Fiber ball

Abstract

Provided is a fiber ball in which synthetic fibers are used and which exhibits excellent heat retaining properties and bulkiness recoverability after compression even when applied to a product.　The fiber ball contains a heat-bondable composite fibers having heat-bonded intersections. It has been found that: excellent bulkiness is exerted by using fiber balls having a specific volume of 100-400 cm3 / g and by forming a large amount of voids not only between the fibers but also between the fiber balls; and the bulkiness can be maintained even when the fiber balls are applied to a product because the fibers are bonded to each other.

Description

Grained cotton

[0001] This invention relates to granular cotton with excellent heat retention properties.

[0002] Traditionally, down and synthetic fibers have been proposed as fillings for bedding and clothing. Down fillings are widely used because they combine excellent heat retention and a pleasant texture. However, down has the problem of losing loft and heat retention when wet, and its supply is unstable due to stricter regulations on hunting and harvesting. It has also been pointed out that it may cause allergies depending on the wearer's constitution.

[0003] As an alternative to down, granular padding using synthetic fibers has been proposed (Patent Documents 1 and 2). In conventional padding using synthetic fibers, there are examples of applying a bulky web as padding. However, although this method is indeed very bulky under no load, the fibers are not bonded to each other, so when applied to a product (for example, when used as padding material between fabrics), the bulkiness decreases, making it difficult to obtain satisfactory heat retention. Furthermore, if heat treatment is performed to bond the fibers together, the bulkiness is easily impaired by the heat treatment, and satisfactory heat retention cannot be obtained. Thus, while padding using synthetic fibers has advantages such as lower moisture absorption and less reduction in heat retention even when wet compared to down, stable supply is possible, and the possibility of allergies is low, it is inferior in heat retention compared to padding using down.

[0004] Japanese Patent Publication No. 2015-155586, Japanese Patent Publication No. 2002-138358

[0005] This invention is based on the prior art described above, and its purpose is to provide granular cotton that has excellent heat retention properties when applied to products, while using synthetic fibers.

[0006] The inventors diligently conducted research to solve the above-mentioned problems. They discovered that granular cotton obtained by heat-bonding the intersections of fibers while maintaining a bulky state and then cutting it to a predetermined size has excellent bulkiness because it forms a large amount of voids not only between the fibers but also between the granular cotton. Furthermore, because the fibers are bonded to each other, the bulkiness can be maintained even when applied to a product. This led to the completion of the present invention.

[0007] In other words, the present invention has the following configuration: [1] A granular cotton containing heat-bondable composite fibers whose intersections are heat-bonded, wherein the specific volume of the granular cotton is 100 to 400 cm³ ３ [2] A granular cotton having a weight of / g. [2] The granular cotton according to [1], wherein the content of the heat-adhesive composite fiber is 50% by weight or more relative to the weight of the granular cotton. [3] The volume of the granular cotton is 0.001 to 125 cm³. ３ [1] or [2], wherein the granular cotton is as described in [1] or [2]. [4] The granular cotton is as described in any of [1] to [3], wherein the shape of the granular cotton is not substantially spherical. [5] The granular cotton is as described in any of [1] to [4], wherein the average fiber diameter of the fibers constituting the granular cotton is 5 to 30 μm. [6] The granular cotton is as described in any of [1] to [5], wherein the heat-adhesive composite fiber is a sheath-core type composite fiber having polyester as the core component and polyolefin as the sheath component. [7] A granular cotton aggregate containing the granular cotton as described in any of [1] to [6], wherein the bulkiness of the granular cotton aggregate is 250 to 500 cm ３ A granular cotton aggregate that is / g. Cotton filling using granular cotton as described in any of [8], [1], to [6].

[0008] According to the present invention, it is possible to provide granular cotton with excellent heat retention properties while using synthetic fibers.

[0009] The present invention relates to granular cotton containing heat-bondable composite fibers whose intersections are heat-bonded, wherein the specific volume of the granular cotton is 100 to 400 cm³. ３ It is characterized by having a specific volume of 100-400 cm³. The inclusion of heat-bonded composite fibers with heat-sealed intersections makes it easier to maintain bulk even under pressure when applied to a product. ３ By using a weight of / g, a large amount of air can be stored in the gaps between the fibers that make up the cotton granules, making it possible to provide excellent heat retention even while using synthetic fibers.

