JP4659487B2 - Hot embossed dry nonwoven fabric and method for producing the same - Google Patents

Description

  The present invention relates to a hot embossed dry nonwoven fabric and a method for producing the same, and in particular, a pulp having high strength both in dry and wet conditions, and an embossed pattern formed by hot embossing does not easily lose its shape when wet. The present invention relates to a hot embossed dry nonwoven fabric using an airlaid nonwoven fabric in which a web is formed of cellulosic fibers and the like and does not contain heat-fusible fibers, and a method for producing the same.

  In addition, the present invention is a heat embossed process using an airlaid nonwoven fabric that does not contain heat-fusible fibers, in which a web is formed of cellulose-based fibers such as pulp, when the embossed pattern can be seen through when moderately wet. The present invention relates to a dry nonwoven fabric and a method for producing the same.

  Furthermore, the present invention relates to a wiper, a coaster, a place mat, a table cloth, a dry towel, a sheet or wet paper made of the hot embossed dry nonwoven fabric.

In recent years, in hotels, restaurants, coffee shops, etc., disposable hand towels made of nonwoven fabric or the like are widely used for business purposes instead of cloth hand towels. As a disposable hand towel for business use, (1) a heat-embossed dry nonwoven fabric, (2) a heat-embossed polyethylene film sandwiched between two tissues (for example, see Patent Document 1), (3) A tissue and a dry non-woven fabric that are heat embossed (see, for example, Patent Document 2) are known.
JP 49-13446 A Japanese Patent Laid-Open No. 60-155797

  Examples of quality characteristics required for the base paper used for disposable hand towels include wet paper strength, hand feeling, flexibility, water absorption, and the like. In particular, in order to produce a hand feeling, paper towels and the like need to be bulky, and therefore, heat embossing using two uneven embossing rolls is generally performed. Regarding the base paper, since the above (2) is the lowest in terms of cost, the amount used is large. Although the hand towel using the dry nonwoven fabric of (1) is high in cost, it is closer to the characteristics of a cloth hand towel, and is therefore in demand as a luxury product. In addition, coasters, placemats, tablecloths, dry towels, etc. are also widely used as products using dry nonwoven fabrics. In addition, wipers, wet tissues, wet towels, etc. made of nonwoven fabric used for wiping off moisture, such as infant excrement and spilled food on the table, and hand towels are widely used at home. It has become to.

  Nonwoven fabric materials used for dry paper such as wet paper and wipers, as well as coasters, placemats, table cloths, dry towels, etc. include natural cellulose fibers such as paper, pulp and cotton, cupra, viscose rayon, Regenerated cellulose fibers such as polynosic rayon and other synthetic fibers are used. Natural cellulose fibers are advantageous in terms of cost, but they are disadvantageous in that they have low wet strength and lack flexibility compared to synthetic fibers. Addition of chemicals to improve wet strength further reduces flexibility. Therefore, as raw materials, a balance between quality such as wet strength and flexibility and cost is achieved by appropriately combining cellulose fibers and synthetic fibers.

  On the other hand, bulky dry non-woven fabrics are generally used as wet towels or the like with a flat surface without being subjected to uneven embossing. As bulky nonwoven fabrics used as these wet paper base papers, airlaid nonwoven fabrics are widely used. Airlaid non-woven fabrics are formed by the airlaid method in which fibers of a predetermined length are defibrated and transported in an air stream, passed through a screen having a wire mesh or pores, and then dropped and deposited on a wire mesh. The intersection of the fibers in the web is heat-fused with a binder fiber, or the intersection of the fibers is joined with an emulsion binder. In air-laid nonwoven fabric, paper strength is enhanced by blending cellulosic fibers such as pulp and synthetic fibers and binding the fibers using the heat-melting characteristics of the blended synthetic fibers (heat-fusible fibers). Although such an air-laid nonwoven fabric can be made, the web is formed only with cellulosic fibers such as pulp as a raw material, and compared with that manufactured by a method of joining fiber intersections by spraying an emulsion binder thereto. There is a problem of high cost. On the other hand, an airlaid nonwoven fabric made of cellulose fibers formed by joining fiber intersections with an emulsion binder has low strength during dry and wet processes, and even if an embossed pattern is formed, when the airlaid nonwoven fabric is wetted, Since the fibers in the center in the thickness direction are not joined by the binder, there is a problem that the embossed pattern is easily broken or disappears even by a small tensile force. Therefore, using airlaid nonwoven fabric that does not contain heat-fusible fibers that also function as a binder in which the web is formed of cellulose fibers such as pulp, it is suitable for wipers or wet papers that are bulky, have high paper strength, and have wet strength, Further, there is a demand for a nonwoven fabric that does not easily lose its embossed pattern even when wet.

