MX2008007410A

MX2008007410A - Strand, substrate, and/or composite comprising re-activatable adhesive composition, and processes for making and/or utilizing same

Info

Publication number: MX2008007410A
Application number: MXMX/A/2008/007410A
Authority: MX
Inventors: K Hall Gregory; Zhou Peiguang
Original assignee: Kimberlyclark Worldwide Inc
Priority date: 2005-12-14
Filing date: 2008-06-09
Publication date: 2008-09-02

Abstract

The present invention is generally directed to webs, components, composites, and strands comprising re-activatable adhesive compositions, as well as health-and-hygiene products employing such webs, components, composites, and strands. By inputting energy to the web, component, composite, or strand (including, for example, an elastic web, component, composite, or strand) comprising a re-activatable adhesive composition, the adhesive is activated (i.e., rendered tacky) so that it can be used to join or adhere the web, component, composite, or strand to another material (or another location on the same web, component, composite, or strand). Generally, energy will be inputted to the adhesive in the form of infrared heat, heat, or ultrasonic energy, although any energy form may be used, so long as the energy is capable of activating the adhesive. Prior to activation, webs, components, composites, and strands comprising such re-activatable adhesives are convenient to handle because the adhesive is not yet tacky. Furthermore, the re-activatable adhesive may be activated at desired locations only, thereby permitting construction of bond patterns that promote desired characteristics (e.g., desired ratios of elastic properties and softness).

Description

THREAD, SUBSTRATE, AND / OR COMPOSITE THAT COMPRISES A REACTIVABLE ADHESIVE COMPOSITION, AND PROCESSES TO MAKE AND / OR USE THE SAME Background People rely on products for health and hygiene to make their lives easier.

Health and hygiene products, such as various disposable absorbent articles (eg, adult incontinence articles and diapers) are generally manufactured by combining several components. These components may include, for example, a liquid permeable top sheet, a liquid impermeable bottom sheet attached to the top sheet; and an absorbent core located between the bottom sheet and the bottom sheet. When the disposable article is used, the liquid permeable top sheet is placed close to the user's body. The upper sheet allows the passage of body fluids in the absorbent core. The lower sheet impervious to liquid helps prevent filtration of fluids held in the absorbent core. The absorbent core is generally designed to have desirable physical properties, for example, high absorbency capacity and high absorption rate, such that body fluids can be transported from the wearer's skin in the disposable absorbent article.

Frequently one or more components of the article for hygiene and health are attached by adhesive together. For example, adhesives have been used to join individual layers of an absorbent article, such as the top sheet (also known as, for example, the side-to-body lining) and the bottom sheet (also known as, for example, the outer cover), together. The adhesive has also been used to attach discrete parts, such as fasteners and leg elastics, to the article. In many cases, the joining of the components forms a laminated structure in which the adhesive is sandwiched between materials (such as polymer film layers and / or layers of woven or non-woven fabrics) that cause the components to be bonded together. In some cases the elastic yarn, or some other elastomeric material, is attached to and / or interleaved among other components.

In many instances, a hot melt adhesive, for example, a formula that is heated to substantially liquefy the formula before application to one or both materials when a laminate is made, is used to make a laminated structure. While such formulas generally work, they can be improved. For example, in making some elastomeric compounds, the rate of adhesive addition can be relatively high, resulting in a relatively expensive compound, and somehow rough or stiff. For example, the production of an elastomeric composite comprises one or more elastic yarns interspersed between, and adhesively bonded to, nonwoven substrates (or views) may require significant amounts of adhesive to ensure that the yarns are satisfactorily bonded to the views not woven, thus giving the compound its elastomeric qualities. At each location where a yarn is bonded by adhesive to one or both views, the compound is stiffer, due to the combination of the yarn, the non-woven sight, and the adhesive is thicker and stiffer than any single yarn or the view is not woven alone. If the compound comprises many such binding sites, then the resulting compound may be stiff, rough, and / or perceived by the users of the compound as not being smooth. In addition, as the number of bonding locations is increased, the elastic qualities of the elastomeric composite may decrease, because more and more of the yarns are attached to the non-woven views, with less and less of the yarns remaining unattached. As less and less of the threads remain free and unbound - and hence readily able to stretch or retract - the resulting composite is less able to stretch and / or retract. Conversely, as more and more of the yarns remain free and unbound, the resulting composite is more able to stretch and retract.

The problem of achieving the desired balance between the integrity of an elastomeric laminate and effecting desired softness / flexibility and elasticity properties can be exacerbated at higher inline speeds typically associated with commercial equipment (eg, the equipment used to make an absorbent article. disposable such as a diaper, which can operate at speeds, for example, of at least 300 feet per minute, suitably 500 feet per minute, particularly 750 feet per minute). As the line speed of the equipment increases, it typically becomes more and more difficult to intermittently join an elastomeric material, such as elastic yarn to a substrate. For example, if the laminate is being made by bonding elastic yarn to a substrate using a hot melt adhesive applied through a nozzle, then intermittent bonding can be achieved by rapidly pressing the adhesive (eg, applying it in a manner discontinuous). But the higher and higher the line speed, the pulsing of the adhesive at higher and higher frequencies can be mechanically difficult, for example, it can be difficult to produce the desired pattern of discrete points of attachment between the elastic material and the substrate .

What is needed is a compound (eg, an elastomeric compound) and the method for making such a compound, which provides for one or more performance characteristics that are comparable to, or better than, one or more of the same performance characteristics. (for example, the bond strength) of a conventional composite, while at the same time having improved softness characteristics. For example, what is needed is a composite comprising elastomeric materials, such as elastomeric yarns, attached to one or more substrates such that the compound has sufficient integrity, elasticity, and softness for use in a product.

Synthesis We have found that the previous treatment of one or more individual components that make a compound with a re-activation adhesive composition, and then causing the compound to activate the adhesive composition on an individual component before joining the component to itself or a second component, can provide for a softer, more flexible compound. In addition, such prior treatment and reactivation can provide desired intermittent and / or discrete bonding patterns between the components. Thus, for example, when an elastomeric material, such elastic yarn, is attached to a substrate, such prior treatment of the substrate and / or yarn with an activated pre-adhesive, followed by selectively entering energy to the adhesive using ultrasonic equipment can provide for accurate Bonding locations between the substrate and the elastomeric material. The ability to perform relatively precise union of locations allows for patterns of bonding locations that more adequately balance strength / integrity, flexibility / softness, and elasticity in a desired shape.

For example, in a representative version of the present invention, a reactivatable adhesive can be selected in such a way that the adhesive has a lower softening point than the softening point (or as described below, when the transition phase from liquid to solid it is relatively more acute, melting point) of the material or component to which it will be applied. The component is then processed in such a way that the component is treated with the reactivatable adhesive. If the component is an elastic yarn, a spool or spool of yarn can be unrolled in such a way that the yarn is continuously directed to a location where the reactivatable adhesive is applied by coating, spraying, printing, or otherwise treating the yarn with the yarn. adhesive. Typically, the reactivatable adhesive will have been heated to a temperature at or above its softening point such that the adhesive can be conducted to, and applied to, the component. further, by selecting an adhesive having a softening temperature lower than that of the component or the substrate to which the adhesive is applied, there is a diminished similarity of the substrate itself losing integrity because the substrate begins to soften. After the reactivatable adhesive has been applied to a component, in this representative example an elastic yarn, the adhesive is allowed to set (eg, sufficient time is given for the adhesive temperature to be lowered such that the adhesive hardens) . The component treated with the reactivatable adhesive is then further processed (for example, for immediate use in making the article of manture, or for storing before use for such manture). For example, if the component is an elastic yarn, and the yarn is stored before use by making a compound used in a manturing article (such as a disposable absorbent article, for example a diaper, or some other health product). and hygiene), then the yarn treated with the reactivatable adhesive can be re-wound to form a spool or spool. When the reel of the treated elastic yarn is to be used (either in the same location where the reel was treated; or in some other location different from the location where the reel was treated), the reel can be unrolled, with the yarn directed to one or more components to which the yarn will be attached. For example, the yarn can be directed to a position between two non-woven substrates. The energy is directed to the reactivatable adhesive to activate its adhesive qualities. One method of directing the energy to the reactivatable adhesive is by conducting the combination of treated elastic yarn and the non-woven views through an operation of the ultrasonic unit. By directing the combination of these materials through the ultrasonic equipment, the energy is absorbed by the reactivatable adhesive. When selecting the amount of ultrasonic energy entered into the combination; the identity of the reactivatable adhesive, particularly its softening point; the identity of the elastic yarn, particularly its softening point; and the identity of the non-woven views, particularly their smoothing points; the adhesive can be activated in such a way that its adhesive qualities are activated while maintaining the integrity of the components of the combinations. For example, these parameters can be selected in such a way that the adhesive softens, flows, and adhesively bonds the yarn to the non-woven views; while the components of the combination (the yarn and the non-woven views) substantially do not soften or flow. In addition, the use of ultrasonic joining equipment provides the opportunity to bond the elastic yarn to the non-woven views in discrete locations. As generally described above and elsewhere, the yarn may intermittently join along its length to other components, such as to one or both fibrous views in an elastomeric laminate (e.g., the yarns are sandwiched between, and attached to , the views) . If the yarn is attached to the views in this manner while in the stretched condition, then the resultant laminate, when allowed to retract (due to retraction of the yarn), will have elastomeric qualities. The energy can be input to activate the reactivatable adhesive either before, during, or after the component carrying the reactivatable adhesive is contacted with the component that is being bound via the activated adhesive.