[0010] (Heat-Adhesive Composite Fibers) The heat-adhesive composite fibers used in the present invention are not particularly limited as long as they can melt with heat and form adhesive points, and examples of their composite form include concentric sheath core type composite fibers, eccentric sheath core type composite fibers, parallel type composite fibers, segmented type composite fibers, or sea-island type composite fibers. Furthermore, the cross-sectional shape of the composite fibers is not particularly limited, and any of the following can be used: round shapes such as circles and ellipses, angular shapes such as triangles and squares, irregular shapes such as star shapes and octave shapes, or hollow shapes.

[0011] The resin constituting the heat-adhesive composite fiber in the present invention is not particularly limited, and examples include polyolefin resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), crystalline polypropylene (PP), or copolymers of propylene and α-olefin (excluding propylene) (Co-PP) with propylene as the main component; polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), copolymerized polyethylene terephthalate (Co-PET), polylactic acid (PLA), polyglycolic acid (PGA), or polybutylene succinate (PBS); polyvinyl alcohol resins, polyvinyl acetate resins, acrylic resins, polystyrene resins, polyurethane resins, polyamide resins, or fluorine resins. While there are no particular limitations on the combination of resins constituting the heat-adhesive composite fiber, from the viewpoint of widening the processing temperature range, it is preferable that the melting point difference be 10°C or more, more preferably 30°C or more, and even more preferably 50°C or more. Examples of combinations include PP / HDPE, PP / LLDPE, PP / Co-PP, PET / HDPE, PET / LLDPE, PET / Co-PET, and PET / PP. Furthermore, from the viewpoint of heat adhesion, it is preferable that the low-melting-point component occupies 50% or more of the surface of the heat-adhesive composite fiber, and more preferably 70% or more. In particular, it is preferable to use a sheath-core type composite fiber in which a polyolefin resin is arranged on the sheath side as the low-melting-point component and a polyester resin is arranged on the core side as the high-melting-point component, and it is even more preferable to use a sheath-core type composite fiber in which polyethylene is arranged as the sheath component as the low-melting-point component and polyethylene terephthalate is arranged as the core component as the high-melting-point component. The polyolefin sheath component strengthens the bonding points of the heat-bondable composite fibers, improving shape stability, as well as enhancing quick-drying properties and flexibility. Furthermore, the polyester core component increases the specific volume of the nonwoven fabric, improving heat retention, flexibility, and shape stability.

[0012] The volume ratio of low-melting-point components to high-melting-point components is not particularly limited, but a larger proportion of low-melting-point components improves the bonding strength between heat-adhesive composite fibers, thereby increasing the strength of the nonwoven fabric. A larger proportion of high-melting-point components improves the bulkiness and flexibility of the nonwoven fabric, as well as making it less susceptible to changes in thickness under load. From this viewpoint, the volume ratio of low-melting-point components to high-melting-point components is preferably 20 / 80 to 80 / 20, and more preferably 30 / 70 to 70 / 30.

[0013] The resin constituting the heat-adhesive composite fiber may optionally contain additives such as antioxidants, light stabilizers, ultraviolet absorbers, neutralizing agents, nucleating agents, epoxy stabilizers, lubricants, antibacterial agents, deodorants, flame retardants, antistatic agents, pigments, or plasticizers, to the extent that they do not impede the effects of the present invention.

[0014] The fineness of the heat-adhesive composite fiber in the present invention is not particularly limited, but in order to obtain excellent fiber-opening properties, easily obtain uniform cotton granules, and have good flexibility and compactness by not increasing the number of bonding points of the heat-adhesive composite fiber too much, it is preferably 0.5 dtex or more, more preferably 0.6 dtex or more, and even more preferably 0.7 dtex or more. Furthermore, in order to easily improve heat retention and have good shape stability of the cotton granules by not reducing the number of bonding points of the heat-adhesive composite fiber too much, it is preferably 20 dtex or less, more preferably 10 dtex or less, and even more preferably 6 dtex or less.

[0015] The fiber length of the heat-adhesive composite fiber is not particularly limited, but in order to increase the intertwining of the fibers and improve the shape stability of the cotton granules, it is preferably 3 mm or longer, more preferably 20 mm or longer, and even more preferably 30 mm or longer. Furthermore, in order to improve the bulkiness and flexibility of the cotton granules, the fiber length is preferably 200 mm or less, more preferably 120 mm or less, and even more preferably 60 mm or less.

