JP2009241968A - Vegetables and fruits packaging body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vegetables and fruits package body which allows simplified transportation or storage of vegetables and fruits without damaging them or without causing deterioration of freshness. <P>SOLUTION: Fibers, including wet-heat-adhesive fibers and composite fibers in which a plurality of resins with different heat-shrinkage rates constitute a phase separation structure, are turned into a web, after which the generated fiber web is subjected to a heat-treatment with high-temperature moisture-vapor, to be turned into a nonwoven fiber aggregate through fusion-bonding and crimping it, the obtained nonwoven fiber aggregate being utilized for preparing a vegetables and fruits packaging body. The proportion (mass ratio) between the wet-heat-adhesive fibers and non-wet-heat-adhesive fibers stands at former/latter being equal to about 10/90 to 70/30. This vegetables and fruits packaging body is constituted of a nonwoven fiber aggregate including the wet-heat-adhesive fibers and the composite fibers in which a plurality of resins with different heat-shrinkage rates constitute the phase separation structure, while, within the interior of the nonwoven fiber aggregate, the adhesive points of the fibers fusion-bonded by the wet-heat-adhesive fibers are approximately uniformly distributed, and the composite fibers are approximately uniformly crimped with an average curvature radius of 20 to 200 μm for interlace-texturing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fruit and vegetable package for transporting or storing fruits and vegetables such as fruits and vegetables without damage, and a method for producing the same.

  Conventionally, as packaging for fruits and vegetables such as peaches, apples, tangerines, and tomatoes, packaging materials (or cushioning materials) with cushioning properties have been used to protect them from damage caused by physical contact during transportation. ing. Furthermore, in addition to such cushioning properties, the fruits and vegetables packaging body is required to have strength and structure for fixing various shapes of fruits and vegetables, and air permeability for maintaining the freshness of fruits and vegetables.

  Various packages for satisfying such characteristics have been proposed. For example, in JP-A-10-287369 (Patent Document 1), a number of slits are formed on a sheet-like base paper. A cushioning body for packaging fresh fruits or the like comprising a buffer base material obtained by bulky deforming a base paper, a support tray for supporting the buffer base material, and a coated paper for holding the buffer base material is disclosed. . However, in this buffer, since the bulky deformable base paper itself is required to be hard, the slit edges and corners of such base paper are very hard and the contents are easily damaged. Moreover, in order to prevent this, it is also described that it is covered with a coated paper, but the convenience is lowered and the effect is not sufficient. Furthermore, it is necessary to adjust the apparent size of the cushioning material by bulky deformation of the sheet-like base paper according to the shape of the box, which is complicated.

  JP-A-11-1274 (Patent Document 2) discloses fruits, vegetables and / or tropical fruits, especially bananas, for transporting and storing products in cardboard boxes or containers that can be used repeatedly. Disclosed is a fruit packing material that is suitable for use and is configured into a bag that can be placed in a transport container, has at least one perforation, and can be easily manufactured from an air cushion foil. However, this packaging material has low air permeability of the foil itself, and there is a high possibility that air does not reach the whole fruit depending on the packaging method. In particular, in order for the air cushion foil to exhibit buffering properties, it is necessary that the foil and the fruit are in close contact with each other. Furthermore, although it is possible to absorb minute shaking and vibration with the air cushion foil, it is difficult to prevent the fruit from rolling due to large shaking or tilting, and finally it is fixed with a separate container etc. It will be necessary.

Furthermore, Japanese Patent Application Laid-Open No. 2007-197067 (Patent Document 3) discloses a packaging container having a container body formed of a synthetic resin sheet and a buffer rug to be put in the container body, the container body being a bottom container. And including a lid container connected to the bottom container, comprising a ventilation means capable of allowing the bottom container and the lid container to be vented inside and outside the container body in a closed state or a packaging state, The bottom container and / or the lid container are provided with a required number of accommodating portions and an engaging body for engaging with the buffering rug and stopping the buffering rug, and the buffering rug has cushioning properties. Then, by engaging the engaging body of the container body, a positioning hole for determining the position of the cushioning rug to a required position and the position of the container body accommodating portion are provided and the packaged object is inserted and deformed. Notches to make It discloses a packaging container having a. In this packaging container, a sponge made of urethane resin is used as a cushioning rug. However, such a urethane resin sponge has low air permeability, and the freshness of fruits and vegetables tends to decrease at the contact portion with the sponge. In particular, in the case of fruits and vegetables that are easily damaged, it is necessary to increase the size and thickness of the cushioning rug, and air permeability becomes a problem. In addition, since this buffer rug is not molded and forms a space for storing fruits by cutting, when packing large fruits and vegetables, a cushioning effect cannot be expressed at the bottom, and a separate cushioning material is used. Need to add. Further, the shape of the packaging container itself is complicated, and productivity and convenience are low.
Japanese Patent Laid-Open No. 10-287369 (Claim 1, FIGS. 1 to 6) JP-A-11-1274 (Claim 1, FIGS. 1 to 3) JP 2007-197067 (Claim 1, paragraph [0030], FIGS. 1 to 11)

  Accordingly, an object of the present invention is to provide a fruit and vegetable package and a method for producing the same that can easily carry or store fruits and vegetables without causing damage or a decrease in freshness.

  Another object of the present invention is to provide a fruit and vegetable package having high breathability and flexibility while maintaining strength for fixing the fruit and vegetable and a method for producing the same.

  Still another object of the present invention is to provide a fruit and vegetable package that can be easily formed, does not have a hard and sharp edge portion, and does not damage fruits and vegetables due to shaking during transportation, and a method for producing the same. There is.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor treated a web containing wet heat-adhesive fibers and latently heat-crimpable composite fibers with high-temperature steam so that the wet heat-adhesive fibers In addition to fusing the web together, the three-dimensional crimp of the composite fiber is expressed and entangled with the fiber, thereby obtaining a fruit and vegetable package that can be easily transported or stored without causing damage or a decrease in freshness. As a result, the present invention has been completed.

  That is, the fruit and vegetable package of the present invention is a fruit and vegetable package composed of a nonwoven fiber assembly including wet heat adhesive fibers and a composite fiber in which a plurality of resins having different heat shrinkage rates form a phase separation structure. Then, the ratio (mass ratio) of the wet heat adhesive fiber and the non-wet heat adhesive fiber is the former / the latter = 10/90 to 70/30, and the wet heat bond is performed inside the nonwoven fiber assembly. The bonding points of the fibers fused by the conductive fibers are distributed substantially uniformly, and the composite fibers are crimped and entangled substantially uniformly with an average curvature radius of 20 to 200 μm. In the present invention, “substantially uniform” in the distribution of fiber adhesion points means that, in the cross section in the thickness direction, the fiber adhesion rate in each of the regions divided into three equal parts in the thickness direction is 3 to 30%, and each It means that the ratio of the minimum value to the maximum value of the fiber adhesion rate in the region is 50% or more. Further, “substantially uniform” in crimping of the composite fiber means that, in the cross section in the thickness direction, the fiber curvature rate of the composite fiber in each of the regions divided into three equal parts in the thickness direction is 1.3 or more, and each It means that the ratio of the minimum value to the maximum value of the fiber curvature rate of the composite fiber in the region is 75% or more. This fruit and vegetable package has a 5% compression stress of about 0.01 to 1.0 N / 30 mmφ and a compression recovery rate of 60% or more. The wet heat adhesive fiber may be a core-sheath type composite fiber formed of a sheath part made of an ethylene-vinyl alcohol copolymer and a core part made of a polyester resin.

  The present invention includes a step of forming a fiber including a wet heat adhesive fiber and a composite fiber in which a plurality of resins having different thermal shrinkage rates form a phase separation structure, and heat-treating the generated fiber web with high-temperature steam. And a method for producing the fruit and vegetable package including the steps of fusing and crimping.

  The fruit and vegetable package of the present invention has a high air permeability and cushioning property because the fibers are entangled uniformly with wet heat adhesive fibers and uniformly crimped inside the nonwoven fiber assembly. In particular, even though the surface is flexible, it has sufficient strength and elasticity to fix the fruits and vegetables, and even fragile fruits and vegetables such as peaches and kiwis can be damaged or fresh. It can be easily transported or stored without causing a drop. That is, the fruit and vegetable holding body of the present invention retains high air permeability and flexibility while maintaining strength for fixing the fruit and vegetables. In particular, the fruit and vegetable package of the present invention can easily form a recess or the like according to the shape of the fruit and vegetable by simply processing the non-woven fiber assembly by a conventional molding method, and has a hard and sharp edge portion in the recess. Does not exist, and even if fruits and vegetables come into contact with it due to shaking during transportation, it will not be damaged.

[Vegetable packaging]
The fruit and vegetable package of the present invention includes a non-woven fabric including wet heat adhesive fibers and a composite fiber (latent crimped composite fiber) in which a plurality of resins having different thermal shrinkage rates (or thermal expansion rates) form a phase separation structure. It consists of a fiber assembly. In this nonwoven fiber assembly, the wet heat adhesive fibers are fused substantially uniformly inside the aggregate, and the composite fibers are crimped substantially uniformly with an average curvature radius of 20 to 200 μm. Is entangled with. As will be described in detail later, this nonwoven fiber assembly is produced by applying high-temperature (superheated or heated) water vapor to the web containing the wet heat-adhesive fiber and the composite fiber at a temperature below the melting point of the wet heat adhesive fiber. It is obtained by exhibiting an adhesive action, causing the fibers to partially adhere to each other, expressing crimps in the composite fiber, and mechanically intertwining the fibers. That is, in the fruit and vegetable package of the present invention, the strength of the aggregate is expressed by fusion with wet heat adhesive fibers, and the stretchability, cushioning properties, and flexibility of the aggregate are expressed by confounding by crimping of the composite fibers. is doing. Furthermore, the fruit and vegetable package of the present invention adheres with a small amount of adhesion points while maintaining moderately small voids by point adhesion or partial adhesion of wet heat adhesive fibers, and the fibers are also bonded by crimping of the composite fibers. Since they are entangled, the fibers are prevented from falling off and have high flexibility and shape retention.