The preceding paragraphs provide a description of a representative version of the present invention. Additional detail is provided in the section of the description that follows. Of course, other versions and additions are possible. For example, instead of the previous treatment of an elastic yarn with a reactivatable adhesive, nonwoven substrates of various types can be previously treated. Any component used in making an article of manufacture (for example, a disposable absorbent article such as a diaper, or other health and hygiene product) may previously be treated with a reactivatable adhesive such that during the making of the article of manufacture, the The energy is admitted to the adhesive in such a way that it is activated and therefore capable of binding the previous treatment component either by itself or to another component.

These and other features, aspects, and advantages of the present invention will be better understood with respect to the following description, appended claims, and accompanying drawings.

Drawings Figure 1 describes a representative version of a process for applying a reactivatable adhesive to the component, in this case to a fabric or substrate.

Figure 2 describes a representative version of a process for applying a reactivatable adhesive to a component, in this case an elastic yarn.

Figure 3 describes a representative version of a process for applying a reactivatable adhesive to a component, in this case an elastic yarn.

Figures 3A and 3B describe representative versions of equipment and / or processes for applying a reactivatable adhesive to a component, in this case an elastic yarn.

Figure 4 describes a version of a configuration of a reactivatable adhesive applied to a component, in this case a fabric or substrate.

Figure 4A describes a version of a configuration of a reactivatable adhesive applied to a component, in this case to an elastic yarn.

DESCRIPTION The present invention is generally directed to reactivatable adhesive compositions, components employing such compositions, products of the highest order made with these products, and processes for making said components and products. Compounds that employ reactivable adhesive compositions generally perform better, and at a lower cost, than compounds that employ conventional hot melt adhesives. In addition, these reactivatable adhesive compositions can typically be processed and applied using conventional hot melt adhesive processing equipment. Generally new equipment will not be necessary to use the adhesive compositions of the present invention.

Before describing representative embodiments of the invention, it is useful to define a number of terms for purposes of this application. These definitions are provided to assist the reader of this document, and the presence or omission of specific terms shall not constitute evidence of knowledge possessed by persons of ordinary skill in the art or arts that relate to the subject matter of this document.

"Woven or non-woven fabric" generally refers to a polymeric fabric having a structure of individual fibers or strands that are between placed, but not in an identifiable manner, or repeatedly. Examples of suitable non-woven fabrics or fabrics include, but are not limited to, meltblown, hydroentanglement, air-laid processes, spin-linked processes, and bonded and bonded fabric processes. The basis weight of the non-woven fabrics is usually expressed in ounces of material per square yard or in grams per square meter and the diameters of the useful fibers are usually expressed in microns. (Note that to convert from ounces per square yard to grams per square meter, multiply ounces per square yard by 33.91).

"Knitted or woven fabric" means a fabric or fabric that contains a fiber structure, strands, or threads that are arranged in an orderly, inter-hooked fashion. Woven fabrics typically contain interwoven fibers in a "warp" or "fill" direction. The warp direction corresponds to the length of the fabric while the direction of the filling corresponds to the width of the fabric. Woven fabrics can be made, for example, from a variety of looms including, but not limited to, shuttle looms, rapier looms, projectile looms, air jet looms, and water jet looms.

"Spunbonded fibers" refer to small diameter fibers that are formed by extruding a molten thermoplastic material as filaments through a plurality of fine spinner capillaries having a circular or other shape, with the diameter of the extruded filaments being rapidly reduced as, for example, in the patents of the United States of America numbers 4,340,563 granted to Appel et al., 3,692,618 granted to Dorschner et al., 3,802,817 granted to Matsuki et al., patents of the United States of America numbers 3,338,992 and 3,341,394 granted to Kinney, 3,502,763 granted to Hartman; U.S. Patent No. 3,502,538 issued to Petersen; and U.S. Patent 3,542,615 issued to Dobo et al. Each of which is incorporated by reference in its entirety and in a manner consistent with this document. Yarn-bonded fibers are generally non-sticky when deposited on a collecting surface. Spunbonded fibers are generally continuous and have average diameters greater than 7 microns, and more particularly between 10 and 30 microns. A yarn-bound material, layer or substrate comprises spunbonded fibers.

"Fusible blown fibers" mean the fibers formed by the extrusion of a molten thermoplastic material through a plurality of thin and usually circular capillary matrix vessels with strands or fused filaments into gas jets heated at high velocity ( example, air) and converging that attenuate the filaments of molten thermoplastic material to reduce its diameter, which can be to a microfiber diameter. After this, the meltblown fibers are carried by the high speed gas jet and are deposited on a collecting surface to form a randomly dispersed meltblown fabric. Such a process is described in US Pat. No. 3,849,241 issued to Butin et al. Melt-blown fibers are microfibers that can be continuous or discontinuous, are generally smaller than 10 microns in average diameter and are generally sticky when deposited on a collecting surface.

The term "micro fibers" are fibers of small diameter that have an average diameter no greater than about 100 microns, for example, having an average diameter from about 0.5 microns to about 50 microns, or more particularly, a diameter average from around 1 miera to around 20 mieras. Microfibers having an average diameter of about 3 microns or less are referred to as ultra fine micro fibers. A description of an exemplary process for making ultrafine micro fibers can be found in, for example, U.S. Patent No. 5,213,881, entitled "A Non Woven Fabric With Improved Barrier Properties".

"Conventional hot-melt adhesive" means a formula that generally comprises several components. These components typically include one or more polymers to provide cohesive strength (eg, aliphatic polyolefins such as poly (ethylene-co-propylene) copolymer; ethylene vinyl acetate copolymers; styrene-butadiene or block styrene-isoprene copolymers, or other copolymers in block styrenics or isoprene rubber materials; a resin or analogous material (sometimes called a binder) to provide adhesive strength (for example, distilled hydrocarbons from petroleum distillates, rosins and / or rosin esters, terpenes derived, for example, from wood or citrus, etc.), probably waxes, plasticizers or other materials to modify the viscosity (eg, flow) (examples of such materials include, but are not limited to, mineral oil, polybutene, paraffin oils, ester oils, and the like) and / or other additives that include, but are not limited to, antioxidants or other stabilizers. A typical hot melt adhesive can contain from about 15 to about 35 weight percent polymer or polymers; from about 50 to about 65 percent by weight of plasticizer or other viscosity modifier, and optionally less than about 1 percent by weight of stabilizer or other additive. It should be understood that other adhesive formulas comprising different percentages by weight of these components are possible.

"Hot melt processable" means that an adhesive composition can be liquefied using a hot melt tank (eg, a system in which the composition is heated such that it is substantially in liquid form, see for example, the adhesive supply referred to in Example 1 below) and conveyor via a pump (eg, a lever pump or a positive displacement pump) from the tank to the point of application near a substrate or other material; or to another tank, system, or operating unit (eg, a separate system, which may include an additional pump or pumps, to supply the adhesive to the application site). The hot melt tanks used to substantially liquefy a hot melt adhesive typically operate in a range from about 100 degrees Fahrenheit to about 450 degrees Fahrenheit. Generally, at the point of application, the substantially liquefied adhesive composition will pass through a nozzle or bank of nozzles, but may pass through some other mechanical element such as a groove. A hot melt adhesive composition should be contrasted with a composition requiring an extruder, and the pressures of attention and temperature characteristics of an extruder, to liquefy, mix, and / or transport the composition. While a hot melt tank and pump in a hot melt processing system can handle viscosities of the adhesive composition in a range from about 100 centipoise to about 50,000 centipoise, an extruder can handle and process viscosities of the adhesive composition in A range from around 10,000 centipoise to viscosities of several hundred thousand centipoises. An advantage of some adhesive compositions of the present invention is that said compositions are hot melt processable. For example, such mixtures of isotactic and atactic polypropylene can generally be substantially liquefied in a hot melt tank and transported to the point of application via a pump.

Unless otherwise noted, "laminated structure" or "laminate" means a structure in which one layer, material, component, fabric, or substrate is adhesively bonded, at least in part, to another layer, material, component, tissue, or substrate. As noted elsewhere in this application, a layer, material, component, fabric, or substrate can be bent and bonded to itself to form a "laminated structure" or a "laminate." 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 of them.

"Softening point" refers to the temperature at which a material softens or flows. It can be measured using the E 28 test of the American Society for Testing and Materials (ASTM) (a determination of the smoothing point using a ring and ball apparatus). It should be noted that the term "softening point" is generally used with respect to an amorphous material, amorphous polymer, or a predominantly amorphous material / polymer, if a material is crystalline, then the temperature at which the material softens and / or flow is the temperature at which the material abruptly changes from a solid phase to a liquid phase. In this instance, the phase transition is characterized as the melting point of the materials. In the present application, a statement that a softening point of the reactivatable adhesive is less than the softening point of a fabric, component, substrate, or yarn means that the softening point of the reactivatable adhesive is less than any of the points of softening or the melting point of said fabric, component, substrate, or yarn.

