KR20200058061A - Back sheet non-woven fabrics for a diaper with hook type fastener - Google Patents

Abstract

The present invention relates to a diaper back sheet nonwoven fabric to which a hook fastening function is applied. The diaper back sheet nonwoven fabric is composed of a thermoplastic polyolefin-based spunbonded long fiber nonwoven sheet. The back sheet nonwoven fabric is formed to have a basis weight of 16-38 gsm (g/m^2) and thus improve shearing strength, so the back sheet nonwoven fabric can be attached to or detached from a hook (30) without a separate loop member (20). The thermoplastic polyolefin-based spunbonded long fiber nonwoven sheet is composed of a single yarn selected from polypropylene (PP) and polyethylene (PE) or a mixture thereof. According to the present invention, convenient usage is ensured, and product production costs can be reduced.

Description

BACK SHEET NON-WOVEN FABRICS FOR A DIAPER WITH HOOK TYPE FASTENER}

The present invention relates to a backsheet nonwoven fabric for diapers that is provided with a hook fastening function, and more specifically, a separate loop by improving the shear strength by adjusting the basis weight of a diaper backsheet nonwoven fabric composed of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet. The entire surface of the backsheet nonwoven fabric without a member secures a fastening force with the hook, and thus is not only convenient for use, but also relates to a backsheet nonwoven fabric for a diaper that is provided with a hook fastening function to reduce product production cost.

In the conventional method of fixing the waistband of an infant diaper, an adhesive film is used or a nonwoven fabric or a knitted fabric is combined with a hook. In the case of using the adhesive film, all parts of the baby's body are allergic and skin disease due to film contact There is a fear that it may cause and it does not harmonize with the back sheet made of only non-woven fabric, so it is insufficient in appearance. In addition, the loop material using a non-woven fabric or a knitted fabric is manufactured by laminating with a film, and thus the process is complicated and the productivity is greatly reduced, which is a factor that increases manufacturing cost.

In addition, since the loop member must be designed with a low density of the loop non-woven fabric in order to have adhesiveness with the hook, there is a problem in that it is difficult to achieve a variety of patterns on the surface and a harmonious appearance with a non-woven backsheet non-woven fabric. The loop member laminated with a film and non-woven fabric is mainly used for the reason that it is possible to form a mechanical bond with a hook with a disposable product such as a diaper for an infant and an adult diaper, as well as a disposable product such as a bed cover or surgical gown.

In these disposable products, hooks and loop fasteners for wearing them have the function of allowing hooks and hooks to be attached and detached from each other in pairs, so they are often used when opening clothes or shoes. And is commonly known as 'velcro' or 'velcro' according to the trade name. Among them, the loop fastener is usually produced by laminating a film on a non-woven fabric or a non-woven fabric of a multi-layer, and such a nonwoven fabric and a laminate with a film can also be used to manufacture disposable products such as diapers.

For reference, the hook has an arch shape, a mushroom shape, a hook shape, etc., so that it is made to fit well by walking opposite to the roof member, and this mechanical coupling prevents each component from being easily separated. That is, the portion where the hook member and the loop member are fastened is required to have a degree of adhesion to maintain normal bonding during use due to the action of a shear strength perpendicular to the surface and a shear strength parallel to the surface.

On the other hand, conventionally, in the manufacturing process of the nonwoven fabric used for the roof member, the nonwoven fabric or the film is laminated by an adhesive or a thermal adhesive, etc. through a process of weaving a fabric or a process of punching a nonwoven fabric. Since the process is separated, there is a problem of low productivity as well as high cost, and also, there is a disadvantage in that the soft texture is reduced due to heat punching, and when the produced product is stored in a roll form, the volume is reduced and the adhesion is reduced. .

In order to compensate for this drawback, in some cases, a non-woven fabric is conveyed by a pair of rollers having irregularities formed thereon to form a corrugation (bending or mound), and then a thermoplastic resin film is formed by a conventional T-DIE in which the resin is extruded from one side. There is a method of bonding, but this is because a single resin film is bonded to one side of the non-woven fabric, so it has an extremely limited use that can only be used for loop fasteners. A laminated sheet having a structure in which a corrugated loop having a bend is formed is used.

