MXPA01006810A - Method of forming meltblown webs containing particles - Google Patents

Method of forming meltblown webs containing particles

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Publication number
MXPA01006810A
MXPA01006810A MXPA/A/2001/006810A MXPA01006810A MXPA01006810A MX PA01006810 A MXPA01006810 A MX PA01006810A MX PA01006810 A MXPA01006810 A MX PA01006810A MX PA01006810 A MXPA01006810 A MX PA01006810A
Authority
MX
Mexico
Prior art keywords
fibers
particles
forming
stream
meltblown
Prior art date
Application number
MXPA/A/2001/006810A
Other languages
Spanish (es)
Inventor
Wilfred Eugene Riddell
Original Assignee
Kimberlyclark Worldwide Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kimberlyclark Worldwide Inc filed Critical Kimberlyclark Worldwide Inc
Publication of MXPA01006810A publication Critical patent/MXPA01006810A/en

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Abstract

A method of forming a meltblown web having meltblown fibers and particles is provided. The particles are heated to a temperature approximating that of the meltblown fibers as they are being extruded. As a portion of any heated particle impacts the skin of one or more solidifying meltblown fibers, that portion of any heated particle penetrates into one or more solidifying particles. Although a portion of any particle becomes embedded in and retained by one or more meltblown fibers, such surface penetration is generally slight desirably leaving a substantial amount of surface area of any particle available for interaction with any medium to which a web may be exposed

Description

METHOD OF FORMING FUSED BLOWN TISSUES CONTAINING PARTICLES fc BACKGROUND OF THE INVENTION This invention relates to melt blown-form fabric methods and in particular to methods for melt blown-form fabrics containing blown and melt fibers containing blown fibers with melt and material. particles.
It has been desired to provide a method for forming melt blown fabrics containing particles for a variety of purposes, wherein a predetermined amount of particles are held to the tissue while minimizing amount of "dusting" (eg particles that fall unstably out of the tissue) that the tissue may suffer.
Several approaches have been proposed to retain the particles within the tissue. One such approach describes a low-pressure, flexible, durable, self-supporting, porous drop sheet product containing uniform three-dimensional arrangement of discrete particles. The sheet product includes, in addition to the particles, a meltblown fabric in which the particles are uniformly dispersed. The particles are physically maintained as by mechanical entanglement, in the tissue even though there is only one point of contact between the fibers blown with fusion and the particles. ("The point of contact occurs when the preformed bodies abut one another.This differs from the" contact area ", such as the result when a liquid material is deposited against the substrate, which flows over the substrate and then the place hardens.) Even though the particles are mechanically entangled within the interstices of the tissue, a part of the particles still desirably falls out of the tissue during handling.
Another approach describes using polymer adhesives to form the meltblown fabric. In addition to being physically trapped in the tissue, the approach particles are also adhered to the surfaces of the meltblown fibr. Although this can be seen as an important improvement over the retention of the particles within the tissue by contact point, this approach achieves its objective with the use of costly adhesive polymers.
For the above reasons, there is a need for an improved method for forming meltblown fabrics having substantially uniform particles and homogeneously dispersed therethrough and retained there by more than a mere point of contact or mechanical entanglement, where powdered is essentially eliminated. Without the addition of expensive polymer adhesives. P SYNTHESIS OF THE INVENTION The present invention is directed to an improved method for forming meltblown fabrics having essentially uniform and homogeneously dispersed particles. through them that satisfies the need to essentially eliminate dusting during the addition of costly adhesive polymers.
An embodiment of the present invention provides a method for forming a meltblown fabric having at least one layer, the method includes forming a first primary stream containing melt blown fibers. A first secondary stream is formed containing basic fibers and fused with the first primary stream 20 so that the first primary stream includes the basic fibr entangled with the meltblown fibers. Then, the first primary stream that includes the basic fibers entangled with the meltblown fibers is directed to a mobile forming surface to form a first layer that has the basic fibers entangled with the blown fibers After the first layer is formed, this embodiment provides the formation of at least one ca containing particles by forming a second primary stream having meltblown fibers. A first tertiary stream is formed containing particles fused with the second primary stream so that the second primary stream contains meltblown fibers containing particles. A second secondary stream is formed containing basic fibers and fused with the primary primary stream so that the second primary stream includes the basic fibers entangled with the co-melt blown fibers containing particles. After. , the second primary stream which includes the basic fibers entangled with the meltblown fibers containing particles is directed onto the first layer on the movable forming surface to form a second layer having the basic fibers entangled with the meltblown fibers containing the particles.
