JP2010007212A - Face mask and method for producing nonwoven fabric for face mask - Google Patents

Abstract

A face mask and a method for producing a non-woven fabric suitable for the face mask are provided.
A face mask is formed by forming a cross-laid web 2 from hydrophilic synthetic short fibers and cellulose short fibers, and laminating a plurality of the cross-laid webs 2 to form a cross-laid web. A non-woven fabric entangled with is used. The fibers are crossed at 90 °. As the synthetic short fiber, PET treated with a durable hydrophilic oil is used, and rayon is used as the cellulose fiber.
[Selection] Figure 1

Description

  The present invention relates to a nonwoven fabric, and more particularly to a nonwoven fabric having stretch performance suitable for a face mask.

  Nonwoven fabrics are used in various applications, and the properties required by the applications used are also different. For wet sheets such as wet tissues and disposable hand towels, a hydrophilic fiber such as rayon, or a cross-laid web in which this hydrophilic fiber and heat-adhesive fiber are mixed is used. In Patent Document 1 (Japanese Patent Laid-Open No. 2001-336056), in such a nonwoven fabric, the tensile strength in the CD direction (width direction) is made stronger than the tensile strength in the MD direction (length direction or machine direction), and a wet sheet is formed. To prevent tearing when pulled out of the container.

  Moreover, as a nonwoven fabric used as a surface material for disposable body warmers, water retention and sufficient strength are required, and further, a material that does not cause environmental problems in processing after use is required. There exists patent document 2 (Unexamined-Japanese-Patent No. 2003-339553) as such a nonwoven fabric. Here, when a web is formed from cellulosic short fibers and a plurality of webs are stacked, the orientations of the fibers are crossed so as to be in different directions. By using cellulosic fibers, water retention is ensured, and a desired strength can be obtained by setting the fiber orientation crossing angle to 10 to 90 °.

  As a non-woven fabric used as a base fabric for external medicine, fit to the body and stretchability are required. There exists patent document 3 (Unexamined-Japanese-Patent No. 8-260313) as such a nonwoven fabric. Here, a stretchable nonwoven fabric mainly composed of a cross-laid web made of crimped fibers is proposed. With such a configuration, it is possible to obtain a nonwoven fabric having a small strength difference between the vertical direction and the horizontal direction and having excellent stretchability.

  By arranging an ultrafine fiber layer containing 10% or more of ultrafine fibers having a fineness of 0.5 dtex or less on one or both surfaces of the hydrophilic fiber layer containing 50% or more of hydrophilic fibers to form an integrated laminated nonwoven fabric, the skin Patent Document 4 (International Publication WO2006 / 016601) discloses a skin covering sheet for impregnating cosmetics with less irritation to the skin and higher wearability, and a face mask using the same.

  Here, a split type composite fiber is used as the ultrafine fiber. The split type composite fiber is a fiber cross-section in which at least one component is divided into two or more of the constituent components, at least a part of the constituent components are exposed on the fiber surface, and the exposed components are in the fiber length direction. Are formed continuously. In Patent Document 4, a non-woven fabric is formed using a composite fiber of 2.2 dtex in thickness and divided into 8 to form a non-woven fabric, and then the composite fiber is divided into ultrafine fibers of 0.275 dtex.

  The nonwoven fabric used for the face mask is impregnated with lotion and attached to the face, so that the active ingredient of the lotion penetrates into the skin and obtains a skin care effect. In this case, the face mask needs to be easily stretchable in order to follow the unevenness of the face. In addition, the face mask does not fall off the face, and when the skin lotion is reduced by drying, the skin care will vary if “floating” occurs in the nonwoven fabric, so “floating” should be avoided. Also, don't tear when stretched.

  Conventional non-woven fabrics for face masks have been mainly used spunlaced non-woven fabrics because they require liquid absorbency, softness, and adhesion to the skin. As the structure of the fibers, simple substances such as cotton, rayon, polyester, polypropylene (PP), and polyethylene (PE), mixed cotton, and laminated products are used.