(Wet heat adhesive fiber)
In the present invention, since the point-bonding between the wet heat-adhesive fibers softened by the wet heat and the intersecting fibers, it is possible to flexibly fix the crimped composite fibers in spite of a small bonding area. And form stability.

The wet heat adhesive fiber is composed of at least a wet heat adhesive resin. The wet heat adhesive resin only needs to be able to flow or easily deform at a temperature that can be easily realized by high-temperature steam and to exhibit an adhesive function. Specifically, a thermoplastic resin that is softened with hot water (for example, about 80 to 120 ° C., particularly about 95 to 100 ° C.) and can be self-adhered or bonded to other fibers, for example, a cellulose-based resin (C such as methylcellulose) _1-3 alkylcelluloses, hydroxyalkyl C _1-3 alkyl celluloses such as hydroxypropyl cellulose, carboxy C _1-3 alkyl cellulose or a salt thereof, such as carboxymethyl cellulose), polyalkylene glycol resin (polyethylene oxide, poly C ₂ such as polypropylene oxide _-4 alkylene oxide), polyvinyl resins (polyvinyl pyrrolidone, polyvinyl ether, vinyl alcohol polymers, polyvinyl acetals, etc.), acrylic copolymers and their salts [acrylics such as (meth) acrylic acid, (meth) acrylamide, etc. Copolymers containing units composed of monomers and their alkali metal salts, etc.], modified vinyl copolymers (such as vinyl monomers such as isobutylene, styrene, ethylene, vinyl ether, and maleic anhydride) Copolymer with unsaturated carboxylic acid or its anhydride or salt thereof), polymer with hydrophilic substituent introduced (polyester, polyamide, polystyrene or salt with introduced sulfonic acid group, carboxyl group, hydroxyl group, etc.) Etc.), aliphatic polyester resins (polylactic acid resins, etc.). Furthermore, among polyolefin resins, polyester resins, polyamide resins, polyurethane resins, thermoplastic elastomers or rubbers (such as styrene elastomers), it can be softened at the temperature of hot water (high-temperature steam) to exhibit an adhesive function. Other resins are also included.

These wet heat adhesive resins can be used alone or in combination of two or more. The wet heat adhesive resin is usually composed of a hydrophilic polymer or a water-soluble resin. Among these wet heat adhesive resins, vinyl alcohol polymers such as ethylene-vinyl alcohol copolymers, polylactic acid resins such as polylactic acid, (meth) acrylic copolymers containing (meth) acrylamide units, A vinyl alcohol polymer containing an α-C _2-10 olefin unit such as ethylene or propylene, particularly an ethylene-vinyl alcohol copolymer is preferred.

  In the ethylene-vinyl alcohol copolymer, the ethylene unit content (copolymerization ratio) is, for example, about 10 to 60 mol%, preferably about 20 to 55 mol%, and more preferably about 30 to 50 mol%. When the ethylene unit is in this range, a unique property of having wet heat adhesiveness but not hot water solubility is obtained. If the proportion of the ethylene units is too small, the ethylene-vinyl alcohol copolymer easily swells or gels with low-temperature steam (water), and its form is likely to change only once wetted with water. On the other hand, when the ratio of the ethylene unit is too large, the hygroscopicity is lowered, and fiber fusion due to wet heat is difficult to be exhibited, so that it is difficult to ensure practical strength. When the ratio of the ethylene unit is particularly in the range of 30 to 50 mol%, the processability into a sheet or plate is particularly excellent.

  The saponification degree of the vinyl alcohol unit in the ethylene-vinyl alcohol copolymer is, for example, about 90 to 99.99 mol%, preferably 95 to 99.98 mol%, more preferably 96 to 99.97 mol%. Degree. When the degree of saponification is too small, the thermal stability is lowered, and the stability is lowered by thermal decomposition or gelation. On the other hand, if the degree of saponification is too large, it is difficult to produce the fiber itself.

  Although the viscosity average degree of polymerization of an ethylene-vinyl alcohol-type copolymer can be selected as needed, it is 200-2500, for example, Preferably it is 300-2000, More preferably, it is about 400-1500. When the degree of polymerization is within this range, the balance between spinnability and wet heat adhesion is excellent.

  The cross-sectional shape (cross-sectional shape perpendicular to the fiber length direction) of the wet heat-adhesive fiber is a general solid cross-sectional shape, such as a round cross-section or an irregular cross-section [flat, elliptical, polygonal, 3-14 Leaf shape, T-shape, H-shape, V-shape, dogbone (I-shape, etc.)], and may be a hollow cross-section.

  The wet heat adhesive fiber may be a composite fiber composed of a plurality of resins including at least a wet heat adhesive resin. The composite fiber only needs to have the wet heat adhesive resin on at least a part of the fiber surface, but from the viewpoint of adhesiveness, the wet heat adhesive resin continuously occupies at least a part of the surface in the length direction. Is preferred.

  Examples of the cross-sectional structure of the composite fiber in which the wet heat adhesive fiber occupies the surface include a core-sheath type, a sea-island type, a side-by-side type, a multilayer bonding type, a radial bonding type, and a random composite type. Among these cross-sectional structures, the core-sheath structure (that is, the sheath part is wet-heat-adhesive, which is a structure in which the wet-heat adhesive resin occupies the entire surface continuously in the length direction because it is a highly adhesive structure. A core-sheath structure made of resin is preferred.

  In the case of a composite fiber, wet heat adhesive resins may be combined with each other, but may be combined with non-wet heat adhesive resins. Non-wet heat adhesive resins include water-insoluble or hydrophobic resins such as polyolefin resins, (meth) acrylic resins, vinyl chloride resins, styrene resins, polyester resins, polyamide resins, polycarbonate resins, Examples include polyurethane resins and thermoplastic elastomers. These non-wet heat adhesive resins can be used alone or in combination of two or more.

  Among these non-wet heat adhesive resins, from the viewpoint of heat resistance and dimensional stability, resins having a melting point higher than that of wet heat adhesive resins (particularly ethylene-vinyl alcohol copolymers), such as polypropylene resins and polyester resins. Resins and polyamide resins, particularly polyester resins and polyamide resins are preferred from the standpoint of excellent balance between heat resistance and fiber-forming properties.

Polyester resins include aromatic polyester resins such as poly C _2-4 alkylene arylate resins (polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), especially polyethylene such as PET. A terephthalate resin is preferred. In addition to the ethylene terephthalate unit, the polyethylene terephthalate resin is not limited to other dicarboxylic acids (for example, isophthalic acid, naphthalene-2,6-dicarboxylic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid, bis (carboxyphenyl) ethane. , 5-sodium sulfoisophthalic acid, etc.) and diols (for example, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexane-1,4-dimethanol, Units composed of polyethylene glycol, polytetramethylene glycol, etc.) may be included at a ratio of about 20 mol% or less.

  Polyamide resins include polyamides 6, polyamides 66, polyamides 610, polyamides 10, polyamides 12, polyamides 6-12 and other aliphatic polyamides and copolymers thereof, half-synthesized from aromatic dicarboxylic acids and aliphatic diamines. Aromatic polyamide is preferred. These polyamide-based resins may also contain other copolymerizable units.

  In the case of a composite fiber composed of a wet heat adhesive resin and a non-wet heat adhesive resin (fiber-forming polymer), the ratio (mass ratio) of both can be selected according to the structure (for example, core-sheath structure). The wet heat adhesive resin is not particularly limited as long as it exists on the surface. For example, wet heat adhesive resin / non-wet heat adhesive resin = 90/10 to 10/90, preferably 80/20 to 15/85, more preferably 60 / 40 to about 20/80. If the proportion of wet heat adhesive resin is too large, it will be difficult to ensure the strength of the fiber, and if the proportion of wet heat adhesive resin is too small, it will be difficult to have the wet heat adhesive resin continuously in the length direction of the fiber surface. Thus, the wet heat adhesiveness is lowered. This tendency is the same when the wet heat adhesive resin is coated on the surface of the non-wet heat adhesive fiber.

  The average fineness of the wet heat adhesive fiber can be selected, for example, from the range of about 0.01 to 100 dtex, preferably 0.1 to 50 dtex, more preferably 0.5 to 30 dtex (particularly 1 to 10 dtex) depending on the application. Degree. When the average fineness is in this range, the balance between the strength of the fiber and the expression of wet heat adhesion is excellent.

  The average fiber length of the wet heat adhesive fibers can be selected, for example, from a range of about 10 to 100 mm, preferably 20 to 80 mm, more preferably about 25 to 75 mm (particularly 35 to 55 mm). When the average fiber length is within this range, the fibers are sufficiently entangled, so that the mechanical strength of the fiber assembly is improved.

  The crimp rate of the wet heat adhesive fiber is, for example, about 1 to 50%, preferably 3 to 40%, more preferably about 5 to 30% (particularly 10 to 20%). The number of crimps is, for example, about 1 to 100 pieces / 25 mm, preferably about 5 to 50 pieces / 25 mm, and more preferably about 10 to 30 pieces / 25 mm.