An alternate embodiment of the present invention provides for the formation of a meltblown fabric having at least one layer, the method includes forming a primary stream of meltblown fibers. A tertiary stream containing particles is formed and fused with the primary stream so that the primary stream includes meltblown fibers containing particles. Then, the primary stream having meltblown fibers containing particles is directed onto the formed surface to form a layer including the meltblown fibers containing particles.
Yet another embodiment of the present invention provides for the formation of a meltblown fabric having at least one layer, the method includes forming a primary stream containing meltblown fibers. A tertiary stream containing particles is formed fused with the primary stream so that the primary stream includes melt blown fibers that contain particles. A secondary stream having basic fibers formed and fused with the primary stream so that primary stream includes basic fibers entangled with the melt blown fibers containing particles. Then, primary stream having the basic fibers entangled with the meltblown fibers containing particles is directed to a mobile forming surface to form a layer that holds the basic fibers entangled with the melt blown fibers containing particles.
DRAWINGS The foregoing and other characteristics, aspect and advantages of the present invention will be better understood in relation to the following description, the attached clauses and the accompanying drawings in which: Figure 1 illustrates a forming apparatus having two units for the formation of blown fibers with fusion with the downstream unit additionally having provision for the application of particles.
Figure 2 illustrates a forming apparatus having three units for the formation of meltblown fibers with the two downstream units additionally having provision for the application of particles.
Figure 3 illustrates a cross-section of a coherent integrated two layer weave of the present invention in which a layer of the fabric includes particles.
Figure 4 illustrates a cross section of an integrated and coherent three-layer fabric of the present invention in which two layers of the fabric include particles.
Figure 5 illustrates a cross section of an integrated and coherent three-layer fabric of the present invention in which a layer of the fabric includes particles.
Figure 6 illustrates an alternate incorporation of a forming apparatus in which the fabric is provided with gravel and is combined with a carrier sheet.
Figure 7 illustrates a view of an absorbent article having a fabric of the invention.
Figure 8 illustrates a cross-section of the absorbent article of Figure 7 taken along line 8-8 of Figure 7.
Figure 9 illustrates a partially short and perspective view of an alternate absorbent article having tissue of the invention.
Figure 10 illustrates a top view of absorbent article having a fabric of the invention that shows the longitudinally engraved lines and a continuous peripheral sel located in the periphery of the absorbent article.
Figure 11 illustrates an enlarged cross-sectional view of a blown fiber with thermoplastic and solidifying polymer melt.
Figure 12 illustrates an amplified view of a particle retained within the fabric of the present invention by surface penetration into more than one meltblown fiber.
Figure 13 illustrates an amplified view of a particle retained within a fabric of the present invention by surface penetration into at least one meltblown fiber.
Figure 14 is a photograph of electron scanning microscope, at an amplification level of 10 illustrating an example of the surface penetration of a particle, having a diameter of about 20 to about 300 microns, inside one or more fibers melt blown a coform fabric of the present invention.
Figure 15 is a photograph of electron scanning microscope, at an amplification level of 10 illustrating an example of the surface penetration of a particle, having a diameter of about 20 to about 300 microns, inside one or more fibers melt blown a coform fabric of the present invention.
Figure 16 is an electron scanning electron microscope photograph at an amplification level of 10 illustrating an example of particle surface penetration, having a diameter of about 20 to about 300 microns, inside one or more fibers blown with melting of coform tissue of the present invention.
Figure 17 is an electron scanning electron microscope photograph, at an amplification level of 10 illustrating an example of the surface penetration of a particle, having a diameter of about 20 to about 300 microns, within one or more fibers melt blown a coform fabric of the present invention.
Figure 18 is a scanning electron microscope photograph at an amplification level of 10 illustrating an example of particle surface penetration, having a diameter of about 20 to about 300 microns in one or more fibers blown with melting of coform tissue of the present invention.