In such spunlace nonwoven fabrics, the following methods have been studied in order to impart stretchability that can follow and adhere to an uneven face as a face mask.
(1) A method in which fibers are selected mainly from polyesters that have properties such that the fibers are slippery and easily stretched.
(2) In order to weaken the entanglement force of the fibers in the width direction (CD direction) and facilitate extension, the configuration of the parallel web used in combination with the cross-laid web is increased, and the fibers are longitudinally (MD direction or machine direction). How to focus on.
(3) A method of entanglement by reducing the water pressure at the time of entanglement in order to weaken the entanglement force on the whole nonwoven fabric and make it easier to stretch.
Such a method has been adopted. Further, in Patent Document 4, the use of ultrafine fibers provides a certain degree of stretching performance, but the production of split-type composite fibers that are the basis of the ultrafine fibers is quite complicated, and further, after being made into a nonwoven fabric, it is divided. There is no expectation of complete division.
JP 2001-336056 A JP2003-339754 JP-A-8-260313 International Publication WO2006 / 016601

  However, the polyester (1) centering on polyester is easy to stretch, but does not absorb water and has poor adhesion to the skin. In the case of (2) with an increased number of parallel webs, the desired stretch cannot be obtained, and the front and back are composed of two layers: a parallel web and a cross web. Due to the difference, wrinkles are likely to occur. In (3), since the entanglement is loose, when entangled, the entanglement is easily disengaged, and it tends to stretch but does not shrink. At the same time, fluffing easily occurs and the fibers remain on the face, causing discomfort. There was a problem such as.

  The present invention has been made in view of the above problems, and has an object to provide a face mask having excellent fit and water absorption, and a method for producing a nonwoven fabric used for such a face mask. .

  In order to achieve the above object, the face mask of the present invention uses a nonwoven fabric entangled with a hydrophilic synthetic staple fiber and a cross-laid web formed of a web composed of cellulose-based staple fibers. It is said.

  The hydrophilic synthetic short fiber is a PET treated with a durable hydrophilic oil, and the cellulosic fiber is a rayon, or the hydrophilic PET is 50 to 90% by weight and the rayon is 50 to 10% by weight. Can be configured. It is also possible to replace part of the rayon with cotton.

  The method for producing a nonwoven fabric for face mask according to the present invention comprises a step of forming a web with hydrophilic synthetic short fibers and cellulosic short fibers, a step of making the web a cross-laid web, And a step of entanglement. The step of entanglement may be configured to be water entanglement.

  According to the nonwoven fabric for face masks of the present invention, the stretchability can be improved by using the synthetic short fibers, and the stretchability is improved, so that the fit property is excellent. In addition, even synthetic fibers that originally have low water absorption can be absorbed around the synthetic fibers by being treated with a hydrophilic oil agent, and water retention can be imparted. Moreover, since the physical property (entanglement force) at the time of moisture is low compared with cotton, it has the characteristic of being easy to extend. Generally, synthetic fibers are treated with a hydrophilic oil to impart hydrophilicity. In the present invention, synthetic fibers treated with a commercially available hydrophilic oil can be used without particular limitation. When water entanglement is performed, the hydrophilic oil may fall off and the hydrophilicity may drop. Therefore, a functional group constituting the synthetic fiber may be modified so that the hydrophilic oil is fixed with high durability. .

Examples of the present invention will be described below.
The nonwoven fabric of the present invention is a blend of short fibers of cellulosic fibers and short fibers of synthetic fibers. As the cellulosic fibers, natural fibers such as cotton and hemp, and regenerated fibers such as rayon can be used. As the synthetic fiber, polyester, polypropylene, PET or the like can be used.

  In the following examples, rayon was used as the cellulosic fiber. Rayon has a characteristic of being easily stretched because it has lower physical properties when wet than cotton. A rayon having a cut length of 38 mm was used.