In addition, the non-woven fabric of the roof system is mainly used as a fastener for disposable products such as personal hygiene materials, clothing, bags, sports goods, protective clothing, and personal wear for adults and infants. As it is used as a product, it is becoming a core technology to lower the total material cost and minimize the manufacturing cost in terms of product design. In addition to this, it should be easy to desorption and be able to be repeatedly used, as well as stable bonding performance and excellent peeling properties.

Therefore, in the field of disposable hygiene products or protective products, there is a need for a roof system capable of improving various performances such as softness and breathability, as well as strengthening a low cost and mechanical coupling system for a loop nonwoven fabric.

As such, in the field of disposable hygiene products or protective products, there is a continuing need for a roof system capable of improving various performances such as low cost for a loop nonwoven fabric, strengthening of a mechanical coupling system, softness and breathability, and the like. In the present invention, instead of attaching a loop member at a designated position on the surface of the backsheet nonwoven fabric, the method of reducing the production cost as well as being convenient for use by providing a hook fastening function by adjusting the basis weight of the backsheet nonwoven fabric itself was studied.

Looking at the prior art for improving the problems of the roof system as described above, Korean Patent No. 10-0195810 (Minnesota Mining and Manufacturing Company, USA) has a fastener in the form of a hook and loop that can be detachably attached. A roofing sheet that can be cut into pieces to form a roof portion, comprising a thermoplastic backing layer extruded in a certain shape, and having a front and rear main surface; Disclosed is a roofing sheet comprising a longitudinally oriented fiber sheet having an unmodified anchor portion adhered to a thermoplastic backing layer at a spaced apart adhesive position and an arc portion protruding from the front surface of the back plate between the adhesive positions. , This has a manufacturing process difficulty in extruding the thermoplastic material to the anchor portion of the fiber sheet after forming the arc portion protruding in the same direction from the anchor portion of the fiber sheet.

In addition, in Korean Patent No. 10-0977384 (Toray Advanced Materials Co., Ltd.), a nonwoven fabric roof sheet having a loop layer on one side is formed through a spun bond method or a spun bond + melt blown method, and is appropriately applied by thermal compression. Since only a portion is filmed, the space between the spaces formed by thermal compression is bulky to provide a bulky shape, and the fibers of the non-thermal compression portion can exhibit excellent adhesion to the adhesive hook projection. It provides a loop nonwoven fabric that has good adhesion stability in physical properties and does not significantly lose adhesion even after repeated adhesions.

And the loop material for the hook and loop type fastener in the Republic of Korea Patent No. 10-1153130 (Donner S.S. et al. 1, France, etc.) is a synthetic nonwoven, which is a loop layer , A support layer, and a plurality of bonding sites, the roof layer is 1.5 to 6.0 dTEX carded nonwoven of thermoplastic crimped staple fibers, and the roof layer has a basis weight of 10 to 35 g / m ² . The support layer is a spunbond or spunmelt non-woven fabric, and the roof layer overlaps with the support layer, and a plurality of bonding portions are combined with a roof layer on the supporting layer, and the bonding portions are substantially air impermeable to 35 to 55 of the surface area of the roof material %.

Recently, the applicant has patented No. 10-1839298 (Rak Industries Co., Ltd.), and the lower layer (S1) is a thermoplastic polyolefin long fiber nonwoven sheet having a fineness of 1 to 2 denier, and the upper layer (S2) is fineness 4 to 6 Denier (denier) thermoplastic polyolefin long fiber non-woven sheet, the lower layer (S1) and the upper layer (S2) is composed of polypropylene (PP) yarn alone or a mixture of polyethylene (PE) yarn, the lower layer (S1) and the upper layer ( The long-fiber nonwoven sheet disposed in S2) is made of 0.2 to 0.5 mm in thickness and 30 to 60 g / m2 by weight by bonding by thermal embossing roll, but the upper layer (S2) has a plurality of waveforms continuous in the longitudinal or transverse direction, or Forms a straight fused portion 11 and a non-fused portion 12, the fused portion 11 has a width of 0.5 to 1.5 mm, an interval of 3 to 5 mm, and the bonding area formed in the nonwoven loop is based on the total surface area. A long fiber nonwoven loop for hook fastening members was developed, characterized in that it is 10-35%.

