). The area of each concave part is 1.14 mm ² , the density of concave parts is 64 pieces/cm ² , and the ratio of the area occupied by convex parts to the entire surface of the embossing roll (pattern) is repeated. Using an embossing roll with an area ratio of 37%, hot embossing was performed at a hot embossing temperature of 123° C. and a linear pressure of 200 N to obtain a spunbond nonwoven fabric having a thermocompression bonded portion with a basis weight of 30 g/m ² . Note that since it is a spunbond nonwoven fabric, the long fibers constituting the nonwoven fabric were mainly arranged in the MD direction due to its manufacturing method.

<Lamination processing>
Using an extrusion laminating device, low-density polyethylene for lamination is put into an extruder, heated to 210°C to melt it, and the molten polyethylene sheet is extruded from a die to a thickness of 10 μm, and the sheet is placed directly under the die. The spunbond nonwoven fabric obtained above is laminated at a distance of about 50 cm, and at the same time, it is introduced between a pair of cooling rolls, and the laminated sheet is pressed between the cooling rolls and joined together to form a packaging material of the present invention. Obtained. In addition, the polyethylene sheet was joined and integrated so that the side in contact with the flat roll became the side facing the polyethylene sheet in the heat embossing process when the spunbond nonwoven fabric formed the thermocompression bonded part. In the spunbond nonwoven fabric of the packaging material, the side in contact with the embossing roll is exposed to the surface, resulting in good abrasion resistance.

<Packaging material>
The spunbond nonwoven fabric before lamination has a thickness of 0.16 mm, a tensile strength (MD direction) of 145 N/5 cm, a tensile strength (CD direction) of 55 N/5 cm, and a tear strength (MD direction) of 3.0 N. The packaging material, which is made by bonding and integrating a polyethylene resin layer (polyethylene sheet), has a thickness of 0.13 mm, a tensile strength (MD direction) of 167 N/5 cm, a tensile strength (CD direction) of 55 N/5 cm, and a tear strength (MD direction). The fuzziness was 2.1 N, and the fuzziness of most of the five test pieces showed no change in the surface condition before the start of the test, and almost no fuzz was observed. Tensile strength, tensile strength, and fluffiness were measured by the methods described below.

Furthermore, it was also possible to easily grasp the printed contents by overlapping the packaging material on A4 paper with letters and pictures printed on it (with the A4 sheet side facing the polyethylene resin layer). Therefore, when the package was made into a package, the characters written on the stored item could be understood through the package.

<Tensile strength (N/5cm width)>
Prepare 10 test pieces with a width of 5 cm and a length of 20 cm, and use a constant speed extension type tensile tester (manufactured by Orientec, product name "UTM-4-1-100") to meet JIS-L-1913. Measured according to the same method. The conditions at this time were a gripping interval of 100 mm and a pulling speed of 200 mm/min. An elongation-load curve was drawn, and the required strength at the maximum load (N/5 cm width) was measured from the obtained elongation-load curve, and the average value of 10 points was taken as the tensile strength.

<Tear strength (N)>
JIS L 1913 tear strength Measured based on the pendulum method. Note that the measurements were made only in the MD direction.

<Fuzziness>
The fluffing property was evaluated according to the JIS L 0849 Abrasion Tester Type II (Gakushin Method) method. In addition, instead of the white cotton cloth for friction, the same cloth as the test piece was used for friction, and the test pieces were worn together. Further, the number of reciprocating friction was 50 times, and the surface condition of the test piece (N=5) at that time was observed.

<Package>
The resulting packaging material was cut into two pieces measuring 180 cm (MD direction) x 90 cm (CD direction), stacked on top of each other so that the polyethylene resin layers faced each other, and the edges of the packaging material were sealed using a heat sealer. A heat-sealed portion with a width of approximately 5 mm was formed at a location approximately 1 cm from the portion on three overlapping sides to form a bag shape. Approximately 5 kg of material was stored through the non-heat-sealed opening, and the opening was similarly heat-sealed to form a package with four sides heat-sealed.

In the package in which the transported object was stored, a cut (approximately 8 mm) cut in the MD direction was made at one location near the heat sealing part at the end of the package to form a notch.

When the package containing approximately 5 kg of transported material was vibrated or exposed, the heat-sealed portion remained unbroken and played a role in protecting the transported material. In addition, when the notch part of the cut was pinched and split in the MD direction, it was easily split and the contents (carried object) could be taken out.