Representative Versions of the Processes to Apply a Reactivable Adhesive to a Woven, Component, Compound and / or Thread In the description of the process that follows, the preparation, processing and application of a reactivatable adhesive composition is described. It should be understood, however, that this description is given as an example. Other processing methods and equipment can be used to prepare and supply various reactivatable adhesive compositions of the present invention to the components used in the subsequent set of compounds, disposable absorbent products and / or personal care devices for health, hygiene or applications. environmental Figure 1 shows a schematic diagram of an apparatus 20, and a method for spraying the reactivatable adhesive composition, on a moving tissue 22. The apparatus 22 may include a programmable control system 24 that is operatively connected to a control system of flow 26. The combination of the programmable control system 24 and the flow control system 26 are configured to control the delivery of the reactivable adhesive composition in liquid form to the moving tissue 22. Generally a reactivatable adhesive composition will be received in solid form in a manufacturing site where the equipment as described in Figure 1 is located. For example, reactivatable adhesive compositions can be received as solid granules, blocks, or some other forms. The solid is then heated in such a way that the reactivatable adhesive composition is in such a form that it can be transported, and applied, to a substrate, or other material. Usually this requires that the reactivated heated adhesive be in substantially liquid form. For the present invention, a reactivable adhesive composition in solid form can be received at a manufacturing site for heating and processing as described above. Alternatively, the separate components of the reactivatable adhesive composition can be received and mixed at the manufacturing site. An example of equipment and methods for heating an adhesive composition, or precursor materials to the adhesive composition, are described in greater detail below.

The apparatus may also include a position sense system that is configured to sense a position of the moving tissue 22 and, in response to this, generate a signal that is sent to the programmable control system 24.

As representatively illustrated in Figure 1, the continuously moving tissue 22 can be delivered by any means known to those skilled in the art, such as the known transport systems. The continuously moving fabric 22 may include any type of layer or fabric of material such as: films, non-woven fabrics, woven fabrics which may include yarns of thermoplastic material, natural material such as cotton yarns and the like; laminated materials; or combinations thereof. As described below in more specific terms, the reactivatable adhesive is sprayed onto the continuously moving tissue 22 in a specific pattern or pattern for subsequent placement of or attached to another material (eg, after the reactivatable adhesive has been allowed to be fixed and after the input of energy - for example, in the form of heat or ultrasonic energy - to "reactivate the fixed adhesive." The other material may be the same as or different from the fabric to which the adhesive was applied. the reactivatable adhesive can be applied to both substrates, and the adhesive then allowed to be fixed, before one or both adhesives are reactivated and corresponding substrates are bonded together.Also, a substrate can be bent and bonded to itself to form a laminated structure after that the adhesive has been reactivated, 0 as described elsewhere, a substrate can be attached to an elastomeric material, such as a elastic yarn It should also be noted that the reactivatable adhesive can be applied in such a way that the adhesive is uniformly coated on the surface of the fabric.

The programmable control system 24 of the present invention is configured to send signals to the flow control system 26 which, in response to them, is configured to initiate a spraying of the reactivatable adhesive in the correct time to provide the desired adhesive pattern on the moving tissue 22. Alternatively, the reactivatable adhesive can be applied in a continuous manner, rather than in the form of discrete patterns. For example, the adhesive can be applied using a slot coater, or in a blown pattern using nozzles, or in a swirl pattern, etc. As representatively illustrated in Figure 1, the flow control system 26 includes an adhesive source 28 that is configured to deliver a reactivatable adhesive through an adhesive supply line 30 to a metering mechanism 32. The reactivatable adhesive can be supplied to the measuring mechanism 32 by any means known to those skilled in the art, such as the use of a pump.

The measuring mechanism 32 is configured to continuously supply at least one independent volumetric flow of reactivatable adhesive to a respective nozzle. As used herein, the term "volumetric flow" refers to a flow of reactivatable adhesive that has been a predetermined volumetric flow rate. Such "volumetric flow" can be provided by a positive displacement metering pump that is configured to deliver a specific volumetric flow that is independent of the manner in which the adhesive is supplied to the metering mechanism 32. As a result, for the reactivatable adhesive which is at a given density, the measuring mechanism 32 is configured to provide a predetermined mass flow rate independent of the reactivatable adhesive in each nozzle. Other adhesive processing and delivery systems use pressure to provide a flow of adhesive. Note, as indicated elsewhere, that the reactivatable adhesive can be supplied using other devices, such as a slot coater, printing operation, or other such operating unit.

The measuring mechanism 32 of the present invention can be configured to deliver a single volumetric flow of re-activatable adhesive to a nozzle or an independent volumetric flow of reactivatable adhesive to each of a plurality of nozzles depending on the number of nozzles required to provide the desired pattern (or substantially uniform application or others) of reactivatable adhesive on moving tissue 22. A suitable device for providing measurement mechanism 32 may include a positive displacement measurement pump that is commercially available from May Coating Technologies, Acumeter division, a business having offices located in Holliston, Massachusetts, under the trademark designation number 19539. The measuring mechanism 32 may include any piston pump or gear pump that are well known to those skilled in the art.

The measuring mechanism 32 can be configured to supply any desired volumetric flow rate of reactivatable adhesive to each nozzle. For example, the measuring mechanism 32 can be configured to provide a predetermined volumetric flow rate from about 1 to about 1000 cubic centimeters per minute and suitably from about 30 to about 180 cubic centimeters of reactivatable adhesive per minute to each nozzle . The measuring mechanism 32 can be configured to provide either a constant or a variable volumetric flow rate of the reactivatable adhesive to each nozzle. For example, if the measuring mechanism 32 is a positive displacement metering pump, the speed at which the pump can be controlled to vary the volumetric flow rate of the reactivatable adhesive to the nozzles.

Each nozzle 38 and 40 as representatively illustrated in Figure 1 can be any device that is capable of providing the desired pattern (or other application, such as a substantially uniform application) of reactivatable adhesive on the moving tissue 22. For example, A suitable nozzle is commercially available from Nordson Corporation, a business having offices located in Duluth, Georgia, under the trademark designation of model number 144906. Another suitable nozzle for use in the present invention is capable of being obtained from IT Dynatec Co., of Hendersonville, Tennessee, under the brand designation number 057B1639, ID # A3. Such nozzles are typically configured to be operated between an ignition position and an off position to control spraying of the reactivatable adhesive from the nozzles. When operating in the ignition position, each nozzle can be configured to spray substantially all of the volumetric flow of reactivatable adhesive that is independently supplied thereto to more adequately control the amount and pattern of the adhesive on the moving tissue. The nozzles 38 and 40 can further be configured to include air jets that can be directed to provide a desired pattern in the spraying of the reactivatable adhesive being dispensed from each nozzle. Such air jets can provide a desired reactivatable adhesive spray pattern, such as a swirl pattern of said adhesive.

After the pattern, or other arrangement, of reactivatable adhesive has been sprayed onto the moving tissue 22, the fabric can also be processed in a variety of ways. Generally the fabric will be provided with sufficient time for the supplied re-activated adhesive to be fixed: for example, solidify. The time available for the adhesive to be fixed can be reduced by the "tempering" of the adhesive (for example, by directing the fabric or substrate comprising the reactivable adhesive applied to a roll that has been cooled so as to more quickly reduce the temperature of the adhesive. applied, by directing cold air jets towards the fabric or substrate, etc.). After the reactivatable adhesive has been fixed, the fabric can be directed to a wire feeder such that the fabric comprising the reactivatable adhesive is wound to form a roll of said fabric.

The reactivatable adhesive can also be applied to other components of a disposable absorbent article or a personal care item for health, hygiene or environmental applications. For example, a reactivatable adhesive can be applied to an elastomeric component, such as a film or yarn. With reference to Figures 2, 4 and 4A, another aspect of the invention may include the movement of a yarn of material, such as the material yarn shown 122, at a selected speed along its direction to the designated machine. A substantially continuous filament 124, such as a filament of reactivatable adhesive, can be directed onto the material yarn (which, optionally, can be under tension) along an oscillating filament path 126, and the filament 124 can be arranged to provide a plurality of filament yarns extending, or otherwise disposed, from the opposite side side regions 130 of the material yarn 122. A total jet 132 may also be directed to operatively string or otherwise wrap the yarns. filament yarns around the material yarn 122. Desirably, a majority of filament yarns are wrapped around their corresponding yarn of material. More desirably, substantially all filament yarns are wrapped around their corresponding yarn 122.

In particular aspects of the invention, the filament can be arranged to provide a plurality of overlaps between the filament 124 and its corresponding yarn 122. The overlap can, for example, generally extend crosswise of the yarn, and can be arranged in a selected series or another pattern along the length in the machine direction, longitudinal of its corresponding thread. In other aspects of the invention, the air jet 132 may be directed to break or otherwise separate the filament 124 into segments of yarn which are cross-linked in alignment on their corresponding yarn of material.