  Further, non-woven fabrics used for conventional wet towels, wet tissues, wet towels and the like generally have a uniform white color as a whole even when dried or wet. In the case of disposable hand towels, especially paper towels, in order to create a hand feeling, uniform uneven embossing is also applied to the entire base paper as necessary, but it is normal practice to add patterns of any shape. Even if a pattern is formed by hot embossing, the conventional wet paper base paper remains generally the same white in both a dry state and a wet state. For this reason, even if an embossed pattern is applied to the paper towel, the pattern is visually recognized due to the difference in surface texture or the presence or absence of shadows due to unevenness, and the attached pattern is difficult to visually recognize. Is rarely directed to the pattern of hand towels. On the other hand, when a bulky air-laid nonwoven fabric is used as wet paper, it is not usually performed with uneven embossing or the like, and patterning by embossing is not performed. In particular, the strength of bulky airlaid nonwoven fabrics with webs formed of cellulose fibers such as pulp, which are weak when wet, can be improved. If it is possible to put a pattern that can be easily seen in a wet state, disposable hand towels can be used as advertising media, and hand towels rich in design can be provided at low cost. Further, the effect of promoting the use of an airlaid nonwoven fabric in which a web is formed of cellulose-based fibers such as pulp can be expected. In addition, if we can provide dry paper products such as coasters, placemats, table cloths, towels, sheets, etc., which can see patterns when wet, patterns that we have never noticed when these products get wet during use will emerge. Therefore, it is conceivable that a new design can be added to the product and a new functionality including an advertising effect can be added.

  An object of the present invention is to provide a dry nonwoven fabric using an airlaid nonwoven fabric which is formed from cellulosic fibers such as pulp and does not contain heat-fusible fibers, which can meet such a demand. Specifically, the strength is high in both dry and wet conditions, and the embossed pattern does not collapse when wet. Logo marks such as product names, embossed patterns such as flower patterns and geometric patterns appear as watermarks, dry paper products such as wipers, coasters, place mats, table cloths, towels and sheets, and wet tissues Pulp and other suitable paper materials for wet paper such as wet towels and wet towels. Loin based web from fibers is formed, it is an object to provide a heat embossed dry nonwoven fabric using the air-laid nonwoven fabric not containing heat-fusible fibers.

  In addition, the present invention provides a dry nonwoven fabric that is heat embossed using an airlaid nonwoven fabric that is formed of cellulosic fibers such as pulp and that has an embossed pattern having the above characteristics and does not contain heat-fusible fibers. The object is to provide a method of manufacturing.

  Furthermore, an object of the present invention is to provide a dry nonwoven fabric product such as a wet paper such as a wet towel, a wiper, and a coaster, a place mat, a table cloth, a towel, a sheet, and the like, which is formed of the dry nonwoven fabric. is there.

  As a result of intensive studies and researches, the inventor has accumulated a plurality of air laid nonwoven fabrics that are formed from cellulosic fibers and do not contain heat-fusible fibers, and heat embossing using a heat embossing roll having a desired pattern. As a result, heat-bonding occurs between the air-laid nonwoven fabrics at the heat-embossed portion, the wet strength of dry and wet air-laid nonwoven fabrics is improved, and the embossed pattern does not easily break when wet. When the nonwoven fabric is wet by heat embossing so as to form microscopic holes, that is, gaps between fibers, that cause capillary action in the hot embossed part by appropriately controlling the heating and pressurizing conditions at the time The embossed part becomes translucent when the minute holes are filled with water, while the surrounding area remains white. Visible translucent portion of the coated portion is raised, embossed portions and found that readily visible as a pattern. In addition, when the pattern is wet, the air-embossing roll having a desired pattern is formed by overlapping an air-laid non-woven fabric that is formed of cellulosic fibers and does not contain heat-fusible fibers and an air-laid non-woven fabric that contains heat-fusible fibers. It has also been found that this can be achieved by carrying out hot embossing using, and the present invention has been made based on these findings.

  That is, the present invention relates to an air-laid nonwoven fabric laminate in which a plurality of air-laid nonwoven fabrics each having a web formed of cellulosic fibers and not including heat-fusible fibers are laminated to each other at the heat-embossed portion by heat-embossing. The present invention relates to a hot embossed dry nonwoven fabric.

  The present invention also provides an airlaid nonwoven fabric in which a web is formed from cellulosic fibers and does not contain heat-fusible fibers, and an airlaid nonwoven fabric in which webs are formed from cellulosic fibers and heat-fusible fibers. The present invention relates to a hot embossed dry nonwoven fabric characterized in that the nonwoven fabric laminate is heat-bonded to each other at a heat embossed portion by heat embossing.