In addition, in the present invention, even if there is no separate non-woven loop member for engaging with the hook, it is not only convenient for the consumer to use, but also by developing a backsheet non-woven fabric for diapers having excellent bonding stability with the hook and soft texture of the surface. The production cost of the product can be reduced.

Republic of Korea Registered Patent Publication No. 10-0195810 (published on June 15, 1999) Republic of Korea Registered Patent Publication No. 10-0977384 (Announcement date August 20, 2010) Republic of Korea Registered Patent Publication No. 10-1153130 (announcement date May 29, 2012) Republic of Korea Registered Patent Publication No. 10-1839298 (Announcement date of March 19, 2018)

The object of the present invention is to improve the shear strength by adjusting the basis weight of the diaper backsheet nonwoven fabric made of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet, thereby securing the fastening force of the entire backsheet nonwoven fabric with a hook without a separate loop member. It is to provide a back sheet non-woven fabric for diapers that is not only convenient to use but also has a hook fastening function that can reduce the production cost of the product.

The backsheet nonwoven fabric for diapers to which the hook fastening function of the present invention is given is a backsheet nonwoven fabric for diapers made of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet, wherein the backsheet nonwoven fabric has a basis weight of 16 to 38 gsm (g / m 2). By improving the shear strength, it is possible to detach and detach the hook without a separate loop member.

The thermoplastic polyolefin-based spunbond long fiber non-woven sheet is composed of yarns selected from polypropylene (PP) and polyethylene (PE) alone or by mixing them, and the back sheet non-woven fabric has a thickness of 0.15 to 0.4 mm by self-bonding between fibers. It uses a fiber structure to be formed, and the shear strength of the backsheet nonwoven fabric is characterized by a vertical peel strength of 1.0 to 2.8 N / inch and a horizontal shear strength of 30 to 55 N / inch.

In the back sheet non-woven fabric for diapers, which is provided with a hook fastening function according to the present invention, the process of manufacturing a separate loop member is omitted, thereby reducing the production cost of the product. Accordingly, the entire surface of the back sheet non-woven fabric forming the outer surface of the diaper acts as a roof sheet. Therefore, it is very convenient for consumers to wear diapers. In addition, since the backsheet nonwoven fabric is made of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet designed to have a structure suitable for fastening with a hook member, there is almost no lint even during repeated use, and the detachability with the hook member is not only good. The soft texture of the nonwoven fabric surface has an excellent effect.

In addition, the backsheet nonwoven fabric for diapers, which is provided with a hook fastening function according to the present invention, eliminates the process of transferring and assembling using a vacuum absorber to attach the loop member to a designated position on the outer front surface of the diaper, thus eliminating the convenience of the product production process. It has the advantage of securing and reducing the defect rate.

1 is a perspective view showing a diaper in which a conventional roof member is assembled.
Figure 2 is a perspective view showing a diaper without a loop member according to the present invention.

Hereinafter, with reference to the drawings will be described with respect to the non-woven backsheet for diapers to which the hook fastening function according to the present invention is provided, which can be easily carried out by a person of ordinary skill in the art to which the present invention pertains. This is for illustrative purposes only, and is not meant to limit the technical spirit and scope of the present invention.

As shown in FIG. 1, a conventional infant diaper is composed of a top nonwoven fabric-an absorbent nonwoven fabric-an absorbent body (SAP / pulp)-a waterproof film (PE film)-a back sheet nonwoven fabric from the inside. , A loop member 20 is attached to the front upper end portion of the backsheet nonwoven fabric 10, and hooks 30 extending from both rear surfaces of the backsheet nonwoven fabric 10 are combined with the roof member 20 to attach diapers. do.

The back sheet non-woven fabric 10 forms the outer surface of the diaper to improve the rustling sound and feel of the waterproof film (PE film) forming its inner surface and prevent tearing phenomenon, in the back sheet non-woven fabric 10 The diaper is detached by detaching or engaging the hook 30 to the assembled roof member 20.

In general, nonwoven webs include meltblowing, spunbonding, air-through bonding, hydroentangling, spunlacing, airlaying, It can be produced from a variety of molding processes, such as carding and other suitable processes. The basis weight (gsm) of the nonwoven web varies depending on the use of the web, and in most cases is about 300 g / m 2 or less, and the basis weight is calculated as the weight of all layers per unit area of the nonwoven web.

