KR20090091163A - Fastener having adjustable fastening strength - Google Patents

Abstract

Clothlike materials may become abraded upon disengagement of mechanical fasteners. This abrasion may cause a decrease in aesthetic appeal, as well as a decrease in functionality of attachment systems. As a result, there has remained a need for improved fastening systems. Moreover, there has remained a need for improved fastening systems for disposable absorbent articles. ® KIPO & WIPO 2009

Description

Fastener with variable fastening strength {FASTENER HAVING ADJUSTABLE FASTENING STRENGTH}

The present invention relates to an improved fastening system. More specifically, the present invention relates to an improved hook and loop fastening system for disposable absorbent articles.

Conventional disposable absorbent articles, such as disposable diapers, have typically included a bodyside liner, an outer cover and an absorbent core positioned between the outer cover and the bodyside liner. In general, disposable absorbent articles have a crotch zone extending between the front and rear zones and connecting the front and rear zones. In addition, such conventional disposable absorbent articles have included a fastening system configured to secure the disposable absorbent article to the waist of the wearer. In addition, disposable absorbent articles have been constructed with various types of elastics in the waist and leg opening regions. Such elastics have been used to reduce leakage of body secretions from disposable absorbent articles and to improve the appearance and wearability of the absorbent articles around the wearer.

Typically, fastening systems in conventional disposable absorbent articles have included a pair of fasteners positioned at the outermost edge of the disposable absorbent article in one of the waist regions. Such fasteners have been configured to releasably engage with complementary fasteners in opposite waist regions of the disposable absorbent article. For example, the fastening system has included a pair of mechanical fasteners such as hook material located at the outermost edge of the disposable absorbent article in the rear region of the disposable absorbent article. In addition, such systems have included complementary fasteners, such as a roof material panel located on the outer surface of the outer cover of the disposable absorbent article in the front region of the disposable absorbent article. In this configuration, disposable absorbent articles have been disposed between the wearer's legs and the hook material has been releasably attached to the loop material to secure the disposable absorbent article around the wearer's waist. In some disposable absorbent articles the roof material panel has been removed and the hook material has been releasably attached to the outer cover of the diaper. This is known as a fasten anywhere configuration.

However, conventional disposable absorbent articles constructed as described above have exhibited several disadvantages. For example, with the demand for more disposable absorbent articles, such as fabrics, manufacturers have made the outer cover and loop material more fluffier and softer, but have made it easier to wear in response. As a result, such cloth-like materials become worn when releasing the mechanical fastening system. This wear can lead to a deterioration of the aesthetics and deterioration of the attachment system.

As a result, there is a need for an improved fastening system. Moreover, there is a need for an improved fastening system for disposable absorbent articles.

We have made extensive research and development efforts to improve the fastening system. The present invention is directed to a fastening system suitable for incorporation into a disposable absorbent article to some extent. The fastening system can include a male component having a female component and a plurality of hook elements configured to releasably engage the female component. The fastening system also has a first normalized peak shear force to release the female component from the male component when the male component is not stretched. The fastening system also has a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched. The first normalized peak shear force is at least 10% greater than the second normalized peak shear force.

Another embodiment of the invention is directed to a fastening system suitable for incorporation into a disposable absorbent article. The fastening system can include a male component having a female component and a plurality of hook elements configured to releasably engage the female component. At least a portion of the plurality of hook elements has a stem and a cap, the cap forming a cap angle. The fastening system also has a first normalized peak shear force for releasing the female component from the male component and the first average cap angle when the male component is not stretched. The fastening system has a second normalized peak shear force to release the female component from the male component and the second average cap angle when the male component is 10% stretched. The first normalized peak shear force is greater than the second normalized peak shear force and the second average cap angle is greater than the first average cap angle.

Another embodiment of the invention is directed to a fastening system suitable for incorporation into a disposable absorbent article. The fastening system can include a male component having a female component and a plurality of hook elements configured to releasably engage the female component. The fastening system also has a first normalized peak shear force to release the female component from the male component when the male component is not stretched. The fastening system has a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched. In addition, the first normalized peak shear force is at least 10% less than the second normalized peak shear force.

Another embodiment of the invention is directed to a fastening system suitable for incorporation into a disposable absorbent article. The fastening system can include a male component having a female component and a plurality of hook elements configured to releasably engage the female component. At least a portion of the plurality of hook elements has a stem and a cap, the cap forming a cap angle. The fastening system has a first normalized peak shear force for releasing the female component from the male component and the first average cap angle when the male component is not stretched. The fastening system has a second normalized peak shear force to release the female component from the male component and the second average cap angle when the male component is 10% stretched. The first normalized peak shear force is smaller than the second normalized peak shear force, and the second average cap angle is smaller than the first average cap angle.

The foregoing and other configurations, embodiments, and advantages of the invention will be better understood with reference to the following description, appended claims, and attached drawings.

1 shows a top view of a disposable absorbent article in an unshrinked unfolded state (i.e., all elastics are wrinkled and deflated) with the body facing surface of the disposable absorbent article facing the viewer and hiding behind Portions of the disposable absorbent article are partially cut away to illustrate the features.

FIG. 2 shows a top view of the disposable absorbent article in its unshrinked unfolded state, with the garment facing surface of the disposable absorbent article facing the viewer, with a portion of the disposable absorbent article partially cut away to show the hidden behind features have.

