MXPA01002593A - Resilient attachment materials for personal care products - Google Patents

Abstract

There is provided a hook and loop attachment means made up of a hook portion and a loop portion where the loop and/or the hook portion is convex and is underlain by a resilient material or hollow area. The hook and loop attachment means is useful in the attachment of personal care products.

Description

i ELASTIC FIXING MATERIALS FOR PRODUCTS FOR PERSONAL CARE FIELD OF THE INVENTION The present invention relates to a structure in a personal care article such as diapers, training pants, absorbent undergarments, adult incontinence products, swimwear, bandages and products for women's hygiene.

BACKGROUND OF THE INVENTION Personal care articles include such items as diapers, training underpants, women's hygiene products such as sanitary napkins, garments and incontinence devices, swimwear, bandages and the like. The most basic design of such articles usually includes a body-side liner, an outer cover and an absorbent core positioned between the body-side liner and the outer cover.

Various securing means have been used to keep the personal care product in place on the user. Ribbon, hook and loop systems and slip-on-garment designs that do not require separate fastening devices, for example, have been used. However, each of these media has its own idiosyncratic deficiency. The tape, for example, sometimes will not adhere properly if there is lotion or other contaminants in the holding area, also known as the "placement area." Hook and loop fasteners sometimes fail due to lateral forces, for example, and slide designs can not be easily opened and closed to check for discharges. There is still a need for fastening means, which are not easily affected by contaminants, resist lateral forces well and which can easily be detached and restrained several times.

It is an object of this invention therefore to provide fastening means which can be detachably detached, which are resistant to contaminants in the laying area and which hold well in relation to the peeling and cutting forces. It is a further object of this invention to provide personal care products that incorporate such superior fastening means.

SYNTHESIS OF THE INVENTION The objects of the invention are achieved by means of hook and loop fastening means, which constitute a hook part and a loop part where at least one of the parts with convex and is underlying by an elastic material or an area hollow The hook and loop fastening means are useful in joining the personal care products.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a photograph of the convex hook component of this invention showing the individual hooks as well as the curvature of the complete hook component.

Figure 2 is a photograph showing the individual hooks and a hook and loop fastener where the hooks face in different directions.

Figure 3 is a drawing of a typical personal care product, in this case, a diaper, showing the front, back and hook and loop components in their relative positions.

Figure 4 shows a cross-sectional view of a hook component having underneath an elastic material which in turn is attached, or is an integral part, of a backing material which can be a personal care product.

Fig. 5 shows a variation of Fig. 4 wherein the elastic underlying material is absent and the hook component is bent in such a way as to cause it to rise out of the plane of the backrest.

Figure 6 shows another variation of Figure 4 where there is a multiplicity of convexities in the hook material. These can be formed by placing an underlying base below the hooks or by bending.

Figure 7 is a photograph showing an underlying gap which can be used in the practice of the invention in a joint position.

Figure 8 is a photograph showing an elastic underlay, which can be used in the practice of the invention in a joint position.

Figure 9 is a photograph showing an elastic underlay, which can be used in the practice of the invention, in a position where the material is being peeled.

DEFINITIONS "Disposable" includes being discarded after use and not being rewashed and reused.

"Frontal" and "posterior" are used throughout this description to designate relationships relating to the garment itself, rather than to suggest any position that the garment assumes when it is placed on a wearer.

"Layer" when used in the singular may have the dual meaning of a single element or a plurality of elements.

By the term "similar hook" what is meant is a hook which essentially uses the same hook as the material of the invention but in which the hook component is flat and not convex. According to Webster's New Collegiate Dictionary (1980), "similar" means 1) having characteristics in common; strictly comparable, 2) similar in substances or essentials; correspondent. Using this commonly acceptable meaning of the word similar, this term means that all other conditions are essentially the same except for the conditions mentioned.

As used herein, the term "polymer" generally includes but is not limited to homopolymers, copolymers such as, for example, block, graft, random and alternating copolymers, terpolymers, etc., and mixtures and modifications thereof. In addition, unless specifically limited in another way, the term "polymer" will include all possible geometric configurations of the molecule. These configurations include, but are not limited to, isotactic, syndiotactic and random symmetries.