[0016] The crimp of the heat-adhesive conjugate fiber is not particularly limited, and the crimp properties such as the number of crimps, crimp percentage, residual crimp percentage, and crimp elastic modulus may be appropriately selected in consideration of the bulkiness, flexibility, mechanical properties and the like of the granular cotton. In addition, the shape of the crimp is also not particularly limited, and zigzag mechanical crimps, three-dimensional crimps such as spiral shapes and omega shapes can be appropriately selected.

[0017] (Granular Cotton) In the granular cotton of the present invention, it is important that the intersection points of the aforementioned heat-adhesive conjugate fibers are thermally bonded. By forming such granular cotton, the bulk is less likely to be collapsed under pressure applied when the granular cotton is applied to a product, and excellent heat retention can be imparted.

[0018] The specific volume of the granular cotton in the present invention is 100 to 400 cm ３ / g, which is important. When the specific volume is 100 cm ３ / g or more, a large amount of air is contained between fibers and between granular cotton, thereby improving heat retention. In addition, when the specific volume is 400 cm ３ / g or less, the number of bonding points between the heat-adhesive conjugate fibers increases, so that the bulk is less likely to decrease even when a load is applied, and heat retention is easily maintained. From this viewpoint, the lower limit of the specific volume is 120 cm ３ / g or more is preferable, 150 cm ３ / g or more is more preferable, 180 cm ３ / g or more is even more preferable, and 200 cm ３ / g or more is particularly preferable. In addition, the upper limit of the specific volume is 380 cm ３ / g or less is preferable, 350 cm ３ / g or less is more preferable, 320 cm ３ / g or less is even more preferable, and 300 cm ３ / g or less is particularly preferable. In addition, the specific volume of granular cotton in the present invention means the specific volume per piece of granular cotton, and the measurement method thereof will be described in detail in the examples.

[0019] The average fiber diameter of the fibers constituting the granular cotton of the present invention is not particularly limited. However, to obtain excellent fiber opening properties and uniform granular cotton, the average fiber diameter is preferably 5 µm or greater, more preferably 6 µm or greater, and even more preferably 8 µm or greater. In addition, to enhance the heat retention of granular cotton, the average fiber diameter is preferably 30 µm or less, more preferably 25 µm or less, and even more preferably 20 µm or less.

[0020] The shape of the granular cotton of the present invention is not particularly limited, and examples include substantially spherical shape, columnar shape, conical shape, triangular prism shape, triangular pyramid shape, quadrangular pyramid shape, cube, cuboid, rod shape, hexagonal prism shape, octagonal prism shape, and polyhedral shape. However, to form an aggregate in which granular cotton pieces are arranged as loosely as possible and to easily improve heat retention, the shape is preferably non-substantially spherical, and more preferably cubic, cuboid, or rod-shaped. Here, the term "substantially spherical" refers to shapes having no flat surface, where the ratio of any of the three orthogonal axes is 2 or less, and also includes true spherical shapes.

[0021] The volume of the granular cotton of the present invention is not particularly limited. However, to easily improve the productivity and handleability of granular cotton, 0.001 cm ３ or greater is preferable, 0.004 cm ３ or greater is more preferable, and 0.009 cm ３ or greater is even more preferable. In addition, to facilitate uniform filling into complex shapes and to easily improve the texture when applied to products, 125 cm ３ or less is preferable, 64 cm ３ or less is more preferable, and 9 cm ３ or less is even more preferable. Note that the volume of granular cotton in the present invention means the volume per granular cotton piece.

[0022] The granular cotton of the present invention is not particularly limited. However, to easily maintain heat retention when applied to products and to make it difficult for fibers constituting the granular cotton to fall off, the content of the aforementioned heat-adhesive conjugate fiber is preferably 50% by weight or greater based on the weight of the granular cotton, more preferably 60% by weight or greater, and even more preferably 70% by weight or greater.