  Further, the present invention relates to the hot embossed dry nonwoven fabric described above, wherein the hot embossed portion is formed with a planar shape of micropores in which capillary action occurs between the nonwoven fabric fibers. It relates to a nonwoven fabric.

Further, the present invention is the airlaid nonwoven fabric, the heat embossing, characterized in that only between the fibers of more nonwoven surface layer portion to spray the binder emulsion to the surface of the web consisting of cellulosic fibers is those points joined It relates to a processed dry nonwoven fabric.

  The present invention also relates to a wet paper such as a disposable hand towel obtained by impregnating one of the above hot embossed dry nonwoven fabrics with water.

  The present invention also relates to a wiper, a coaster, a place mat, a table cloth, a towel or a sheet made of any one of the above hot embossed dry nonwoven fabrics.

  Further, the present invention is a method in which a web is formed from cellulosic fibers, and a plurality of air-laid nonwoven fabrics that do not contain heat-fusible fibers are laminated, and heat embossing is performed by a heat embossing roll, and the plurality of sheets are formed at a heat embossed portion It is related with the manufacturing method of the hot embossed dry nonwoven fabric characterized by heat-sealing each airlaid nonwoven fabric of each other.

  Further, the present invention is a state in which a web is formed from cellulosic fibers, and an airlaid nonwoven fabric that does not include heat-fusible fibers and an airlaid nonwoven fabric in which webs are formed from cellulosic fibers and heat-fusible fibers, The present invention relates to a method for producing a hot embossed dry nonwoven fabric characterized in that heat embossing is performed with a hot embossing roll and the nonwoven fabrics are heat-sealed to each other at a heat embossed portion.

  Further, the present invention provides the above hot embossed dry nonwoven fabric manufacturing method, wherein the hot embossed portion is formed with a fine hole in which a capillary phenomenon occurs between the nonwoven fabric fibers in a planar shape. The present invention relates to a method for producing a dry nonwoven fabric.

In a preferred embodiment of the present invention, the airlaid nonwoven fabric is one in which cellulosic fibers are made of pulp. In another preferred embodiment of the present invention, the wet paper is wet towel, wet tissue, or wet towel. Furthermore, in another preferred embodiment of the present invention, the hot embossing is performed at a feed rate of 120 to 180 ° C. and 20 to 60 m / min under a pressure of 200 to 500 kg / cm ² .

  Hereinafter, the present invention will be described in detail. In the present invention, as a nonwoven fabric, a web is formed from cellulosic fibers, and an airlaid nonwoven fabric that does not contain heat-fusible fibers is used. If necessary, a web is formed from cellulosic fibers and heat-fusible fibers. Airlaid nonwoven fabric is used. The nonwoven fabric containing the heat-fusible fiber of the present invention seems to reinforce the strength of the hot embossed dry nonwoven fabric formed using only the air-laid nonwoven fabric not containing the heat-fusible fiber, particularly when wet. In such a case, it is used together with an airlaid nonwoven fabric that does not contain heat-fusible fibers. An airlaid nonwoven fabric in which a web is formed from cellulosic fibers used in the dry nonwoven fabric of the present invention and does not contain heat-fusible fibers, is defibrated cellulose fibers of a predetermined length and transported on an air flow, After passing through a wire mesh or a screen having pores, a web is formed by air-laying method in which it falls and deposits on a wire mesh, and an intersection of fibers only on the surface layer portion of the web is joined by spraying an emulsion binder. It is manufactured. In addition, an airlaid nonwoven fabric in which a web is formed from cellulosic fibers and heat-fusible fibers is defibrated with a predetermined length of these fibers and transported in a flow of air to form a screen having a wire mesh or pores. After passing, a web is formed by an air array method in which the fiber is dropped and deposited on a wire mesh, and the intersection of the fibers in the web is heat-fused with a hot-melt fiber as a binder fiber, or an emulsion It is formed by joining fiber intersections with a binder.

  The cellulosic fibers constituting the air laid nonwoven web may be any of the cellulosic fibers conventionally used in the production of nonwoven fabrics, as appropriate depending on the required water absorption, nonwoven fabric strength, etc. Should be adopted. Examples of cellulosic fibers include natural cellulose fibers such as cotton, pulp and hemp, and regenerated cellulose fibers such as rayon fiber, tencel fiber, and cupra. These cellulosic fibers can be used alone or in combination of two or more. Of these cellulosic fibers, cotton, rayon fiber, pulp or tencel fiber is preferably used from the viewpoint of improving the touch of the nonwoven fabric, but pulp is preferable from the viewpoint of imparting a pattern and cost.

