JP2020068869A - Wet tissue using composite nonwoven fabric and production method of nonwoven fabric - Google Patents

Abstract

To provide wet tissue which allows each sheet to be taken out smoothly.SOLUTION: Wet tissue is configured such that a sheet SH uses a composite nonwoven fabric obtained by water flow cross-connection of a pulp fiber web PFW and a spun bond nonwoven fabric SW as a raw fabric, the sheet SH is folded and a plurality of the folded sheets are laminated and are stored in a packaging container in a wet state. The pulp fiber web PFW side is an irregular surface CS which is subjected to heat embossment processing, the sheet SH is folded in a C-folding state so that the pulp fiber web PFW side is directed outside, the vertically adjacent sheets are laminated so that irregular surfaces CS of the sheets are in contact with each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a wet tissue produced using a composite non-woven fabric composed of a spunbonded non-woven fabric and a pulp fiber web, and more specifically, a composite non-woven fabric sheet (tissue) is folded, laminated and wet. The present invention relates to a wet tissue that is commercialized in a state of being housed in a packaging container.

There are various wet tissues on the market for people and objects. As for the raw material for wet tissue, it is generally required that it has a high hydrophilicity and can hold a chemical solution, that it has sufficient strength even in a wet state, and that it has a good texture. Conventionally, a composite-type non-woven fabric containing a bonded fiber and a synthetic fiber has been widely used.
In recent years, since importance is attached to required strength and cost reduction, a composite non-woven fabric including a spunbonded non-woven fabric and a pulp fiber web manufactured by the technique disclosed in Patent Document 1 is used as a raw fabric. Wet tissue is also being offered.

Japanese Patent No. 2533260

  In the sheet made of the composite non-woven fabric, the pulp fibers are rich in hydrophilicity and also have flexibility, whereby properties such as water absorption and texture can be obtained. On the other hand, the spunbonded non-woven fabric has durability and functions as a backing layer, and contributes to improvement of the strength and shape stability of the sheet.

The wet tissue including the above-mentioned sheet is formed into a product by stacking a plurality of sheets folded into a predetermined shape and storing the stacked sheets in a flexible packaging or a molding container. In the sheet which is the original fabric of the composite non-woven fabric, there is a pulp fiber web side (pulp side) where a large amount of pulp fibers are exposed and a spun bond non-woven fabric side (spun bond side) opposite the side. As described above, the pulp surface side is often stored with the pulp surface side facing outward because of its excellent water absorption and texture.
However, in the above wet tissue, since the hydrophilicity is more strongly exerted in the wet state on the pulp surface side, when the pulp surfaces of the vertically adjacent sheets come into contact with each other, the affinity of the chemical liquid (water) acts strongly. Therefore, when the user takes out the upper sheet, the lower sheet may stick to the sheet and may be difficult to remove, or the lower sheet may be pulled out together.
Therefore, an object of the present invention is to provide a wet tissue, which is improved so that a user can smoothly take out each sheet even when a composite nonwoven fabric made of a spunbonded nonwoven fabric and a pulp fiber web is used as a raw fabric. is there.

  The above-mentioned object is a wet tissue that is formed by stacking a plurality of sheets of a composite non-woven fabric obtained by hydroentangling a pulp fiber web and a spun-bonded non-woven fabric and then stacking the sheets in a wet state in a packaging container. And the pulp fiber web side is a heat-embossed uneven surface, the sheet is folded in a C-fold form with the pulp fiber web side facing outward, and the vertically adjacent sheets are separated from each other. It can be achieved by a wet tissue characterized by being laminated such that the uneven surfaces are in contact with each other.

  The ratio of the contact area between the uneven surfaces is preferably 60% or more with respect to the total contact area where the sheets arranged vertically adjacent to each other are in contact with each other.

Further, it is preferable that the difference in thickness between the pressure-bonded portion which is pressure-bonded by the hot embossing treatment to form the concave portion and the non-pressure-bonded portion which is not pressure-bonded and becomes the convex portion is 0.06 mm or more.
The area ratio of the pressure-bonded portion is preferably 5 to 30%.
Further, the spunbonded non-woven fabric side may be a heat-embossed uneven surface.

Further, the basis weight of the pulp fiber web in the raw fabric is 15 g / m ² or more, and the basis weight of the spunbonded nonwoven fabric is 8 g / m ² or more, and the mass composition ratio of the raw fabric (spunbonded nonwoven fabric). / Pulp fiber web) is preferably 15/85 to 50/50.

  Then, the above-mentioned object is a method for producing a composite non-woven fabric used as a raw material for the wet tissue described above, and includes a step of heat embossing treatment for forming an uneven surface on the pulp fiber web side, The hot embossing treatment is also performed by a method for producing a composite non-woven fabric, which is carried out at a crimping linear pressure of 20 Kgf or more.