[0023] The granular cotton of the present invention may contain fibers other than the aforementioned heat-adhesive conjugate fibers within a range that does not impair the effects of the present invention. Such fibers are not particularly limited, and examples include natural fibers such as cotton, silk, linen and wool, semi-synthetic fibers such as acetate, regenerated fibers such as rayon and cupra, and synthetic fibers such as polypropylene, polyester, acrylic, nylon and vinylon. In view of high heat resistance, low hygroscopicity and easy availability, polyester fibers are preferable. The polyester fibers are not particularly limited, and examples include polyethylene terephthalate (PET) fibers, polybutylene terephthalate (PBT) fibers, polytrimethylene terephthalate (PTT) fibers, polylactic acid (PLA) fibers, polyglycolic acid (PGA) fibers, polybutylene succinate (PBS) fibers and conjugate fibers thereof. Among these, polyethylene terephthalate, polytrimethylene terephthalate, and conjugate fibers of polyethylene terephthalate and polytrimethylene terephthalate are preferable. When fibers other than the heat-adhesive conjugate fibers are contained, the content ratio is not limited as long as the effects of the present invention are not impaired, and may be 5 to 50% by weight based on the weight of the granular cotton. When the content is 5% by weight or more, the effect of containing fibers other than the heat-adhesive conjugate fibers is easily obtained. When the content is 50% by weight or less, the proportion of the heat-adhesive conjugate fibers does not become excessively low, heat retention is easily maintained, and fibers are less prone to falling out. (Granular cotton aggregate)

[0024] The granular cotton aggregate of the present invention is not particularly limited as long as it contains the aforementioned granular cotton. In order to easily improve heat retention and bulk sustainability, the granular cotton is preferably contained in an amount of 30% by weight or more, more preferably 50% by weight or more, based on the weight of the granular cotton aggregate.

[0025] The bulkiness of the granular cotton aggregate of the present invention is not particularly limited. In order to allow a large amount of air to be contained between fibers and between granular cotton pieces to easily improve heat retention, the bulkiness is 250 cm ３ / g or more, preferably ３ / g or more, more preferably 300 cm ３It is even more preferable that the amount is 1 / g or more. In addition, to increase the number of bonding points of the heat-adhesive composite fibers, the bulk does not decrease easily when a load is applied, and it is easier to maintain heat retention, 500 cm ３ It is preferable that the amount be less than or equal to 450 cm². ３ It is more preferable that it be less than or equal to 420 cm². ３ It is even more preferable that the amount is less than or equal to / g. The method for measuring bulkiness will be explained in detail in the examples.

[0026] (Method for manufacturing granular cotton) The method for manufacturing granular cotton in the present invention is not particularly limited, but preferably includes a step of forming a web containing the heat-adhesive composite fibers described above (hereinafter sometimes referred to as the "web forming step"), a step of heat-treating the web while maintaining bulkiness and heat-bonding the intersections of the heat-adhesive composite fibers to obtain a nonwoven fabric (hereinafter sometimes referred to as the "heat treatment step"), and a step of cutting the obtained nonwoven fabric to a predetermined size (hereinafter sometimes referred to as the "cutting step"). With such a manufacturing method, bulkiness can be imparted by forming a large amount of voids not only between fibers but also between granular cotton, and furthermore, granular cotton can be obtained that maintains its bulkiness because the fibers are bonded to each other.

[0027] (Web Forming Process) The method for forming a web containing heat-adhesive composite fibers is not particularly limited, but it may be a short-fiber web formation method using the short fibers (staples or chops) of the heat-adhesive composite fibers described above, such as the carding method, airlaid method, or wet method, or a long-fiber web formation method such as the spunbond method, meltblown method, or tow opening method. However, the carding method is preferred in order to easily obtain bulky granular cotton. In this invention, "web" refers to a fiber aggregate in which fibers are entangled to some extent, and the intersections of the heat-adhesive composite fibers are not bonded.

[0028] (Heat Treatment Process) Next, the web is heat-treated while maintaining its bulkiness, and the intersections of the heat-adhesive composite fibers are heat-bonded to obtain a nonwoven fabric. The heat treatment method is not particularly limited, but examples include blowing a heat transfer medium from the top or bottom surface of the web, or introducing the web into a furnace (under no-wind conditions) filled with a heat transfer medium. The above heat treatment may be carried out under atmospheric pressure, high pressure, low pressure, or vacuum, but it is preferable to carry it out under atmospheric pressure from the viewpoint of simplifying the equipment. Furthermore, in the heat treatment process, it is preferable to introduce the web into the furnace using a conveyor belt or the like and obtain the nonwoven fabric continuously. The heat transfer medium is not particularly limited, and examples include hot air or superheated steam, but it is preferable to use superheated steam from the viewpoint of the mechanical properties of the nonwoven fabric and productivity.

