KR102002586B1 - Thermal Bonded Nonwoven With Natural Fibers - Google Patents

Abstract

The present invention is a heat-bonded nonwoven fabric containing a natural fiber, low-melting sheath core composite fiber and natural fiber mixed in a weight ratio of 50:50 ~ 80:20 is a non-woven fabric formed by heat bonding, the low melting point ciscore composite fiber is inherent Core part and melt flow index (MI), either polyethylene terephthalate or polypropylene, having a viscosity (IV) of 0.50 to 0.60 dL / g, are composed of high density polyethylene (HDPE) having 15 to 35 (g / 10min, 230 ° C). It relates to a heat-bonding nonwoven fabric containing natural fibers characterized by consisting of a sheath portion.

Description

Thermal Bonded Nonwoven With Natural Fibers

The present invention is a heat-bonded nonwoven fabric containing natural fibers, more specifically, a low-melting sheath core composite fiber and a natural fiber after mixing the heat-bonded non-woven fabric has a feature of excellent water absorption and retention and excellent softness.

In the field of absorbents for hygiene products such as urinary incontinence pads, feminine products, and infant diapers, the demand for miniaturization and thinning, as well as high absorbency, is increasing. Accordingly, it is necessary to improve the performance of the water-retaining material in the absorbent body and to improve the shape stability.

Conventionally, as such an absorber, a powdery polymer absorber and a fibrous polymer absorber are known. As the powdery polymer absorber, synthetic polymer-based polyacrylic acid compounds, polyvinyl compounds, and the like are known, and natural polymers are also known. Cyanomethyl cellulose, carboxymethyl cellulose, and the like are known.

Moreover, as a fibrous polymer absorbent material, the fiber manufactured by the method of mixing and spinning the sodium salt of carboxymethylcellulose in viscose rayon, the fiber manufactured by the method of carboxymethylating regenerated cellulose fiber, and acrylonitrile The double-structured fiber etc. which hydrolyzed the fiber and formed the polyacrylic-acid absorption layer in the outer surface are known.

At this time, in the case of the absorbent in the form of powder, desorption phenomenon may occur in the manufacturing process or distribution, or desorbed from the absorbent. In addition, due to agglomeration phenomenon due to gelation during absorption, it is impossible to reuse and gelled. As the absorber moves according to the wearer's movement, there is a problem that the distribution in the absorber is easily biased to one side and may cause stickiness to the wearer.

On the other hand, the fibrous absorbent material prepared by mixing carboxymethyl cellulose sodium salt with viscose rayon has both advantages of high usability and properties as a fiber because both viscose rayon and carboxymethyl cellulose are cellulose-based. There is a problem that the water-retaining property is insufficient, the whole fiber has water absorbency, and when absorbed, the fiber itself gels to reduce morphological stability and low fiber strength at drying.

In addition, when cotton fibers or synthetic fibers are manufactured in a nonwoven fabric and used as an absorbent material, the shape stability is excellent, but the liquid absorption ability is considerably inferior, and the liquid retention property, which is the ability to hold a liquid when pressed, has a problem.

On the other hand, in the case of applying the polyacrylic acid-based superabsorbent fiber as the absorbent material, the absorption ability is excellent, but gelation occurs during the absorption, so that the propagation speed of the absorbed liquid is decreased due to the gel blocking phenomenon and swelling is large, thereby reducing the space between the fibers. Absorption efficiency may decrease. Therefore, when the polyacrylic acid-based superabsorbent fibers are used alone, even if a high content is used, the effects are limited.

In addition, it is not easy to reuse due to gelation or deterioration of touch when absorbed, and is mainly buried for disposal after use, but since it is not biodegradable, there is a concern about environmental pollution, and thus the amount of usage is required to be reduced.

Therefore, there is a need to develop a thin-film absorbent material having excellent absorption characteristics and having design, activity, comfort, and ease.

The present invention is to solve the problems of the prior art as described above is to improve the adhesion between the constituent fibers of the nonwoven fabric, and to include a natural fiber characterized in that using a low melting point synthetic fibers as binder fibers to maintain the micro-fiber space Heat bonded nonwoven fabric.

In another aspect, the present invention provides a heat-bonding nonwoven fabric containing a binder fiber as the sheath core composite fiber and the core portion of the natural fiber consisting of polyester fiber to improve the shape stability of the nonwoven fabric.