3A shows a side view of the first hook material.

3B shows a side view of the hook material of FIG. 3A in an extended state.

4A shows a side view of the second hook material.

4B shows a side view of the hook material of FIG. 4A in an extended state.

5A shows a side view of a third hook material.

FIG. 5B shows a side view of the hook material of FIG. 5A in an extended state. FIG.

6A shows a side view of a fourth hook material.

FIG. 6B shows a side view of the hook material of FIG. 6A in an extended state.

7 shows a representative test sample.

The present invention relates to improved fasteners and improved fasteners for use in disposable absorbent articles. As used herein, the term "disposable" refers to articles that are not intended to be washed or otherwise restored for reuse, but intended to be discarded after limited use. The disposable absorbent article of the present invention will be described in terms of a disposable diaper designed to be worn over the lower body of the infant. The improved fastening system of the present invention is equally applicable to the use of other types of disposable absorbent articles, such as adult incontinence garments, children's training pants, surgical gowns and the like.

With regard to the referred side of the disposable absorbent article and its components, many upper or body facing surfaces are configured to face the wearer's body when the disposable absorbent article is worn to the wearer for normal use. Many opposing bottom or garment facing surfaces are configured to face away from the wearer's body when the disposable absorbent article is worn on the wearer.

As used herein, two materials or elements are "joined" to mean that two materials or elements are directly bonded to each other, or two materials or elements are indirectly bonded to each other, or It refers to a state in which two substances or elements are indirectly coupled through an intermediate element. Likewise, methods of joining two materials or elements are integrally formed with, or known in the art, adhesive bonds, sonic bonds, thermal bonds, pinning, stitching, or the art. Methods for attaching the elements together through various other attachment techniques and combinations thereof.

"Stretchable" means an elastic or extensible material, which when exerted to one or more dimensions, at least partially exerts a force to move the material to its original dimensions; Elastic), a material that retains (stretchable) an elongated structure.

It can be seen that the stretchable, elastic or stretchable properties of the stretchable material are determined when the material dries. In addition, the ratio of elongation, extension or permanent deformation can be determined according to the following formula.

100 * [(LL ₀ ) / (L ₀ )]

L = elongated length

L ₀ = initial length

Referring now to the drawings, FIG. 1 shows a disposable absorbent article, such as disposable diaper 30, in an unshrinked unfolded state (ie, all elastomers have wrinkles and shrinkage removed). In order to more clearly show the internal structure of the diaper 30, part of the structure is partially cut away, and the surface of the diaper 30 in contact with the wearer is in a state facing the viewer. 1 and 2 show a disposable diaper 30 having a front zone 32, a rear zone 34 and a crotch portion 36 located between the front and rear zones. The diaper 30 includes a back sheet 38, a top sheet 40 and an absorbent core 42 positioned between the back sheet and the top sheet. The outer edge of the diaper 30 includes a periphery 44 having a lateral edge 46 extending in the longitudinal direction opposite to the transverse direction, an end edge 48 extending in the transverse direction opposite to the longitudinal direction, It forms a system of elastomeric gathering members, such as a system comprising leg elastics 50 and waist elastics 52. The longitudinal side edges 46 form the leg openings 54 of the diaper 30 and are optionally curved contoured. Transverse end edge 48 is shown in a straight line, but may optionally be curved. In addition, the diaper 30 may include additional components that aid in the absorption, dispersion, and storage of body waste. For example, diaper 30 may be a transport layer as described in US Pat. No. 4,798,603 to Meyer et al., Or as described in European Patent Application Publication No. 0539703, issued May 5, 1993. The same surge management layer may be included.

As representatively shown in FIG. 1, the diaper 30 defines a generally longitudinally extending length dimension 56 and a laterally extending width dimension 58. The diaper 30 may have any desired shape, such as rectangular, I-shaped, generally hourglass-shaped, or T-shaped.

In the form shown, the back sheet 38 forms a length and width that match the length and width of the diaper 30. The absorbent core 42 generally defines a length and width that are less than the length and width of the back sheet 38, respectively. Thus, the periphery of the diaper 30, for example the periphery of the back sheet 38, extends longitudinally opposite the transverse direction of the absorbent core 42 and / or the length of the absorbent core 42. It can extend beyond the distal end edge 62 extending laterally opposite in the direction, to form the side margin 64 and the end margin 66 of the diaper 30. The top sheet 40 is generally in the same space as the back sheet 38, but may optionally cover an area larger or smaller than the area of the back sheet as needed. The back sheet 38 and top sheet 40 are intended to face the garment and the wearer's body, respectively, during use. As used herein, when describing the top sheet 40 with respect to the back sheet 38 or vice versa with the back sheet 38 with respect to the top sheet 40, " associated " The term includes a configuration in which the top sheet is directly bonded to the back sheet, and a configuration in which the top sheet is indirectly bonded to the back sheet by attaching a portion of the top sheet to the intermediate member and then attaching the intermediate member to at least a portion of the back sheet. do. For example, top sheet 40 and back sheet 38 may be combined with adhesive bonding, sonic bonding, thermal bonding, pinning, stitching, or various other attachment techniques known in the art and combinations thereof. The same attachment mechanism (not shown) may be coupled to each other at least in part of the diaper periphery 44.