  The pulp preferably used in the air-laid nonwoven fabric constituting the hot embossed dry nonwoven fabric of the present invention may be any cellulose pulp that is normally used when paper is made, for example, softwood, hardwood, etc. Non-wood fibers such as wood fiber, manila hemp, kenaf, bagasse and the like can be mentioned. For pulping cellulose fibers, chemical pulp methods such as kraft pulp method and sulfite pulp method, semi-chemical pulp method, mechanical pulp method and the like are known, but any method may be used. Cellulose fibers can be used in a generally employed manner, and can be bleached, semi-bleached, or unbleached, and these can be used alone or in combination of two or more. In addition, when creating an airlaid nonwoven fabric that does not contain the heat-fusible fiber using pulp, since only the nonwoven fabric surface layer is bonded with a binder, there is a problem of wet strength, when the nonwoven fabric is wet when an embossed pattern is formed. The problem of pattern collapse or disappearance is particularly noticeable, but such a problem is solved by the present invention.

  On the other hand, the heat-fusible fiber may be a thermoplastic fiber that can be melted and fused in the manufacturing process of the nonwoven fabric, and a single fiber such as polyester, vinylon, nylon, or the core is polyethylene, polypropylene, or polyester, So-called core-sheath type composite fibers such as polyester and ethylene / vinyl acetate may be used alone, or two or more of these may be used in combination. When heat fusible fibers are dry-blended with cellulosic fibers such as pulp by the airlay method, the heat fusible fibers are melted and softened by heating, and the heat fusible fibers are spot-bonded to cellulosic fibers such as pulp, thereby increasing the bulk. The non-woven fabric is formed and the paper strength is improved. And since the cellulosic fiber is mutually joined by the melt softening of the synthetic fiber, even if it absorbs water, a part of nonwoven fabric will not peel off. The heat-fusible fiber is usually used in the form of a short fiber staple fiber (fiber length: 20 to 51 mm), and the fineness is appropriately selected according to the texture of the obtained nonwoven fabric, for example, 1.0 to 3.0 denier. Something about is used. The blending ratio of the cellulosic fibers such as pulp and the heat-fusible fiber may be set to an appropriate ratio in consideration of water absorption, strength, heat embossability, and the like. For example, the cellulosic fiber is generally 50 to 90% by weight, and the heat-fusible fiber is generally 50 to 10% by weight. When the blending ratio of the heat-bonding synthetic fiber is less than 10% by weight, for example, paper strength as a hand towel may be insufficient. On the other hand, when it exceeds 50% by weight, flexibility as a hand towel is lost and cost increases. Is not suitable.

  On the other hand, emulsion binders used in the production of nonwoven fabrics include acrylic copolymers, styrene / butadiene copolymers, vinyl acetate / ethylene copolymers, vinyl acetate / acrylic copolymers, vinyl acetate homopolymers, acrylonitrile polymers, etc. Various polymers are known. As the air laid nonwoven fabric used in the present invention, an appropriate one is selected according to the properties required for the nonwoven fabric.

  In the present invention, by heating and pressurizing a plurality of laminated airlaid nonwoven fabrics using a hot embossing roll, the binder resin contained in the surface layer portion of the airlaid nonwoven fabric is melted, and the airlaid nonwoven fabrics are fused to each other. is there. Conventionally, in an air laid nonwoven fabric that does not include a heat-fusible fiber in which a web is formed from cellulosic fibers, a pattern is not applied to the air laid nonwoven fabric by hot embossing itself. If it is attached, a white embossed pattern will be formed on the white background, so it cannot be confirmed without careful attention to the pattern itself, and it was not sufficient to achieve the purpose of decoration effect, advertising effect, etc. Is. In addition to this, even if an embossed pattern is applied, the nonwoven fabric intermediate layer is not bonded between fibers by a binder, so when the nonwoven fabric is wet, the wet strength is not sufficient, for example This is because there is a problem that the pattern is broken or disappears when a force such as light pulling in a wet state is applied. However, in the present invention, the dry and wet strength of the dry nonwoven fabric as a whole has been improved by laminating airlaid nonwoven fabric composed of a plurality of cellulosic fibers and heat embossing them. In this way, a heat-fusible fiber in which a web is formed from a plurality of cellulosic fibers is not subjected to patterning by heat embossing in a state where airlaid nonwoven fabrics composed of a plurality of cellulosic fibers are laminated. It is expected that simply embossing an air-laid nonwoven fabric that does not contain water will greatly improve the overall strength of the nonwoven fabric when dry and wet, and that the hot embossed pattern will not easily collapse or disappear. It was impossible. In addition, if it is desired to further reinforce the strength of the hot embossed dry nonwoven fabric, if necessary, an airlaid nonwoven fabric containing heat-fusible fibers can be used as a base paper for producing the hot embossed nonwoven fabric. You may use with the air laid nonwoven fabric which consists of fibers and does not contain a heat-fusible fiber. When using the airlaid nonwoven fabric containing the heat-fusible fiber, an airlaid nonwoven fabric made of cellulosic fibers not containing one heat-fusible fiber and an airlaid nonwoven fabric containing one heat-fusible fiber are laminated. The form of the combination, such as heat embossing, laminating an airlaid nonwoven fabric made of cellulosic fibers not containing a heat fusible fiber across an airlaid nonwoven fabric containing a heat fusible fiber, and heat embossing, etc. Be free.