Figure 19 is a photograph of electron scanning microscope, at an amplification level of 10 illustrating an example of the surface penetration of a particle, having a diameter of about 5 to about 25 microns, within one or more fibers blown with fusion of coform tissue of the present invention.
DESCRIPTION OF THE INVENTION.
The meltblown fabrics formed according to the methods of the present invention generally include at least one layer having melt blown fibers and particles.
As used herein, the term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of thin matrix capillaries as only circular, such as filaments or filaments fused into a high velocity stream. of heated gas, usually air, which attenuates the filaments of molten thermoplastic material to reduce its diameter. Afterwards, the meltblown fibers are carried by high velocity gas stream and are deposited on a collector surface to form a blown fiber fabric. with fusion disbursed at random. Meltblowing is generally described, for example, in US Pat. Nos. 3,849,241 issued to Bunti 4,307,143 issued to Meitner et al., And 4,707,398 issued to Wisneski et al., Each of which is incorporated herein by reference. .
In a typical melt blowing process, extruded filament or fiber generally begins the cooling process when leaving a forming matrix. When cooling blown fiber with individual melting, it begins to solidify. The solidification process typically starts on the outside of the meltblown fiber and moves toward the center of the meltblown fiber. As the meltblown fib is cooled, a surface or skin 700 is developed as illustrated in Figure 11. Even when a skin may be present, an inner molten or semi-fused core 702 usually remains until the core of the blown fibers is melted. they are cooled and reach their solidification temperature. Known methods for incorporating the particulate material into a melt blown fabric provide for the introduction of a particulate material at about room temperature inside a stream of blown fibers with melting. In the absence of adhesive polymers, this particulate material at room temperature is maintained in any melt blown fabric resulting from any point of contact or mechanical entanglement with the co-melt blown fibers. Even though both the mechanical entanglement and the point of contact are somewhat effective in keeping a part of this material in particles in the tissue, there is still a part of particulate material that is not at a point of sufficient contact with the meltblown fibers nor has it been mechanically entangled sufficiently in the co-meltblown fibers and therefore remains either fugitive or easily fugitive with the handling of tissue. As a result of a part of particulate material remaining fugitive or making it easily fugitive, these tissues suffer from the dusty problem. Alternatively, where the adhesive polymers are used, the particulate material added at ambient temperature is maintained in any fabric by adhesive to the surface of the meltblown fibers. Even when use of adhesive polymers essentially reduces dusting, adhesive polymers are relatively expensive when compared to polymers that do not contain adhesive.
Unlike situations where the particulate material is held within a meltblown fabric by a mechanical entanglement or knit contact, the present invention provides an improved and hitherto unknown method for retaining the particles in the blown fabrics with melting which It essentially eliminates dusting without the use of expensive polymer adhesives. This novel invention provides for the use of any heat stable particle that can withstand the force of the impact with the skin of one or more co-melt blown fibers and still maintain essentially its integrity of particle.
(The term "heat stable", as used herein, generally refers to any particle whose chemical or other physical properties remain unchanged as a result of the heat encountered by the particle). Although it is not desired to be bound by any particular theory, it is believed that by heating the particles to a temperature approaching that of the fibers that are being extruded from a forming matrix, a part of each particle generally impacts penetrates within. of the skin of one or more fibers blown co-melting. When this is then penetrated into one or more of the solidified melt-blown fibr, apart from the heated particle, it is imbibed and retained by one or more of the solidified melt-blown fibr. Even when a particle part is made embedded and retained by one or more meltblown fibr, that "surface penetration" of particle in one or more meltblown fibers is desirably leaving in a lightweight form generally a substantial amount of the area of surface of the particle available for interaction with any medium to which a tissue of the invention can be exposed. Figures 12 to 19 illustrate examples of the surface penetration of a variety of one or more particles into one or more melt blown fibers.
Referring now to Figure 1, a forming apparatus, generally indicated with the numeral 20 is illustrated as including two blown-on units, 30 and 130, and movable perforated band apparatus, generally indicated with number 60. The first blowing unit with melt 30 includes a forming die 32 having a die tip 33 and a duct pair 34 and 36. A material delivery and delivery device 38 delivers the polymer to the extruder 40 for delivery to the forming die 32. A first primary stream including meltblown fibers are formed by a known meltblowing technique, such as disclosed in United States of America Patent No. 4,100,32 issued on July 11, 1978 to Anderson et al., which is incorporated herein by reference. Basically, the forming method involves extruding a molten polymeric material through the forming matrix 32 into the polymer streams and attenuating the polymer streams by converging the heated gas streams, usually ai supplied through the ducts 34 and 36.