Preferably, top sheet 40 provides a body facing surface that is flexible and soft to the touch and does not irritate the wearer's skin. In addition, the top sheet 40 may be less hydrophilic than the absorbent core 42 to provide the wearer with a relatively dry side, and is sufficiently porous to have liquid permeability so that liquid can easily penetrate through the thickness of the top sheet 40. Can be. Preferred topsheet 40 is a web material such as porous foam, reticulated foam, perforated plastic film, natural fibers, synthetic fibers (e.g., polyester or polypropylene fibers) or a combination of natural and synthetic fibers. It can be produced by a wide selection of materials). Preferably, top sheet 40 is used to help separate the wearer's skin from the liquid held in the absorbent core 42.

Various woven and nonwoven fabrics can be used for the top sheet 40. For example, the top sheet 40 can be composed of a spunbonded web or meltblown of polyolefin fibers. In addition, the top sheet 40 may be a bonded-cared web composed of natural fibers and / or synthetic fibers. Top sheet 40 may be comprised substantially of a hydrophobic material, which may be optionally treated with a surfactant or other method to impart the desired level of wettability and hydrophilicity. Specifically, the top sheet 40 is a nonwoven, spunbond or poly, consisting of about 2.8 to about 3.2 denier fibers formed of a web having a basis weight of about 22 gsm and a density of about 0.06 g / cc. It can be a propylene fabric.

In addition, the top sheet 40 may be a surface treated with a surfactant mixture in approximately 0.3 weight ratio, and the surfactant mixture is approximately 3% of the AHCOVEL Base N-62 surfactant and the GLUCOPON 220UP surfactant based on the total weight of the surfactant mixture. Mixtures mixed in a ratio of 1 are included. AHCOVEL BASE N-62 surfactants are purchased from Hodgson Textile Chemicals Inc., with offices in Mount Holly, Northern Carolina, and utilizes hydrogenated ethoxylated castor oil and sorbitan monooleate. Mixtures mixed at a weight ratio of 55:45. GLUCOPON 220UP surfactants are purchased from Henkel Corporation, Gulf Mills, Pennsylvania, and include alkyl polyglycosides. In addition, the surfactant may include additional components such as aloe. The surfactant can be applied by any conventional means such as spraying, printing, brush coating, foams and the like. The surfactant may be applied to the entire top sheet 40 or selectively applied to a special portion of the top sheet, such as a central portion along the longitudinal centerline of the diaper, to provide greater wettability to that portion.

Preferably, the back sheet 38 may be comprised of either liquid permeable or liquid impermeable material. In general, the back sheet 38 is preferably formed of a material that is substantially liquid impermeable. For example, conventional back sheet 38 may be made of a thin plastic film or other flexible liquid impermeable material. In addition, the back sheet 38 may be formed of a polyethylene film having a thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil). If desired to provide a back sheet 38 with a more cloth-like feel, the back sheet may comprise a polyethylene film laminated thereon of a nonwoven web, such as a spunbond web of polyolefin fibers, on its lower or opposite side. For example, a polyethylene film having a thickness of approximately 0.015 mm (0.6 mil) can thermally laminate spunbond webs of polyolefin fibers therein, the fibers having a thickness of approximately 1.5 to approximately 2.5 denier per filament, and nonwoven webs. Has a basis weight of approximately 24 gsm (0.7 osy). Methods of forming outer covers similar to such fabrics are known to those skilled in the art. In addition, the back sheet 38 may be a stretchable material, a method of forming such a material may be found in US Pat. No. 5,226,992 to Morman, and more various examples of stretchable materials are given to VanGompel et al. No. 6,264,641, the entire disclosure of which is incorporated herein by reference in a manner consistent with this specification.

In addition, the back sheet 38 is composed of a layer of woven or nonwoven fibrous webs that is constructed or treated in whole or in part to impart a desired level of liquid impermeability to selected areas adjacent to or near the absorbent core 42. Can be formed. In addition, the back sheet 38 is optionally made of a micro-porous “breathable” material that prevents liquid discharge from passing through the back sheet while allowing vapor to escape from the absorbent core 42. Can be configured.

The absorbent core 42 will comprise a matrix of hydrophilic fibers, such as a web of cellulosic fluff, mixed with particles of a high-absorbency material, commonly known as a superabsorbent material. Can be. In certain forms, the absorbent core 42 comprises a mixture of superabsorbent hydrogel-forming particles and wood pulp fluff. Wood pulp fluff may be exchanged with synthetic polymers, meltblown fibers or combinations of meltblown fibers and natural fibers. The superabsorbent particles may be mixed substantially uniformly or heterogeneously with the hydrophilic fibers.

Absorbent core 42 may have any of a variety of shapes. For example, the absorbent core 42 may be rectangular, I-shaped or T-shaped. It may be considered that the absorbent core 42 is often narrower in the crotch than in the front or rear region.

Super-absorbent materials can be selected from natural, synthetic and modified natural polymers and materials. The superabsorbent material may be an inorganic material such as silica gel or an organic compound such as a crosslinked polymer. The term "crosslinked" refers to any effective means of making a material that is normally water soluble swellable but substantially water insoluble. Such means include, for example, physical entanglement, crystalline domains, covalent bonds, ionic complexes and associations, hydrophilic bonds such as hydrogen bonds and hydrophobic bonds or van der Waals forces. It may include.