On the other hand, the roof member 20 is laminated with a spunbond long fiber nonwoven web disposed in a lower layer and an upper layer on a conveyor belt which is normally driven to provide a multi-layered nonwoven fabric having excellent mechanical properties, and thermal emboss roll. After bonding by assembling it to the backsheet nonwoven fabric 10, it has a function of combining with the hook 30, but due to this, the cost of material increases according to the manufacture of the roof member 20 and the assembly of the backsheet nonwoven fabric 10. The productivity decrease, of course, also has a problem of printability for printing in various patterns on the surface of the backsheet nonwoven fabric 10 or the roof member 20 in appearance.

To improve this problem, as shown in Figure 2, the backsheet nonwoven fabric 10 for diapers to which the hook fastening function of the present invention is made is a thermoplastic polyolefin-based spunbond long fiber nonwoven fabric sheet, and the backsheet nonwoven fabric 10 ) The total surface of the backsheet nonwoven fabric (10) forming the outer surface of the diaper without a separate loop member (20) by forming a basis weight of 16 to 38 gsm (g / m2) to improve the shear strength, detachable from the hook (30) Function.

The backsheet non-woven fabric 10 uses a spunbond non-woven fabric manufacturing technology, due to the high basis weight and density or high denier filament yarn, the vertical strength and horizontal detachment force with the hook 30 ( As a result of improving the shear strength), spunbond nonwoven fabrics are formed of quenched and stretched strands by high-speed air by melt extrusion of thermoplastic resin extrudates, collected on the surface, and applied by embossing pattern by heat or pressure. It means a non-woven fabric with reinforced bonded filaments. In addition, the backsheet non-woven fabric 10 is basically preferred to use low elongation and high strength properties of polypropylene (PP) long fibers, but it is also possible to supplement the flexible properties by using polyethylene (PE) long fibers.

As described above, the backsheet nonwoven fabric 10 is made of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet, and forms a basis weight of 16 to 38 gsm (g / m 2) to improve shear strength, thereby eliminating the need for a separate loop member 20. Desorption with the hook 30 is now possible. For reference, the basis weight of the backsheet nonwoven fabric 10 used in a general diaper in which the roof member 20 is assembled is 13 to 15 gsm.

The backsheet nonwoven fabric 10 uses a fiber structure formed of 0.15 to 0.4 mm in thickness by self-bonding between fibers, and the shear strength of the backsheet nonwoven fabric 10 is vertical strength through actual experiment. It was studied that 1.0 to 2.8 N / inch and horizontal shear strength were 30 to 55 N / inch.

Accordingly, it was confirmed that the backsheet non-woven fabric 10 of the present invention does not deteriorate mechanically and does not easily detach even when detached from the hook 30 more than 10 times, and lint hardly occurs without any occurrence of the backsheet. It has been investigated that the soft texture of the nonwoven fabric 10 sheet surface is not only good, but also significantly reduces product manufacturing cost. The back sheet non-woven fabric 10 is produced by using a thermoplastic polyolefin-based spunbond long fiber non-woven sheet composed of a yarn selected from polypropylene (PP) and polyethylene (PE) alone or by mixing them to produce a product that meets the required characteristics. Can be.

As described above, the present invention has been completed through numerous experiments, but the present invention will be described below through preferred embodiments that can be easily understood and practiced by those skilled in the art.

[Example]

A polypropylene resin was melt-spun to adjust the basis weight to 14, 16, 25, 38, and 40 gsm, respectively, to prepare a long-fiber nonwoven fabric having a width of 1000 mm, and a backsheet nonwoven fabric having a different basis weight and thickness using the long-fiber nonwoven fabric. The types of are as shown in [Table 1] below.

-Basis weight: KS K 0514 [Method for measuring mass of cloth: small test piece method-mass of test piece (g) / area of test piece (cm 2) × 10000]

-Thickness: KS K ISO 9073 [Textile-Non-woven fabric test method-Part 2 thickness measurement]

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Basis weight (g / ㎡) 16 25 38 14 40 Thickness (mm) 0.15 0.25 0.35 0.13 0.37

[Experimental Example]

Peel strength, shear strength, air permeability, tactile feel, etc. for the backsheet nonwoven fabric according to the above examples were measured in the following manner, and the average values of the experimental results for the performance indicators are shown in [Table 2] below.