A first secondary stream 44 which includes individualized wood or other basic fibers is formed fused within the first primary stream 42 include meltblown fibers such as to entangle the individualized wood fibers with the single pass melt blown fibers. These individualized wood fibers typically have a length of about 0.5 to about 10 mm, a maximum length-to-width ratio of about 10: 1 about 400: 1. A typical cross section of an individualized fib of wood has an irregular width of around 10 microns and a thickness of about 5 microns. In the illustrated forming apparatus, the first secondary stream 44 e formed by a pulp sheet comminution apparatus 52 of the first meltblowing unit 30. (The pulped sheet pulp apparatus described herein is of the type described in FIG. Patent of the United States of America No. 3,793.67 granted on February 26, 1974, to Appel which is incorporated here by reference). The shredding apparatus 52 includes conventional defibrator roll 46 having dient shredders for shredding the sheets of wood pulp 48 individualized wood fibers. The wood pulp sheets are radially fed along a defibrillator roll radius to the defibrator roll 46. They are the teeth of the defibrator roll 46 which comminute the wood pulp sheets 48 into individualized wood fibers. The resulting individualized wood fibers are brought to the primary primary stream 42 through a forming duct 50. duct 54 provides a process gas as usually air to the collector roll 46 in an amount sufficient to serve as a means for carrying the wood fibers individualized through the forming duct 50 at a speed approaching that of the shredding teeth. The process gas may be supplied by conventional means such as a blown not shown. It has been found that in order to avoid agglomeration or lumping of significant fiber, generally mentioned as fiber flocculation, the individualized wood fibers must be carried through the forming duct 50 at essentially the same speed from which they leave the teeth. defibrator after separation of the wood pulp sheets 48. Apparatus described for the formation of a meltblown fibr tissue having wood fibers entangled there, t tissue now mentioned as a coform, is known and is fully described in the previously mentioned United States of America patent No. 4,100,324 issued on July 11, 1978 to Anderson et al. The first primary stream 42, including the wood fibers entangled there from the first secondary stream 44, is then directed to a movable forming surface 62 that passes under the forming matrix 32. movable forming surface 62 is provided with such suction devices 64 and 66 driven by the blowers and 70 that withdraw the gas from below the movable formed surface 62 and provide a uniform placement of the blown fibrins with entangled melt and of the wood fibers on the movable forming surface. The mobile forming surface 62 desirably has a permeable band. In addition to being supported by the first roller 72, the movable forming surface 62 is also supported by a second roller 74. Even when two suction devices are illused, the number and size of the suction devices below the moving forming surface may be increased. vary in any suitable manner well known in art. In addition, the mobile perforated band apparatus 60 can be provided with dust collecting devices, shown, to prevent the escape of any particulate fibers into the atmosphere.