  Furthermore, when performing heat embossing in the present invention, by performing heat embossing at an appropriate pressing force, heating temperature, and paper passing speed, the capillaries are formed in the heat embossed portion by densifying the nonwoven fabric and melting the binder resin in the heat embossed portion. A region having fine pores where the phenomenon occurs is formed in a planar shape, and a pattern is formed by this hot embossed region or a combination of the processed regions, so that the hot embossed dry nonwoven fabric of the present invention is moderately wetted with water. When this is done, the hot embossed part can be observed as a translucent pattern. This is because, even when the hot embossed dry nonwoven fabric is made of cellulosic fibers that do not contain heat-fusible fibers and consists only of air-laid nonwoven fabrics, the web is made from cellulosic fibers that do not contain heat-fusible fibers. The same applies to the case where the air-laid nonwoven fabric formed and the air-laid nonwoven fabric containing heat-fusible fibers are used in combination.

  The size of the embossed surface when performing hot embossing may be an appropriate size. In the case of aiming to obtain a transparent design, it is sufficient that each embossed region has a size that can be clearly recognized visually when each embossed region contains water and becomes translucent. The shape may be circular, linear, or any other shape. For example, when the hot embossing region for forming the pattern is circular, the diameter of the embossed portion is preferably about 1 to 2 mm or more. In the case of a line figure, the line width is preferably about 1 mm or more.

  Heat embossing for patterning on a nonwoven fabric will be briefly described with reference to FIG. 1. A hot roll 1 having a convex pattern such as a desired company name, a logo, or a pattern formed on the surface, and a smooth surface. A web is formed from two cellulosic fibers between the hot roll 2 and the air-laid nonwoven fabric 3, 3 'containing no heat-fusible fiber is fed into the roll, and heat embossing is performed at the roll facing portion. Is called. Although the embossing roll in FIG. 1 consists of the combination of the roll which has a convex pattern, and a smooth roll, the aspect of the hot embossing in this invention is not restricted to this. For example, two convex pattern rolls formed so that their convex patterns overlap each other at the roll facing portion may be used, and the nonwoven fabric may be fed between the two rolls to heat and pressurize the nonwoven fabric. Moreover, you may use a flat plate type | mold instead of roll shape. Moreover, the heat roll 2 having a smooth surface may have an elastic layer on the surface. In FIG. 1, two identical airlaid nonwoven fabrics are used, but these raw materials need not be the same, for example, an airlaid material in which a web is formed from cellulosic fibers and does not contain heat-fusible fibers. The nonwoven fabrics may have different basis weights, and may be three or more instead of two. The air-laid nonwoven fabric used may be a combination of an air-laid nonwoven fabric that does not contain heat-fusible fibers and an air-laid nonwoven fabric that does not contain heat-fusible fibers.

  The air-laid nonwoven fabric that is formed from the cellulose fibers used in the present invention and does not contain heat-fusible fibers maintains bulkiness, so that only the intersections of the fibers near the surface (surface layer portion) are joined by a binder. The emulsion binder is sprayed from both surfaces of the web in such an amount. Therefore, as shown in FIG. 2, the binder 34 is usually not present in the center layer 32 although it is present in the nonwoven fabric surface layers 31 and 33.

  FIG. 3 shows a partial plan view of a heat-embossed nonwoven fabric. In FIG. 3, a composite pattern composed of an embossed region 5 composed of oblique diagonal lines in two directions composed of small round points and an embossed region 6 of a petal pattern is attached. FIG. 3 is merely an example of a pattern, and an arbitrary pattern can be applied to the nonwoven fabric by changing the pattern of the embossing roll.