[0029] The temperature of the heat transfer medium is not particularly limited, but if it is higher than the melting point or softening point of the low-melting-point component constituting the heat-adhesive composite fiber, and lower than the melting point or softening point of the high-melting-point component constituting the heat-adhesive composite fiber, it becomes easier to bond the intersections of the heat-adhesive composite fiber while suppressing deformation of the web. From this viewpoint, the lower limit of the temperature of the heat transfer medium is more preferably 10°C or more higher than the melting point or softening point of the low-melting-point component constituting the heat-adhesive composite fiber, and even more preferably 20°C or more higher than the melting point or softening point of the low-melting-point component constituting the heat-adhesive composite fiber. Furthermore, the upper limit of the temperature of the heat transfer medium is more preferably 10°C or more lower than the melting point or softening point of the high-melting-point component constituting the heat-adhesive composite fiber, and even more preferably 20°C or more lower than the melting point or softening point of the high-melting-point component constituting the heat-adhesive composite fiber.

[0030] The air velocity of the heat transfer medium is not particularly limited, but is preferably 0.5 m / s or less, more preferably 0.3 m / s or less, and even more preferably 0.1 m / s or less, in order to easily obtain the desired specific volume.

[0031] The processing time for the heat treatment process is not particularly limited, but is preferably 60 seconds or less, and more preferably 30 seconds or less. If the processing time is 60 seconds or less, it is possible to manufacture nonwoven fabrics with satisfactory productivity.

[0032] (Cutting process) Next, the obtained nonwoven fabric is cut to a predetermined size. The cutting method is not particularly limited, and known methods and equipment such as a push cutter, shear cutter, rotary cutter, slitter, die cutter, laser cutter, crusher, shredder, or a combination thereof can be used.

[0033] The granular cotton of the present invention can be suitably used as stuffing for bedding such as comforters, mattresses, and pillows; as stuffing for clothing such as down jackets and quilted fabrics; and as stuffing for outdoor equipment such as sleeping bags and cooler bags. In particular, it is suitable for use in clothing, especially as stuffing for down jackets.

[0034] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The methods or definitions for measuring the physical properties shown in the examples are shown below. Furthermore, all physical property measurements below were performed after the nonwoven fabric was heat-treated in an oven at 110°C for 5 minutes to reset the stress on the cotton granules.

[0035] <Fineness of heat-bondable composite fibers> The fineness of heat-bondable composite fibers and non-bondable fibers was measured in accordance with JIS L 1015.

[0036] <Average fiber diameter of fibers constituting the cotton granules> The cotton granules were photographed at a magnification of 100 to 200 times using a scanning electron microscope (Hitachi High-Tech Corporation, SU-8000). The fiber diameter of the fibers constituting the cotton granules was measured using image analysis software (ImageJ). The fiber diameter was the average value when 50 fibers were measured. <Shape of the cotton granules> The shape of the cotton granules was confirmed visually.

[0037] <Weight of the cotton granules> The weight (g) of each cotton granule was measured using an electronic balance (Shimadzu Corporation, AUW120D). The weight was the average of five measurements.

[0038] <Volume of the cotton granules> Using calipers, measure the lengths (cm) of the three axes (X-axis, Y-axis, Z-axis) of the cotton granules, and determine the volume (cm) of the cotton granules according to their shape. ３ The volume was calculated as the average of five measurements.

[0039] <Specific volume of granular cotton> The weight (g) and volume (cm³) of the granular cotton obtained above. ３ The specific volume of the granular cotton was calculated from the following formula: Specific volume (cm³) ３ ( / g) = Volume of cotton granules (cm³) ３ ) ÷ Weight of cotton granules (g)