In another aspect, the present invention provides a heat-bonding nonwoven fabric containing a natural fiber containing a cellulose structure to increase the absorbency.

In order to solve the above problems, the present invention is a heat-bonded nonwoven fabric containing natural fibers, a low melting point ciscore composite fiber and natural fibers mixed in a weight ratio of 50:50 ~ 80:20 is a non-woven fabric formed by heat bonding, the The low melting cis-core composite fiber has a core portion and melt flow index (MI) of either polyethylene terephthalate or polypropylene having an intrinsic viscosity (IV) of 0.50 to 0.60 dL / g. Provided is a heat-bonded nonwoven fabric containing natural fibers characterized by being composed of a sheath composed of high density polyethylene (HDPE).

The present invention also provides a heat-bonded nonwoven fabric containing natural fibers characterized in that the weight ratio of the sheath portion to the core portion is from 60:40 to 60:40.

In another aspect, the present invention provides a heat-sealing non-woven fabric containing a natural fiber characterized in that the low-melting cis-core composite fiber is cut to 3.5 to 5.0 times stretch orientation after spinning, 30 to 60 mm after the crimping process.

In another aspect, the present invention provides a heat-sealed non-woven fabric containing a natural fiber, characterized in that the natural fiber is characterized in that at least one of a hydrophilic natural fiber or a rayon fiber that is a hydrophilic semi-synthetic fiber.

In another aspect, the present invention provides a heat-sealed non-woven fabric containing natural fibers characterized in that the natural fiber is formed by coating the cellulose fiber evenly chitosan.

The present invention has a non-woven fabric using a low melting point synthetic fiber to improve the adhesion between the constituent fibers, maintaining the micro-space between fibers has an excellent absorbency effect.

In addition, the present invention is characterized in that the binder fiber is a sheath core composite fiber, the core portion is composed of polyester fibers to improve the shape stability of the nonwoven fabric.

In addition, the present invention is characterized in that the cellulose structure of the natural fiber increases the absorbency.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First, in describing the present invention, a detailed description of related known functions or configurations will be omitted so as not to obscure the subject matter of the present invention.

As used herein, the terms 'about', 'substantially', and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the stated meanings are set forth, and an understanding of the present invention may occur. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

The present invention relates to a heat-bonded nonwoven fabric containing natural fibers, a low-melting cis-core composite fiber and a natural fiber mixed with a weight ratio of 50:50 ~ 80:20 nonwoven fabric formed by heat bonding.

The low-melting sheath core composite fiber has an intrinsic viscosity (IV) of 0.50 to 0.60 dL / g of polyethylene terephthalate or polypropylene, and a core portion and a melt flow index (MI) of 15 to 35 (g / 10 min, 230 ° C.). It can be composed of a sheath consisting of high density polyethylene (HDPE).

The core portion may be formed of polyester or polypropylene resin, and more specifically, the polyester resin may be polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polytrimethylene terephthalate (Poly). Trimethylene terephthalate (PTT) can be used.

When the intrinsic viscosity of the polyester resin is high, the morphology of the core portion may increase when the sheath core type heat-bonded composite fiber is manufactured, so that the inherent viscosity of the polyester forming the core portion is preferably 0.50 to 0.60 dL / g. something to do.

A polypropylene resin may be used instead of the polyester resin of the core part, and the melt flow index (MI) may be 15 to 35 (g / 10 min, 230 ° C.).

The sheath part is characterized by a low melting point polymer having a melting point of about 80 ° C. to 165 ° C. and a melt flow index (MI) of 15 to 35 (g / 10 min, 230 ° C.). Polyolefins suitable as such low melting polymers include polyethylenes such as high density polyethylene, medium density polyethylene, low density polyethylene and linear low density polyethylene, polypropylene such as isotactic polypropylene and atactic polypropylene; Polybutylenes such as poly (1-butene) and poly (2-butene); Polypentenes such as poly (2-pentene), and poly (4-methyl-1-pentene); Polyvinyl acetate; Polyvinyl chloride; polystyrene; And copolymers thereof, such as ethylene-propylene copolymers, and combinations thereof.

The low-melting sheath core composite fiber may be fused with the same cis core composite fiber or natural fiber adjacent to the melted sheath resin by the interweaving role as an adhesive. In addition, the low-melting cis-core composite fiber is characterized by being cut to 3.5 ~ 5.0 times stretch orientation after spinning, 30 ~ 60mm after the crimping process, it may be advantageous to secure the space between fibers by the crimping process.