-Peel strength: LK-QC-T001 Peel strength [Measure the detachment force while opening the space between the two by applying a force in the direction of 180 degrees between the loop and the hook]

-Shear strength: LK-QC-T002 Tensile shear strength [Measure desorption force by applying a straight force to the loop and hook]

-Air permeability: KS K ISO 9237 [Textile-Method for measuring air permeability of cloth-Air flow rate flowing vertically through the test piece under conditions of a certain area, pressure and time]

-Tactility: Ten experts were selected for the nonwoven fabric of the back sheet, and the average value of the tactile sensation was measured (excellent ◎> ○> △> × defect).

Performance indicator Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Peel strength (N / inch) 1.4 2.0 2.8 0.3 3.0 Shear strength (N / inch) 38 45 55 15 57 Aeration (cfm) 570 490 380 620 370 touch ◎ ○ △ ◎ ×

As shown in [Table 2], when comparing the experimental results of Examples 1 to 3 and Comparative Examples 1 and 2, in the case of Comparative Example 1 (existing backsheet nonwoven fabric), compared to Examples 1 to 3, Peel The strength (development target value of 1N / inch or more) and shear strength (development target value of 30N / inch or more) are insufficient, and in Comparative Example 2 (non-woven fabric for existing roof members), the density increases as the basis weight increases, so the Peel Strength and Shear Although the strength is improved, the air permeability is rather low and the touch is poor, so it is not suitable for a non-woven backsheet for diapers, whereas Examples 1 to 3 have excellent Peel strength and Shear strength as a whole and a non-woven backsheet having hook fastening function It was confirmed to achieve the final development goal as.

In addition, when a separate loop member is used, it must have a minimum air permeability of less than 400 cfm to stably transport and attach to the vacuum absorber used during the diaper manufacturing process, but the backsheet nonwoven fabric of the present invention is entirely attached to the outside of the diaper. It was confirmed that there was no problem in the manufacturing process even with high air permeability.

And as a result of measuring safety according to the Common Safety Standard for Children's Products No. 2017-0118, Chlorophenols 0.5 mg / kg or less [KS K 0733], Phthalates 0.1% or less [Gas chromatography mass spectrometry ( GC-MS) method], Formaldehydes 20mg / kg or less [KS K ISO 14184-1], Heavy metals 0.1mg / kg or less, volatile organic compounds (VOCs) not detected It was confirmed that it was within the reference value.

Therefore, the backsheet non-woven fabric for diapers, which is provided with a hook fastening function according to the present invention, has a mechanical strength at a level equal to that of a vertical peel force and a horizontal peel force compared to a conventional embossed nonwoven loop member, even when repeatedly detachable from a hook. Since the bonding power is excellent and the occurrence of lint has been improved, the technical idea of the present invention, such as diapers, personal wear for adults and infants, personal hygiene materials or clothing, bags, sports goods, protective clothing, bed covers or disposable products such as surgical gowns, etc. It can be used in a variety of uses and forms without departing from the scope.

10: back sheet nonwoven fabric (PP)
20: Loop material
30: Hook

Claims (4)

In the diaper backsheet nonwoven fabric (10) made of a thermoplastic polyolefin spunbond long fiber nonwoven fabric sheet,
The back sheet nonwoven fabric 10 has a hook fastening function characterized in that it can be detached from the hook 30 without a separate loop member 20 by improving the shear strength by forming a basis weight of 16 to 38 gsm (g / m 2). Non-woven backsheet for diapers. According to claim 1,
The thermoplastic polyolefin-based spunbond long fiber non-woven sheet is a diaper back sheet non-woven fabric having a hook fastening function, characterized in that it is composed of a yarn selected from polypropylene (PP) and polyethylene (PE) alone or by mixing them. According to claim 1,
The backsheet nonwoven fabric 10 is a diaphragm backsheet nonwoven fabric provided with a hook fastening function, characterized in that it uses a fiber structure formed of 0.15 to 0.4 mm in thickness by self-bonding between fibers. According to claim 1,
The shear strength of the backsheet nonwoven fabric 10 is a diaper bag with a hook fastening function, characterized in that the vertical peel strength is 1.0 to 2.8 N / inch and the horizontal shear strength is 30 to 55 N / inch. Sheet nonwoven fabric.

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