[0040] <Height of the granular cotton or cotton-like material aggregate> 5 g of granular cotton or cotton-like material was placed in an acrylic cylinder with an inner diameter of 13.4 cm and a height of 40 cm. Next, the mouth of the cylinder was covered with a polyethylene gusset bag, and a 1 cm diameter opening was formed in the polyethylene gusset bag. The tip of an air gun was inserted into this opening and air was blown in for 5 seconds to allow air to be absorbed into the granular cotton and to disperse it evenly. The height of the granular cotton or cotton-like material aggregate at this time was measured and defined as the unloaded height T0 (cm). Next, the gusset bag was removed and 0.15 gf / cm² was applied to the granular cotton or cotton-like material aggregate. ２ The load plate was slowly placed on top, and the height was measured after 2 minutes, which was defined as the initial height T1 (cm). After measuring the initial height T1, 1.5 gf / cm² was applied to the load plate. ２ With the weights added, the total pressure was 1.65 gf / cm². ２ The height was measured after 2 minutes and defined as the compressed height T2 (cm). After measuring the compressed height T2, the load plate and weights were removed to remove the load, and after 4 minutes, the load plate was placed back on and the height was measured immediately afterward and defined as the recovered height T3 (cm). Each height was the average of the two measurements.

[0041] <Bulkiness of the granular cotton aggregate or cotton-like aggregate> From the initial height T1 (cm) obtained above, the bulkiness of the granular cotton aggregate or cotton-like aggregate (cm) can be calculated using the following formula. ３ The bulkiness (cm) was calculated. ３ / g)=141(cm ２ ) × T1 (cm) ÷ 5 (g) Note: 141cm ２ This refers to the cross-sectional area of ​​the cylinder.

[0042] <Bulk retention rate of granular cotton aggregate or cotton-like material aggregate> From the unloaded height T0 (cm) and initial height T1 (cm) obtained above, the bulk retention rate (%) of the granular cotton aggregate or cotton-like material aggregate was calculated using the following formula: Bulk retention rate (%) = T1 (cm) ÷ T0 (cm) × 100

[0043] <Compressibility of granular cotton aggregate or cotton-like material aggregate> From the initial height T1 (cm) and compressed height T2 (cm) obtained above, the compressibility of the granular cotton aggregate or cotton-like material aggregate was calculated using the following formula: Compressibility (%) = (T1 (cm) - T2 (cm)) ÷ T1 (cm) × 100

[0044] <Recovery Rate of Granular Cotton Aggregates or Cotton-like Material Aggregates> From the initial height T1 (cm) and recovered height T3 (cm) obtained above, the recovery rate of the granular cotton aggregates or cotton-like material aggregates was calculated using the following formula: Recovery Rate (%) = T3 (cm) ÷ T1 (cm) × 100

[0045] <Heat Retention Rate> 9.6g of granular cotton or cotton-like material was enclosed in a polyester cushion cover (40cm x 40cm), and the heat retention rate was measured in accordance with JIS L 1096 A method. The heat retention rate was the average value of two measurements.

[0046] [Example 1]

[0047] As a heat-bondable composite fiber, the core is polyethylene terephthalate (intrinsic viscosity (measured using an isogamous mixture of phenol and tetrachloroethane solvent at a concentration of 0.5 g / 100 ml and a temperature of 20°C): 0.65 dl / g, melting point 250°C), and the sheath is high-density polyethylene (density: 0.956 g / cm³). ３ A concentric sheath-core composite fiber with a zigzag mechanical crimp (fineness 1.7 dtex, fiber length 45 mm, hollowness: 0%) was prepared by arranging melt flow rate (190°C load 21.18 N): 16 g / 10 min, melting point 130°C) in a volume ratio of 50 / 50, and a web made of heat-adhesive composite fibers was fabricated by the carding method. The obtained web was introduced into a furnace filled with 200°C superheated steam for 10 seconds to obtain a nonwoven fabric that is a precursor to granular cotton (basis weight 40 g / m²). ２(1 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain cubic cotton granules.

[0048] [Example 2] As a fiber other than the heat-adhesive composite fiber (other fiber), a spiral-shaped, three-dimensional crimped fiber made of a single component polyethylene terephthalate manufactured by Jiangsu Haike Fiber Co., Ltd. (fineness: 2.8 dtex, hollowness: 30%) was prepared. Next, a web was prepared by the carding method, in which 70 parts by weight of the heat-adhesive composite fiber and 30 parts by weight of the other fiber were mixed, similar to Example 1. The obtained web was introduced into a furnace filled with superheated steam at 200°C for 10 seconds to obtain a nonwoven fabric which is a precursor to granular cotton (basis weight 40 g / m²). ２ (1.2 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain rectangular granules.