As used herein, the term "non-woven fabric or fabric" means a fabric having a structure of individual fibers or threads, which are interleaved, but not in an identifiable manner as in a knitted fabric. Fabrics or non-woven non-woven fabrics have been formed from many processes such as, for example, meltblowing processes, spinning processes and carded and bonded weaving processes. The basis weight of non-woven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and useful fiber diameters are usually expressed in microns. (Note that to convert from ounces per square yard to grams per square meter, you must multiply ounces per square yard by 33.91).

"Spunbond fibers" refer to small diameter fibers that are formed by extruding the thermoplastic material effused as filaments of a plurality of fine capillary vessels of a spinning organ. Such a process is described in, for example, U.S. Patent No. 4,740,563 issued to Appel et al., And U.S. Patent No. 6,692,618 issued to Dorschner et al., In the patent of the United States of America. United States of America No. 3,802,817 issued to Matsuki et al., In US Pat. Nos. 3,338,992 and 3,341,394 issued to Kinney, in United States Patent No. 3,502,763 issued to Hartman, and in the U.S. Patent No. 3,542,615 issued to Dobo et al. The fibers may also have shapes such as those described in U.S. Patent Nos. 5,277,976 to Hogle et al., 5,466,410 issued to Hills and 5,069,970 and 5,057,368 to Largman et al. conventional "Conjugated fibers" refer to fibers which have been formed from at least two polymers arranged in different zones placed essentially constant across the cross section of the fibers and which extend continuously along the length of the fibers. Conjugated fibers are taught in U.S. Patent No. 5,108,820 issued to Kaneko et al .; in U.S. Patent No. 5,336,552 issued to Strack et al .; and in U.S. Patent No. 5,382,400 issued to Pike et al.

The "carded and bonded fabric" refers to fabrics that have been made of basic fibers which are sent through a combing or carding unit, which separates or breaks and aligns the basic fibers in the machine direction to forming a fibrous nonwoven fabric oriented generally in the machine direction. Such fibers are usually purchased in bales, which are placed in an opener / mixer, or shredder, which separates the fibers before the carding unit. Once the tissue is formed, it is then joined by one or more of the various known joining methods. One such bonding method is the powder binding, wherein a powder adhesive is distributed through the tissue and then activated, usually by heating the fabric and the adhesive with hot air.

The "personal care product" means diapers, underpants, absorbent underpants, adult incontinence products, swimwear, bandages and products for women's hygiene.

"Women's hygiene products" mean sanitary pads or pads or panty liners.

The "cutting force" refers to the forces acting generally parallel to the substrate plane of the hook and loop fastening system.

"Peel forces" refers to forces that generally act perpendicular to the substrate plane of the hook and loop fastening system.

METHODS OF TESTING AND MATERIALS Peel Test: The peel force value measures the force needed to peel and separate a hook and loop fastening system can be determined according to the normal procedure ASTM D5170, approved on September 15, 1991 and published in November 1991; with the following details. The curl material to be tested was cut into a rectangle of 75 millimeters (3 inches) by 152 millimeters (6 inches) with the longest dimension in the direction transverse to the machine. The curl material is placed under the gripping plate of a machine rolled down. The hook material is placed on the upper part of the curl material and joined by means of the rolling machine downwards using a 2 kilogram roller. A suitable roll down machine is part number HR-100 available from Chemsultants International, of Mentor, Ohio. During the engagement of the fastener components, the roller is wound onto the test specimen through a cycle in the direction of the "width" in the transverse direction of the sample. In addition, the initial peeling by hand to "raise the curls" is omitted. After the hook and loop material is properly secured, the combination is placed on the test apparatus, an Instron Model 2712-004 tension tester with 102 millimeters (4 inches) of rubberized grip faces (Instron Corporation, Canton , Massachusetts 02021). The hook base is inserted in the upper handle and the curl in the lower one so that the movement of the handles outwards from one another will result in a peeling that separates the two materials. The loosening is removed and the machine is switched on. The tester is set with a cross head speed of 500 millimeters / minute, and a measuring length of 76 millimeters. Measurements start at 10 millimeters and end at 46 millimeters and are in grams. The reported value of the peel test result is a peel load value that is used by the MTS TESTWORKS software with a maximum criterion of 2%. Additionally, the peel force value is normalized to be stated in terms of force per unit length of the "width" dimension of the fastener component on the test sample, such as grams per inch or grams per centimeter. The MTS TESTWORKS program, is available from MTS Systems Corporation, a business that has offices in Eden Prairie, Minnesota.