In the present invention, the binder 34 of the surface layer portions 31, 33, 31 ′, 33 ′ of the nonwoven fabrics 3, 3 ′ is melted and the upper and lower nonwoven fabrics are required to be fused during hot embossing. . Further, in the hot embossed dry nonwoven fabric of the present invention, it is preferable that micropores having a size causing capillary action in the embossed portion, that is, microscopic gaps are formed between the fibers. For this reason, the roll heating temperature, the embossing pressure, and the sheet passing speed during hot embossing are adjusted. The patterning by hot embossing varies depending on various conditions such as the type and amount of binder used in the nonwoven fabric and the thickness of the base paper, but is usually a roll temperature of 120 to 180 ° C. under a pressure of 200 to 500 kg / cm ² , 20 It is performed at a paper feeding speed of ˜60 m / min. The embossing pressure is usually adjusted by the gap between the rolls in the embossed part. The preferable roll temperature, roll gap, and paper feeding speed are a heating temperature of about 150 to 170 ° C., a roll gap of a hot embossed portion of about 0.2 to 0.5 mm, and a paper feeding speed of about 20 to 60 m / min. However, this is merely an example, and it is needless to say that the embossing conditions are not limited to those described above. For example, if the melting temperature of the binder resin is low, the feed rate can be increased, or the roll gap can be increased or decreased depending on the thickness and basis weight of the nonwoven fabric. In short, the heat embossing conditions for patterning are the fine pores having a size that causes the capillary air phenomenon to occur in the embossed portion of the nonwoven fabric, that is, the laminated airlaid nonwoven fabric is heat-sealed during the heat embossing. Any condition may be used as long as the gap is formed between the fibers.

  The hot embossed dry nonwoven fabric of the present invention formed by embossing in this way is shown in FIG. The two air-laid nonwoven fabrics are heat-sealed to each other at the heat embossed portion 7 and the density of the nonwoven fabric is increased. This improves the dry and wet strength of the air-laid nonwoven fabric, and prevents the embossed pattern from collapsing or disappearing when the hot embossed pattern formed on the hot embossed dry nonwoven fabric is wetted and lightly tensioned. it can. This is presumably because the two air-laid nonwoven fabrics were heat-sealed by hot embossing and the nonwoven fabric was densified by hot embossing. In addition to this, depending on the heat embossing conditions, it is also conceivable that the fibers inside the nonwoven fabric that have not been joined by the binder until now may be joined further by the molten binder. At this time, in the hot embossed portion 7, when micropores having such a size that capillarity occurs between fibers forming the nonwoven fabric, when the embossed nonwoven fabric is impregnated with water, the embossed in which the micropores are formed In the processed portion, water fills the fine pores between the fibers due to capillary action, thereby forming a translucent portion in the hot embossed portion 7. On the other hand, since the capillarity hardly occurs in the film plane direction, the non-embossed portion 8 remains white as long as it is below a certain amount of water and becomes a white non-transparent portion.

  Explaining the embossing of the pattern by taking a hand towel as an example, the disposable hand towel usually contains about 500% of the weight of the nonwoven fabric. When the hot embossed dry nonwoven fabric of the present invention has such a water content, the nonwoven fabric portions (5, 6 in FIG. 3 and 7 in FIG. 4) crushed by embossing have fibers by capillary action. Water enters between them to fill the fine pores between the fibers. As a result, the embossed portion becomes translucent, while the non-embossed portion does not cause capillary action, so that the space between the fibers is not completely filled with water and remains white. For this reason, the translucent pattern clearly appears against the background of the natural white color of the nonwoven fabric. For example, if the wet towel pattern is made into a company name or logo mark, the company name or logo mark will appear in the hand towel before use, and an advertising effect will be obtained, and repeated flower patterns and geometric patterns etc. If the pattern is added, it is possible to give an aesthetic effect or a high-class hand towel to the user. When the nonwoven fabric contains about 500% of the weight of the nonwoven fabric, depending on the type of the base paper, the non-embossed portion is not completely white but somewhat translucent, and the pattern is somewhat It may appear out of focus. However, even in such a case, when the hand towel is taken out of the bag and the hand is wiped, for example, when the water content is about 300%, the pattern clearly appears. In any case, when the moisture further evaporates from the hand towel, the embossed portion also becomes white due to the evaporation of moisture from the pattern portion that has been translucent until now, and finally the translucent pattern disappears. For this reason, patterns appear and disappear while using hand towels, giving a sense of surprise to people using hand towels and giving a strong impression of company names, logos, patterns, etc. it can.

  Furthermore, when the water content of the nonwoven fabric is increased, the non-embossed portion is also completely wetted with water, so that the entire hand towel becomes translucent. However, the hand towel with the pattern of the present invention in which the whole is in a translucent state in this way is initially translucent, but the wet towel disappears during use, as described above. Gradually, the non-embossed portion becomes white and opaque, while the embossed portion remains held in a translucent state. For this reason, even in such a case, a pattern appears in the hand towel while using.

  The use mode of the patterned non-woven fabric of the present invention has been described by taking a hand towel as an example, but the same applies when wet paper is used in the form of wet tissue or wet towel.