(Latent crimped composite fiber)
The latent crimpable conjugate fiber is a fiber having an asymmetric or layered (so-called bimetal) structure that causes crimping by heating due to a difference in thermal contraction rate (or thermal expansion rate) of a plurality of resins (latent crimped fiber) ). A plurality of resins usually have different softening points or melting points. The plurality of resins include, for example, polyolefin resins (low density, medium density or high density polyethylene, poly C _2-4 olefin resins such as polypropylene), acrylic resins (acrylonitrile units such as acrylonitrile-vinyl chloride copolymer) Acrylonitrile-based resin, etc.), polyvinyl acetal resin (polyvinyl acetal resin, etc.), polyvinyl chloride resin (polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylonitrile copolymer, etc.), polychlorinated Vinylidene resins (vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-vinyl acetate copolymer, etc.), styrene resins (heat-resistant polystyrene, etc.), polyester resins (polyethylene terephthalate resin, polytrimethylene terephthalate resin, polybutylene) Poly C _2-4 alkylene arylate resins such as terephthalate resin and polyethylene naphthalate resin), polyamide resins (polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc. aliphatic polyamide resins) , Semi-aromatic polyamide resins, polyphenylene isophthalamide, polyhexamethylene terephthalamide, poly-p-phenylene terephthalamide and other aromatic polyamide resins), polycarbonate resins (bisphenol A type polycarbonate, etc.), polyparaphenylene benzobis You may select from thermoplastic resins, such as an oxazole resin, a polyphenylene sulfide resin, a polyurethane-type resin, and a cellulose resin (cellulose ester etc.). Further, each of these thermoplastic resins may contain other copolymerizable units.

  Among these resins, in the present invention, a non-wet heat adhesive resin (or heat-resistant hydrophobic resin having a softening point or melting point of 100 ° C. or higher is not melted or softened even when heat-treated with high-temperature steam and the fibers are not fused. Resin or non-aqueous resin), for example, polypropylene resin, polyester resin, and polyamide resin are preferable. In particular, aromatic polyester resin and polyamide resin are preferable from the viewpoint of excellent balance of heat resistance and fiber forming property. preferable. In the present invention, the resin exposed on the surface of the composite fiber is preferably a non-wet heat adhesive fiber so that the fusion by the composite fiber does not occur even when treated with high-temperature steam.

  The plurality of resins constituting the composite fiber may have different heat shrinkage rates, and may be a combination of resins of the same system or a combination of different resins.

  In this invention, it is preferable that it is comprised with the combination of resin of the same type | system | group from the point of adhesiveness. In the case of a combination of resins of the same system, a combination of a component (A) that forms a homopolymer (essential component) and a component (B) that forms a modified polymer (copolymer) is usually used. In other words, the homopolymer that is an essential component is crystallized more than the homopolymer by, for example, copolymerizing and modifying a copolymerizable monomer that lowers the crystallinity, melting point, or softening point. The melting point or the softening point may be lowered as compared with the homopolymer. Thus, a difference may be provided in the thermal shrinkage rate by changing the crystallinity, melting point or softening point. The difference in melting point or softening point may be, for example, about 5 to 150 ° C, preferably about 50 to 130 ° C, and more preferably about 70 to 120 ° C. The ratio of the copolymerizable monomer used for the modification is, for example, 1 to 50 mol%, preferably 2 to 40 mol%, more preferably 3 to 30 mol% (particularly 5 to 5 mol%) with respect to all monomers. 20 mol%). The composite ratio (mass ratio) of the component forming the homopolymer and the component forming the modified polymer can be selected according to the structure of the fiber. For example, the homopolymer component (A) / modified polymer component (B) = 90/10 to 10/90, preferably 70/30 to 30/70, more preferably about 60/40 to 40/60.

  In the present invention, the composite fiber is a combination of an aromatic polyester resin, particularly a polyalkylene arylate resin (a) and a modified polyalkylene arylate resin (b) because it is easy to produce latent crimpable conjugate fibers. It may be a combination. In particular, in the present invention, a type that develops crimp after web formation is preferable, and the combination is also preferable in this respect. By producing crimp after the web formation, the fibers can be efficiently entangled and the web shape can be maintained with a smaller number of fusion points, so that appropriate flexibility can be realized.

The polyalkylene arylate resin (a) is composed of an aromatic dicarboxylic acid (such as symmetric aromatic dicarboxylic acid such as terephthalic acid or naphthalene-2,6-dicarboxylic acid) and an alkanediol component (such as ethylene glycol or butylene glycol such as C _{3- 6} alkanediol etc.) and a homopolymer. Specifically, poly C _2-4 alkylene terephthalate resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) are used, and generally a general PET having an intrinsic viscosity of about 0.6 to 0.7. PET used for fibers is used.

On the other hand, in the modified polyalkylene arylate resin (b), the melting point or softening point of the polyalkylene arylate resin (a), which is an essential component, is a copolymer component that lowers the crystallinity, such as an asymmetric aromatic dicarboxylic acid. Further, a dicarboxylic acid component such as alicyclic dicarboxylic acid or aliphatic dicarboxylic acid, an alkanediol component having a chain length longer than the alkanediol of the polyalkylene arylate resin (a) and / or an ether bond-containing diol component can be used. These copolymerization components can be used alone or in combination of two or more. Among these components, as dicarboxylic acid components, asymmetric aromatic carboxylic acids (isophthalic acid, phthalic acid, 5-sodium sulfoisophthalic acid, etc.), aliphatic dicarboxylic acids (C _6-12 aliphatic dicarboxylic acids such as adipic acid, etc.) ) such as is commonly, as the diol component, alkane diol (1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, etc. C _3-6 alkanediol such as neopentyl glycol), (poly) Oxyalkylene glycol (polyoxy C _2-4 alkylene glycol such as diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, etc.) is widely used. Among these, asymmetric aromatic dicarboxylic acids such as isophthalic acid, polyoxy C _2-4 alkylene glycol such as diethylene glycol, and the like are preferable. Furthermore, the modified polyalkylene arylate-series resin (b) is, C _2-4 alkylene arylate (ethylene terephthalate, polybutylene terephthalate, etc.) as the hard segment may be an elastomer as a soft segment such as (poly) oxyalkylene glycol .

  In the modified polyalkylene arylate resin (b), as the dicarboxylic acid component, the ratio of the dicarboxylic acid component (for example, isophthalic acid) for lowering the melting point or the softening point is, for example, relative to the total amount of the dicarboxylic acid component, It is 1-50 mol%, Preferably it is 5-50 mol%, More preferably, it is about 15-40 mol%. The ratio of the diol component (for example, diethylene glycol) for reducing the melting point or the softening point as the diol component is, for example, 30 mol% or less, preferably 10 mol% or less (for example, 0 mol%) with respect to the total amount of the diol component. .About 1 to 10 mol%). When the proportion of the copolymer component is too low, sufficient crimps are not expressed, and the form stability and stretchability of the nonwoven fiber aggregate after the crimps are reduced. On the other hand, if the proportion of the copolymer component is too high, the crimping performance will be high, but it will be difficult to spin stably.

  Modified polyalkylene arylate resin (b) is used in combination with polyvalent carboxylic acid components such as trimellitic acid and pyromellitic acid, and polyol components such as glycerin, trimethylolpropane, trimethylolethane, and pentaerythritol as necessary. And may be branched.

  The cross-sectional shape of the composite fiber (cross-sectional shape perpendicular to the length direction of the fiber) is a general solid cross-sectional shape such as a round cross-section or an irregular cross-section [flat shape, elliptical shape, polygonal shape, 3-14 leaf shape, It is not limited to T-shape, H-shape, V-shape, dogbone (I-shape), etc.], and may be a hollow cross-section, but is usually a round cross-section.

  As the cross-sectional structure of the composite fiber, a phase separation structure formed in a plurality of resins, for example, a core-sheath type, a sea-island type, a blend type, a parallel type (side-by-side type or multilayer bonding type), a radial type (radial bonding) Type), hollow radiation type, block type, random composite type and the like. Among these cross-sectional structures, a structure in which the phase portions are adjacent (so-called bimetal structure), a structure in which the phase separation structure is asymmetrical, for example, an eccentric core-sheath type, A parallel structure is preferred.

  If the composite fiber has a core-sheath type structure such as an eccentric core-sheath type, the core portion is not damaged if it has a heat shrinkage difference with the non-wet heat adhesive resin of the sheath portion located on the surface. Consists of wet heat adhesive resin (for example, vinyl alcohol polymers such as ethylene-vinyl alcohol copolymer and polyvinyl alcohol) and thermoplastic resin having a low melting point or softening point (for example, polystyrene, low density polyethylene, etc.) May be.

  The average fineness of the composite fiber can be selected from a range of, for example, about 0.1 to 50 dtex, preferably 0.5 to 10 dtex, and more preferably 1 to 5 dtex (particularly 1.5 to 3 dtex). If the fineness is too thin, it is difficult to produce the fiber itself, and it is difficult to secure the fiber strength. Moreover, it becomes difficult to express a beautiful coiled crimp in the step of expressing crimp. On the other hand, if the fineness is too thick, the fiber becomes stiff and it is difficult to express sufficient crimp.

  The average fiber length of the composite fiber can be selected from a range of, for example, about 10 to 100 mm, preferably 20 to 80 mm, and more preferably about 25 to 75 mm (particularly 40 to 60 mm). If the fiber length is too short, it becomes difficult to form a fiber web, and in addition, in the step of developing crimps, entanglement between fibers becomes insufficient, and it becomes difficult to ensure strength and stretchability. In addition, if the fiber length is too long, it becomes difficult to form a fiber web with a uniform basis weight, and a lot of fibers are entangled at the time of web formation, which interferes with each other when crimping occurs. This makes it difficult to develop flexibility and cushioning properties.

  By applying heat treatment to this composite fiber, crimp is developed (appears) and becomes a fiber having a substantially coiled (spiral or helical spring-shaped) three-dimensional crimp.

  The number of crimps before heating (mechanical crimp number) is, for example, about 0 to 30 pieces / 25 mm, preferably about 1 to 25 pieces / 25 mm, and more preferably about 5 to 20 pieces / 25 mm. The number of crimps after heating is, for example, 30 pieces / 25 mm or more (for example, 30 to 200 pieces / 25 mm), preferably about 35 to 150 pieces / 25 mm, and more preferably about 40 to 120 pieces / 25 mm. It may be about 45 to 120 pieces / 25 mm (especially 50 to 100 pieces / 25 mm).