Test of Cort a The value of cutting force measures how well the hook and the curl remain hooked against a cutting force in plane and can be determined according to the normal procedure ASTM D-5169, tested on September 15, 1991 and published in November 1991 with the following particulars. The materials are prepared in the same manner as in the peel test except that the unprinted curl material is cut to a size of 25 millimeters (1 inch) in the machine direction by 152 millimeters (6 inches) in the direction transversal to the machine). After the down roll machine has hooked the hook and loop materials together as described above, they are removed and placed in the Instron Model 2712-004 tension tester, hooks on the top handle, curls in the lower, so that the movement of the handles one out of another will not result in a peeling with separation of the two materials. The loosening is removed and the machine is started. The tester is set with a crosshead speed of 500 millimeters per minute, and a measured length of 76 millimeters. The measurements are started at 10 millimeters and at the end at 46 millimeters and are in grams. The value of shear force is normalized to be declared in terms of force per unit area of the test specimen, such as grams-force per square inch (or gmf / cm2).

Mafcarial gauge (thickness): The gauge of a material is a measure of thickness and was measured at 0.05 pounds per square inch with a Starrett-type volume tester, in units of millimeters.

Density: The density of the materials was calculated by dividing the weight per unit area of a sample in grams per square meter (gsm) by the volume of the sample in millimeters (mm) to 68.9 pascal and multiplying the result by 0.001 for convert the value to grams per cubic centimeter (g / cc). A total of three samples were evaluated and averaged for the density values.

DETAILED DESCRIPTION OF THE INVENTION Personal care products include such items as diapers, training underpants, women's hygiene products such as sanitary pads, linings for panties and plugs, garments and incontinence devices, swimwear, bandages and the like. The most basic design of such articles typically includes a side-to-body liner, an outer cover and an absorbent core positioned between the body-side liner and the outer cover. Some kind of fastening means is also necessary so that the product remains in place.

Optional layers will include the fluid transfer and distribution layers.

The side-to-body layer is sometimes referred to as a side-to-body lining or top sheet. In the direction of the thickness of the article, the lining material is the layer against the wearer's skin and from this the first layer in contact with the liquid or other exudate of the wearer spreads. The lining also serves to isolate the user's skin from liquids maintained in an absorbent structure and must be docile, soft feeling and non-irritating.

The body side liner may be surface treated with a selected amount of surfactant or may be processed in another manner to impart the desired level of wettability and hydrophilicity. If a surfactant is used, it may be an internal additive or applied to the layer by any conventional means, such as spraying, brush coating and the like, before depositing the next layer.

The absorbent or fluid retaining core layer must absorb the liquid from the side layer to the adjacent body in a controlled manner so that the liquid can be stored out of contact with the body. The retention materials generally comprise binders, synthetic fibers and natural fibers. Even when any of the layers of a product are pair * to it. Personal care can optionally contain a superabsorbent, the fluid retention layers are the most logical layer to contain such a component.

The side-to-garment lining layer, also referred to as a bottom sheet or outer cover, is the layer farthest from the wearer. The outer cover works to prevent body exudates contained in an absorbent structure from wetting or soiling the wearer's clothing, bedding or other materials in contact with the personal care product. The outer cover has traditionally been formed of a thin thermoplastic film, such as a polyethylene film, which is essentially impermeable to liquid, but which may optionally be composed of a microporous and gas permeable "breathable" or vapor, which is permeable to vapors or gas but essentially impermeable to liquid.

The optional fluid transfer layer, also referred to as the emergence layer, is more typically interposed between and in intimate liquid communication contact with the body-side liner and another layer, such as an absorbent or distribution core layer. of fluid. The emergence or fluid transfer layer allows the movement of fluid through itself, generally in the Z direction, for example, outward from the side to the body and towards the side of the garment.