  Further, when a non-woven fabric is used in a dry state, such as a paper towel, and a hand wet with water is wiped with the dry non-woven fabric, a semi-transparent pattern can be expected to appear on the non-woven fabric. Another example of using such an effect is, for example, pet sheets. When the dry nonwoven fabric of the present invention having a pattern such as a logo mark is used, since the logo mark appears immediately when the sheet gets wet, the effect that the sheet can be replaced without delay is obtained. In addition, on coasters, place mats, table cloths, etc., when a cold drink is placed on the coaster, the coaster gets wet with water droplets that form around the cup. The pattern comes out. Placemats and tablecloths can be expected to have the same effect as the coasters described above, and if they happen to get wet with water, a logo mark, pattern, etc. will appear in the area, which will surprise the user. Can be given.

  Further, in the patterned nonwoven fabric of the present invention, the processed portion has a high density, so that the capillary action works in the lateral direction, and in addition to the filter effect by longitudinal absorption, which is a feature of the dry nonwoven fabric, the entire surface has uniform water absorption. It becomes possible. This characteristic is effective when a drug is evenly contained in a wet towel or the like.

  When the patterned dry nonwoven fabric of the present invention is used as wet paper for wet toweling, wet tissue, wet towels, etc., the wetting liquid can contain chemicals such as fragrances, bactericides, and antibacterial agents as in the past. . In addition, the production of wet towels, wet tissues, wet towels and the like may be performed in the same manner as in the past. For example, wet hand towels are manufactured by patterning a dry non-woven base paper by hot embossing, folding it, applying a water shower containing chemicals, cutting it into a predetermined size with a cutter, It is made into a roll shape, and it is carried out by a method such as flat folding and then folding the bag into a film.

Examples of the present invention will be described below, but the present invention is not limited thereto.
Example 1
In this example, Kinocloth KOB40 (Oji Kinocloth Co., Ltd.) is an airlaid nonwoven fabric produced by forming a web from pulp and spraying an emulsion binder on both sides of the web and having no bonding between the fibers by the binder. Manufactured; US basis weight 40 g / m ² ) was used as the base paper. As the heat embossing device, a device such as the one shown in FIG. 1 in which a roll 1 (embossed area ratio 8%) having a convex pattern and a smooth roll 2 face each other with a 0.15 mm gap at the embossed portion is used. In a state where two KOB40s are stacked, the heat embossing device is supplied to the heat embossing device, passed between the two embossing rolls 1 and 2 heated to 160 ° C. at a paper passing speed of 40 m / min, and heat embossing of the kinocross KOB40. Then, a dry nonwoven fabric laminate was obtained which was heat embossed in a state where two kinocross KOB40s were stacked. The dry and wet tensile strength of the dry nonwoven fabric laminate was measured under the following strength measurement test conditions. The results are shown in Table 1.
Moreover, the disposable wet wet towel was manufactured through the process similar to the past using this hot embossed dry-type nonwoven fabric laminated body. A semi-transparent pattern appeared clearly in the wet towel.

<Strength measurement test>
The tensile strength when the nonwoven fabric was dry and wet (water retention amount: 300%) was measured using a shopper type tester (180 mm between chucks). The test piece was measured at a width of 50 mm. The test result was calculated as an average value of 5 tests (unit: g).

Comparative Examples 1 and 2
In order to compare with the hot embossed dry nonwoven fabric obtained in Example 1, airlaid nonwoven fabric with a web formed from pulp, kinocloth KOB80 (Oji Kinocross Co., Ltd.) manufactured by the same method as kinocloth KOB40 of Example 1. Tensile 80g / m ² ), dry and wet tensile strength using one sheet (not heat embossed) and two unheated kino cloth KOB40 (made by Oji Kinocross Co., Ltd.) Was measured under the same conditions as in Example 1. The results are shown in Table 1.

  It can be seen from Table 1 that the strength of the nonwoven fabric is greatly improved by hot embossing in both dry and wet conditions. In addition, the processed portion of the hot embossed dry nonwoven fabric of the present invention did not lose its shape when it was slightly pulled when wet. Further, the bulkiness of the air laid nonwoven fabric was not changed after the hot embossing. In addition, what heat-embossed kino cloth KOB80 on the conditions similar to Example 1 had the pattern of the heat embossing part collapsed by pulling lightly when wet.

Example 2
Using high cloth HAZ40 (manufactured by Oji Kinocloth Co., Ltd .; 40 tsubo / m ² ), a pulp airlaid nonwoven fabric containing kinocloth KOB40 and heat-fusible fibers, heat embossing under the same conditions as in Example 1 with kinocross KOB40 as the upper layer Processing was performed. Thereby, compared with the case where only kino cloth KOB40 was used, the hot-embossed dry nonwoven fabric of still greater strength was obtained. Also, when wet, a translucent pattern clearly emerged.