At this time, when the weight ratio of the natural fiber exceeds 50, the weight ratio of the low melting point ciscore composite fiber of the binder role is less than 50, and sufficient fusion between the mixed fibers may be difficult. On the contrary, when the weight ratio of the natural fiber is less than 20, This may be a problem for the softness or absorbency of the fibers.

Next, the natural fiber is characterized by including at least one of hydrophilic natural fiber or rayon fiber which is a hydrophilic semisynthetic fiber.

Natural fibers are mainly composed of cellulose and mainly correspond to cotton fibers (seed fibers) and hemp fibers (bast fibers). Cotton fibers, in particular, are irregular in the cross section of the fiber but have hollows. Good durability and absorbency, especially excellent fit. It absorbs dirt well, is hygienic and easy to wash.

Rayon fibers, which are semisynthetic fibers, may also be used. Rayon fibers treat wood-based pulp with alkali to dissociate intermolecular hydrogen bonds, creating a viscous viscous solution. The solution is made of fibers that are bound back to fibrillar molecules through a nozzle. The fibers are called rayon. They are silky on the surface, silky to the touch, and draped. Excellent absorbency, low static electricity and comfortable to wear.

Preferably, rayon fibers and cotton fibers, which are natural fibers, may be mixed and used at a predetermined ratio.

In addition, the natural fiber may be one formed by uniformly coating chitosan on the cellulose fiber. Cellulose fiber has a water content of 10wt% or less, contains at least 90% or more of cellulose, has a thickness of 4 μm to 80 μm and a length of 1 mm to 100 mm, and is a natural seed fiber, stem fiber, leaf fiber and root fiber. Cotton, hemp, pulp, sisal, abaca, kapok, flex, jute, ramie, hamp, kenab, coil, sacchaton and other regenerated fibers viscose rayon, dongammonium rayon, polynosic rayon, lyocell, tencel , Cellulose acetate, cellulose triacetate and the like are useful.

The chitosan solution used in the present invention is prepared by dissolving chitosan in a solvent at a concentration of 0.1wt% to 15wt% by weight. As chitosan, it is useful that the polymerization degree is between 20 and 10,000 and the deacetylation degree is between 60% and 99%, and more preferably, the polymerization degree is between 100 and 5,000 and the deacetylation degree is between 70% and 95%. . As the solvent, any one selected from an acid aqueous solution, an inorganic salt aqueous solution and an organic solvent may be used.

Hereinafter, an embodiment of a method for producing a sheath core hollow composite fiber excellent in flexural strength according to the present invention is shown, but the present invention is not limited to the embodiment.

Example  One

60% by weight of polyethylene terephthalate having an intrinsic viscosity of 0.55 dL / g as a composition of the core part and 40% by weight of high density polyethylene having a flow flow index of 20 (g / 10 min, 230 ° C) as a sheath part were put into separate extruders. Melted.

The molten core part and the sheath part composition were introduced into the sheath-core release cross-section nozzle and then spun at a spinning speed of 1100 m / min. After spinning, the film was stretched by 4.0 times, and crimped to cut 51 mm to prepare fibers.

 A cotton fiber was prepared from natural fibers, sheared to 50 mm, mixed with 60% by weight of the ciscore composite fiber and 40% by weight of natural fibers to prepare a thermal adhesive nonwoven fabric using air through bonding after carding.

Example  2 ~ 4

It is the same as Example 1 except using the natural fiber content of the numerical value of Table 1, and using the natural fiber uniformly coat | covered the surface using the predetermined weight% of chitosan solvent compared with a cellulose fiber.

Comparative example  1 ~ 2

Natural fiber content% is the same as Example 1 except having described in Table 1.

Comparative example  3 ~ 4

It is the same as Example 1 except using PET short fiber or HDPE short fiber instead of cis core composite fiber.

* Property evaluation

Strike through

0.5cm × 4.0cm × 4.0cm specimens were prepared for the nonwoven fabrics of Examples and Comparative Examples, and water permeability of 5 ml of artificial material was measured using a Lister machine of Lenzing Instructment based on ISO-9073-14.

2. Wetback

Samples of 0.5 cm × 4.0 cm × 4.0 cm were prepared for the nonwoven fabrics of Examples and Comparative Examples, and a load of 4 kg was applied to the nonwoven fabrics for 5 minutes on a 40 ml artificial material using a Lenzing Instructment Lister machine based on ISO-9073-14. After that, the degree of reverse leakage of residual moisture was measured.