An optional distribution layer may be interposed above (towards a user) of the fluid retention layer and must be capable of moving the fluid from the initial deposit point to where storage is desired. The fluid distribution layer, therefore, in addition to allowing the movement of fluid through itself in the Z-direction, also moves the fluid in the X and Y directions. The distribution must take place at an acceptable rate so that the target discharge area, usually the crotch area, is ready for the next download. The time between downloads may vary from just a few minutes to hours, generally depending on the age of the user and the product for the personal care in question.

The breathable outer cover discussed above is an example of this approach, which has previously been used to increase the capacity of air entering the product. The breathable outer cover allows air to pass and, in the bench test, can provide good air flow rates as measured by the conventional ASTM permeability test. Even though an outer cover with breathing capacity will allow the flow of air through it, in actual use there is no way to guarantee the flow of air át. through the product and even the skin, since this method is completely passive. The provision of dynamic airflow remedies this by avoiding exclusive confidence about the passive air intake and forcing or pulling the air inside the product to the region between the skin and the product.

Various fastening means have been used to keep the personal care product in place on the user. Adhesive tape, mechanical systems and slip-on garment designs that do not require separate fastening devices, for example, have been used. Oils and dusts less easily contaminate the fastening means, such as the mechanical fastening systems that contaminate the adhesive tape fastening systems. Additionally, mechanical fastening systems can be used again in an easy way. All of these features provide advantages when applied to a disposable diaper that is intended to be worn over an infant, for example. Also, a resurfable mechanical fastening system provides the infant's advantage that it can be checked to determine if the disposable diaper has been soiled during the period of use.

Mechanical fastening systems typically employ two components-a male component (hook) and a female component (curl). The hook component usually includes a plurality of semi-rigid hook-shaped elements anchored or connected to the base material. The curl component generally includes a backing material from which a plurality of the vertical curls project. The hook-shaped elements of the hook component are designed to engage the loops of the loop material, thereby forming mechanical joints between the hook and loop elements of the two components.

The curl component of the fastening system is typically placed on the body of the garment and the hook component of the fastening system is placed on the strip or "ear" which may be elastic. For example, U.S. Patent No. 5,664,302 discloses hook and loop fasteners wherein the curl material is underlying a substrate, which is a sheet of elastic material. Hook fastener materials and methods for making such hook fastener materials are described in U.S. Patent Nos. 5,326,415; 5,318,741; 5,230,851; 5, 058, 247 and 5, 116, 657. Examples of hooks for hook and loop fasteners can also be found in United States of America Patent No. 4,984,339, assigned to Velero Industries, BV of the Netherlands. An example of a suitable curl material can be found in U.S. Patent No. 5,858,515 assigned to Kimberly-Clark World ide, Inc.

Figure 3 shows a typical personal care product, in this case a disposable diaper 20 which has a front part 21 and a back part 24. The front part 21 has a curl component 22 immediately in the "rest area". or fastening area for the hook component 23 which is on an "ear" 25 which is attached, or in integral part of, the back 24. A "disposable diaper" is an attempted and balanced personal care product to be used by an infant. Some examples of the disposable diapers described in U.S. Patent No. 5,151,092, U.S. Patent No. 5,242,436, and U.S. Patent No are incorporated by reference. 3,860,003 all of which are hereby expressly incorporated by reference.

The hooks are desirably formed from a stiffener, the sturdy material so that the wearer or caretaker can easily grasp the hook to release the fastener system and so that the hooks open and cover without failure. This resistance is what allows the hook to continue its curved configuration after being bent as a result, for example, of the looseness of the interenganchantes materials that match.

The term elastic refers not only to the hook but also to the backing material and backing structure. The backing material is that material to which the base of the hook is attached and which is usually the same material from which the hook is formed. The backrest structure refers to the combination of the backing material of the hook and curl and the underlying material, as well as its configuration.