  Since the nonwoven fiber aggregate in the present invention is crimped with high-temperature steam, the composite fiber is characterized in that the crimp of the composite fiber appears substantially uniformly inside the aggregate. Specifically, for example, in the cross section in the thickness direction, the number of fibers forming one or more coil crimps in the central portion (inner layer) of each region divided in three in the thickness direction is, for example, 5-50 pieces / 5 mm (length in the surface direction) × 0.2 mm (thickness), preferably 5-40 pieces / 5 mm (length in the surface direction) × 0.2 mm (thickness), more preferably 10-40 pieces / 5 mm (length in the surface direction) × 0.2 mm (thickness). In the present invention, since most crimped fibers and aggregates (from the vicinity of the surface of the aggregate to the center) have a uniform number of crimps, high flexibility even without rubber or elastomer. And has a practical strength even if it does not contain an adhesive. In the specification of the present application, the “region divided into three in the thickness direction” means each region divided into three equal parts by slicing in a direction orthogonal to the thickness direction of the nonwoven fiber assembly.

  Furthermore, the fact that the crimps are uniform inside the fiber assembly according to the present invention can be evaluated, for example, by the fact that the fiber curvature is uniform in the thickness direction. The fiber curvature is a ratio (L2 / L1) of the fiber length (L2) to the distance (L1) between both ends of the fiber (crimped fiber), and the fiber curvature (particularly in the central region in the thickness direction). The fiber curvature ratio is, for example, 1.3 or more (for example, 1.35 to 5), preferably 1.4 to 4 (for example, 1.45 to 3.5), and more preferably 1.5 to 3 ( In particular, it is about 1.6 to 2.5). In the present invention, as will be described later, in order to measure the fiber bending rate based on an electron micrograph of the cross section of the fiber assembly, the fiber length (L2) is a straight line obtained by stretching the three-dimensionally crimped fiber. It does not mean the fiber length (actual length) made into a shape, but the fiber length (fiber length on the photograph) obtained by stretching the two-dimensionally crimped fibers shown in the photograph into a straight line. That is, the fiber length (fiber length on the photograph) in the present invention is measured shorter than the actual fiber length.

  Furthermore, in the present invention, since the crimps are expressed substantially uniformly inside the aggregate, the fiber curvature is uniform. In the present invention, the uniformity of the fiber bending rate can be evaluated by, for example, comparing the fiber bending rate in each layer that is divided into three equal parts in the thickness direction in the cross section in the thickness direction of the aggregate. That is, in the cross section in the thickness direction, the fiber curvature rate in each region divided in three in the thickness direction is in the above range, and the ratio of the minimum value to the maximum value of the fiber curvature rate in each region (the fiber curvature rate is the maximum). The ratio of the minimum area to the above area is, for example, about 70% or more (for example, 70 to 100%), preferably 75 to 99%, more preferably about 80 to 98% (particularly 82 to 97%).

  As a specific method for measuring the fiber curvature and its uniformity, a method of taking a cross-section of a fiber assembly with an electron micrograph and measuring the fiber curvature for a region selected from each region divided into three equal parts in the thickness direction Is used. The area to be measured is measured in an area of 2 mm or more in the length direction for each of the surface layer (surface area), inner layer (center area), and back layer (back area) divided into three. Further, the thickness direction of each measurement region is set so that each measurement region has the same thickness width in the vicinity of the center of each layer. Furthermore, each measurement region includes 100 or more (preferably about 300 or more, more preferably about 500 to 1000) fiber pieces that are parallel in the thickness direction and capable of measuring the fiber curvature in each measurement region. Set as follows. After setting each of these measurement regions, after measuring the fiber curvature rate of all the fibers in the region, calculating the average value for each measurement region, the region showing the maximum average value and the minimum average value The uniformity of the fiber curvature is calculated by comparison with the region shown.

  As described above, the crimped fibers constituting the nonwoven fiber aggregate have a substantially coil-shaped crimp after the crimp is developed. The average curvature radius of a circle formed by the coil of crimped fibers can be selected, for example, from a range of about 10 to 250 μm, for example, 20 to 200 μm (for example, 20 to 150 μm), preferably 30 to 150 μm (for example, 40 to 150 μm), more preferably about 50 to 120 μm (especially 60 to 100 μm). Here, the average radius of curvature is an index representing the average size of the circle formed by the coil of crimped fibers, and when this value is large, the formed coil has a loose shape, in other words It means having a shape with a small number of crimps. In addition, when the number of crimps is small, the entanglement between the fibers is also reduced, which is disadvantageous for exhibiting sufficient cushioning properties and flexibility. Conversely, when a coiled crimp having an average radius of curvature that is too small is manifested, the fibers are not sufficiently entangled, making it difficult to ensure web strength, and also exhibiting such a crimp. Production of latent crimpable conjugate fibers is also very difficult.

  In the composite fiber crimped into a coil shape, the average pitch of the coil is, for example, about 0.03 to 0.5 mm, preferably about 0.03 to 0.3 mm, and more preferably about 0.05 to 0.2 mm.

  The ratio (mass ratio) of the wet heat adhesive fiber and the composite fiber (latent crimped composite fiber) is from the range of the former / the latter = 1/99 to 99/1 (for example, 10/90 to 90/10). For example, 10/90 to 70/30, preferably 15/85 to 65/35, more preferably 20/80 to 65/35 (particularly about 25/75 to 60/40. The ratio of both In this range, the balance between the fiber entanglement due to the crimp of the composite fiber and the fusion of the wet heat adhesive fiber is good, and the cushioning property and flexibility are improved.

  In addition to these fibers, the nonwoven fiber assembly may contain other fibers as long as the properties of the fibers are not impaired. As other fibers, for example, fibers composed of non-wet heat adhesive resins exemplified in the section of wet heat adhesive fibers, fibers composed of resins exemplified in the section of latent crimpable composite fibers, Cellulosic fibers [for example, natural fibers (cotton, wool, silk, hemp, etc.), semi-synthetic fibers (acetate fibers such as triacetate fiber), regenerated fibers (rayon, polynosic, cupra, lyocell (for example, registered trade name: “ Etc.), etc.], and inorganic fibers (for example, carbon fiber, glass fiber, metal fiber, etc.) can be used. The average fineness and average fiber length of the other fibers are the same as those of the latent crimpable conjugate fiber. These other fibers can be used alone or in combination of two or more.

  Of these other fibers, regenerated fibers such as rayon, semi-synthetic fibers such as acetate, polyolefin fibers such as polypropylene and polyethylene, polyester fibers, and polyamide fibers are preferable. In particular, from the viewpoint of blendability, the same type of fiber as the latent crimpable conjugate fiber may be used. For example, when the latent crimpable conjugate fiber is a polyester fiber, the other fibers are also polyester fibers. May be.

  The ratio of the other fibers is, for example, 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less (for example, about 0.1 to 5% by mass) with respect to the entire fiber assembly. .

  Nonwoven fiber aggregates are further made of conventional additives such as stabilizers (heat stabilizers such as copper compounds, UV absorbers, light stabilizers, antioxidants, etc.), antibacterial agents, deodorants, fragrances, It may contain a colorant (such as a dye / pigment), a filler, an antistatic agent, a flame retardant, a plasticizer, a lubricant, and a crystallization rate retarder. These additives can be used alone or in combination of two or more. These additives may be carried on the surface of the fiber or may be contained in the fiber.

(Characteristics of fruits and vegetables packaging)
The fruit and vegetable package of the present invention has a non-woven fiber structure obtained from the web composed of the fibers, and the external shape can be selected according to the shape of the fruit and vegetables to be accommodated. Or it is the shape which can accommodate all, and the sheet form or plate shape which has a recessed part for accommodating fruit and vegetables may be sufficient.

  Furthermore, in the fruit and vegetable package of the present invention, in order to obtain a non-woven fiber structure having a good balance between air permeability and cushioning properties, the inner shape of the fiber assembly is bonded to the fibers by fusing heat and heat adhesive fibers. While the state is appropriately adjusted, adjacent or intersecting fibers need to be entangled with each other in the crimped coil portion due to crimping of the composite fiber.

  Specifically, the non-woven fiber assembly is a crossing point of a composite fiber or other wet heat adhesive fibers crimped by wet heat adhesive fibers (that is, an intersection of wet heat adhesive fibers, crimped with wet heat adhesive fibers) It is preferably fused at the point of intersection with the composite fiber. In the present invention, in the non-woven fiber assembly, the fibers constituting the non-woven fiber structure are bonded at the contact points of each fiber by wet heat adhesive fibers, but the form of the fiber assembly is formed with as few contacts as possible. In order to hold, it is preferable that the adhesion points are distributed substantially uniformly from the vicinity of the surface of the assembly to the inside thereof. For example, when the aggregate is plate-shaped, it is uniformly distributed from the surface of the aggregate to the inside (center) and back side along the surface direction and thickness direction (particularly the thickness direction that is difficult to make uniform). It is preferable. When the adhesion points are concentrated on the surface or inside, the cushioning property is lowered, and the form stability in a portion having few adhesion points is lowered. For example, if the conventional method is used for a long time at a high temperature in order to develop sufficient adhesion and crimp, the portion close to the heat source is excessively adhered and the cushioning property (especially flexibility with respect to the initial stress) is lowered. Further, the latent crimpable conjugate fiber (for example, the low melting point resin portion) melts and adheres, and cushioning properties and flexibility are lowered.

  On the other hand, the non-woven fiber assembly in the present invention is distributed almost uniformly from the vicinity of the surface of the assembly to the inside thereof, and efficiently fixes the fibers. Even though the elastomer component is not used, morphological stability can be exhibited, and both cushioning and sag resistance can be achieved. Furthermore, since each fiber is fused by the wet heat adhesive fibers, the fibers can be prevented from falling off. For example, even if the fiber aggregate is cut into a desired size and used, the fibers are removed from the cut surface. Is suppressed, and the structure is not easily destroyed.