[The invention's effect]
The dry nonwoven fabric patterned by the hot embossing process of the present invention is a web formed of cellulosic fibers such as pulp, and an airlaid nonwoven fabric in which only the fibers of the surface portion are joined by a binder is used. In both dry and wet conditions, the tensile strength is greatly improved, and the hot embossed pattern does not disappear even if pulled slightly when wet.

  Further, the dry nonwoven fabric patterned by the hot embossing of the present invention has a heat-embossed portion that is translucent or opaque white depending on the moisture content, and has an appropriate water content when used as wet paper such as disposable towels. In some cases, the embossed part appears as a semi-transparent pattern in the background color of the white nonwoven fabric, and a decorative effect is obtained, and by attaching the company name or logo mark etc. by embossing, It is also possible to use wet paper such as disposable hand towels as an advertising medium.

  Furthermore, when the dry embossed dry nonwoven fabric of the present invention is used as dry paper towels, napkins, wiping paper, sheets, coasters, placemats, table cloths, etc., when these wet with water, the logo marks on the nonwoven fabric, etc. Because the pattern of comes out, new added value including advertising effects can be given to these papers, and on sheets etc., we can see wet marks and replace wet sheets without delay, There is also an effect that a clean environment can be maintained.

  Furthermore, in addition to the absorption characteristics in the thickness direction of the dry nonwoven fabric, the processed portion can also absorb in the surface direction of the nonwoven fabric, so that the effect of being able to evenly contain the drug in the nonwoven fabric such as a wet towel. is there.

It is explanatory drawing explaining the method to manufacture the hot-embossed dry nonwoven fabric of this invention. It is a cross-sectional schematic diagram of the airlaid nonwoven fabric used when manufacturing the hot embossed dry nonwoven fabric of this invention by which the web was formed with the cellulosic fiber and only the fiber of the surface part was joined by the binder. FIG. 2 is a partial plan view of a hot embossed dry nonwoven fabric of the present invention that is patterned by hot embossing. It is a cross-sectional schematic diagram of the hot-embossed dry nonwoven fabric of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat roll 2 which has convex pattern Surface smooth heat roll 3, 3 'Airlaid nonwoven fabric 4 Dry type nonwoven fabric in which pattern was formed by hot embossing 5 Point-like hot embossing part 6 Petal-like hot embossing part 7 Heat embossing Part 8 Non-embossed part 31, 31 ', 33, 33' Surface layer part (fiber bonding part by binder)
32, 32 'center part (fiber non-joining part by binder)
34 Binder

Claims (11)

The air-laid nonwoven fabric laminate in which a plurality of air-laid nonwoven fabrics that are made of cellulosic fibers and do not contain heat-fusible fibers are laminated and heat-bonded to each other at the heat-embossed portion by heat embossing. Hot embossed dry nonwoven fabric. An airlaid nonwoven fabric laminate in which an airlaid nonwoven fabric in which a web is formed from cellulosic fibers and does not contain heat-fusible fibers and an airlaid nonwoven fabric in which webs are formed from cellulosic fibers and heat-fusible fibers are laminated. A heat-embossed dry nonwoven fabric characterized in that the heat-embossed portions are heat-bonded to each other by processing. 3. The hot embossed dry nonwoven fabric according to claim 1 or 2, wherein in the hot embossed portion, micropores in which capillary action occurs between the nonwoven fabric fibers are formed in a planar shape. The hot-embossed dry nonwoven fabric according to any one of claims 1 to 3, wherein the cellulosic fiber is pulp. The air-laid nonwoven fabric, in any one of claims 1 to 4, characterized in that only between more nonwoven surface layer portion of the fiber spraying the binder emulsion to the surface of the web consisting of cellulosic fibers is those points joined The hot embossed dry nonwoven fabric as described. A wet paper impregnated with water in the hot embossed dry nonwoven fabric according to any one of claims 1 to 5. The wet paper according to claim 6, wherein the wet paper is a wet towel. A wiper, a coaster, a place mat, a table cloth, a towel or a sheet comprising a hot embossed dry nonwoven fabric according to any one of claims 1 to 5. A web is formed from cellulosic fibers, and a plurality of air-laid nonwoven fabrics that do not contain heat-fusible fibers are laminated. A method for producing a hot embossed dry nonwoven fabric characterized by fusing. In a state where a web is formed from cellulosic fibers and an air-laid nonwoven fabric not containing heat-fusible fibers and an air-laid nonwoven fabric in which webs are formed from cellulosic fibers and heat-fusible fibers are laminated, A method for producing a hot embossed dry nonwoven fabric, characterized by performing hot embossing and thermally fusing the nonwoven fabrics together at a hot embossed portion. The method for producing a hot-embossed dry nonwoven fabric according to claim 9 or 10, wherein the hot-embossed portion is formed with planar fine holes in which capillary action occurs between the nonwoven fabric fibers.

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