In yet other aspects, directing the substantially continuous filament of the reactivatable adhesive 124 on the material yarn 122 can provide the filament yarns in the form of a plurality of filament arcs 126 extending from or otherwise disposed in the regions of lateral side 130 of the material yarn 122. Desirable arrays of the adhesive filament can provide a plurality of substantially continuous filament arcs, and the arcs can be arranged in an alternating, stepped pattern with respect to their corresponding individual yarn of material. In other aspects, the technique of the invention can further include a contact of the material and wrapping wire of the reactivatable adhesive after the adhesive has been allowed to be fixed, on a selected substrate, such as the base layer 142, to form a compound of the invention. substrate 140. A power source, e.g., ultrasonic equipment, heat transfer equipment such as a heated roller or heated etched roller, rotary high-speed pressure bonding equipment, or other joining operation (not shown) is used to activate the adhesive so that it can be used to adhere the yarn to the substrate, as noted above, this can be done in such a way that the adhesive is re-activated in discrete or intermittent locations to help optimize the balance of strength / integrity , softness / flexibility, and elasticity sought. Alternatively, the reactivable adhesive material and wrapping yarn are not immediately applied to a substrate, but instead are given sufficiently long for the reactivatable adhesive to be fixed before the yarn is re-wound to form the reel or coil of the reagent. yarn wrapped in the reactivatable adhesive. As mentioned above, a roller that is cooled, hot air jets, or other unit operations can be used to accelerate the reduction of the temperature of the adhesive so that it sets more quickly.

A suitable energy source, as representatively shown by applicator 154, can direct a single, substantially continuous filament 124 of the desired material onto each individual strand of material 122 along an individual oscillating filament path 126. In the array representatively shown, the selected filament is composed of reactivatable adhesive. The position of the adhesive filament 124 is reciprocated in a back-and-forth movement, substantially continuous to provide the desired path of the desired oscillating filament 126 which crosses over the material yarn 124 and extends past the opposite side-side regions in the direction 130 cross of the thread. The combination of the path of the oscillating filament and the movement in the machine direction of the material yarn can cooperate to form a plurality of filament yarns, such as the representatively displayed filament arcs 128, which are arranged serially and which they extend from regions of the laterally opposite side 130 of each individual thread of material. With respect to each individual thread of material, the placement of the resulting series or sequences of filament arcs from one side of the material yarn to the other side of the yarn. Along the direction to the longitudinal wire machine, the immediately adjacent arcs are slid and staggered from each other by approximately half a cycle of their corresponding path of the oscillating filament 126.

The desired air jet 132 can be provided by any conventional air steering mechanism, such as a nozzle, tube, orifice, ring, baffle, blade, or the like, as well as combinations thereof. With reference to Figure 2, the mechanism for supplying the air jet 132 can include a system of air jet nozzles 135 which are separately constructed from the first applicator 154. Alternatively, the air jet nozzles 135 can be configured as integrated parts. or components of the first applicator 154 (e.g., Figures 2 through 3B). There may be an air jet nozzle, or a plurality of air jet nozzles as described in Figures 3 and 3B.

The applicator 154 may, for example, include a system of air jets which extrude or otherwise assist in drawing the desired adhesive filament 124 from the applicator. The air jet system can also be used to substantially simultaneously provide the desired air jets 132 to wrap the desired portions of the reactivatable adhesive filaments 124 around their corresponding strands of material 122. Consequently, directing the air jet can to be conducted in cooperation with the directing filament of reactivatable adhesive. In various configurations of the invention, each air jet 135 (either one or a plurality) and its corresponding air jets 132 can be oriented generally perpendicular to the local direction of the machine 134. In particular arrangements of the invention, the jet of air 135 and the associated air jets 132 may be selectively inclined or otherwise angled along the machine direction, and the amount of angle may be within the range of about ± 45 degrees relative to a line which is perpendicular to the direction to the machine, as representatively shown in Figure 2.

With reference to Figures 2 and 3, particular aspects of the invention can provide a selected opening distance 150 between applicator nozzles 104 and their corresponding material yarns 122 (also yarns 156, and / or 162). In particular aspects, the nozzle to wire opening distance 150 can be at least a minimum of about 4 millimeters. The nozzle to wire opening distance can alternatively be at least about 8 millimeters, and optionally, can be at least 12 millimeters to provide improved performance. In other aspects, the nozzle to wire opening distance 150 may be no more than a maximum of about 28 millimeters. The nozzle to wire opening distance may alternatively not be more than about 24 millimeters, and optionally, may not be more than about 20 millimeters to provide improved effectiveness. For example, the distance between nozzle and wire 150 may be important to regulate the size and distribution of the filament yarns or arcs 128 along the lateral side regions of each yarn of material.

In another aspect of the invention, the technique can provide an opening distance 152 between the material yarns and their associated substrate layer (if any, as described above, in an embodiment of the invention, the elastomeric material treated with the reactivatable adhesive is directed to a rewind yarn for rewinding the elastomeric material after the reactivatable adhesive has been set with any optional acceleration of the actuation time used, eg, a cold roll), such as the base layer 142 and / or the laminated composite 148. In desired configurations, the opening distance 152 may be at least a minimum of about 3 millimeters. The opening distance may alternatively be at least about 4 millimeters, and optionally, it may be at least about 5 millimeters to provide improved performance. In other aspects, the opening distance 152 may be no more than a maximum of about 12 millimeters. The opening distance may alternatively be no more than about 9 millimeters, and optionally, may be no more than about 7 millimeters to provide improved effectiveness. For example, the opening distance of the yarn substrate 152 should be of sufficient length to obtain the desired wrapping of each individual adhesive filament 124 around its corresponding yarn of material.

Still other aspects of the invention can provide a selected separation distance in the machine direction 166 between the location of applicator nozzles 104 and the location of their associated assembly mechanism (e.g., assembly roller), or in some embodiments, a rewind yarn for rewinding to the yarn comprising the reactivatable adhesive. In particular aspects, the separation distance 166 may be at least a minimum of about 15 centimeters. The separation distance 186 may alternatively be at least about 20 centimeters, and optionally, may be at least about 25 centimeters to provide improved performance. In other aspects, the separation distance 166 may be no more than a maximum of about 200 centimeters. The separation distance 166 may alternatively be no more than about 125 centimeters, and optionally, may be no more than about 25 centimeters, to provide improved effectiveness. For those embodiments where the elastomeric material comprises of a reactivatable adhesive is not applied to a substrate, but is rewound, then the distance 166, coupled with the linear speed of the yarn in the direction of displacement 194, must allow sufficient time for the Reactivable adhesive is fixed before the elastomeric material is rewound.

For those embodiments where the yarn comprising the reactivatable adhesive is applied to a substrate 142, then the nozzle assembly, the separation distance 166 is desirably selected to allow the reactivatable adhesive to be fixed before contacting the substrate with concurrent energy input. to reactivate the adhesive in a location close to the wire being attached to the substrate. In particular aspects, the time between the application of the reactivatable adhesive filament and the material thread assembly can provide a time of the applicator assembly that is at least a minimum of about 0.003 seconds. The time of the applicator set may alternatively be at least about 0.004 seconds; and optionally it can be at least around 0.005 seconds to provide improved performance. Other times it may be selected to provide sufficient time for the reactivatable adhesive to be fixed. And again, as noted elsewhere, a cold roll directs cold air flows, or other equipment can be used to accelerate the rate at which heat is conducted from the adhesive (for example, the rate at which the adhesive temperature decreases) such that the adhesive sets more quickly.

With reference to Figures 3 to 3B the applicator 154 may include a plurality of nozzles of the applicator 104, and each of the nozzles of the applicator may have an associated system of immediately adjacent air jets 135. The nozzles of the applicator 104 and the air jets 135 are generally aligned along the local cross direction 136, and each nozzle of the applicator 104 has a cooperating pair of air jets 135. An air jet is located on each side side in the cross direction of the corresponding applicator nozzle, and each air jet is oriented generally perpendicular to the direction to the local machine 134. In particular arrangements of the invention, the air jets 135 and their associated air jets 132 can selectively be filled or otherwise put into angle along the cross direction, and the amount of the angle may be within the range of about ± 15 degrees relative to the line which is perpendicular to the address to the local machine (for example, Figure 3B). In desired arrangements, each air jet can be filled by the selected angle to direct its air jet in a direction that is inclined towards its corresponding nozzle of the applicator.

In the various configurations of the invention, the desired temperature of the reactivable adhesive employed may depend on the particular composition of the adhesive material. It has been found that a warmer temperature provides a relatively better distribution pattern of the reactivatable adhesive filaments 124. If the temperature of the adhesive-reactivatable, however, is very high, the adhesive may excessively degrade and the filament of reactivable adhesive 124 may exhibit excessive breaking.