[0049] [Comparative Example 1] 50 g of the same heat-adhesive composite fiber as in Example 1 was placed in a polyethylene gusset bag. The tip of an air gun was inserted into the opening of the gusset bag, and while holding the surrounding area with a hand, air was blown in for 5 seconds to open the fibers and obtain a cotton-like material.

[0050] [Comparative Example 2] A cotton-like material (a mixture of 90% down and 10% feathers, with a fill power of 750) extracted from an ultralight down jacket (Uniqlo) was used.

[0051] [Comparative Example 3] We used granular cotton (single polyester fiber, roughly spherical, fibers not bonded to each other) extracted from a Pufftech parka (Uniqlo).

[0052] [Example 3] The nonwoven fabric obtained in the same manner as in Example 1 was cut with a utility knife into 1 cm x 5 cm pieces to obtain rod-shaped cotton granules.

[0053] [Example 4] The nonwoven fabric obtained in the same manner as in Example 1 was cut with a utility knife into 1 cm x 10 cm pieces to obtain rod-shaped cotton granules.

[0054] [Example 5] The nonwoven fabric obtained in the same manner as in Example 1 was cut with a utility knife into 1 cm x 20 cm pieces to obtain rod-shaped cotton granules.

[0055] [Example 6] Basis weight 20 g / m ２ A nonwoven fabric was obtained in the same manner as in Example 1, except that the thickness was set to 1 cm. The obtained nonwoven fabric was cut with a utility knife into 0.5 cm x 0.5 cm pieces to obtain cubic cotton granules.

[0056] [Example 7] The nonwoven fabric obtained in the same manner as in Example 6 was cut with a utility knife into 0.5 cm x 5 cm pieces to obtain rod-shaped cotton granules.

[0057] [Example 8] The nonwoven fabric obtained in the same manner as in Example 6 was cut with a utility knife into 0.5 cm x 10 cm pieces to obtain rod-shaped cotton granules.

[0058] [Example 9] The nonwoven fabric obtained in the same manner as in Example 6 was cut with a utility knife to 0.5 cm x 20 cm to obtain rod-shaped cotton granules.

[0059] [Example 10] As a heat-adhesive composite fiber, a concentric sheath-core type composite fiber with a zigzag mechanical crimp was prepared, with polyethylene terephthalate (melting point 250°C) as the core and copolymerized polyethylene terephthalate (melting point 163°C) as the sheath arranged in a volume ratio of 50 / 50 (fineness 4.4 dtex, fiber length 51 mm). In addition, as a fiber other than the heat-adhesive composite fiber (other fiber), a fiber with a spiral three-dimensional crimp made of a single component polyethylene terephthalate (fineness: 2.8 dtex, hollowness: 30%) was prepared. Next, a web was prepared by the carding method, in which 50 parts by weight of the heat-adhesive composite fiber and 50 parts by weight of the other fiber were mixed. The obtained web was introduced into a furnace filled with 200°C superheated steam for 10 seconds to obtain a nonwoven fabric which is a precursor to granular cotton (basis weight 30 g / m²). ２ (1.0 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain cubic cotton granules.

[0060] [Example 11] A nonwoven fabric was obtained in the same manner as in Example 10, except that 50 parts by weight of heat-adhesive composite fiber and 50 parts by weight of other fibers were used (basis weight 30 g / m²). ２(1.0 cm thick). The obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain cubic cotton granules.

[0061] [Example 12] A web was prepared by mixing 70 parts by weight of the heat-adhesive composite fiber used in Example 10 and 30 parts by weight of other fibers used in Example 2. The obtained web was then introduced into a furnace filled with 200°C superheated steam for 10 seconds to obtain a nonwoven fabric which is a precursor to granular cotton (basis weight 40 g / m²). ２ (1.2 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain rectangular granules.