  Specifically, in the fruit and vegetable package of the present invention, the fibers constituting the non-woven fiber structure have a fiber adhesion rate of 30% or less (for example, 3 to 30%), preferably 4 to 4 by fusing the wet heat adhesive fibers. It is bonded at 25%, more preferably 5 to 20% (especially 7 to 20%). Although the fiber adhesion rate in this invention can be measured by the method as described in the Example mentioned later, the ratio of the cross section number of the fiber which adhered 2 or more with respect to the cross section number of all the fibers in a non-woven fiber cross section is shown. Therefore, a low fiber adhesion rate means that the proportion of fusion of a plurality of fibers is small. In the present invention, since the adhesion rate is low as described above, a good cushioning property can be exhibited in the fiber assembly in combination with the coiled crimp of the composite fiber described later.

  Regarding the uniformity of fusion, for example, in the case of a plate-like body, it is preferable that in the cross section in the thickness direction of the aggregate, the fiber adhesion rate in each of the three regions divided in the thickness direction is in the above range. Furthermore, the ratio of the minimum value to the maximum value of the fiber adhesion rate in each region (ratio of the minimum region to the region with the maximum fiber adhesion rate) is, for example, 50% or more (for example, 50 to 100%), preferably 60. It is about -99%, More preferably, it is about 65-98% (especially 70-95%). In the present invention, since the fiber adhesion rate has such uniformity in the thickness direction, the form can be maintained even at a few fusion points, the cushioning property and the air permeability can be improved, and the flexibility and the form stability can be maintained. It can be compatible with sex.

  In the present invention, the “region divided into three in the thickness direction” means each region divided into three equal parts by slicing in a direction orthogonal to the thickness direction of the plate-like assembly.

  The fiber adhesion rate, which indicates the degree of fusion, is simply calculated based on the number of bonded fiber cross-sections in a predetermined region by taking a photograph of an enlarged cross-section of the fiber assembly using a scanning electron microscope (SEM). Can be measured. However, when the fibers are fused in bundles, such as when the ratio of wet heat adhesive fibers is large, each fiber is fused in bundles or at intersections, so it can be observed as a single fiber. It can be difficult. In this case, for example, the fiber adhesion rate can be measured by releasing the adhesion of the adhesion portion by means such as melting or washing and comparing with the cut surface before the release.

  As described above, in the fruit and vegetable package of the present invention, not only fusion by wet heat adhesive fibers is uniformly dispersed and point-bonded, but also these point-bonds have short fusion point distances (for example, several tens to The network structure is stretched densely at several hundred μm). Due to such a structure, the fruit and vegetable package of the present invention has a high followability to strain due to the flexibility of the fiber structure even when an external force acts, and each fusion point of finely dispersed fibers. Therefore, it can be estimated that high morphological stability is exhibited. On the other hand, conventional porous molded bodies, foams, and the like are constituted by wall-like interfaces around the pores and have low air permeability.

  Furthermore, the internal shape of the fruit and vegetable package of the present invention is a fiber in which each fiber is adjacent to or intersects by a crimped coil portion when the crimp of the composite fiber is expressed and the shape is changed to a coil shape. Or crimped fibers and wet heat adhesive fibers) are intertwined with each other and restrained or latched.

  Although there is no particular limitation on the orientation of each fiber, for example, in the case of a sheet shape or a plate shape, the arrangement state of the fibers constituting the nonwoven fiber assembly may be appropriately adjusted. That is, the fibers constituting the fiber assembly (in the case of a coiled crimped fiber, the axial direction of the coil) may be arranged so as to intersect each other while being arranged substantially parallel to the sheet surface. . In the present specification, “orientated substantially parallel to the surface direction” means, for example, a portion where a large number of fibers are locally oriented along the thickness direction, such as entanglement by a needle punch. Means a state where does not exist repeatedly. When the fiber assembly is entangled with a needle punch, the ratio of the fibers along the thickness direction increases, so it becomes difficult to deform the fiber assembly in the surface direction. It will not return. Therefore, from the viewpoint of arranging the fibers in parallel, it is preferable that the degree of entanglement of the fibers by the needle punch is reduced or not entangled.

  Further, in such a plate-like assembly, when the fibers are arranged in parallel to the sheet surface, adjacent or intersecting fibers are entangled with each other in the crimped coil portion. Even in the thickness direction (or oblique direction), the fibers are slightly entangled. In particular, in the present invention, in the fiber assembly, after the web is formed, the fibers are entangled in the process of contracting into a coil shape, and the fibers are appropriately restrained by the entangled coil portion. Furthermore, since the entangled fibers are fused by the wet heat adhesive fibers, they exhibit cushioning properties.

  On the other hand, in the fiber assembly, if there are many fibers oriented in the thickness direction (perpendicular to the sheet surface), the fibers also form coiled crimps, so the fibers are extremely complicated. It will be intertwined. As a result, other fibers are restrained or fixed more than necessary, and further, the expansion and contraction of the coil constituting the fibers is inhibited, so that the flexibility of the entire fiber assembly, and hence the cushioning property, is reduced. Therefore, it is desirable to orient the fibers as parallel as possible to the sheet surface.

  The fruit and vegetable package of the present invention usually has anisotropy between the flow direction (MD direction) and the width direction (CD direction) in the production process, as well as the anisotropy between the surface direction and the thickness direction. ing. That is, the fruit and vegetable package of the present invention is not only the fiber (in the case of a coiled crimped fiber, the axial direction of the coil) is substantially parallel to the surface direction, but is also aligned substantially parallel to the surface direction. The resulting fibers tend to be substantially parallel to the flow direction. As a result, when a rectangular fiber assembly is manufactured, anisotropy appears between the flow direction and the width direction in the manufacture of the fiber assembly.

Since the fruit and vegetable package of the present invention has a non-woven fiber structure, it has voids formed between the fibers. Unlike the resin foam such as sponge, these voids are not independent voids but are continuous, and thus have high air permeability. Air permeability of the fiber assembly of the present invention, 1 cm ³ / cm ² · sec or more air permeability by Frazier method (e.g., 1~300cm ³ / cm ² · sec), ^2-preferably 3~250cm ³ / cm Second (for example, 5 to 250 cm ³ / cm ² · second), more preferably about 10 to ²⁰⁰ cm ³ / cm ² · second, and usually about 15 to 100 cm ³ / cm ² · second. If the air permeability is too small, natural air entry and exit becomes difficult. On the other hand, if the air permeability is too high, the air permeability becomes high, but the fiber gap in the package becomes too large and the cushioning property is lowered. In this invention, since it has such a high air permeability, even if the fruits and vegetables package and the fruits and vegetables are in close contact with each other, sufficient air permeability is exhibited, and the freshness of the fruits and vegetables is not lowered during transportation and storage.

As for the density of the fruit and vegetable package of the present invention, specifically, the apparent density can be selected from a range of about 0.02 to 0.2 g / cm ³ , for example, 0.03 to 0.18 g / cm ^3. , preferably 0.04~0.17g / cm ^3, more preferably 0.05~0.15g / cm ³ order. If the apparent density is too low, the air permeability is improved, but the form stability is lowered. On the other hand, if the apparent density is too high, the form stability and the strength can be secured, but the air permeability and the cushioning property are lowered. In the present invention, by combining fusion with high uniformity and crimping, it is possible to express cushioning properties and flexibility while maintaining the shape of the fruit and vegetable package despite its relatively low density. It is possible.

The basis weight (weight per unit area after heating) of the fruit and vegetable package of the present invention can be selected, for example, from the range of about 50 to 10000 g / m ² , preferably 150 to 5000 g / m ² , more preferably 200 to 3000 g / m ² (particularly 300~2000g / m ²⁾ approximately. If the basis weight is too small, it is difficult to ensure cushioning and form stability, and if the basis weight is too large, it is too thick to allow high-temperature steam to sufficiently enter the web during wet heat processing and melt in the thickness direction. It becomes difficult to form an assembly with uniform wearing and crimping.

  The fruit and vegetable package of the present invention has excellent cushioning properties, in particular, low initial stress and soft touch. That is, since it is easy to compress and deform in the initial stage of compression, it has a rigidity (strength) that does not easily deform even if compression is continued while it is flexible and does not damage fruits and vegetables. The fruit and vegetables can be fixed to such an extent that they do not roll. Specifically, the compressive stress required for 5% compression is, for example, 2 N / 30 mmφ or less (preferably 0.01 to 2.0 N / 30 mmφ, more preferably 0.03 to 1.0 N / 30 mmφ, particularly 0.05 to 0.5 N / 30 mmφ). Furthermore, the 25% compression stress (stress when compressed by 25%) is, for example, 0.1 to 30 N / 30 mmφ (for example, 0.1 to 25 N / 30 mmφ), preferably 1 to 20 N / 30 mmφ, and more preferably 1 About 5 to 15 N / 30 mmφ. On the other hand, the 50% compressive stress (stress when compressed by 50%) is, for example, about 30 to 150 N / 30 mmφ, preferably about 40 to 100 N / 30 mmφ, and more preferably about 45 to 100 N / 30 mmφ. Within such a range, the balance between cushioning properties and strength (or form retention) is excellent. Furthermore, in 50% compression recovery behavior in at least one direction, 25% compression stress [compression stress (X)] in the first 50% compression behavior and return stress at 25% compression in the return behavior after 50% compression The ratio (Y / X) to [recovery stress (Y)] may be 10% or more, for example, 15% or more (for example, about 15 to 60%), preferably 18% or more, and more preferably 20 % Or more (for example, about 20 to 50%). The higher this ratio, the better the cushioning properties.In this invention, this ratio is high, so even though it is a soft touch, even if the repulsive force is slowly increased according to the load, the load can be released. The form is restored.