In particular aspects, the filament material 124 may be provided at a viscosity that is at least a minimum of about 1,000 centipoise (at a temperature of 160 degrees centigrade). The viscosity may alternatively be at least about 12,000 centipoise, and optionally may be at least 16,000 centipoise to provide improved performance. In other aspects, the viscosity may not be more than a maximum of about 50,000 centipoise. The viscosity may alternatively be no more than about 22,000 centipoise, and optionally, may be no more than about 19,000 centipoise to provide improved effectiveness. It should be noted that for some materials, for example materials comprising acetate vinyl ethyl, the viscosity of the material at 350 degrees Fahrenheit can reach 100,000 centipoise, suitably 250,000 centipoise, or even higher.

In additional aspects, the filament 124 may be provided at a filament speed that is at least a minimum of about 0.04 meters per second. The filament speed can alternatively be at least about 0.06 meters per second, and optionally it can be around 0.3 meters per second to provide improved performance. In other aspects, the speed of the filaments may be no more than a maximum of about 5 meters per second; properly of no more than a maximum of about meters per second; particularly of no more than a maximum of around 15 meters per second. The speed of the filaments may alternatively be no more than about 3 meters per second, and optionally, may be no more than about 1.4 meters per second to provide improved effectiveness.

The air pressure supplied to one or more applicators of the reactivatable adhesive can be provided at a selected pressure. In particular aspects, directing the air jet 132 may include an expedition of the air jet under an air pressure that may be at least a minimum of about 7 kilo-pascals (caliber). The air pressure can alternatively be at least about 20 kilo-pascals, it can be at least about 27 kilo-pascals to provide improved performance. In other aspects, the air pressure may be no more than a maximum of about 140 kilo-pascals. The air pressure may alternatively be no more than about 103 kilo-pascals, and optionally may not be more than about 55 kilo-pascals to provide improved effectiveness.

If the pressure is very low, the filaments of adhesive 124 may not be distributed in the desired oscillating pattern, and there may be insufficient wrapping of the reactivatable adhesive filaments around their corresponding strands of material. A relatively higher pressure can provide a greater distribution pattern over a greater distance in the cross direction. Higher air pressure, however, can produce a finer, relatively smaller diameter adhesive filament 124, but higher air pressure can generate excessive "blowing" of the reactivatable adhesive in a gap outside of the corresponding material yarns.

In particular aspects, directing the air jet 132 can provide an air jet velocity that is at least a minimum of about 38 meters per second. The speed of the air jet can alternatively be at least about 190 meters per second, and optionally it can be at least about 380 meters per second to provide improved performance. In other aspects, the speed of the air jet may not be more than a maximum of about 3800 meters per second. The speed of the air jet can alternatively be no more than about 1900 meters per second, and optionally, it can be no more than about 800 meters per second to provide improved benefits.

Directing the filament of adhesive 124 along the path of the oscillatory filament 126 may extend over a total crossing distance in the cross direction 138 (eg, Figure 4) which may be at least a minimum of about 0.01 centimeters . The crossing distance may alternatively be at least about 0.1 centimeter, and optionally, may be at least about 0.2 centimeter to provide improved performance. In other aspects, the crossing distance may be no more than a maximum of about 0.6 centimeters. The crossing distance may alternatively be no more than about 0.5 centimeters, and optionally may be no more than about 0.4 centimeters to provide improved effectiveness. In desired configurations, the path of the oscillatory filament 126 may operatively pass through the filament 124 by passing both the laterally opposite lateral regions 130 of the selected material yarn by substantially equal distances.

In still other aspects, the path of the filament 126 can be configured to reciprocate from back to front at a crossing frequency which can be at least a minimum of about 100 hertz. The frequency may alternatively be at least about 500 hertz, and optionally may be at least 1,000 hertz to provide improved performance. In other aspects, the frequency can be no more than a maximum of about 10,000 hertz. The frequency may alternatively be no more than about 6,000 hertz, and optionally, may not be more than about 4,500 hertz to provide improved effectiveness. In a desired configuration, the frequency can be around 1200 hertz.

Directing and depositing the filament of the reactivatable adhesive 124 in the selected yarn of material can provide an added adhesive which can be at least a minimum of about 0.004 grams of reactivatable adhesive per meter in length of the corresponding yarn material (grams / meter) . The added reactivable adhesive may alternatively be at least about 0.008 grams per meter, and optionally, may be at least about 0.012 grams per meter to provide improved performance. In other aspects, the added reactivable adhesive can be no more than a maximum of about 0.24 grams per meter. The added reactivable adhesive may alternatively be no more than about 0.07 grams per meter, and optionally, may be no more than about 0.04 grams per meter to provide improved effectiveness.

The air jet 132 may be operably directed to wrap a substantial majority of the filament arcs 128 around its corresponding strand of material 122. In particular aspects, directing the air jet 132 may operatively deposit and maintain at least about 60% of the filament yarns or arcs 128 on their corresponding yarns of material (e.g., yarns 122, 156 and / or 162). Alternatively, directing the air jet 132 can operatively deposit at least about 75% of the filament yarns on its selected yarns of material, and optionally it can operatively deposit at least about 90% of the filament yarns on its selected yarns. of material. In desired configurations, directing the air jet can operatively deposit substantially 100% of the filament yarns on their selected yarns of material.

In other aspects, directing the air jet 132 can be configured to disengage no more than about 40% by weight of the directed reactivatable adhesive away from the corresponding yarns of material. The directing of the air jet can alternatively disengage no more than about 25 percent by weight of the directed reactivatable adhesive out of the material yarn, and optionally, can disengage no more than about 10 percent by weight of the directed reactivatable adhesive outside of the corresponding threads of material.

In other aspects, the movement of the selected yarn of material can provide a yarn speed that is at least about 0.05 meters per second. The wire speed can alternatively be at least about 0.25 meters per second, and optionally, it can be at least about 3 meters per second to provide improved performance. In other aspects, the wire speed can be no more than a maximum of about 10 meters per second. The wire speed can alternatively be no more than about 6 meters per second, and optionally, it can be no more than about 5 meters per second to provide improved effectiveness.

While various aspects or features of the invention have been described with respect to the particular applicator 154, it should be readily apparent that such features can be incorporated into various locations within the technique of the invention. For example, the features may be additionally or alternatively incorporated in the locations of the applicators 158 and / or 164. Suitable applicator devices may include an IT model device, OMEGA UFD, as previously described in detail.

Of course, as noted above, the reactivatable adhesive can be applied in other ways. For example, the adhesive can be applied to a component using an extruder, slot coater, or other equipment to conduct and deliver the heated material to a component such as a substrate or yarn. Alternatively, the reactivatable adhesive can be a meltblown in a substrate or fabric.

It should be noted that the above examples are just a few versions of the present invention by which a reactivatable adhesive can be applied to a fabric, component, composite, and / or yarn. Other processes may be used, so long as they result in a fabric, component, composite, or yarn that has been treated with a reactivatable adhesive and allow sufficient time for at least some part of the reactivatable adhesive to be fixed. Then, upon inputting energy to activate the adhesive, the fabric, component, composite, or yarn can be attached or glued to some other fabric, component, composite, or yarn. Before the reactivable adhesive is activated, the fabric, component, composite or yarn can conveniently be handled without having to accommodate the agglutinate normally present in hot melt adhesives liquefied. Further, if the fabric, component, composite, or yarn comprising the reactivatable adhesive is unwound in a process different or separate from that to which the fabric, component, composite, or yarn was prepared, then the fabric, component, composite, or yarn comprises the reactivatable adhesive that can be conveniently bonded to other materials without the problems or issues that concern the liquefied and apply the hot melt adhesive in the same location of the process.

The reactivatable adhesive can be applied by an extruder, drum discharger, grinding melter, in the form of meltblown / spray / groove coating on a fabric, such as an elastic film. The coated elastic film is rolled up, transferred to the product conversion line, and then unrolled, cut into a slot in patches and placed on the fabric of the product. The coated elastic film is then activated via thermal bonding, pressure, ultrasonic bonding, or other means and attached to the product.

The reactivatable adhesive can be applied by spraying cast melt (MB), slot coating, printing, dripping, threading, swirling, engraving, or scratching on one or both surfaces of a fabric, including a film or laminate. The method of rolling, transferring, and reactivating in conversion as previously described can be used to incorporate the elastic member in the product.

Representative Versions of Processes for Making Higher Order Sets Comprising a Fabric, Component, Compound, and / or Thread Comprising a Reactivable Adhesive In the description that follows, representative versions of processes for making higher order assemblies (e.g., a product, or a subset in a product) comprising a fabric, component, composite, and / or yarn comprising an adhesive reactivatable are described. It should be understood that, this description is given as an example. Other processing methods and equipment can be used to prepare such assemblies, including, for example, disposable absorbent products and / or articles for personal care for health, hygiene or environmental applications.