  In the hot embossing treatment, a single-sided embossing treatment for forming an uneven surface only on the pulp fiber web side or a double-sided embossing treatment for forming an uneven surface on both the pulp fiber web side and the spunbond nonwoven fabric side is performed. You may.

  According to the present invention, it is possible to provide a user-friendly wet tissue in which the upper sheet can be smoothly taken out even if a sheet made of a composite nonwoven fabric made of a spunbonded nonwoven fabric and a pulp fiber web is used.

It is the schematic diagram which expanded the cross section of the sheet | seat of the wet tissue of this invention. It is the figure shown about the embossing device which performs heat embossing processing on the original fabric of wet tissue. It is the figure shown in order to explain the mode of folding of the sheet | seat in the wet tissue of this invention. It is the figure shown about the case where a sheet was made to fold twice.

FIG. 1 is an enlarged schematic view showing a cross section of one sheet (tissue) SH included in the wet tissue of the present invention.
The sheet SH shown in FIG. 1 has a pulp fiber web PFW on the upper side and a spunbonded nonwoven fabric SW on the lower side. The composite non-woven fabric, which is the original fabric of the sheet SH, is integrated by a hydroentangling treatment in which a high-pressure water jet (water flow) is sprayed from above with a pulp fiber web PFW placed on a spunbonded non-woven fabric SW. is there.

The above-mentioned pulp fiber web PFW is formed by using, for example, a softwood bleached kraft pulp (NBKP) fiber selected from the group consisting of radiata pine, slash pine, southern pine, lodgepole pine, spruce and Douglas fir. Is preferred. A pulp fiber web made of any one of the pulp fibers may be used, or a pulp fiber web formed by mixing two or more may be used. Pulp It is preferable to use pulp having an average fiber length of 1.0 to 5.0 mm. The method for producing the pulp fiber web is not particularly limited, and dry air laid, or those produced by a general wet papermaking method or a wet papermaking method can be widely adopted.
The synthetic resin fibers used in the spunbonded nonwoven fabric SW can be selected from nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polystyrene and the like, and polypropylene is preferably used.

As described above, the pulp fiber web PFW has excellent water absorbency and texture, and the spunbonded nonwoven fabric SW functions to reinforce the sheet and maintain the outer shape.
Regarding the raw fabric of the composite nonwoven fabric, the basis weight of the pulp fiber web is 15 g / m ² or more, and the basis weight of the spunbond nonwoven fabric is 8 g / m ² or more, and the mass composition ratio of the raw fabric (spunbond nonwoven fabric / It is preferable to employ one having a pulp fiber web of 15/85 to 50/50.

As shown in FIG. 1, the pulp fiber web PFW side of the sheet SH has an uneven surface. Such uneven surface CS can be formed using a heat embossing device.
The form illustrated in FIG. 1 is a form called single-sided embossing, and the sheet SH can be embossed by using the hot embossing device EA shown as an example in FIG.
In FIG. 2, the upper roller a1 of the heat embossing device EA is provided with protrusions pr at predetermined intervals along the circumferential direction, and the lower roller a2 has a flat peripheral surface. The two rollers are arranged with a predetermined distance. A heater HE as a heating means is provided inside each roller. Therefore, when the sheet SH is sent to the hot embossing device EA with the pulp fiber web PFW side facing upward, the heat embossing treatment is performed as shown in FIG. 1 to form the uneven surface CS on the pulp fiber web PFW side. ..
It is sufficient that at least the uneven surface CS is formed on the pulp fiber web PFW side, but the uneven surface may also be formed on the spunbonded nonwoven fabric SW side. In this case, the lower roller a2 in FIG. 2 is changed to a roller having protrusions similarly to the upper roller a1, and the sheet is processed by the heat embossing device EA so that both front and back surfaces of the sheet become uneven (double-sided embossing). Good.
In addition, it is preferable that the crimping linear pressure in the heat embossing process is set to 20 kgf or more. Thereby, the recess CR can be reliably formed.

FIG. 3 schematically shows a state of the sheets SH laminated in a folded state when the wet tissue according to the present invention is stored in a package or a container and is in a product form.
Each sheet SH is folded in a so-called C-fold form with the pulp fiber web PFW side facing outward, and a plurality of sheets SH are vertically stacked in the same posture. Here, in FIG. 3, the state of the circled portion is shown enlarged. The lower surface of the sheet SH-a located on the upper side is the pulp fiber web PFW side surface. Then, the upper surface of the folded back portion of the sheet SH-b located on the lower side also becomes the pulp fiber web PFW side surface. Therefore, the pulp fiber web PFW surfaces of the sheets SH-a and SH-b that are vertically adjacent to each other are in contact with each other.