  As the synthetic fiber, PET (polyethylene terephthalate) was used. Synthetic fibers such as PET do not absorb water, but hydrophilic PET is used in the present invention. Hydrophilic PET is obtained by treating PET with a durable hydrophilic oil. By treating with a hydrophilic oil in this way, water can be absorbed around the synthetic fiber. Further, since it is durable, the oil agent does not melt when a nonwoven fabric is formed by entanglement of fibers by water entanglement, and water absorption can be maintained even when used as a face mask. For example, Toyobo's product number “70L” can be used as the PET suitable for such purposes. This PET used was a cut length of 44 mm.

  The mixing ratio of hydrophilic PET and rayon is desirably 50 to 90% by weight for hydrophilic PET and 50 to 10% by weight for rayon. It is because the stretchability of the nonwoven fabric is insufficient when the hydrophilic PET is less than 50% by weight. This is because if it exceeds 90% by weight, the rayon is reduced and water retention is insufficient. However, cotton may be blended instead of part of the rayon.

  The above PET and rayon (and cotton) are mixed to form a fiber web. In the present invention, the card method is used as a method for forming the fiber web. However, the air method is not limited to the card method and can be selected.

FIG. 1 is a diagram showing a process of forming a cross-laid web of the present invention. A card web 1 having a thickness of 10 to 20 g / m ² is formed with the card 10. The direction of the fibers of the card web 1 is somewhat along the machine direction, that is, the spinning direction. This card web is overlapped by the cross wrapper 12 in the direction in which the fibers intersect to form a cross-laid web 2.

  FIG. 2 is a view showing the cross-laid web 2 immediately after the card web 1 is laminated through the cross wrapper 12. The card web 1 is bent at an intersection angle α to become a cross-laid web 2. The crossing angle α at this time is the crossing angle of the fibers constituting the card web, and this crossing angle α is considerably smaller than 90 °. The cross-laid web 2 is in a state where a plurality of card webs 1 are stacked.

  The cross-laid web 2 can be drafted to form a cross-laid web 3 having a crossing angle of 90 ° as shown in FIG. In this case, the crossing angle between the fibers in the crosslaid web 3 is 90 °. At this time, the basis weight can be finely adjusted by slightly changing the draft amount.

  In the embodiment of the present invention, the cross raid web 2 is drafted into the cross raid web 3, but the draft is not essential. Since the crossing angle is preferably 90 °, the initial crossing angle α should be 90 °. The crossing angle of the fibers is preferably 90 °, but is not limited to this angle.

  In this invention, it is comprised only by a cross-laid web and does not overlap a parallel web (the card web 1 which is not spun | folded with the web spun from the card | curd) partially like the past. Therefore, it is less likely to wrinkle when stretched in the CD direction and can be suitably used as a face mask.

  4 to 10 card webs 1 are overlapped to form a cross-laid web 2, and a draft is added thereto to form a cross-laid web 3, which is subjected to a hydroentanglement process to obtain a nonwoven fabric. The entanglement method is not limited to the water flow entanglement method, and other methods such as a needle punch method may be used. In the present invention, the water entanglement method is used.

  In the water flow entanglement method, a water flow to which water pressure is applied by a nozzle head is ejected from both the front and back surfaces of the cross-laid web 3 to entangle the fibers. In the nozzle head, a large number of nozzles are arranged in the width direction (CD direction) orthogonal to the conveyance direction (MD direction) of the cross-laid web 3. A plurality of such nozzle heads are arranged on the front and back of the cross-laid web 3 so that the water pressure can be changed for each nozzle head.

  The water flow from each nozzle is continuously jetted, and while the cross-laid web 3 is being conveyed, the water flow from the nozzles on both sides from the front and back is received and the fibers are entangled.

  As shown in FIG. 3, the crossing angle of the fibers is, for example, 90 °, and in this case, the fiber is inclined 45 ° in the conveying direction. In this case, the cross-laid web 3 should have the same physical properties in the transport direction (MD direction) and the width direction (CD direction).