Once a fabric, component, composite, or yarn comprising a reactivatable adhesive has been prepared, it must be used in a variety of ways such as in the construction of disposable absorbent articles. Alternatively, the fabric, component, composite, or yarn can be used for various articles for personal care for hygiene, health and / or environmental applications. Examples of such articles and devices include, but are not limited to, diapers, baby wipes, underpants, swimming shorts, and other related garments and disposable products.; female care products, including sanitary napkins, wipes, menstrual pads, panty liners, panty shields, catamenial items, inter-labial inserts, tampons, tampon applicators, menstrual garments, and / or other disposable garments and related products; adult care products, including cleansing wipes, pads, containers, incontinence products, incontinence garments, urinary shields, and other disposable garments and related products; service, industrial and home products, including wipes, towels, bath tissue, paper towels, hand towels, napkins, facial tissue, and related clothing and products; non-woven materials, including nonwoven roll goods, and other related disposable products; products for the comfort of the home, including cushions, pillows, pillows, masks, and other related disposable products; body care products, including products for the cleaning or treatment of skin and other related disposable products, such as related products for spas; products for professional and consumer health care, including products to apply cold or hot therapy, wraps or supports for joints or other parts of the body, surgical covers, health products-upper respiratory, products for the control of infections , products for temperature management, face masks, hospital gowns, wipes, wraps, covers, containers, filters, and other disposable clothing and related products; products for household cleaning; and similar.

The fabric, component, composite, or yarn can be used in any health and hygiene product, such as a disposable absorbent article. The main difference between the use of the present invention, and past practice, is that the present invention is directed to a tissue, component, composite, or yarn in which the reactivatable adhesive has been allowed to be fixed, thereby facilitating the handling of the Woven, component, composite, or yarn before the adhesive is activated. Furthermore, the present invention allows for the selectivity in activating these desired adhesive parts or locations for the article of manufacture. As noted above, generally, in a location where two components are joined by an adhesive, that location - which comprises the combined combination of two components and the adhesive - is thicker and stiffer than those locations where the two components remain unbound . Greater the number of such binding locations, the greater the similarity that the resulting composite comprising these two components stuck together is stiff. By using processes to selectively input energy such as thermal point bonding or ultrasonic unit operations, the reactivatable adhesive can be activated at only these locations desired by the manufacturer.

If the preparation of the component comprising a reactivatable adhesive is decoupled from the process by which a compound or product is made with said component, other benefits may be realized. First, if desired, the speed at which the component comprising a reactivatable adhesive is prepared can be different than the rate at which the compound or product employing said component is made. Thus, for example, the speed at which the component is prepared may be slower to achieve a more uniform coating of the reactivatable adhesive or for another desired benefit. At a slower speed it is also allowed for an increased time for the reactivatable adhesive to be fixed before the component is rolled up or accumulated in some other way before use when a higher order assembly comprising the component is made (by example, a product). Second, by decoupling these processes, a manufacturing operation whereby a product employing a component comprising a reactivatable adhesive is made can be more efficient, clean, or simple. Also, the process decoupling facilitates a company to make and sell the component comprising a reactivatable adhesive and another company to buy and use said component in a product.

Another benefit generally, in some cases, is the possible reinforcement of the component to which the reactivatable adhesive is applied. Thus, for example, applying a reactivatable adhesive comprising a mixture of atactic and isotactic polypropylene materials can serve to reinforce the substrate to which it is applied, such as a nonwoven material comprising a polypropylene fiber. As noted above, the reactivatable adhesive can be formulated in such a way that its softening point is less than the softening point of the material to which the adhesive is applied. In this example, the mixture of atatotic and isotactic polypropylene polymers can be selected such that the mixture has a softening point that is less than that of the polypropylene fiber used in making the substrate. In this way the adhesive, when applied at or above its softening temperature, is less likely to degrade to the substrate. In addition, when the adhesive is re-activated, the input energy can be selected such that the adhesive becomes tacky (for example, it begins to liquefy), but the substrate maintains its integrity (for example, substantially maintains its solid form). Mixtures of amorphous and crystalline polymers for binding are described in U.S. Patent Application Serial No. 00 / 259,037, entitled "Hot Melt Adhesive Based Mixture of Amorphous and Crystalline Polymers to Join Multiple Layers", filed on December 29, 2000. This application is incorporated by reference in its entirety in a manner consistent with this.

Fabrics, components, composites, and yarns comprising a reactivatable adhesive can be incorporated into a number of compounds or products. Examples of such disposable absorbent articles and / or articles are disclosed in U.S. Patent No. 4,940,464, entitled "Pledge for Disposable Incontinence or Underpants," which is hereby incorporated by reference in its entirety; U.S. Patent No. 5,904,675, entitled "Absorbent Article with Improved Elastic Margins and Containment System", which is hereby incorporated by reference in its entirety, with column 7, lines 7 through 34, describing the use of elastic threads with a containment fin, and column 9, line 20 to column 10, line 26, which describes elastic members; U.S. Patent No. 5,904,672, entitled "Absorbent Article having improved Wax Region Drying and Manufacturing Method", which is hereby incorporated by reference in its entirety, with column 11, line 39 a column 12, line 2, which describes the elastic leg members; and U.S. Patent No. 5,902,207, entitled "Absorbent Article Having a Collection Duct", which is incorporated herein by reference in its entirety. It should be understood that the present invention is applicable to other structures, compounds, or products that incorporate one or more elastic threads.

As noted above, the tissue, component, composite, or yarn comprising a reactivatable adhesive will be exposed to thermal, infrared, ultrasonic, or other energy binding in subsequent joining operations or processing steps. For example, at a location proximate the location to which a yarn comprising a reactivatable adhesive is bonded to a substrate, the yarn or combination of the yarn and the substrate, may pass through an operation of the bonding unit ultrasonic where the thread, the substrate, or both are exposed to ultrasonic energy. With reference to PCT international publication number WO 995290, which is hereby incorporated by reference in its entirety in a manner consistent with this document, the publication discloses the use of ultrasonic bonding to form side seams or seals in the underpants. disposable (see, for example, page 29, lines 10-25; further details regarding the formation of such side seals is described in U.S. Patent No. 4,610,681, which was issued September 9, 1986). , and is entitled "Disposable Underpants Having Discrete Outer Seals", and which is hereby incorporated by reference in a manner that is consistent with this, and U.S. Patent No. 4,641,381, which was granted February 10, 1997, and is entitled "Disposable Underpants such as Underpants for Children and Similar", which is also incorporated by reference in a manner consistent with this document).

Specific examples of composite materials, laminates, and disposable absorbent articles with which reactivatable adhesives of the present invention can be used are described in the following patents and patent applications of the United States of America numbers: 4,798,603 granted on January 17, 1989 to Meyer and others; 5,176,668 granted on January 5, 1993 to Bernardin; ,176,672 issued on January 5, 1993 to Bruemmer and others; 5,192,606 granted on March 9, 1993 to Proxmire et al .; 5,904,675 titled "Absorbent Article with Improved Elastic Margins and Containment Systems". Each of the foregoing patents of the United States of America is incorporated by reference in its entirety and in a manner consistent with this document. It should be understood that the present invention is applicable to other structures, compounds, or products incorporating the reactivable adhesive compositions of the present invention.

Representative Versions of Reactivable Adhesive Compositions Reactivable adhesives can be prepared using a variety of chemistries. Chemistry can be selected based on its ability to adhere to, and function as an adhesive with, the tissues, components, composites, or yarns that are anticipated to join one another. One criterion for the selection is the smoothing point of the selected chemistry of the reactivatable adhesive compared to the softening points of the fabrics, components, composites or yarns to be treated with said adhesive. Frequently the chemistry will be selected in such a way that the reactivatable adhesive has a lower softening point compared to the softening points of the materials to be treated with the adhesive. When selecting the chemistry of the reactivable adhesive so that it does not have a lower softening point compared to the softening point of the materials to be treated with the adhesive (as well as other materials that will be attached to the fabric, composite, component, or yarn) comprising the reactivatable adhesive), the amount of energy necessary to activate the adhesive is decreased. In addition, the integrity of the fabric, composite, component, or yarn to which the adhesive is associated (as well as the integrity of the other materials that will bind to the fabric, composite, component, or yarn comprising the reactivatable adhesive) is maintained, in that the energy input is sufficient to activate (for example, make it binder) the reactivatable adhesive, but it is not high enough to soften and / or melt the other materials that are being bonded. In some versions of the invention, the chemistry of the reactivatable adhesive is selected to have a smoothing point of between about 60 degrees centigrade and about 160 degrees centigrade. Suitably the smoothing point or temperature is between about 60 degrees centigrade and about 150 degrees centigrade. The softening point or temperature can also be between around 60 degrees Celsius and around 140 degrees Celsius. Alternatively, the softening point of the reactivatable adhesive may be between about 60 degrees centigrade and about 130 degrees centigrade. 0 the softening point of the reactivatable adhesive can be between about 60 degrees centigrade and about 100 degrees centigrade.

Possible polymers for use in reactivatable adhesive compositions include, for example, ethylene vinyl acetate (EVA) copolymers, ethylene methyl acrylate (FMA), amorphous poly-alpha-olefin olefins (APAO), isotactic polypropylene (I-PP), polypropylene atactic, high melt flow rate thermoplastic elastomers, such as styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-ethylene-butene-styrene (SEBS), styrene-ethylene-propylene- styrene (SEPS), metallocene polyethylene copolymerized with octane and / or butane and / or hexane, as well as other additives (binders, plasticizers, and antioxidants), commonly incorporated in adhesives, and the like, including combinations of the foregoing.