Examples of synthetic, polymer, and superabsorbent materials include ammonium salts of alkali metals, poly (acrylic acid) and poly (methacrylic acid), poly (acrylamide), poly (vinyl ether), vinyl ethers and alpha-olefins. One maleic anhydride copolymer, poly (vinyl pyrolidone), poly (vinyl morpholinone), poly (vinyl alcohol) and mixtures thereof Include. In addition, suitable polymers for use in the absorbent core include hydrolyzed acrylonitrile-grafted starch, acrylic acid grafted starch, methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose. Natural and modified natural polymers, and natural gums such as alginate, xanthum gum, locust bean gum and the like. In addition, mixtures of natural absorbent polymers and whole or partially synthetic absorbent polymers may be useful. The procedure for preparing synthetic, absorbent gelling polymers is described in US Pat. No. 4,076,663 to Masuda et al. And US Pat. No. 4,286,082 to Tsubakimoto et al.

The super absorbent material can be of various geometric shapes. The highly absorbent material is preferably in the form of individual particles. However, the super-absorbent material can also be in the form of fibers, flakes, rods, spheres, needles and the like. Usually, the high absorbent material is provided to the absorbent core 42 in an amount of a weight ratio of about 5 to about 100 relative to the total weight of the absorbent core.

In addition, the disposable absorbent articles described herein include fasteners 82 for securing the absorbent articles about the waist of the wearer. The diaper 30 in the form shown includes such a fastener 82. In one or more forms, the fasteners 82 are located in the rear region 34 of the diaper 30 and are located inside each of the longitudinally extending side edges 46. The fastener 82 may be configured to surround the wearer's hips and engage with the back sheet 38 of the front region 32 of the diaper 30 to hold the diaper 30 to the wearer. Preferably, the fastener 82 may be releasably coupled directly with the garment facing surface of the back sheet 38. Preferably, the fastener 82 includes a mechanical fastening system. Alternatively, the diaper 30 may include a fastening panel 68 positioned in the front region 32 of the garment facing surface of the back sheet 38. In this configuration, the fastener 82 may be releasably engaged with the fastening panel 68 to hold the diaper 30 around the wearer's waist. This configuration allows the waist opening to be resized in very small increments to fit the waist of the wearer over a wide range. The fastener 82 can have a variety of shapes and sizes to fasten the diaper 30 as desired around the waist of the wearer.

Preferably, the first fastener component and the cooperating fastener component include complementary elements of a mechanical fastening system that cooperate to cooperate. Mechanical fastener components may be provided by mechanical shaped fasteners, such as hooks, which include components that mechanically interlock together in complementary cooperation.

For example, as shown in FIGS. 1 and 2, the mechanical fastening system can be a hook and loop type fastening system. Typically, such fastening systems comprise coupling members in the form of "hooks" or hook-like male components, and cooperating "loops" or loops that releasably interconnect and engage with the hook components. It includes a loop-like female component. Preferably, the interconnect is selectively release and reattachable. Conventional systems are available, for example, under the VELCRO trademark.

Configurations using a selectively releasable interlocking mechanical fastening system may, for example, position a first fastener component in the ear portion 89 and connect the cooperating second fastener component to the fastening panel 68. Can be located. For example, in a representatively illustrated hook and loop fastener, the fastening component attached to the ear portion 89 may comprise a hook-type mechanical coupling element, and the complementary fastening component may be a loop-type fastening element. The fastening panel may include.

In addition, in various configurations of the present invention the relative position and / or material of the first fastening component and its cooperating complementary fastening components can be varied.

Examples of conventional hook and loop fastening systems and components are described in US Pat. No. 5,019,073 to Roessler et al., The entire disclosure of which is hereby incorporated by reference in a manner consistent with this specification. Other examples of hook and loop fastening systems are described in US Pat. Nos. 5,605,735 and 6,030,373 to VanGompel et al., The entire disclosure of which is incorporated herein by reference in a manner consistent with this specification.

The loop material may comprise a nonwoven, woven or knit fabric. For example, a suitable loop material fabric may consist of a 2 bar wrap knit fabric and other types of knit fabrics available from Gruildford Mills, Inc., Greensboro, North Carolina, under trade number # 34285. Can be. Suitable loop materials are also available from 3M, which has supplied nylon woven loops under their SCOTCHMATE brand. 3M has also supplied 3M knitted loop tape and linerless loop webs with adhesives at the back of the web.