As illustrated in FIG. 1, a first meltblowing unit 30 places under a layer of meltblown fibers having wood fibers or other basic fibers entangled therein as a first layer 80. This first layer 80b below a second melt blowing unit 130 in which a second layer 82 is placed on it and is joined to the first layer 80. The second layer 82 is formed by the second meltblowing unit 130. The second melt blow unit includes an extruder 140 fed by a supply of material and delivery device 138. The extruder 14 feeds a forming die 132, which is generally similar to the forming die 32 of the first co-melt blowing unit 30, in the sense that the forming matrix 132 of the second meltblowing unit 130 has a die tip 133 and a pair of ducts 134 and 136 through which the gas streams usually supplied to a second stream are supplied. rimaria 142. By fusing the gas streams from ducts 134 and 136 and bringing the extruded fibers into the second primary stream 142, the extruded fibers are melt blown into the co-melt blown fibers. The second meltblown unit 130, however, differs from that of the first meltblown unit 30e and additionally there is provided a particulate surface generally indicated as a particle supply unit 160 including a storage hopper 162, which has a supply device 164 leading to a high velocity heated gas source 166, usually air and a feeder duct 168 that provides a first tertiary stream 170 of heated particles to merge with the second primary stream 142. With the merger with the second primary stream 142, parts of the heated particles of the first tertiary stream glue and penetrate into the skin of one more solidifying meltblown fibers and are embedded and retained by one or more of the meltblown fibers. The melt blown fibers containing resultant particles are subsequently entangled with the individualized made fibers supplied by a second secondary stream 144 which exits through a forming duct 150 of shredding apparatus 152 of the second blow-molding unit 130 and fused with the second primary stream 14 In the shredder 152, the defibrator roll 146 rotates and shreds the wood pulp sheets 148 as they are unwound from a pulp supply roll 149. The wood pulp sheets are shredded and passed to through the forming duct 150 and fusing with the second primary stream 14 The process gas as usually air, is supplied through a conduit 154 of the shredding apparatus 152. The second primary stream 142, now having the fibers of entangled with the meltblown fibers that contain particles, is then directed as a second layer 82 on the first layer 80 at a point of placement 165. A suction device 66 helps in the placement. Some of the meltblown fibr and the wood fibers of the second ca 82, when placed down, become entangled somewhat with the melt blown fibr and the wood fibers of the first layer along a formation line 85. This entanglement is such that a coherent integrated two-layer fabric is formed suitable for processing and use purposes. However, in case the first layer 80 and the second layer 82 have separate pulls, these are generally separated on the formation line 85. After leaving the first roll 72, the two layer fabric can be further processed by known means such as cutters and stackers not shown. Moving the forming surface 62, in addition to being supported by the first roller 72, is also supported by the second roller 74.
The apparatus of Figure 2 is a modified embodiment of the apparatus of Figure 1 in which the first meltblown unit 30 and the second meltblown unit 130 are placed above a useful formed surface 62. Below the surface mobile formator is located at least three suction devices 64, 66 169. In addition to the first-second melt blow units, there is now a third melt blow unit 230. This third melt blow unit 230 also includes how the first and second melt blow units do, at a extruder 240 fed by a supply of materi and a delivery device 238, leading to a formed die 232. The forming die 232 has there a die tip 23 and a sea of ducts 234 and 236 through which the gas streams heated, usually air, is supplied to a third primary stream 242. By fusing the gas streams from the ducts 234 and 236 and bringing the extruded fibr into the third primary stream 242, the extruded fibr are melt blown into the blown fibers. fusion. As the second meltblowing unit 130, third meltblown unit 230 differs from that of the first meltblown unit 30 in that a particle source is additionally provided generally indicated as a particle delivery unit 260 including a hopper storage 262 having a supply device 264 carrying a source of gas heated to speed 266, usually air, and a feeder duct 268 providing a second tertiary stream 270 of heated particles to merge with the third primary stream 24 With the melt of the second tertiary stream 270 with third primary stream 242, parts of the heated particles stick and penetrate the skin of one or more solidifying meltblown fibers and are embedded in and retained by one or more of the meltblown fibers . The meltblown fibr containing resultant particles are subsequently entangled with the individualized fibers made available by a third secondary stream 244 exiting through a forming duct 250 of shredding apparatus 252 of the third melting blow unit 230 and being merges with the third primary stream 2 in the shredding apparatus 252, the collector roll 246 rotates the pulp sheets 248 as they are unwound from a pulp supply roll 249. The pulp sheets are shredded and passed through the pulp web 249. formed duct 250 and operated with the third primary stream 242. The process g, usually air, is supplied through conduit 254 of the shredding apparatus 252. In Figure 2, u first layer 80 is placed by the first blowing unit c fusion 30. A second layer 82, which contains particles originated from the second meltblowing unit 130 and a third layer 84 which is originated of the third unit of blowing with fusion 230 is placed below. Some of the meltblown fibers and the wood fibers of the second layer 82 when placed below, intermingle somewhat with the meltblown fibr and the wood fibers of the first layer 8 along a line of formation 85. Some of the meltblown fibr and wood fibers of the third layer 84, when placed below, are somewhat intermixed with the meltblown fibers and the wood fibers of the second layer 82 along a 85 'training line. This intermingling is such that an integrated coherent three-layer fabric 89. is formed suitable for processing and use purposes. However, in case the first layer 82 and the second layer 82 are pulled and separated, these are generally separated on the formation line 82. In a similar manner in case the second layer 82 and the third layer 84 are pulled and separated, these will generally be separated on the formation line 85 '. After leaving the forming apparatus 2 the integrated and coherent three-layer fabric 89 can be treated by conventional means such as stack cutters to prepare it for use in an absorbent article. Consequently, the forming apparatus as illustrated in Figure 2 is capable of forming blown fabrics with melting c particles in either or both of the second and third layers or with only the second layer containing particles if the particle supply unit 260 is not operated.