One version of a reactivatable adhesive comprises atactic polypropylene or poly alpha-olefin (APAO) (eg, 0-80% by weight of, for example, Eastman P1010 or P1023, both of which are amorphous polypropylene, available from Eastman Chemical Company, a business with offices in Kingsport, Tennessee, Rextac 2115, another amorphous or atactic polypropylene, available from Huntsman Polymer, Co., A business with offices in Houston, Texas, high melt crystalline polypropylene (for example, 5-30) % by weight of, for example, Sunoco CP15000P) (melt flow rate from 500 to 2000), available from Sunoco Corporation, a business with offices in Pittsburg, Pennsylvania, or from Exxon PP 3746G, available from ExxonMobile Chemical Company, a business with offices in Houston, Texas, styrene-ethylene-propylene-styrene (SEPS) of high melt flow and / or styrene-isoprene-styrene (SIS), thermoplastic elastomers, metallocene polypropylene / polypropylene, and / or ethylene-vinyl acetate up to 30% by weight (for example, from Septon Polymers, available from Kurary Limited, of Japan; Kraton polymers, available from Kraton Polymers, Inc., of Houston, Texas; Styrene-isoprene-styrene (SIS) Exxon Dexco polymers, available from ExxonMobile Chemical Company, of Houston, Texas; ESCORENE ULTRA, also available from ExxonMobile; Dupon Dow: Engage 8400 series, ELVAX 240, available from E.I. DuPont de Nemours & Company, of Wilmington, Delaware), are agglutinizers (20-65% by weight, eg, Escorez series from ExxonMobile, H-100 from Eastman Chemicals), or other hydrocarbon resins from petroleum distillates, rosin and / or rosin esters , polyterpenes derived from wood or from synthetic chemicals. Other additives (0-10% by weight) such as antioxidants (Irganox 1010, from Ciba Specialty), colorant / filler (for example, titanium dioxide or CaCo3), and viscosity modifiers (0-20%) such as mineral oil , can be used in the adhesive formula.

EXAMPLES Example 1 A spunbond-meltblown-spunbond (SMS) bonded material of 0.65 ounces per square yard, available from Kimberly-Clark Corporation, was previously coated by spraying a reactivatable adhesive, in this case a polypropylene-based adhesive material. , at added levels of 5.6 and 7.5 grams of adhesive per square meter of material (for each of the two spray nozzles, see description below). The spunbond-melt-spunbonded (SMS) -bonded material was a polypropylene melt blown layer sandwiched between two layers of polypropylene spunbonded, and has a melting point of about 170 degrees centigrade. The reactivatable adhesive polypropylene material, designated SA-15s, was formulated by combining the following materials in the aforementioned proportions (listed in percentages by weight): 30% P1010 (an atactic polypropylene available from Eastman Chemical); 17% of 3746G (a crystalline polypropylene available from ExxonMobil), 45% of Escorez 5380 (a hydrocarbon glutinizer, available from ExxonMobil), 7.5% Septon 2002 (styrene-ethylene-propylene-styrene material (SEPS) known as Septon polymer) , available from Kurary Ltd., Japan) and 0.5% Irganox 1010 (an antioxidant material, available from Ciba Specialty Chemical). The reactivable polypropylene adhesive has a softener point of about 312 degrees Fahrenheit, determined using the E28 test, from the American Society for Testing and Materials (ASTM).

The spunbond-melt-spunbonded (SMS) -bonded material was unwound at a rate of about 100 feet per minute. The fabric has a width of 126 millimeters. The fabric of material was directed to a conventional equipment for melting and spraying a hot melt adhesive on a fabric. The SA-15s polypropylene formula, which as noted above, has a smoothing point of around 312 degrees Fahrenheit was determined using the E28 test, from the American Society for Testing and Materials (ASTM) (a one-point determination). smoothed using a ring and ball apparatus), was heated and sprayed on the fabric at each of the identified levels of addition (eg, at 5.6, and 7.5 grams per square meter) for each of the two nozzles. The reactivated heated adhesive was sprayed through two nozzles, the tips of which were approximately 3.5 inches from the surface of the fabric. The two nozzles were arranged in such a way that two, 1-inch-wide strips of a blow-type pattern with random fusion of adhesive were sprayed onto the tissue surface at the edge of the fabric (leaving an uncoated line of 75). millimeters in the middle of the tissue between the two one-inch-wide bands of reactivatable adhesive, with each of the bands at the edge of the fabric). The fabric was then directed to, and contacted to a cooled roller, to accelerate the cooling, and thus the fixed, of the reactivatable adhesive. The surface of the fabric leading to the adhesive contacts the surface of the cooled roller. The previously coated fabric was then rolled into a roll, with the time between the application of the reactivatable adhesive and the winding of the roll being about 1-2 seconds or so.

A laboratory scale ultrasonic linker, Branson 931 Smart Activator, available from Branson Ultrasonics Corporation, of Danbury, Connecticut, was then used to sandwich the elastic yarns between the two layers of the melt-bonded spin-bonded pre-coating material. with spinning (with a reactivable adhesive of previous coating oriented inwards towards the elastic threads). The equipment was operated at a pressure of 350 kilopascals and with a residence time of around 0.05 to 0.1 seconds (dwell time refers to the contact time between the horn and the anvil of the laboratory scale ultrasonic attachment). A thread of Lycra Xa (T151) (with a linear density of 1100 decitex), available from Invista, which has offices in Wichita, Kansas, was stretched to 250% and interspersed while in a stretched condition, between two layers of 0.65 ounces per square yard of spunblown-melt-bonded yarn-bound material (SMS ) of previous coating, with the reactivable adhesive of previous coating oriented inwards towards the Lycra yarn. The anvil pattern consisted of protruding points from the surface of the anvil, with each point being approximately 1 millimeter in diameter. The points were uniformly located across the surface of the anvil, with the distance between points in a given row being around 5 millimeters. The distance between the individual rows of points was around 2.5 millimeters. The percentage of joint area, for example, that percentage area of the anvil equaling the total area of the raised points that protrude from the surface of the anvil, was around 6%. In addition, the density of the raised points was around 8 per square centimeter.

It should be noted that if ultrasonic equipment is used for the input energy to reactivate the reactivatable adhesive; Many other patterns can be selected, both for decorative and functional reasons. As noted above, an advantage of the present invention is the ability to effect discrete binding locations and binding patterns. Consequently, when the ultrasonic equipment is used, different shapes, lines, or other raised configurations can be used to reactivate the reactivatable adhesive. In addition, the density and / or% of the bonding area of these shapes, lines and other raised configurations can be changed, depending on the properties sought for the composite using the reactivatable adhesive (e.g., balancing stretch, softness, and compound integrity). ).

We qualitatively tested the resulting compounds by repeatedly stretching these to their maximum stretch. These representative compounds of the invention remained intact during repeated stretching - for example, each had integrity and was adapted for use in an elastomeric material to be used in higher order assemblies. The compounds made using the lowest level of aggregate (5 grams per square meter of adhesive that can be activated again) and the lowest residence time (0.05 seconds) were fixed and worked well.

We compared the compounds of the invention with a compound prepared in the same manner using the ultrasonic equipment at laboratory scale, but without the SMS material being pre-coated with an adhesive that can be reactivated. Under the same ultrasonic operating conditions, we were able to attach the Lycra thread to the SMS material. When attempting to attach the Lycra material to the SMS material without an adhesive that can be activated again under more vigorous ultrasonic operating conditions, for example longer dwell times exceeding 0.1 seconds, the Lycra yarn failed (e.g. enough was inserted into the yarn so that its polymeric constituents began to flow, thereby facilitating the separation of the yarn).

Example 2 An SMS material (spunblown-melt-bonded with yarn) of 0.65 ounces per square yard, available from Kimberly-Clark Corporation, was pre-coated in the same manner at the same aggregate levels, and using the same adhesive as can be reactivated described in Example 1. But instead of making a representative compound of the present invention using laboratory scale ultrasonic equipment, a roll of the pre-coated SMS material was cut slits in half along its length. length so that the two tissues of the SMS material previously coated, each with a single band of adhesive were formed. These two tissues of the pre-coated SMS material were placed on unrolling pedestals, with the tissues being unwound and directed, at a line speed of about 390 feet per minute, to the ultrasonic bonding equipment. Each of the two fabrics were bent to form a flattened "J" shape: For example a flat linear part of the "J" shape contiguous with a lower "U-shaped" part, with each corresponding band of adhesive that it can be reactivated by being bent so that the adhesive was located on the inwardly directed and opposite surfaces of the "U-shaped" bottom of the "J". In this manner, the adhesive on one part of the inwardly directed surface will contact one thread and the adhesive on the other part of the same surface directed inwardly but opposite to the lower part of the U-shape of the tissue of "shape". of J ". Prior to the fabrics and the opposing surfaces of re-activated adhesive located on the inner surface of the U-shaped bottom of the "J-shaped" tissue they made contact with each other between the horn and the anvil of the ultrasonic equipment, two threads of Lycra XA (T151) from Invista (with a linear density of 1,100 DeciTex) were unrolled, stretched to an elongated length that was 250% longer than the length of the yarn in its rolled / spool form, and placed as described above, with a thread wrapped inside each U-shaped bottom part of the "J-shaped" fabric. For example, the yarn was placed so that it was in the form of a sandwich between the re-activated adhesive located on the opposite inner surfaces of the U-shaped bottom of the "J-shaped" fabric. Both tissues, and the corresponding threads, were fed into the ultrasonic equipment so that the adhesive that can be reactivated on the opposite inner surfaces of the U-shaped bottom of the "J-shaped" fabric became tacky, joining thus, and having the yarn in the form of a sandwich between the adhesive layers that can be reactivated to form a U-shaped, flat, bottomed portion of the "J" shaped fabric (for example an elastomeric compound in which the elastic yarn was attached at discrete locations along its length to the SMS material).