  As described above, the fruit and vegetable package of the present invention has low initial stress, is flexible in touch, and deforms immediately after the fruits and vegetables are placed on the package, so that the fruits and vegetables are damaged by the load of the fruits and vegetables themselves. Can be prevented. On the other hand, since the fruits and vegetables are transported and stored, the function of receiving the fruits and vegetables over a long period of time is important as the function of the fruits and vegetables package. In the present invention, the 25% compressive stress retention over time was used as an index representing such characteristics of the fruit and vegetable package. The fruit and vegetable package of the present invention has an excellent retention rate of 25% compression stress over time, and the retention rate after 30 minutes is, for example, 50% or more, preferably 60 to 99%, more preferably 65 to 95% ( In particular, it is about 70 to 90%). Furthermore, the retention after 2 hours is, for example, about 30% or more, preferably 40 to 90%, more preferably about 50 to 85% (especially 55 to 80%), and has a high compression stress retention. ing. In particular, when this value is stabilized at the initial level of 50% or more, it becomes possible to hold the fruits and vegetables flexibly for a long time. The compressive stress retention rate in the present invention can be determined as the ratio of the compressive stress before and after when held for a predetermined time in a state compressed by 25%, as described in the examples described later.

  The fruit and vegetable package of the present invention may have a compression recovery rate of 60% or more (for example, 60 to 100%), for example, 80% or more (for example, 80 to 99.9%), preferably 90% or more ( For example, it may be 90 to 99.5%), more preferably 92% or more (for example, 92 to 99%). The compression recovery rate in the present invention indicates the recovery rate when the return stress after compression becomes “0” in the 50% compression recovery behavior.

  The fruit and vegetable package of the present invention is excellent in form stability, and the elongation at break in at least one direction (for example, the length direction in the case of a plate-like assembly) may be 30% or more, preferably 50. % Or more (for example, 50 to 250%), more preferably about 80% or more (for example, 80 to 200%). When the elongation at break is in this range, the shape stability of the fruit and vegetable package is high.

  In the fruit and vegetable package of the present invention, in at least one direction, the deformation rate after 30% elongation (30% return strain) is, for example, 20% or less (for example, 3 to 20%), preferably 15% or less (for example, 5 to 15%), more preferably 10% or less (for example, 5 to 10%). When the strain is in this range, the form stability against deformation is high.

  When the fruit and vegetable package of the present invention is plate-shaped or sheet-shaped, the thickness is not particularly limited, but can be selected from a range of about 1 to 500 mm, for example, 2 to 200 mm, preferably 3 to 100 mm, and more preferably. It is about 5-50 mm (especially 10-30 mm). If the thickness is too thin, it will be difficult to develop cushioning properties. In addition, you may laminate | stack and use a sheet-like fiber assembly.

  Furthermore, even if the fruit and vegetable package of this invention is plate shape or sheet shape, there are few dispersion | variation in thickness (thickness unevenness), and thickness is substantially uniform. Specifically, in the length of 5 mm or more in the sheet surface direction, the ratio of the minimum value to the maximum value of the sheet thickness (minimum value / maximum value) is 90% or more (for example, 90 to 99.9%), preferably Is 93% or more (for example, 93 to 99%), more preferably 95% or more (for example, 95 to 98%). Thus, although the fruit and vegetable package of this invention is a non-woven fiber structure, since thickness is uniform, it can be utilized effectively as various fruit and vegetable packages.

  The fruit and vegetable package of the present invention may have water repellency, and the expression of water repellency is due to the hydrophilicity attached to the fibers by exposing the fibers to water or water vapor in the manufacturing process described below. This is because the substances possessed are washed away and the original properties of the resin are developed on the surface of the fiber. Specifically, this water repellency is preferably 3 or more (preferably 3 to 5 points, more preferably 4 to 5 points) in the JIS L1092 spray test. Furthermore, in the fruit and vegetable package of the present invention, the fiber oil agent adhering to the fibers is also washed away by the cleaning effect of water and water vapor, and the skin irritation is also reduced.

  The fruit and vegetable package of the present invention may have an appropriate surface hardness, and is an FO type durometer hardness test (a test according to JIS K6253 “Testing method for hardness of vulcanized rubber and thermoplastic rubber”). ) Is, for example, about 10 or more, preferably about 15 or more, and more preferably about 20 to 100 (particularly 25 to 50). The fruits and vegetables package having such hardness can fix fruits and vegetables moderately and is excellent in moldability.

(Manufacturing method for fruit and vegetable packaging)
The method for producing a fruit and vegetable package of the present invention comprises a step of forming a fiber containing the wet heat adhesive fiber and the latent crimpable conjugate fiber, and heat-treating the produced fiber web with high-temperature steam for fusing and wrinkling. Shrinking.

  In the method for producing a fruit and vegetable package of the present invention, first, the wet heat-adhesive fiber and the fiber containing the latent crimpable conjugate fiber are formed into a web. As a method for forming the web, a conventional method, for example, a direct method such as a spun bond method or a melt blow method, a card method using melt blow fibers or staple fibers, a dry method such as an air array method, or the like can be used. Among these methods, a card method using melt blown fibers or staple fibers, particularly a card method using staple fibers is widely used. Examples of the web obtained using staple fibers include a random web, a semi-random web, a parallel web, and a cross-wrap web.

  Next, the obtained fiber web is sent to the next process by a belt conveyor, heat-treated with high-temperature steam, and the fibers are three-dimensionally bonded to each other by fusion of wet-heat adhesive fibers. The fibers are entangled by the expression of crimps. In the present invention, by using a method of treating with high-temperature steam as a heating method, uniform fusion and crimping can be expressed from the surface to the inside of the fiber assembly. In addition, as a pre-process of a fusion | melting and crimping process, from the point etc. which suppress a fiber scattering, some fibers of the obtained fiber web are made into low pressure water (for example, 0.1-1.5 MPa). , Preferably 0.5 to 1 MPa water) may be slightly entangled by a method such as spraying or spraying (spraying) and entanglement.

  Specifically, the obtained fiber web is sent to the next process by a belt conveyor, and then exposed to a superheated or high-temperature steam (high-pressure steam) stream to obtain a fiber assembly having a non-woven fiber structure. That is, when the fiber web transported by the belt conveyor passes through the high-speed and high-temperature steam flow ejected from the nozzle of the steam spraying device, the fibers adhere to each other due to the fusion of the wet heat adhesive fibers by the sprayed high-temperature steam. In addition to three-dimensional adhesion, the crimp of the latent crimpable fiber moves while changing the shape of the latent crimpable conjugate fiber into a coil having a specific radius of curvature. Confounding develops. In particular, since the fiber web in the present invention has air permeability, high-temperature water vapor penetrates into the inside, and a fiber assembly having a substantially uniform structure can be obtained.

  The fiber web is subjected to high temperature steam treatment on a belt conveyor, but the fiber web shrinks simultaneously with the high temperature steam treatment. Therefore, it is desirable that the fiber web to be supplied is over-feed according to the size of the target fiber aggregate immediately before being exposed to high-temperature steam. The overfeed ratio is about 110 to 300%, preferably about 120 to 250%, with respect to the length of the target fiber assembly.

  The belt conveyor to be used is not particularly limited as long as it can be subjected to high temperature steam treatment without disturbing the form of the fiber web used for processing, and an endless conveyor is preferably used. In addition, a general independent belt conveyor may be used, and another belt conveyor may be combined as necessary, and the web may be transported with the web sandwiched between both belts. By conveying in this way, when processing a fiber web, it can suppress that the form of the fiber web conveyed by external force, such as the water used for a process, high temperature steam, and a conveyor's vibration, deform | transforms. It is also possible to control the density and thickness of the treated non-woven fibers by adjusting the distance between the belts.

  In order to supply water vapor to the fiber web, a conventional water vapor jet apparatus is used. As this steam spraying device, a device capable of spraying steam substantially uniformly over the entire width of the web at a desired pressure and amount is preferable. When two belt conveyors are combined, water vapor is supplied to the web through a water-permeable conveyor belt or a conveyor net placed on the conveyor. A suction box may be attached to the other conveyor. Excess water vapor that has passed through the fiber web can be sucked and discharged by the suction box. Further, in order to perform steam treatment on both sides of the front and back of the fiber web at a time, in a conveyor opposite to the conveyor on which the steam spraying device is mounted, more than the portion on which the steam spraying device is mounted. You may install another water vapor | steam injection apparatus in the conveyor of a downstream part. If there is no steam injection device and suction box in the downstream part, if you want to steam-process the front and back of the fiber web, you can substitute it by inverting the front and back of the fiber web once processed and passing through the processing device again Good.

  The endless belt used for the conveyor is not particularly limited as long as it does not hinder the conveyance of the fiber web or the high-temperature steam treatment. However, when high-temperature steam treatment is performed, the surface shape of the belt may be transferred to the surface of the fiber web depending on the conditions. In particular, in order to obtain a fiber assembly having a flat surface, a net with fine mesh may be used. The upper limit is about 90 mesh, and a net that is roughly coarser than 90 mesh (for example, a net of about 10 to 50 mesh) is preferable. A finer mesh net than this has low air permeability and makes it difficult for water vapor to pass through. The mesh belt is made of metal, heat-treated polyester resin, polyphenylene sulfide resin, polyarylate resin (fully aromatic polyester resin), aromatic polyamide resin, etc. The heat resistant resin is preferable.

  Since the high-temperature steam sprayed from the steam spraying device is an air stream, unlike the hydroentanglement process or the needle punch process, the fibers in the fiber web that is the object to be processed enter the inside of the fiber web without largely moving. . When the water vapor flow enters the fiber web and the wet heat action, the water vapor flow efficiently covers the surface of each fiber existing in the fiber web in a wet heat state, and uniform heat bonding and heat crimping are possible. Conceivable. In addition, since the heat can be sufficiently conducted to the inside of the fiber as compared with the dry heat treatment, the degree of crimp in the surface and the thickness direction becomes substantially uniform.