  However, when the fibers are entangled by the water flow entanglement method, since the water flow from the nozzle is continuously jetted, the fibers are entangled in the MD direction, but the water flow is discontinuous in the CD direction. There are unentangled parts. Therefore, the binding force of the fibers in the width direction is weak. Therefore, the tensile strength in the MD direction is strong, the stretchability is lowered and is not easily stretched, the tensile strength in the CD direction is weak, the stretchability is increased, and the stretch becomes easy. Moreover, although the nonwoven fabric after entanglement will be wound up, since winding tension | tensile_strength is added, it is thought that it has also influenced that the coupling force of MD direction goes up further.

  As for the water pressure at the time of hydroentanglement, if the water pressure is high, the intertwining of fibers becomes dense and the tensile strength of the nonwoven fabric increases, but the stretchability decreases. When the water pressure is low, the stretchability is increased, but the tensile strength is lowered and is easily broken. In the present invention, as a medium pressure, both the tensile strength and the stretchability are maintained within a desired range.

  A typical example of the entanglement method other than the water flow entanglement method is a needle punch method. In this method, needles are driven from both sides of the web to entangle the fibers. However, it can be said that the water-entanglement is more desirable for the non-woven fabric produced by needle punching because traces of needle holes remain and the texture becomes slightly worse.

  FIG. 4 is a performance comparison table between the non-woven fabric for face masks manufactured by the above manufacturing method and the conventional non-woven fabric for face masks.

  The measuring method of the maximum point load, maximum point elongation, and 10% load is as follows. First, a sample of 5.0 cm × 20 cm is taken as a test piece from the nonwoven fabric. As for the number of test pieces, five samples are taken for the 20 cm side in the MD direction (machine direction) and in the CD direction (width direction). Here, the MD direction indicates the conveyance direction of the cross-laid web 3 when the cross-laid web 3 is made by the cross wrapper 12, and the CD direction indicates a direction orthogonal to the conveyance direction.

  The test piece was gripped at a spacing of 10 cm (initial length) and applied to a tensile tester (Tensilon) at a tensile speed of 20 cm / min to obtain an average value of five pieces.

  The maximum point load is the maximum value of the load when the test piece is pulled until it is cut. The maximum point elongation is a numerical value expressed as a percentage by dividing the length immediately before cutting when the test piece is pulled until it is cut, by the initial length. The 10% load is a load applied to the test piece when the test piece is extended 10% from the initial length.

  As a face mask, it is important to adhere along the unevenness of the face, but for that purpose, stretchability is important. That is, the greater the maximum point elongation and the smaller the 10% load, the easier the elongation with a weak force, and the better the stretchability. Further, when a non-woven fabric is used as a face mask, the fit to the face is improved when the lateral direction is more easily stretched than the vertical direction of the face. The maximum point elongation in the MD direction or CD direction is preferably 100% or more, and the 10% load in the same direction is preferably 1 N or less. In the case of water entanglement, the CD direction tends to extend more than the MD direction, and therefore the MD direction is usually the vertical direction of the face and the CD direction is the horizontal direction of the face.

  Example 1 is of the present invention and is a non-woven fabric made only of a cross-laid web made of a blend of hydrophilic PET and rayon. This is because the maximum point elongation in the CD direction is 100% or more, and the 10% load in the CD direction is 1N or less. In addition, since it is hydrophilic PET, it has water retention, suitable entanglement, and no fuzz. In other words, it has optimum conditions for a face mask having a stretch function.

  Comparative Example 1 is a blend of cotton and PET, in which a cross-laid web and a parallel web are laminated. The maximum point elongation in the CD direction exceeds 100%, but the 10% load greatly exceeds 3.19N and 1N, and lacks stretchability.