In addition, the loop material may comprise a nonwoven fabric having a continuous bonded area that forms a plurality of discrete unbonded areas. Fibers or filaments within separate unbonded regions of the fabric are dimensionally stabilized by continuous bond regions surrounding or enclosing each unbonded region so that no support or backing layer of film or adhesive is required. Specifically, the unbonded region is designed to allow space to remain sufficiently open or large between the fibers or filaments within the unbonded region to receive and engage the hook elements of complementary hook material. Specifically, the pattern-unbonded nonwoven fabric or web may comprise a spunbond nonwoven web formed from a single component or a plurality of component melt-spun filaments. One or more sides of the nonwoven fabric may include a plurality of discrete unbonded regions surrounded or surrounded by continuous bonded regions. The continuous bonding region bonds or melts the outer surface of the nonbonding region with the portion of the fiber or filament that extends into the bonding region while leaving the fiber or filament in a substantially unbonded or unbonded region, thereby forming a nonwoven web. Stabilize the fibers or filaments that form. Preferably, the degree of bonding or melting within the bonding region is sufficient to keep the nonwoven web nonfiber in the bonding region, leaving the fiber or filament in the nonbonding region to serve as a "loop" to receive and bind the hook element. . Examples of suitable point-unbonded fabrics that are not modified are described in US Pat. No. 5,858,515 to Stokes et al., The entire disclosure of which is set forth herein in a manner consistent with this specification. See.

As used herein, the term “spunbond web” is used to extrude a molten thermoplastic, such as a filament, from a number of typically circular fine capillaries having a diameter of the extruded filaments, and then to, for example, fluid drawing ( A web formed by rapid reduction by fluid drawing or other well known spun bonding machanisms. The manufacture of spunbond nonwoven webs is shown in US Pat. No. 4,340,563 to Appel et al., The entire disclosure of which is incorporated herein by reference in a manner consistent with this disclosure.

The loop material need not be limited to separate or isolated patches on the outer surface of the article. Instead, the loop material may be provided by a substantially continuous outer fibrous layer that is assembled, integrated or otherwise joined to extend over a predetermined surface area of the desired article. For example, the outer fiber layer may be arranged to extend over the entire exposed surface area of the outer cover, such as cloth used with the article. The outer cover may also include an outer nonwoven layer that functions like a cooperating fastener component.

The engagement force between the selected first fastener component and its predetermined cooperating second fastener component must be large and sufficiently durable to adequately secure the article to the wearer during use. Specifically, where a fastening shear force of a sufficiently high level is provided by the configuration, in particular by the fastening system, the fastening engagement is at least approximately 40 grams per inch of “width” of the engagement between the first fastener component and the second fastener component. It is possible to provide a peel value of -gmf or more. In other configurations, the fastening coupling may provide a peel force value of approximately 100 gmf / inch (3.937 gmf / mm) or more to provide improved advantages. In a preferred configuration, the fastening engagement may provide a peel force value of at least about 200 gmf per inch (25.4 mm) of the "width" of the engagement between the first fastener component and the second fastener component. As an alternative, the peel force is at least about 300 gmf / inch (11.811 gmf / mm) and optionally at least about 400 gmf / inch (15.748 gmf / mm) to further provide improved benefits. In another embodiment, the peel force is approximately 1,200 gmf / inch (47.244 gmf / mm) or less. Alternatively, the peel force is about 800 gmf / inch (31.496 gmf / mm) or less, and optionally about 600 gmf / inch (23.622 gmf / mm) or less to provide improved performance.

The engagement force between the selected first fastener component and its predetermined cooperating second fastener component is one square inch (645.16 mm ² ) of the engagement region between the first fastener component and the second fastener component. It can additionally provide a shear force value of approximately 400 gmf or more per sugar. As an alternative, the shear force is greater than approximately 1,000 gmf / in ² (1.550 gmf / mm ² ) and optionally greater than approximately 1,700 gmf / in ² (2.635 gmf / mm ² ). In other embodiments, the shear force can be up to approximately 4,400 gmf / in ² (6.820 gmf / mm ² ) or more. As an alternative, the shear force is about 3,900 gmf / in ² (6.045 gmf / mm ² ) or less, and optionally about 3500 gmf / in ² (5.425 gmf / mm ² ) or less to provide improved performance.

Depending on the specific design and end use, the coupling force between a given male component and a given female component may be adjustable. Through this adjustment, the bonding force can be strengthened while wearing, and the bonding force can be reduced while being removed. The adjustment of the binding force can be linked to the amount by which the hook material is stretched. For example, the binding force of the stretched hook material can be increased or decreased compared to the same hook material in the non-stretched state.

When comparing the bonding force between stretched hook materials, the force should be normalized to the non-stretched state. For example, by 25% stretching hook material, the number of hooks per square inch is reduced to 0.8 times {1 / [(100 + 25) / 100] = 0.8} compared to the number of hooks of non-stretching hook material. . The reduction in hooks per square inch reduces the binding force per square inch by 0.8 times, but will prove to be the same standardized binding force when measured by the included test method. In addition, when comparing the hook material with the loop material and then stretching, the comparison is performed by bonding the hook material in the stretched state to the loop material and then testing the bonding force. It is contemplated that physical manipulation of the combined hook and loop system can change the engagement force.

In the stretched state, an increase in cohesion may be necessary. For example, when a caregiver wears a product very loosely (at least stretched) on a child, a first level of cohesion is required. However, if the caregiver wears the same product tighter (very stretched) on the same child, for example just before playtime, increased levels of coupling are needed.

Alternatively, in the stretched state it may be necessary to reduce the binding force. Many carers remove the product by pulling or stretching the hook material when they remove the product from the user. In this condition, it may be advantageous for the hook to reduce the engagement force when the caregiver removes or stretches the hook material. In this respect, a "high" level of coupling is achieved during use and a relatively "low" level of coupling is achieved during removal. This makes it easier to remove and less damaging loop material using a given level of bonding force.