Previous investigators have discovered that absorbent articles including a interlocking fastening component have an elastic concave backing structure and are well suited to maintain adequate attachment to the attachment system and such system is described in the United States of America patent. No. 5,722,968, incorporated herein by reference in its entirety. This patent teaches that the edges and corners of the contoured and elastic interlocking fastening components do not project tangentially outwardly from the user's body as in the case with the conventional flat interlock fastening components and result in the edges and the edges. corners of contoured interlocking fastening components that penetrate deeply into matching interlocking materials. This deep penetration ensures that clothing or other materials that pass over the garment fastening system are less likely to get stuck on the corners and protruding edges. It is thought that this is a particularly significant problem for small individuals, where the angles of curvature of the body may be greater than for less thin individuals.

The inventors have surprisingly found that a shaped clamping component opposite to that taught in U.S. Patent No. 5,722,968, for example, one that is convex, provides superior strength to the peeling forces.

The convexity of the present invention is clearly visible in the photograph, which is Figure 1, which in this case shows the individual hooks and the clear curvature of the hook component. Figure 4 is a cross-sectional view of a component of hooks 1 which is convex and which has underneath an elastic material 2 which in turn is connected in some way to the backrest 3. The backrest 3 can be, for example , the ear as shown in figure 3. The incorporation of an elastic material under the hooks can also be seen in figure 8 where the hooks are fastened to the curls on both sides of the elastic material, and in figure 9 wherein the hook component is partially disconnected from the curl component.

Figure 5 shows a component of hooks 1 which is bent or folded in such a way as to rise out of the flat surface of the backrest 3 without the requirement of. In the configuration of figure 5, a hollow or empty area 4 is below the hook component 1. Another embodiment has a hollow area below the hooks and is visible in the photograph which is figure 7. Figure 6 is a variation of Figure 4 wherein the multiple convexities are formed in the hook component 1 on an underlying 5 which can be an elastic or hollow material, in the same way as the singular convexities are formed.

As previously noted, the hook component can be placed on the ears, straps or body of a personal care product. The curls, therefore, can also be on either the ears, the straps, or the body of the product for personal care. In an alternate embodiment, the loops may have an elastic material underneath in a manner similar to that shown in FIG. 4, for example, while the loops may have a relatively flat material below. The curl material can also alternatively be folded so that multiple convexities are formed and so that the curls have below hollow or empty areas in a manner similar to that shown in Figure 5. The rigidity of the curls can be controlled by the amplitude and frequency of the folds.

The ability of the elastic interlock fastening component to retain its configuration can be increased by controlling the construction of the backing structure. The back structure of the interlocking fastening component is desirably formed of a construction or of a material having sufficient memory characteristics so that the backing structure will return approximately to its original configuration after repeated engagement and disengagement cycles with a complementary clamping component. Because the elastic interlock fastening components are desirably incorporated on the ears or the binding strips, the elastic interlock fastening components must maintain their curvature in order to remain effective during use. For reasons of comfort and performance, the absorbent articles are generally constructed of flexible components so that they conform to the user's body. Additionally, the curl of the fastening system, which either forms an integral part of the garment or is a separate element attached to the garment, desirably comprises a generally flexible material. Consequently, the curl tends to conform to the shape of the wearer and increase comfort, however, this invention does not want it to be limited to the incorporations in which only the terry material is that which is closest to the body of a wearer .

The width component, comprises many individual hooks or "tines," and this may have such individual hooks aligned in several directions, for example, there is no provision against hooks facing different directions. Figure 2, in fact, shows the hooks pointed in two directions. The individual hooks can be arranged in the direction of the machine, in the transverse direction or at any angle between the two. Even when the theoretical arrangement of individual hooks is almost infinite, it is practically these are made in only a small number of forms; all in one direction or half in each of two directions. It should be noted that these particularities of the placement of individual hooks depend on the end use and the objective of the researcher and not all can be recited here in a possible way. However, these are within the understanding and capacity of those skilled in the art without undue experimentation. The present invention effects the hook configuration due to the movement of the elastic backing structure which results in the movement of the hooks inwardly and away from each other as the elastic backing structure responds to the movement of the user and the cutting forces on the product for personal care.

In order to determine the amount of increase in life resistance to the present invention, various configurations were tested according to the side and cut tests described in the test methods section mentioned above. These configurations were (1) a control plane; (2) a round sponge rubber core; (3) a "D" shaped sponge rubber core; and (4) a double "D" shaped sponge rubber core. The results are given in the table given below.