In the conventional wet tissue, as described above, in a sufficiently wet sheet, there is a problem that the pulp fiber webs PFW stick to each other at the contact surface, and it may be difficult to take out the upper sheet SH. there were.
In the wet tissue according to the present invention, the occurrence of the sticking phenomenon is suppressed by forming the uneven surface on the pulp fiber web PFW. The present inventor examined in detail the cause of sticking, and confirmed that when the pulp surfaces are brought into contact with each other in a sufficiently moist environment, the adjacent sheets stick strongly due to the surface tension of the chemical liquid (water). As a new structure for coping with this, it is an idea to provide an uneven surface on the pulp fiber web PFW side. By providing the uneven surface on the PFW side of the pulp fiber web, it becomes easier for the water present therebetween to escape, and the adjacent sheets can be appropriately separated from each other, so that the surface tension can be reduced. Understood, the present invention was reached (see the enlarged view of FIG. 3).

By the way, as shown in FIG. 3, in the C-folded form, there is an area where the inner spunbonded nonwoven fabric SW is exposed, and this exposed area SW-x comes into contact with the upper sheet SH. It is necessary to keep the ratio of this exposed region SW-x low. Specifically, the ratio of the contact area in which the concavo-convex surfaces CS of the pulp fiber web PFW contact each other is 60% or more with respect to the total contact area in which the sheets SH arranged adjacent to each other vertically contact each other. Is preferably designed as follows. That is, the contact ratio with the exposed area SW-x is set not to exceed 40%.
In the case of a sheet SH that has been subjected to a double-sided embossing treatment in which an uneven surface is formed on the spunbonded nonwoven fabric SW side as well as the pulp fiber web PFW side, the sheet is formed by the uneven surface CS provided on the pulp fiber web PFW side. By designing not only to prevent sticking of each other but also to have sufficient sheet thickness and sheet strength, it is possible to make a bulky product with no difference in front and back.

The pulp fiber web includes a crimped portion CR which is thermocompression-bonded by the hot embossing treatment and becomes a concave portion, and a non-crimped portion UC which is not subjected to such a treatment and becomes a convex portion as shown in FIG. The uneven surface CS is formed by forming a plurality on the surface of the PFW. Here, it is preferable to form the crimp portion CR so that the difference d in thickness between the crimp portion CR and the non-crimp portion UC is 0.06 mm or more. If the difference d is smaller than 0.06 mm, it becomes difficult to secure a sufficient distance between the sheets, and as a result, the surface tension is insufficiently reduced, and the effect of suppressing sticking described above may be weakened. To be done.
Further, it is preferable to design the surface of the pulp fiber web PFW so that the area ratio of the crimp portion CR is 5 to 30%. When the area ratio is 5% or less, the effect of suppressing sticking due to the provision of the uneven surface becomes weak. On the other hand, if the area ratio exceeds 30%, there is a concern that the strength of the sheet may be reduced more than the sticking suppressing effect by the embossing treatment.

By the way, as shown in FIG. 4, the wet tissue may be composed of a sheet SH in the form of two folds in which the central portion is further folded to the sheet SH in the C-folded form shown on the left side. The sheet SH-1 of the first example shown in the upper right side is a case where the sheet SH in the C-folded state is internally folded so that the opening portions face each other. The sheet SH-2 of the second form example shown in the lower right side is a case where the sheet SH in the C-fold form is outwardly folded so that the opening portion faces outward.
In either of the first and second forms, since the positional relationship in which the pulp fiber web PFW surface side having the uneven surface is in contact with each other is maintained, each sheet can be smoothly drawn out. However, the second embodiment is more preferable in that the end portion of the sheet SH can be easily pinched.

  The sheet SH described above is cut into a predetermined size from the original fabric of the composite non-woven fabric, undergoes a step of folding it, a step of impregnating the non-woven fabric with a chemical solution, a step of cutting, etc. Is finished. A known device for manufacturing wet tissue can be used. In the folding step, the sheet SH can be formed into the above-described C-fold form by using a known folding device, for example, a multi-stand type interfolder. Further, by using a rotary folder, a C-folded continuous sheet is folded and cut at the central position, so that both of the above-mentioned two-fold form of inner folding and outer folding can be obtained at once. Then, as the chemical liquid and the like, those exemplified below can be used.