  The nozzle for injecting the high-temperature steam may be a plate or a die in which predetermined orifices are continuously arranged in the width direction, and may be arranged so that the orifices are arranged in the width direction of the fiber web to be supplied. There may be one or more orifice rows, and a plurality of rows may be arranged in parallel. A plurality of nozzle dies having a single orifice array may be installed in parallel.

  When using a type of nozzle having an orifice in the plate, the thickness of the plate may be about 0.5 to 1 mm. The diameter and pitch of the orifice are not particularly limited as long as the target fiber fixation and the fiber entanglement accompanying crimp expression can be efficiently realized, but the orifice diameter is usually 0.05 to 2 mm, Preferably it is 0.1-1 mm, More preferably, it is about 0.2-0.5 mm. The pitch of the orifices is usually about 0.5 to 3 mm, preferably about 1 to 2.5 mm, and more preferably about 1 to 1.5 mm. If the orifice diameter is too small, the processing accuracy of the nozzle becomes low and the processing becomes difficult, and the operational problem that clogging is likely to occur easily occurs. On the other hand, if it is too large, it will be difficult to obtain a sufficient water vapor injection force. On the other hand, if the pitch is too small, the nozzle holes become too dense and the strength of the nozzle itself is reduced. On the other hand, if the pitch is too large, there are cases where high-temperature water vapor does not sufficiently hit the fiber web, making it difficult to ensure web strength.

  The high-temperature water vapor used is not particularly limited as long as the target fiber fixation and appropriate fiber entanglement can be realized along with the expression of the crimp of the fiber, and may be set depending on the material and form of the fiber used. For example, it is about 0.1 to 2 MPa, preferably about 0.2 to 1.5 MPa, and more preferably about 0.3 to 1 MPa. If the water vapor pressure is too high or too strong, the fibers forming the web will move more than necessary, causing turbulence, or the fibers will melt too much to partially retain the fiber shape, May be entangled more than necessary. Also, if the pressure is too weak, the amount of heat necessary for fiber fusion and crimp development cannot be given to the web being processed, or water vapor cannot penetrate the web, causing fiber fusion spots in the thickness direction. May cause uneven crimp. In addition, it may be difficult to control the uniform ejection of water vapor from the nozzle.

  The temperature of the high-temperature steam is, for example, about 70 to 150 ° C, preferably about 80 to 120 ° C, and more preferably about 90 to 110 ° C. The processing speed of the high temperature steam is, for example, 200 m / min or less, preferably 0.1 to 100 m / min, and more preferably about 1 to 50 m / min.

  If necessary, a plurality of plate-like fiber assemblies may be stacked to form a stacked body, or may be stacked with other materials to form a stacked body. Further, it may be processed into a desired form (various shapes such as a cylindrical shape, a quadrangular prism shape, a spherical shape, and an ellipsoidal shape) by molding.

  After the fibers of the fiber web are partially wet-heat bonded in this way to develop crimps, moisture may remain in the resulting non-woven fiber assembly, so the fiber assembly can be dried as necessary. May be. As for drying, it is necessary that the fibers on the surface of the aggregate that are in contact with the heating element for drying do not melt due to the heat of drying, and the fiber form does not disappear. it can. For example, a large dryer such as a cylinder dryer or tenter used for drying nonwoven fabrics may be used, but the remaining moisture is very small and can be dried by a relatively light drying means. Therefore, a non-contact method such as far-infrared irradiation, microwave irradiation, electron beam irradiation, or a method of blowing or passing hot air is preferable.

  Furthermore, as described above, the fruit and vegetable package of the present invention is obtained by adhering wet heat adhesive fibers with high-temperature steam, but partially (such as bonding of the obtained fiber aggregates), other conventional ones. It may be bonded by a method, for example, a processing method such as partial hot-pressure fusion (such as hot embossing) or mechanical compression (such as needle punch).

  The shape of the non-woven fiber assembly thus obtained is usually a plate shape or a sheet shape. The plate-like aggregate (a laminated body laminated to a desired thickness as required) may be cut and used as it is as a fruit and vegetable package, but usually the shape of the intended package (for example, The plate-like aggregate is secondarily formed by thermoforming according to the shape having a recess corresponding to the shape of the contents. Secondary molding methods include, for example, compression molding, pressure forming (extrusion pressure forming, hot plate pressure forming, vacuum pressure forming, etc.), free blow molding, vacuum forming, bending, matched mold forming, hot plate forming, wet heat. Press molding can be used. In particular, since the reproducibility of the mold is high, the mold may be used for pressure molding. For example, at a temperature of 100 to 150 ° C. (particularly about 120 to 140 ° C.), 0.05 to 2 MPa (particularly 0 .1 to 1 MPa). The shape and size of the concave portion formed by the secondary molding can be selected according to the type of fruit and vegetables, and may be, for example, a cup shape (inner hemisphere inside) or a partial concave portion thereof. .

  The fruit and vegetable package of the present invention can be used as a package that is fixed in contact with the fruits and vegetables in a container such as a cardboard box, a paper box, a wooden box, or a plastic case, or in a storage case (outer box). In addition, since the fruit and vegetable package of this invention has high air permeability and cushioning property, it is not restricted to the package inside an outer box, You may comprise outer box itself with the fruit and vegetable package of this invention. Examples of the fruits and vegetables contained in the fruit and vegetable package of the present invention include fruits such as peach, grape, apple, pear, mandarin orange, kiwi, papaya, mango and strawberry, vegetables such as tomato and melon, mushrooms such as shiitake mushrooms and matsutake mushrooms. Etc. Among them, it is particularly useful for packaging soft and vulnerable fruits and vegetables such as peaches, grapes, kiwis and tomatoes.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Each physical property value in the examples was measured by the following method. In the examples, “parts” and “%” are based on mass unless otherwise specified.

(1) Average curvature radius Using a scanning electron microscope (SEM), a photograph of the cross section of the non-woven fiber assembly was magnified 100 times. The radius of the circle when drawing a circle along the spiral of the fibers forming the spiral (coil) of one or more rounds among the fibers shown in the photograph of the cross section of the non-woven fiber assembly taken The radius of the circle when the crimped fiber was observed from the coil axis direction) was determined, and this was taken as the radius of curvature. In addition, when the fiber has drawn the spiral in the ellipse shape, 1/2 of the sum of the major axis and the minor axis of the ellipse was used as the radius of curvature. However, in order to exclude the case where the crimped fiber does not exhibit sufficient coil crimping or the case where the spiral shape of the fiber is reflected as an ellipse, the major axis and minor axis of the ellipse Only the ellipses whose ratio is in the range of 0.8 to 1.2 were measured. In addition, the measurement was performed with respect to an SEM image taken for an arbitrary cross section, and was shown as an average value of n number = 100.

(2) Fiber curvature and uniformity thereof An electron micrograph (magnification × 100 times) in a cross section of the nonwoven fiber assembly was taken, and in the projected portion of the taken fiber, in the thickness direction, the surface layer, the inner layer, The measurement area was set so as to be divided into three equal parts in the back layer, and in the vicinity of the center of each layer, the length direction was 2 mm or more and 500 or more measurable fiber pieces were included. For these regions, the end-to-end distance (shortest distance) between one end of the fiber and the other end was measured, and the fiber length of the fiber (fiber length on the photograph) was measured. That is, when the end portion of the fiber is exposed on the surface of the nonwoven fiber assembly, the end portion is used as it is as an end portion for measuring the distance between the end portions, and the end portion is inside the nonwoven fiber assembly. When buried, the boundary part (end part on the photograph) buried inside the nonwoven fiber assembly was used as an end part for measuring the distance between the end parts. At this time, among the photographed fibers, a fiber image that cannot be confirmed to be continuous over 100 μm or more was excluded from measurement. And fiber curvature was computed from ratio (L2 / L1) of the fiber length (L2) of the fiber with respect to the distance (L1) between edge parts. In addition, the measurement of fiber curvature calculated the average value for every surface layer, inner layer, and back layer divided into three equal to the thickness direction. Furthermore, the uniformity in the thickness direction of the fiber curvature was calculated from the ratio between the maximum value and the minimum value of each layer.

  In FIG. 1, the schematic diagram about the measuring method of the image | photographed fiber is shown. FIG. 1 (a) shows a fiber in which one end is exposed on the surface and the other end is buried inside the non-woven fiber assembly. In the case of this fiber, the end-to-end distance L1 is the end of the fiber. This is the distance from the part to the boundary part buried in the nonwoven fiber assembly. On the other hand, the fiber length L2 is a length obtained by two-dimensionally stretching the fiber of the portion where the fiber can be observed (the portion from the end portion of the fiber until it is buried in the non-woven fiber assembly) on the photograph.

  FIG. 1 (b) shows a fiber in which both ends are embedded in the nonwoven fiber assembly. In the case of this fiber, the end-to-end distance L1 is determined by the both ends of the portion exposed on the surface of the nonwoven fiber assembly ( This is the distance between the two ends on the photo. On the other hand, the fiber length L2 is a length obtained by two-dimensionally stretching the portion of the fiber exposed on the surface of the nonwoven fiber assembly on the photograph.