The fastening system can include a female component and a male component having a plurality of hook elements. The male component can be configured to releasably engage with the female component. The fastening system can also have a first normalized peak shear force to release the female component from the male component when the male component is not stretched. The fastening system may have a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched. The first normalized peak shear force may be at least 10% greater than the second normalized peak shear force. Alternatively, the first normalized peak shear force may be at least 20% greater than the second normalized peak shear force. Alternatively, the first normalized peak shear force may be at least 33% greater than the second normalized peak shear force. The coupling force of this fastening system decreases as the male component is stretched.

When a load of 250 g / in (9.843 g / mm) is applied, a portion of the male component of the fastening system may be stretched more than 10%. As an alternative, when a load of 250 g / in (9.843 g / mm) is applied, a portion of the male component of the fastening system may stretch at least 15%. A portion of the male component of the fastening system may be elastic.

3A and 3B show a prophetic example of the first hook material and show a decrease in binding force in the stretched state. 3A shows a side view of the first hook material in an unstretched state, and FIG. 3B shows a side view of the hook material of FIG. 3A after stretching. The hook material shown in FIG. 3A includes a plurality of hook elements, the plurality of hook elements having a stem 80 and a cap 82. The cap also defines a characteristic cap angle 84. Cap angle 84 is the smallest angle that the tangent to the lower side of cap 82 makes with the vertical line. The average cap angle 84 is the average of the entire cap angle 84 of the individual hooks that make up the hook material. In theory, a smaller cap angle 84 provides greater engagement. 3A shows the hook material in its non-stretched (0%) state with a first average cap angle. 3B shows the hook material in the stretched (eg 10%) state with a second average cap angle. The second average cap angle 84 is greater than the first average cap angle 84. This theoretical hook material will have a greater normalized peak shear force in the unstretched state than in the stretched state.

Many other designs may be used to achieve a reduction in engagement force and / or an increase in cap angle 84. The cap angle 84 can be increased by designing the hook material such that when a stretching force is applied the force is transferred to the individual hooks and then deformed. The deformation of the hook can be made to fit the purpose, for example by modifying only part of the hook in the hook material, or by changing the amount of deformation of the hook in accordance with a given amount of stretching of the hook material. This change can be achieved by the choice of material, by the specific thickness of the material, by the choice of the physical structure of the individual hooks, and further by the construction or structure of the base or support material.

3A and 3B show side views of the first hook material in an unstretched and stretched state. One way the material stretches is by deformation of the hook element. The hook element, more specifically the cap 82, is opened, thereby creating a lower engagement force. 4A and 4B show side views of the second hook material in an unstretched and stretched state. This material describes a second design in which the hook element can be deformed when the material is stretched. The hook element, more specifically the cap 82, is opened, thereby creating a lower engagement force.

The hook material may be designed such that after 10% stretching, the average cap angle 84 of the material may be at least 20 ° greater than the average cap angle when the material is not stretched. Alternatively, the hook material may be designed such that after 10% stretching, the average cap angle 84 of the material may be at least 40 ° greater than the average cap angle when the material is not stretched.

The fastening system can be designed such that the normalized peak shear force of the unstretched material is at least 10% greater than the normalized peak shear force of the material after 10% stretch. As an alternative, the fastening system can be designed such that the normalized peak shear force of the unstretched material is at least 25% greater than the normalized peak shear force of the material after 10% stretch.

An increase in cohesion may be required in a stretched state, for example in a caregiver requiring a higher or lower amount of cohesion. 5A and 6A show examples of hook material in an unstretched state, where the stretch can increase the engagement force by reducing the cap angle 84. 5A and 6A illustrate the male component of a fastening system that includes a plurality of hook elements. The male component can be configured to releasably engage with the female component of the fastening system. The fastening system may have a first normalized peak shear force to release the female component from the male component when the male component is not stretched. The fastening system may have a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched. The first normalized peak shear force may be at least 10% less than the second normalized peak shear force. Also, depending on the desired end use, the first normalized peak shear force may be at least 20% less than the second normalized peak shear force.

5A and 5B show a precursor of the first hook material and show an increase in engagement force in the stretched state. 5A shows a side view of the first hook material in an unstretched state, and FIG. 5B shows a side view of the hook material of FIG. 5A after stretching. The hook material shown in FIG. 5A includes a plurality of hook elements, the plurality of hook elements having a stem 80 and a cap 82. The cap also defines a characteristic cap angle 84. 5A shows the unstretched (0%) hook material with a first average cap angle. 5B shows the hook material in the stretched (eg 10%) state with a second average cap angle. The second average cap angle 84 is smaller than the first average cap angle 84. This theoretical hook material will have a greater normalized peak shear force in the stretched state than in the unstretched state.

Many other designs may be used to achieve an increase in engagement force and / or a reduction in cap angle 84. The cap angle 84 can be reduced by designing the hook material so that when an elastic force is applied, the force is transferred to the individual hooks and subsequently deforms the individual hooks. The deformation of the hook can be made to fit the purpose, for example by modifying only part of the hook in the hook material, or by changing the amount of deformation of the hook in accordance with a given amount of stretching of the hook material. This change can be achieved by the choice of material, by the specific thickness of the material, by the choice of the physical structure of the individual hooks, and further by the construction or structure of the base or support material.