Table Peel material with maximum load Maximum load cut, (grams / 2 inches wide) grams / inch2 45 2115 566 2388 575 3025 546 3384 The inventors have found, as can be seen from the results of the Table, that the hook-and-loop fastener in which at least one component is convex with an elastic material or an underlying hollow area has at least 20 percent higher peel strength in relation to that similar hook material without a backing material or an underlying hollow. In addition, the shear strength is also higher and can be 50 percent higher or higher. The values in the Table also indicate that a more elastic material, such as numbers 3 and 4, gives a greater increase in cut resistance than a relatively less elastic material such as that of number 2. The strength of the hook and loop systems according to the invention it is also somewhat superior to that of the mechanical fasteners using the concave hook fasteners. The inventors believe that the source of such superiority should be the rounded orientation of the hook and loop fastening material. It is believed that when the hook and loop fastening system is placed under peeling forces, the components engage with each other even more strongly as a component rolls upward in response to the imposition of the peel force.

The peeling and cutting forces peak during the test as the materials are pulled and separated. After the peak, the tension force required to separate the pieces eventually to zero when the pieces are completely separated. In the incorporations with more than one convexity, however, the force tends to fall after a peak corresponding to the first convexity and then rise for the second convexity, again reaching a peak and falling. Placing a multiplicity of convexities under one component of a hook and loop system results in a multiplicity of peaks in the force required to pull the materials and separate them. Appropriately, the sizing and spacing of these convexities can result in a more uniform force to separate the parts since the valleys between the peaks can be made minimal.

As will be appreciated by those skilled in the art, changes and variations to the invention are considered to be within the ability of those skilled in the art. Such changes and variations are attempted by the inventors that are within the scope of the invention.

It should also be noted that any patents, applications or publications mentioned herein are incorporated by reference in their entirety.

Claims (21)

R E I V I N D I C A C I O N S

1. Hook and loop fastening means comprising a part of hooks and a part of curls, wherein at least one of said parts has at least one convex part.

2. The means for fastening hooks and curls as claimed in clause 1, characterized in that said convex part has an underlying of an elastic material.

3. The means for fastening hooks and curls as claimed in clause 1, characterized in that said convex part has an underlying of a vacuum.

4. The means for fastening hooks and curls as claimed in clause 1, characterized in that said fastening means have a maximum peel strength of at least 20 percent or greater than a fastening means lacking a convex part .

5. The means for fastening hooks and curls as claimed in clause 1, characterized in that they have two convex parts.

6. A personal care product comprising the hook and loop fastening means as claimed in clause 1.

7. The personal care product as claimed in clause 6, characterized in that it is a diaper.

8. The personal care product as claimed in clause 6, characterized in that it is a training brief.

9. The product for personal care as claimed in clause 6, characterized in that it is a product for incontinence.

10. The personal care product as claimed in clause 6, characterized in that it is a bandage.

11. The personal care product as claimed in clause 6, characterized in that it is a product for the hygiene of women.

12. The hook and curl fastening means as claimed in clause 3, characterized in that said hollow area is formed by folding.

13. The hook and curl fastening means as claimed in clause 3, characterized in that said fastening means have a maximum peel strength of at least 20 percent greater than a fastening means lacking a convex part.

14. The hook and loop fastening means as claimed in clause 3, characterized in that they have two convex parts.

15. A personal care product comprising the hook and loop fastening means as claimed in clause 3.

16. The personal care product as claimed in clause 15, characterized in that it is a diaper.

17. The personal care product as claimed in clause 15, characterized in that it is a training underpants.

18. The personal care product as claimed in clause 15, characterized in that it is a product for incontinence.

19. The personal care product as claimed in clause 15, characterized in that it is a bandage.

20. The personal care product as claimed in clause 15, characterized in that it is a product for the hygiene of women.

21. A personal care product comprising hook and loop fastening means wherein said fastening means have a maximum skinning strength of at least 20 percent or greater, and a peak cut resistance of at least 50 percent higher, than means of attachment that lack a convex part. R E S U E N Hook and loop fastening means made of a part of hooks and a part of loops are provided wherein the part of curls and hooks is convex and has underneath an elastic material or a hollow area. The hook and loop fastening means are useful in securing personal care products.