(3) Fiber Adhesion Rate Using a scanning electron microscope (SEM), a photograph in which the cross section of the fiber assembly was enlarged 100 times was taken. The number of fiber cut surfaces (fiber end surfaces) that can be found in each region (front surface, inside (center), back surface) divided into three equal parts in the thickness direction. The ratio of the number of cut surfaces where the fibers are bonded to each other was determined. Of the total number of fiber cross sections that can be found in each region, the ratio of the number of cross sections in a state where two or more fibers are bonded is expressed as a percentage based on the following formula. In addition, in the part which fibers contact, there exists a part which is simply contacting, without melt | fusion, and a part which has adhere | attached by melt | fusion. However, by cutting the fiber assembly for microscopic photography, the fibers in contact with each other are separated from each other by the stress of each fiber on the cut surface of the fiber assembly. Therefore, in the cross-sectional photograph, it can be determined that the contacting fibers are bonded to each other.

Fiber adhesion rate (%) = (number of cross sections of fibers bonded two or more) / (total number of cross sections of fibers) × 100
However, for each photograph, all the fibers with visible cross sections were counted, and when the number of fiber cross sections was 100 or less, a photograph to be observed was added so that the total fiber cross section number exceeded 100. In addition, the fiber adhesion rate was calculated | required about each area | region divided into three equally, and the uniformity in the thickness direction was computed from the ratio of the maximum value and the minimum value.

(4) Weight per unit (g / m ² )
Measured according to JIS L1913 “Testing method for general short fiber nonwoven fabric”.

(5) Thickness (mm), apparent density (g / cm ³ )
The thickness was measured according to JIS L1913 “Test method for general short fiber nonwoven fabric”, and the apparent density was calculated from this value and the basis weight value.

(6) Number of crimps Evaluated according to JIS L1015 “Testing method for chemical fiber staples” (8.12.1).

(7) Surface hardness It measured according to the FO type durometer hardness test (the test based on the "hardness test method of vulcanized rubber and thermoplastic rubber" of JIS K6253).

(8) Air permeability Measured by the fragile method according to JIS L1096.

(9) 25% stress, 50% stress, 25% recovery / compression stress ratio, compression recovery rate According to JIS K6400-2 “7.3 Compression Deflection Measurement Method B”, a 40 mmφ circular pressure plate is applied at 100 mm / min. 25% from the force-deflection curve when moving at speed and pushing to 50% of the initial thickness of a 30 mmφ cylindrical sample and then immediately returning at the same speed (when the load is removed at the same speed) Read the stress value at the time of compression and the stress at the time of 50% compression, respectively, and take the recovery stress (25% return stress) when it is returned to 25% as well as 25% compression stress and 50% compression stress, respectively. The ratio with the compressive stress was taken to obtain a ratio of 25% recovery / compressive stress. Further, the compression recovery rate when the return stress after compression became “0” was measured.

(10) 25% compressive stress retention rate According to the 25% compressive stress measurement method, when the compression is performed to the target compressibility (25% compression), the measurement pressure plate (compressor) is stopped, and this The stress at the time was recorded, and the stress after a predetermined time (30 minutes, 1 hour, 2 hours) was read while maintaining this state. The value representing the ratio of the stress after each lapse of time to the stress at the time of stopping the pressure plate in terms of percentage was defined as the stress retention rate.

(11) Evaluation of damage to fruits and vegetables due to transportation After placing one peach in the recess of the package obtained in the examples and comparative examples, the peach was packed in an outer box 15 cm long x 15 cm wide x 18 cm high, The package was fixed to a shaker (manufactured by Yamato Scientific Co., Ltd., “MK161 type”), and shaken for 1 hour under the condition of 30 rpm by a swirling shake method, and a simulation test of shaking due to transportation was performed. The degree of peach damage after shaking was evaluated according to the following criteria.

◎: No damage to peaches ○: Some damage to peaches △: Damage to peaches ×: Strong damage to peaches

Example 1
Core-sheath type composite staple fiber having a core component of polyethylene terephthalate and a sheath component of ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, saponification degree 98.4 mol%) as wet heat adhesive fibers (Co., Ltd.) “Kuraray”, “Sophista”, fineness 3 dtex, fiber length 51 mm, core-sheath mass ratio = 50/50, number of crimps 21/25 mm, crimp ratio 13.5%) was prepared.

  On the other hand, the latent crimpable fiber is composed of a polyethylene terephthalate resin (component A) having an intrinsic viscosity of 0.65 and a modified polyethylene terephthalate resin (component B) obtained by copolymerization of 20 mol% of isophthalic acid and 5 mol% of diethylene glycol. Side-by-side type composite staple fiber (manufactured by Kuraray Co., Ltd., “PN-780”, 1.7 dtex × 51 mm length, mechanical crimp number of 12/25 mm, 130 ° C. × 1 minute after heat treatment of 62/25 mm ) Was prepared.

The core-sheath type composite staple fiber (wet heat adhesive fiber) and the side-by-side type composite staple fiber (latent crimpable composite fiber) are wet heat adhesive fiber / latent crimped composite fiber = 30 / After blending at a ratio of 70, a card web having a basis weight of about 100 g / m ² was produced by the card method, and 11 sheets of this web were stacked to form a card web having a total basis weight of 1100 g / m ² .

  The card web was transferred to a belt conveyor equipped with a 50 mesh, 500 mm wide stainless steel endless wire mesh. In addition, the belt conveyor which has the same metal mesh is equipped on the upper part of the metal mesh of this belt conveyor, and it rotated in the same direction at the same speed, respectively, and used the belt conveyor which can adjust the space | interval of these metal meshes arbitrarily. .

  Next, the steam web is introduced into the steam jetting device provided in the lower belt conveyor, and 0.4 MPa of high-temperature steam is ejected (perpendicularly) from the device so as to pass in the thickness direction of the card web. Steam treatment was performed to obtain a non-woven fiber assembly. In this steam spraying device, a nozzle is installed in the lower conveyor so as to spray high-temperature steam toward the web via a conveyor net, and a suction device is installed in the upper conveyor. Further, another jetting device, which is a combination of the arrangement of the nozzle and the suction device reversed, is installed on the downstream side in the web traveling direction of the jetting device, and steam treatment is performed on both the front and back sides of the web. did.

  In addition, the hole diameter of the water vapor | steam injection nozzle was 0.3 mm, and the water vapor | steam injection apparatus with which the nozzle was arranged in 1 row at 1 mm pitch along the width direction of the conveyor was used. The processing speed was 3 m / min, and the distance (distance) between the upper and lower conveyor belts on the nozzle side and the suction side was 20 mm. The nozzles were arranged on the back side of the conveyor belt so as to be almost in contact with the belt.

  The obtained nonwoven fiber assembly had excellent cushioning properties and high breathability. Further, the obtained nonwoven fiber assembly was dried with hot air at 120 ° C. for 1 minute, and then press-molded with a mold under conditions of 135 ° C. and 0.5 MPa for 120 seconds to form a cocoon-like shape (diameter: A hemispherical recess having a diameter of 100 mm, a height of 30 mm, and a thickness of 10 mm was formed. Table 1 shows the evaluation results of the fiber assembly and the fruit and vegetable package.

Example 2
After mixing the wet heat adhesive fiber and the latent crimpable conjugate fiber in a mass ratio of wet heat adhesive fiber / latent crimped conjugate fiber = 55/45, a card web having a basis weight of about 100 g / m ² is obtained. A fruit and vegetable package was obtained in the same manner as in Example 1 except that 16 sheets were stacked. The results are shown in Table 1.

Example 3
A fruit and vegetable package was obtained in the same manner as in Example 1 except that six card webs were stacked. The results are shown in Table 1.

Comparative Example 1
After mixing the wet heat adhesive fiber and the latent crimpable conjugate fiber in a mass ratio of wet heat adhesive fiber / latent crimpable conjugate fiber = 80/20, a card web having a basis weight of about 100 g / m ² is obtained. A fruit and vegetable package was obtained in the same manner as in Example 1 except that 24 sheets were stacked. The results are shown in Table 1.

  As is apparent from the results in Table 1, the fruit and vegetable packages obtained in the examples have excellent cushioning properties and high air permeability, and are free from peach damage due to shaking experiments. Compared to this, the fruit and vegetable package obtained in the comparative example has low cushioning and breathability, and peach damage is severe.

FIG. 1 is a schematic diagram showing a method for measuring fiber curvature in the present invention.

Claims (6)

  A fruit and vegetable package comprising a non-woven fiber assembly comprising a wet heat adhesive fiber and a composite fiber in which a plurality of resins having different heat shrinkage rates form a phase separation structure, the wet heat adhesive fiber and the non-heat adhesive fiber The ratio (mass ratio) with the wet heat adhesive fiber is the former / the latter = 10/90 to 70/30, and the bonding point of the fiber fused with the wet heat adhesive fiber inside the nonwoven fiber assembly Is a fruit and vegetable package in which the composite fibers are crimped substantially uniformly with an average curvature radius of 20 to 200 μm and entangled.   In the cross section in the thickness direction, the fiber adhesion rate in each region divided into three equal parts in the thickness direction is 3 to 30%, and the ratio of the minimum value to the maximum value of the fiber adhesion rate in each region is 50% or more. The fruit and vegetable package according to claim 1.   In the cross section in the thickness direction, the fiber bending rate of the composite fiber in each region divided into three equal parts in the thickness direction is 1.3 or more, and the minimum value relative to the maximum value of the fiber bending rate of the composite fiber in each region The fruit and vegetable package of Claim 1 or 2 whose ratio is 75% or more.   The fruit and vegetable package according to any one of claims 1 to 3, wherein the 5% compression stress is 0.01 to 1.0 N / 30 mmφ, and the compression recovery rate is 60% or more.   The wet-heat adhesive fiber is a core-sheath type composite fiber formed of a sheath part composed of an ethylene-vinyl alcohol copolymer and a core part composed of a polyester resin. Crab fruit and vegetable package.   A step of forming a fiber comprising wet heat adhesive fibers and a composite fiber in which a plurality of resins having different thermal shrinkage rates form a phase separation structure; and heat-treating the produced fiber web with high-temperature steam to fuse and The manufacturing method of the fruit and vegetable package in any one of Claims 1-5 including the process to shrink | contract.

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