5A and 5B show side views of the first hook material in an unstretched and stretched state. One way the material stretches is by deformation of the hook element. The hook element, more specifically the cap 82, can be redirected to hold the loop material more firmly and thereby create a higher bonding force. 6A and 6B show side views of the second hook material in an unstretched and stretched state. This material describes a second design in which the hook element can be deformed when the material is stretched. The hook element, more specifically the cap 82, is reorientated to hold and support the material more firmly, thereby creating greater bonding force.

The hook material may be designed such that after 10% stretching, the average cap angle of the material may be at least 20 ° less than the average cap angle when the material is not stretched. Alternatively, the hook material can be designed such that after 10% stretching, the average cap angle of the material can be at least 40 ° less than the average cap angle when the material is not stretched. The average cap angle 84 can be at least 90 ° when the material is not stretched.

The shear strength of the mechanical fastening system can be determined according to the following method.

Test Method: Shear Strength

Test procedure

This procedure is a tensile bench test that measures the shear force required to separate a mechanical fastening system that combines two materials. The shearing force that separates is measured by determining the load value when the two materials spread parallel to their contact plane. The shear strength test value is an indication of how well the mechanical fastening system remains coupled to shear force in the plane. The sample is pulled in the tensile tester until the sample is open. Shear strength is the result of peak load. Shear strength can be normalized by the force per standardized area by dividing the peak load by the unstretched contact area.

1. Overview

Material samples of two material layers assembled by mechanical fastening systems such as hook and loop systems are assembled. The fastening system overlaps and overlaps two pieces of material in the mounting area. Samples are prepared by aligning, applying the loop material to the stabilized hook material, and rotating a 4.5 lb. (2.04 kg) mechanical roller over a fastening system that engages the fastener. The sample is then placed between the clamps on the tensile tester. One piece of material is supported by the upper clamp and the other piece is supported by the lower clamp. The fastening system is arranged between the clamps and is approximately parallel to the edge of the clamp face. The width of the hook material is 13 mm, the width of the loop material is approximately 64 mm, and the hook overlaps the loop 50 mm in the longitudinal direction (not stretched). The gauge length is 3 inches (76 mm) between the edges of the clamp face. The term "load" refers to the gram value measured by the load cell of a tensile tester.

The jaws are separated at a control rate of 12 inches / min (305 mm / min) until the fastening system is opened. This process records the load values generated on the material. The load is recorded on the computer as a function of elongation.

The load values of samples with unstandardized widths and lengths can be normalized by multiplying or dividing the factors, whereby the sample overlap area is deformed from 13 mm to 50 mm. For example, the peak load value obtained by spreading a 50 mm long sample 1 inch wide (25.4 mm) should be multiplied by 13 / 25.4.

Suitable materials include hook and loop fastening systems, which may include or be attached to the materials used to form the disposable garments described herein.

2. Devices and materials

2.1 MTS Tensile Tester Model Tensile tester of constant rate of extension (CRE), such as Sintech 1 / G; Available from MTS System Corporation, Eden Prairie Technology Drive 1400, Minnesota, USA

2.2 load cell: a suitable cell selected such that most of the peak load values fall between 10% and 90% of the total scale value of the load cell recommended by the manufacturer; For example, the Model 100N available from MTS System Corporation, Eden Prairie Technology Drive 1400, Minnesota, USA

2.3 Operating software and data acquisition systems such as MTS Test Works® for Windows software version 3.10; Available from MTS System Corporation, Eden Prairie Technology Drive 1400, Minnesota, USA

2.4 Grips: Pneumatically operated grips, upper and lower parts identical to part number 38.00716 available from MTS System Corporation

2.5 Grip Sides: 25 x 75 mm (1 x 3 inch) interconnects, such as those available from MTS System Corporation.

2.6 Rollers: 4.5 lb. (2.04 kg) mechanical rollers available from Mentor Kahlsantant International, Ohio, USA

2.7 plexiglass, 1/4 "x 4" x 4 "(63.5mm x 101.6mm x 101.6mm)

3. Adjustable

Reasonable environmental conditions are required for the test. The instruments used must be calibrated as described in the manufacturer's instructions for each instrument.

4. Test specimen (shown in Figure 5)

A hook material sample 102 having an unstretched width of 13 mm and an unstretched length of 50 mm is attached to a piece of rigid material, such as a piece of plexiglass 110. The material may be attached to the plexiglass without stretching so that the dimensions of the hook are 13 mm by 55 mm. As an alternative, the material may be attached to the plexiglass in a stretched state such that the dimensions of the hook material are 13 mm x 55 mm (10% stretched state). This method standardizes the bond strength for stretching of the material. When testing a sample of material taken from an absorbent article, the dimensions of the hook material 102 and the loop material 101 can be adjusted. The results should be standardized for the overlapping sizes tested.

The loop material sample 101 is cut to have a width of approximately 2.5 inches (64 mm) and a length of approximately 4 inches (102 mm). The loop sample 101 is positioned above the hook material sample 102 such that the loop material sample 101 completely overlaps (c) the hook material sample 102 perpendicular to the 64 mm wide edge at the center on the 64 mm. The bound material must not be touched or pressed.