The ultrasonic equipment included a DuKane 3005 Auto Trace ultrasonic unit, 240 volts with a 20 kilohertz generator and a 2-inch horn. As with the bench scale ultrasonic equipment discussed in Example 1, an anvil with a high-point pattern was used to reactivate the adhesive that can be reactivated. The equipment was operated at an anvil load pressure of 32 pounds per square inch and a dwell time of about 0.05 to 1 millisecond. After the resulting composite left the operation of the ultrasonic unit, it was incorporated into a disposable absorbent article for conventional personal care, in this case a diaper by adhesively bonding the composite along its non-elasticized edge to the remaining part of the other diaper components. The compound was bound while in its fully elongated state, and then allowed to retract once attached to the other diaper components. As stated above, a diaper is a version of a health and hygiene device that may employ various embodiments of the present invention.

The rotating ultrasonic union has a pattern consisting of nine angled bands of point-joined regions, equally spaced (1,075 millimeters apart) along the axis of the yarn location, and the end capped by two more densely packed regions and larger points of union. The flat placement of the bonding pattern can further be described as follows: a continuous sealing joint consisted of a broken chevron pattern with a width of 0.289 millimeters to join the free ends of the SMS nonwoven material. The rotating union pattern had an overall circumference of 33.88144 millimeters. A distance of 6,143 millimeters in the direction of the yarn (on the fold side) between the end cap regions for each set of functional joined areas, wherein in this region of 6,143 millimeters in width the yarns are mechanically cut at the process and are allowed to jump back to the anchor end cap joining regions.

The nine angled strips can also be described as an arrangement of 0.011 millimeter squares (with a tolerance of 0.009 millimeters) arranged in a perfectly square grid with a spacing of 0.020 millimeters (with a tolerance of 0.001 millimeters). The band is at an angle of 70 degrees from the axis of the yarn direction / placement with the outer dimensions of the parallelogram being 0.940 millimeters (in the direction of transverse filament) by 0.125 millimeters (in the direction of filament).

The two end capping band regions can further be described as solid regions with seven shaved 0.031 millimeter channels, with a slot depth of 0.015 millimeters, each of these seven shaved channels being angled at 70 ° from the axis of placement / direction of filament. After grooving, the remaining eight bands have the outer dimensions of the parallelogram being 0.040 millimeters (in the direction of transverse filament) by 0.125 millimeters (in the filament direction). The overall end cap region or regions had the following filament direction dimensions: 1,260 millimeters wide (on the bending side) and tapered at 0.75 millimeters (on the sealing joint side).

We qualitatively tested the resulting compounds by repeatedly stretching them to their maximum stretch. These representative compounds of the invention will remain intact during repeated stretching-for example each had an integrity and was adapted to be used as an elastomeric material to be used in higher order assemblies.

Claims

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

1. A process to make a compound, the process comprises the steps of: provide a first substrate; treating at least a portion of the first substrate having an adhesive having a softening point below the smoothing point of the first substrate; leave the adhesive to settle so that the adhesive is no longer sticky; winding the first treated substrate to form a roll; then unwinding the first treated substrate; inserting energy into the first unrolled treated substrate, thereby activating at least a portion of the coated adhesive on the first substrate, wherein the energy input is effected before, concurrently or after the first substrate is brought into contact with the second substrate; providing the second substrate; joining at least a portion of the first substrate to at least a portion of the second substrate to form a compound, wherein the first substrate and the second substrate are at least partially bound by the activated adhesive.

2. The process as claimed in clause 1, characterized in that not all the adhesive is activated.

3. The process as claimed in clause 2, characterized in that the adhesive is activated by ultrasonic energy.

4. The process as claimed in clause 3, characterized in that the adhesive is activated at discrete locations.

5. The process as claimed in clause 1, characterized in that the first substrate, the second substrate or both are elastomeric.

6. The process as claimed in clause 2, characterized in that the adhesive is activated by heat.

7. The process as claimed in clause 6, characterized in that the adhesive is activated at discrete locations, and where the locations are characterized by a pattern.

8. The process as claimed in clause 1, characterized in that the adhesive has a softening point between about 60 degrees centigrade and 160 degrees centigrade.

9. The process as claimed in clause 2, characterized in that the adhesive is activated by pressure.

10. The process as claimed in clause 5, characterized in that the first substrate, the second substrate or both are in a stretched condition when they are joined.

11. A process for making a compound, the compound comprises the steps of: provide a first substrate; treating at least a portion of the first substrate with an adhesive having a smoothing point lower than the smoothing point of the first substrate; allow the adhesive to settle so that the adhesive is no longer sticky; bringing energy to the first treated substrate, thereby activating at least a portion of the coated adhesive on the first substrate, wherein the energy input is effected before, concurrently or after the first substrate is brought into contact with the substrate; provide the second substrate; joining at least a portion of the first substrate to at least a portion of the second substrate to form a compound, wherein the first substrate and the second substrate are at least partially bound by the activated adhesive.

12. The process as claimed in clause 11, characterized in that the adhesive is activated by ultrasonic energy.

13. The process as claimed in clause 11, characterized in that the first substrate, the second substrate or both are elastomeric.

14. The process as claimed in clause 13, characterized in that the first substrate, the second substrate or both are in a stretched condition when they are joined.

15. An elastic yarn previously treated with an adhesive that can be reactivated and adapted for use in a higher order assembly, the elastic yarn comprises: an elastic yarn having a softening point; an adhesive bonded to at least a part of the surface of said yarn, wherein said adhesive has a softening point that is lower than the softening point of the elastic yarn, and wherein the adhesive is not tacky.

16. The yarn as claimed in clause 15, characterized in that the elastic yarn comprises polyurethane.

17. The yarn as claimed in clause 15, characterized in that the elastic yarn comprises spandex, isoprene rubber or styrenic block copolymers.

18. The yarn as claimed in clause 15, characterized in that the adhesive comprises a mixture of atactic and isotactic polypropylene.

19. A roll of elastic yarn as claimed in clause 15.

20. The yarn as claimed in clause 15, characterized in that the higher order assembly is a product of health-and hygiene.

21. A nonwoven substrate previously treated with an adhesive that can be re-activated and adapted for use in a higher order assembly, the non-woven substrate comprises: a non-woven substrate comprising a meltblown, spunbonded or extruded fibrous material, wherein the non-woven substrate has a softening point; and an adhesive bonded to at least a portion of the surface of said substrate, wherein said adhesive has a softening point that is lower than the softening point of the substrate, and wherein the adhesive is non-tacky.

22. The substrate as claimed in clause 21, characterized in that the substrate comprises a polyolefin.

23. The substrate as claimed in clause 21, characterized in that the adhesive comprises a mixture of atactic and isotactic polypropylene.

24. A roll of the substrate as claimed in clause 21.

25. The substrate as claimed in clause 21, characterized in that the higher order assembly is a health and hygiene product.

26. The process as claimed in clauses 1, 11 or 21, characterized in that said first and second substrates are woven, said process further comprising the steps of: providing an elastic yarn; Y joining at least a portion of the elastic yarn to at least a portion of said first substrate, said second substrate or both when said first and second substrates are joined, wherein said elastic yarn is in a stretched condition when they are joined, and in wherein said elastic yarn is placed between said first and second substrates, when they are joined. SUMMARY The present invention is generally directed to fabrics, components, composites and yarns, comprising re-activatable adhesive compositions as well as health and hygiene products employing such fabrics, components, composites, and yarns. By energizing the tissue, component, composite, or yarn (including, for example, an elastic fabric, component, composite, or yarn) comprising an adhesive composition that can be reactivated, the adhesive is activated (for example it becomes sticky). so that it can be used to join or adhere the fabric, component, composite or yarn to another material (or elsewhere on the same fabric, component, compound or yarn). Generally, the energy will be put into the adhesive in the form of infrared heat, heat, or ultrasonic energy, even though any form of energy can be used, as long as the energy is able to activate the adhesive. Prior to application, fabrics, components, composites, and yarns comprising such adhesives that can be reactivated are convenient for handling because the adhesive is not yet tacky. In addition, the adhesive that can be activated can be activated at desired locations only, thus allowing the construction of bonding patterns that promote the desired characteristics (for example the proportions of elastic properties and softness desired).