  Comparative Example 2 is a non-woven fabric composed of 100% cotton fiber and only a cross-laid web, but has a low water pressure when entangled. Although the maximum point elongation in the CD direction is better than that of Comparative Example 3, it is far below 100%, and the 10% load is large and insufficient.

  Comparative Example 3 is a non-woven fabric composed of only a cross-laid web and made of 100% cotton as in Comparative Example 2, and has a higher water pressure at the time of entanglement. The maximum point elongation is 30% in the MD direction and only 50% in the CD direction.

FIG. 5 is a table showing the water pressure at the time of entanglement between the example and the comparative examples 1 to 3. A plurality of nozzle heads are provided along the conveying direction of the front and back surfaces of the cross-laid web 3. In each nozzle head, holes having a nozzle diameter of 0.1 mm are arranged at intervals of 0.6 mm. In FIG. 5, for example, 5 × 40 × 70 on the front side of the embodiment has three nozzle heads on the front side, and the water pressure is 5 kgf / cm ² from the upstream side in the conveyance direction of the cross-laid web 3. 40kgf ^/ cm 2, in the sense that has become a 70kgf / cm ^2. In addition, there are also three nozzle heads on the back side, which are provided so as to be shifted from the front side nozzle head in the transport direction, and the water pressure from the upstream side in the transport direction is 50 kgf / cm ² , 20 kgf / cm ² , It means that it is 70 kgf / cm ² . The same applies to each of the comparative examples, but in Comparative Examples 2 and 3, there are two nozzle heads on the front side.

  FIG. 6 shows 10 subjects who put the same cosmetic material impregnated in Example and Comparative Examples 1 to 3 on their faces, and evaluated the elongation of the face mask, fit, and skin contact. Results are shown. The fuzz is visually observed.

  “Elongation” is an evaluation of whether or not the face can be extended to cover the peripheral edge of the face. “Fit” is an evaluation of whether the face mask is in close contact with the skin. “Skin contact” is an evaluation of the touch of the skin.

  ◎ indicates that 90% or more of the subjects are determined to be good, ○ indicates that 70% or more and less than 90% of the subjects are determined to be good, and △ indicates that 40% or more and less than 70% of the subjects are good X indicates that less than 40% of the subjects were determined to be good.

  From the result of FIG. 6, only the Example of this invention was more than (circle) in all of elongation, a fit feeling, and per skin.

It is a figure which shows the process of forming the cross-laid web of this invention. It is a figure which shows the cross-laid web after passing a cross wrapper. It is a figure of the state which drafted the cross-laid web of FIG. It is a performance comparison table of the nonwoven fabric for face masks of the present invention and the conventional nonwoven fabric for face masks. It is a table | surface which shows the water pressure at the time of the intertwining of an Example and Comparative Examples 1-3. A table showing the results of having 10 test subjects wear the same cosmetic material impregnated in Examples and Comparative Examples 1 to 3 on their faces, and evaluating the elongation, fit, and skin perception of the face mask. is there.

Explanation of symbols

1 Card Web 2 Cross Raid Web 3 Cross Raid Web 10 Card 12 Cross Wrapper

Claims (6)

  A face mask characterized by using a nonwoven fabric intertwined with a cross-laid web formed of a hydrophilic synthetic short fiber and a web composed of cellulose-based short fibers.   The face mask according to claim 1, wherein the hydrophilic synthetic short fiber is PET treated with a durable hydrophilic oil, and the cellulosic fiber is rayon.   The face mask according to claim 2, wherein the hydrophilic PET is 50 to 90% by weight and the rayon is 50 to 10% by weight.   4. The face mask according to claim 3, wherein a part of the rayon is replaced with cotton.   It comprises a step of forming a web with hydrophilic synthetic short fibers and cellulosic short fibers, a step of making the web a cross-laid web, and a step of tangling the cross-laid web. A method for producing a nonwoven fabric for a face mask.   The method for producing a nonwoven fabric for face mask according to claim 5, wherein the step of entanglement is hydroentanglement.

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