Comparative example 1
Spunbond nonwoven fabric composed only of polyethylene terephthalate (manufactured by Unitika Co., Ltd., product name "Marix 70303WSO", single fiber fineness 3 dtex, basis weight 30 g/m ² , partial heat-bonded parts are formed in the form of scattered dots, the shape of the crimped part is (approximately rectangular, crimped area ratio 16%) was prepared.

A polyethylene sheet was laminated on the above spunbond nonwoven fabric in the same manner as in Example 1, and a laminated sheet was obtained by integrating the lamination.

The laminated sheet, in which a polyethylene resin layer (polyethylene sheet) is bonded and integrated with spunbond nonwoven fabric, has a thickness of 0.15 mm, a tensile strength (MD direction) of 99 N/5 cm, a tensile strength (CD direction) of 48 N/5 cm, and a tear strength (MD Direction) was 3.6N, and the fluffing property was determined at 5 test pieces.Most of the test pieces had fluffs generated on the surface due to friction, and some of the generated fluffs became entangled to form fluffs. Furthermore, when the notch portion of the cut was pinched and divided in the MD direction, it was not possible to divide it easily.

As is clear from the comparison between Example 1 and Comparative Example 1, Comparative Example 1 is inferior to the laminated sheet of Example in terms of tensile strength and fluffing properties. In addition, the tear strength of the Example is smaller, indicating that the Example can be easily torn and removed when taking out the contents. In Comparative Example 1, the nonwoven fabric is made of long fibers that do not have a core-sheath type structure, so even if polyethylene resin layers are laminated, ease of tearing starting from the notch cannot be obtained.

1... Packaging material 2... Spunbond nonwoven fabric 3... Polyolefin resin layer 4... Heat sealing part 5... Opening part 6... Heat sealing planned part 7... Machine direction (MD direction)
8...Transverse direction (CD direction)
9...notch

Claims (9)

A polyolefin resin layer is formed on one side of a spunbond nonwoven fabric made of a core-sheath composite filament whose sheath is made of a polyolefin polymer and whose core is made of a thermoplastic polymer with a melting point higher than that of the polyolefin polymer in the sheath. The spunbond nonwoven fabric has a thermocompression bonded part, and the thermocompression bonding part maintains the fiber form by melting or resolidifying the polyolefin polymer in the sheath part of the core-sheath composite filament. In a package obtained from a packaging material in which core portions are bonded together and a continuous concave thermocompression bonded portion surrounds a non-thermocompression bonded portion,
The packaging is made by stacking the packaging materials so that the polyolefin resin layer sides face each other and heat-sealing at least the machine direction of the spunbond nonwoven fabric, and providing a notch cut in the machine direction near the heat-sealed part. body . The package according to claim 1, wherein the thermoplastic polymer of the core is a polyester polymer, and the melting point of the core is 30° C. or more higher than the melting point of the polyolefin polymer constituting the sheath. The package according to claim 1 or 2, wherein the melting point of the polyolefin resin layer is approximately the same as the melting point of the polyolefin constituting the sheath component. The package according to any one of claims 1 to 3, wherein the spunbond nonwoven fabric has a basis weight of 20 to 40 g/m ² . The package according to any one of claims 1 to 4, wherein the single fiber fineness of the core-sheath type composite long fiber is 1 to 10 decitex. The package according to any one of claims 1 to 5, wherein the non-thermocompression bonded portions are elliptical, and the long axes of the ellipses are arranged alternately. The package according to claim 6, wherein the spunbond nonwoven fabric is heat-sealed not only in the machine direction but also in the transverse direction. The package according to claim 6 or 7, which contains an article to be packaged. forming a spunbond nonwoven fabric made of core-sheath type composite long fibers in which the sheath part is made of a polyolefin polymer and the core part is made of a thermoplastic polymer having a melting point higher than the melting point of the polyolefin polymer in the sheath part;
The obtained spunbond nonwoven fabric is passed through a heat embossing device consisting of an embossing roll and a flat roll, which has an emboss pattern in which convex portions are continuous and surround concave portions, so that continuous concave thermocompression bonded portions are formed on the spunbond nonwoven fabric. Forming a pattern surrounding the non-thermocompression bonded part,
In the spunbond nonwoven fabric having the obtained pattern, a polyolefin resin layer is laminated on the surface of the spunbond nonwoven fabric that comes into contact with the flat roll when passed through the hot embossing device to form a packaging material,
Next, the packaging materials are stacked so that the polyolefin resin layer sides thereof face each other, and the packaging materials are heat-sealed in the machine direction, and a notch cut in the machine direction is provided near the heat-sealed portion.
A method for producing a package characterized by

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