[0062] [Example 13] As a heat-adhesive composite fiber, a concentric sheath-core type composite fiber with a zigzag mechanical crimp was prepared, with polyethylene terephthalate (melting point 250°C) as the core and copolymerized polyethylene terephthalate (melting point 163°C) as the sheath arranged in a volume ratio of 50 / 50 (fineness 2.2 dtex, fiber length 51 mm). In addition, as a fiber other than the heat-adhesive composite fiber (other fiber), a fiber with an ohm (Ω) shaped three-dimensional crimp made of polyethylene terephthalate single component (fineness: 1.5 dtex, hollowness: 5%) was prepared. Next, a web was prepared by the carding method, in which 50 parts by weight of the heat-adhesive composite fiber and 50 parts by weight of the other fiber were mixed. The obtained web was introduced into a furnace filled with 200°C superheated steam for 10 seconds to obtain a nonwoven fabric which is a precursor to granular cotton (basis weight 40 g / m²). ２ (1.0 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain rectangular granules.

[0063] [Example 14] As a heat-adhesive composite fiber, a concentric sheath-core type composite fiber with a zigzag mechanical crimp was prepared, with polylactic acid (melting point 170°C) in the core and low-melting point polylactic acid (melting point 120°C) in the sheath in a volume ratio of 50 / 50 (fineness 2.2 dtex, fiber length 45 mm). A web made of the heat-adhesive composite fiber was prepared by the carding method. The obtained web was introduced into a furnace filled with 130°C superheated steam for 10 seconds to obtain a nonwoven fabric which is a precursor to granular cotton (basis weight 40 g / m²). ２(1.0 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain rectangular granules.

[0064] [Example 15] As a heat-adhesive composite fiber, a spiral-shaped, three-dimensional crimped eccentric sheath-core composite fiber (fineness 5.6 dtex, fiber length 51 mm) was prepared, with polypropylene (melting point 165°C) as the core and high-density polyethylene similar to Example 1 as the sheath arranged in a volume ratio of 50 / 50. A web made of the heat-adhesive composite fiber was prepared by the carding method. A nonwoven fabric was obtained by introducing the obtained web into a furnace filled with 150°C superheated steam for 10 seconds (basis weight 25 g / m²). ２ (1.0 cm thick). The wind speed of the superheated steam was set to less than 0.1 m / s. Next, the obtained nonwoven fabric was cut into 1 cm x 1 cm squares with a utility knife to obtain rectangular granules.

[0065] [Example 16] A granular cotton aggregate was prepared by mixing the granular cotton of Example 1 and the cotton-like material of Comparative Example 2 in a 50:50 ratio.

[0066] [Example 17] The cotton granules from Example 1 and the cotton granules from Comparative Example 3 were mixed in a 50:50 ratio to form a cotton granule aggregate.

[0067] The physical properties of the materials obtained in Examples 1-2 and Comparative Examples 1-3 are shown in Table 1, the physical properties of the materials obtained in Examples 3-9 are shown in Table 2, the physical properties of the materials obtained in Examples 10-13 are shown in Table 3, and the physical properties of the materials obtained in Examples 14-17 are shown in Table 4.

[0068]

[0069]

[0070]

[0071]

[0072] The granular cotton of the present invention, while using synthetic fibers, possesses excellent heat retention properties and can therefore be suitably used as padding for bedding such as comforters, mattresses, and pillows; as padding for clothing such as down jackets and quilted fabrics; and as padding for outdoor equipment such as sleeping bags and cooler bags.

Claims

1. A granular cotton containing heat-bondable composite fibers whose intersections are heat-bonded, wherein the specific volume of the granular cotton is 100 to 400 cm³. ３ granular cotton, which is / g.

2. The granular cotton according to claim 1, wherein the content of the heat-adhesive composite fiber is 50% by weight or more relative to the weight of the granular cotton.

3. The volume of the granular cotton is 0.001 to 125 cm³. ３ The granular cotton according to claim 1 or 2.

4. The cotton granules according to claim 1 or 2, wherein the shape of the cotton granules is not substantially spherical.

5. The granular cotton according to claim 1 or 2, wherein the average fiber diameter of the fibers constituting the granular cotton is 5 to 30 μm.

6. The granular cotton according to claim 1 or 2, wherein the heat-adhesive composite fiber is a sheath-core type composite fiber having polyester as the core component and polyolefin as the sheath component.

7. A granular cotton aggregate containing granular cotton according to any one of claims 1 to 6, wherein the bulkiness of the granular cotton aggregate is 250 to 500 cm ３ A granular cotton aggregate that is / g.

8. A cotton filling using granular cotton according to any one of claims 1 to 6.

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