The specimen is placed in a rigid plane, and then the test sample is pressed at once with a standard mechanical roller of 4.5 lb (2.04 kg) by rotating the roller back and forth longitudinally across the hoop / loop coupling area on the loop material sample 101. Lose. The centerline of the sample should be aligned with the centerline of the roller face.

Specimens are tested using the tensile test procedure below. At least four specimens from each sample should be tested and the results averaged.

5. Procedure

Tensile Tester Test Conditions:

No preload

Test speed 305mm / min

Gauge Length (h) 3 Inch (76mm)

Number of cycles 1

A. Using the tension frame push button controller in the crosshead position, move the grip to provide a gauge length h of 3 inches (76 mm). Weigh the vessel of the crosshead channel against this initial gauge length.

B. Without touching the fastening area, keep the material sample so that the hook material is above and the loop material is below. Position the plexiglass so that the hook attaches to the upper jaw 103 of the tester. The hook material is positioned in the upper jaw 103 such that the hook material is centered in the horizontal direction and the loop material extends below the center of the upper jaw 103.

C. Close the upper jaw 103 on the specimen and weigh the vessel of the load channel.

D. Hold the specimen to minimize slack of the specimen, do not place the specimen under tension, and close the lower jaw 104 on the loop material.

E. Perform the test using the above parameters by clicking on the operation button.

F. When the test is complete, save the data to a sample file.

G. Remove the specimen from the jaws 103 and 104.

H. Run additional specimens of a given sample using steps B through G. All sample data should be stored in one file.

I. Continue testing all samples in this manner.

J. Data are recorded as peak load and total energy in the load-elongation curve.

Having described the invention in more detail, various changes and modifications may be made without departing from the spirit of the invention. All such changes and modifications are intended to be within the scope of the present invention as defined by the appended claims.

Claims (24)

Fastening system suitable for integration into disposable absorbent articles, Female components, A male component having a plurality of hook elements configured to releasably engage with the female component, The fastening system has a first normalized peak shear force to release the female component from the male component when the male component is not stretched, The fastening system has a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched, The fastening system wherein the first normalized peak shear force is at least 10% greater than the second normalized peak shear force. The method of claim 1, The fastening system wherein the first normalized peak shear force is at least 20% greater than the second normalized peak shear force. The method of claim 1, Fastening system wherein at least a portion of the male component is at least 10% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 1, Fastening system wherein at least a portion of the male component is at least 15% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 1, At least a portion of the male component is elastic. Fastening system suitable for integration into disposable absorbent articles, Female components, A male component having a plurality of hook elements configured to releasably engage with the female component, At least a portion of the plurality of hook elements has a stem and a cap defining a cap angle, The fastening system has a first normalized peak shear force to release the female component from the male component and a first average cap angle when the male component is not stretched, The fastening system has a second normalized peak shear force to release the female component from the male component and a second average cap angle when the male component is 10% stretched, And the first normalized peak shear force is greater than the second normalized peak shear force and the second average cap angle is greater than the first average cap angle. The method of claim 6, And the second average cap angle is at least 20 ° greater than the first average cap angle. The method of claim 6, And the second average cap angle is greater than or equal to 90 degrees. The method of claim 6, The fastening system wherein the first normalized peak shear force is at least 10% greater than the second normalized peak shear force. The method of claim 6, Fastening system wherein at least a portion of the male component is at least 10% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 6, Fastening system wherein at least a portion of the male component is at least 15% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 6, At least a portion of the male component is elastic. Fastening system suitable for integration into disposable absorbent articles, Female components, A male component having a plurality of hook elements configured to releasably engage with the female component, The fastening system has a first normalized peak shear force to release the female component from the male component when the male component is not stretched, The fastening system has a second normalized peak shear force to release the female component from the male component when the male component is 10% stretched, And the first normalized peak shear force is at least 10% less than the second normalized peak shear force. The method of claim 13, The fastening system wherein the first normalized peak shear force is at least 20% less than the second normalized peak shear force. The method of claim 13, Fastening system wherein at least a portion of the male component is at least 10% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 13. Fastening system wherein at least a portion of the male component is at least 15% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 13, At least a portion of the male component is elastic. Fastening system suitable for integration into disposable absorbent articles, Female components, A male component having a plurality of hook elements configured to releasably engage with the female component, At least a portion of the plurality of hook elements has a stem and a cap defining a cap angle, The fastening system has a first normalized peak shear force to release the female component from the male component and a first average cap angle when the male component is not stretched, The fastening system has a second normalized peak shear force to release the female component from the male component and a second average cap angle when the male component is 10% stretched, The first normalized peak shear force is less than the second normalized peak shear force, and the second average cap angle is less than the first average cap angle. The method of claim 18, And the second average cap angle is at least 20 ° less than the first average cap angle. The method of claim 18, And the first average cap angle is at least 90 degrees. The method of claim 18, And the first normalized peak shear force is at least 10% less than the second normalized peak shear force. The method of claim 18, Fastening system wherein at least a portion of the male component is at least 10% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 18, Fastening system wherein at least a portion of the male component is at least 15% stretchable when a load of 250 g / in (9.843 g / mm) is applied. The method of claim 18, At least a portion of the male component is elastic.

Images