3. Softness

The nonwoven fabrics of Examples and Comparative Examples were converted into scores using a 10-person emotional evaluation for 0.5cm × 4.0cm × 4.0cm specimens. It was subjectively rated on a scale of 100.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Sheath
core
complex
fiber Core part PET PET PP PP PET PET
PET
Short fibers

HDPE Short Fiber Sisbu HDPE HDPE HDPE HDPE HDPE HDPE natural
fiber
weight%
40 50 45 45 70 10 40 40 Chitosan fiber
(weight%) 0 0 5 6 0 0 0 0 Strike
through 1st (s) 1.16 0.89 1.24 0.83 2.01 2.34 3.01 3.25 2nd (s) 2.11 1.36 1.51 1.36 3.22 2.96 3.51 4.52 3rd (s) 3.01 1.75 2.02 1.71 5.00 4.00 4.03 5.23 Wetback (g) 0.17 0.21 0.23 0.19 3.02 4.21 4.01 5.03 Softness 75 80 80 80 90 50 60 80

As can be seen from Table 1, Strike through and Wetback are the properties of water absorption and retention of the nonwoven fabric.

Examples 1 to 4 are 40 to 50% by weight of natural fibers and 50 to 60% by weight of ciscore composite fibers, so that the homogeneous composition of the ciscore composite fibers having a binder function during thermal bonding after blending Fusion between fibers is achieved.

Therefore, the binding force and space between the constituent fibers are secured, and the absorption ability is excellent due to the capillary phenomenon caused by the microspace and the structural characteristics of the natural fiber. Natural fiber is contained, so the softness is more than 75 is measured.

On the other hand, in Comparative Example 1, the binding strength between the constituent fibers of the nonwoven fabric is 70 wt% of the natural fiber and 30 wt% of the ciscore composite fiber which is the binder fiber. As a result, empty spaces are formed between the constituent fibers, so that the absorbing power is lowered, and residual moisture is extracted to the outside by a constant load. As a result, the Strike through takes a long time and residual moisture is easily extracted into the back spring.

On the contrary, in Comparative Example 2, since 10% by weight of natural fiber and 90% by weight of ciscore composite fiber, which is binder fiber, the bonding between the constituent fibers of the nonwoven fabric by thermocompression bonding is strong, so that the empty space is smaller than that of the embodiment, thus absorbing power and water holding power small. As a result, the Strike through takes a long time and residual moisture is easily extracted into the back spring.

Comparative Example 3 is a binder fiber in the case of PET short fibers, there is no low melting point resin of the sheath portion, and the bonding strength is low when heat-bonding similarly to Comparative Example 1, the absorption and retention capacity is low. As a result, the Strike through takes a long time and residual moisture is easily extracted into the back spring.

Comparative Example 4 is composed of only HDPE short fibers, all used as an adhesive during thermocompression, so that the empty space is smaller, and thus the absorbency and water retention are smaller. As a result, the Strike through takes a long time and residual moisture is easily extracted into the back spring.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

Claims (5)

Heat-sealed nonwoven fabric containing natural fibers,
Low-melting cis-core composite fiber and natural fiber mixed in a weight ratio of 50:50 ~ 80:20 is a non-woven fabric formed by heat bonding,
The low-melting sheath core composite fiber has an intrinsic viscosity (IV) of 0.50 to 0.60 dL / g of polyethylene terephthalate or polypropylene, and a core portion and a melt flow index (MI) of 15 to 35 (g / 10 min, 230 ° C.). Is composed of a sheath made of high density polyethylene (HDPE)
The natural fiber is coated with cellulose fiber evenly chitosan, the natural fiber has a water content of less than 10wt%, thickness 4㎛ ~ 80㎛, length 1mm ~ 100mm, the degree of polymerization of chitosan is characterized in that 100 ~ 5,000 Heat-sealed nonwoven fabric with natural fibers.
The method of claim 1,
The heat-sealing nonwoven fabric containing natural fibers, characterized in that the weight ratio of the sheath portion to the core portion is 60:40 ~ 60:40.
The method of claim 1,
The low-melting cis-core composite fiber is a heat-bonded non-woven fabric containing natural fibers, characterized in that cut to 3.5 ~ 5.0 times stretch orientation after spinning, 30 ~ 60mm after the crimp process.

delete delete