Examples of chemicals that can be used in this wet tissue are given below.
The wet tissue is manufactured by impregnating the chemical liquid with a dry weight of the raw fabric at a ratio of, for example, 200 to 500 wt% or less.
The chemical solution may be sequentially set according to the application, but it is preferable that the chemical solution contains an antiseptic agent for keeping it stable for a long period of time and a moisturizing agent for protecting the skin during wiping.
Preservatives include benzoic acid and its salts, chlorcresol, chlorobutanol, salicylic acid and its salts, solhibinic acid and its salts, dehydroacetic acid and its salts, trichlorohydroxydiphenyl ether, paraoxybenzoic acid ester and its sodium salt, phenoxyethanol, phenol. , Sodium lauryl dianoethylglycine, resorcin, isopropylmethyphenol, cetylpyridinium chloride, benzalkonium chloride, chlorhexidine hydrochloride, orthophenylphenol, chlorhexidine gluconate and the like can be blended. These preservatives can be used alone or in combination of two or more kinds. Further, the content of the preservative is preferably 0.1% by mass or more and 5.0% by mass or less with respect to the chemical liquid.

As the moisturizer, glycerin, polyhydric alcohol such as pentaerythritol, lactic acid, organic acids such as sodium pyrrolidonecarboxylate, urea, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, polyethylene glycol, Alkylene glycols such as diethylene glycol monoethyl ester, and also natural oils and fats, long-chain fatty acids, fatty acid esters, lanolin, lanolin alcohols, lanolins such as polyoxyethylene beeswax, phospholipids, ceramides that act as emollients for oil-soluble components. Natural moisturizing ingredients such as aloe extract and the like can be added. These moisturizers can be used alone or in combination of two or more kinds. Further, the blending amount of the moisturizer is preferably 0.0001 mass% or more and 10.0 mass% or less with respect to the chemical liquid.
In addition, various components commonly used in quasi-drugs and cosmetics, for example, alcohols such as ethanol and isopropanol, gelling agents, emulsifiers, thickeners, pH adjusters, sequestering agents, etc. You may mix | blend a surface active agent, a stabilizer, a discoloration preventing agent, a fragrance | flavor, a coloring agent, etc. suitably.

  The wet tissue of the present invention described above is a composite non-woven fabric composed of pulp fibers and spunbond, so that water retention, wet strength, excellent texture, and embossed wet tissue with improved wipeability. Become. Further, since the wet tissue of the present invention is arranged so that the pulp fiber web side having the uneven surface is in contact, it can be provided as a user-friendly product in which each sheet can be taken out smoothly.

  Although the description of the embodiment has been completed, the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the scope of the invention.

SH (SH-a, SH-b) Sheet (Tissue)
SW Spunbond non-woven fabric MD Fiber flow direction (longitudinal direction)
PFW Pulp fiber web EA Embossing HE heater a1 Upper roller pr Protrusion a2 Lower roller CR Crimping part UC Non-crimping part d Difference in thickness between crimping part and non-crimping part CS Rough surface

Claims (8)

A wet tissue that is a plurality of laminated sheets of a composite nonwoven fabric obtained by hydroentangling a pulp fiber web and a spunbonded nonwoven fabric into a folded form, and stored in a packaging container in a wet state,
The pulp fiber web side has a heat-embossed uneven surface,
The sheet is folded in a C-fold form with the pulp fiber web side facing outward, and the vertically adjacent sheets are laminated so that the uneven surfaces contact each other. Wet tissue to do.   The ratio of the contact area between the concave-convex surfaces is 60% or more with respect to the total contact area where the sheets arranged vertically adjacent to each other are in contact with each other. Wet tissue.   The thickness difference between the pressure-bonded portion which is pressure-bonded by the hot embossing treatment to be a concave portion and the non-pressure-bonded portion which is not pressure-bonded and is a convex portion is 0.06 mm or more. Wet tissue.   The wet tissue according to claim 3, wherein an area ratio of the pressure-bonded portion is 5 to 30%.   The wet tissue according to any one of claims 1 to 4, wherein the spunbonded non-woven fabric side is a heat-embossed uneven surface. The basis weight of the pulp fiber web in the raw fabric is 15 g / m ² or more, and the basis weight of the spunbond nonwoven fabric is 8 g / m ² or more, and the mass composition ratio of the raw fabric (spunbond nonwoven fabric / pulp). The wet tissue according to any one of claims 1 to 5, characterized in that the fibrous web is 15/85 to 50/50. A method for producing a composite non-woven fabric used as a raw material for the wet tissue according to any one of claims 1 to 6,
Including a step of hot embossing treatment for forming an uneven surface on the pulp fiber web side,
The method for producing a composite non-woven fabric, wherein the hot embossing treatment is performed at a crimping linear pressure of 20 Kgf or more.   In the hot embossing treatment, a single-sided embossing treatment for forming an uneven surface only on the pulp fiber web side or a double-sided embossing treatment for forming an uneven surface on both the pulp fiber web side and the spunbond nonwoven fabric side is performed, The method for producing the composite non-woven fabric according to claim 7.

Images