Because meltblown fibers are typically much longer, thinner, safer, and more flexible than wood fibers, meltblown fibers twist around and entangle coarse and relatively short hardwood fibers as soon as the two fibers run. of fibers are fused. This entangled interconnects the two different types of fibers with fasteners between persistent and strong fibers without molecular, adhesive or significant hydrogen bonds. In the resulting matrix, the meltblown fibers retain a high degree of flexibility, with many of the meltblown fibers being spaced and separated by engagement with relatively rigid wood fibers. The entangled wood fibers are free to change their orientation when the matrix is subjected to various types of distortion forces, but the elasticity and flexibility of the network fibers blown with fusion have to return the fibers of wood to their original positions when the forces distort they are removed. An integrated and coherent weave is essentially formed by mechanical entanglement and intermixing of different fibers.
This invention has also been described with the formation of a two or three layer fabric. However, it is also within the invention to form coform fabrics having only a single layer as well as coform fabrics having three-layer m. For example, the forming apparatus as illustrated in Figure 1 is capable of forming single-layer coform fabrics including particles if the first melt blowing unit 30 is not operated. Accordingly, it is also within the present invention that the wovens may have a single cap containing particles or including multiple layers having one or more layers containing particles in a variety of multilayer configurations.
Figure 3 is illustrative of a cross section through a coherent integrated two-layer weave such as that formed by the method as illustrated by Figure 1. A first layer 80 includes mader fibers entangled with meltblown fibers that does not contain particles. A second layer 82 includes mader fibers entangled with melt blown fibers containing particles. The particles 86 are also illustrated in FIG. 3. A forming line 85 of the first layer 80 and the second layer 82 is somewhat irregular since some of the meltblown fibers and the wood fibers of each layer are intermixed. fr Figure 4 is illustrative of a cross section through a coherent integrated three-layer weave 89 such as that which can be formed by the method and apparatus of Figure 2. As illustrated in the cross-section, a first layer 80 includes fibers made entangled with blown fibers with fusion that do not contain particles. A second layer 82 and a third layer 84 each u include entangled wood fibers with melt blown fibers containing particles. The particles 86 are also illustrated in Figure 4. A formation line 85, between The first layer 80 and the second layer 82 is somewhat irregular as are some of the fibers blown with, melt and the wood fibers of the first and second layers which are intermixed. Similarly, a line of formation 85 ', between the second layer 82. and the third layer 84 is somewhat irregular when intermixed some of the melt blown fibers and the wood fibers of the second and third layers.
Figure 5 illustrates an alternate embodiment of a meltblown fabric formed in accordance with the invention.
In Figure 5, an integrated and coherent fabric having three layers is illustrated. A first layer 80 and a third layer includes the entangled wood fibers with the meltblown fibers that do not contain particles. A second layer 8 includes the entangled wood fibers with the melt blown fibers containing particles. The particles 86 are also illustrated in Figure 5. A formation line 85 in the first layer 80 and the second layer 82 is somewhat irregular in that some of the meltblown fibers and the wood fibers of the first and second layers are intermixed. . In for similar, a forming line 85 ', between the second layer 82 and the third layer 84, is somewhat irregular as some of the meltblown fibers and the wood fibers of the second and third layers are intermixed. The structure of this fabric has the advantage that the particles are not exposed on their outer surface of the fabric.
Figure 6 illustrates a forming apparatus such as that previously illustrated in Figure 1, but having some of the various optional peripheral devices that may be included with a forming apparatus according to the embodiments of the present invention. A base sheet 41 can be placed on a movable forming surface 62 before the application of a first layer 80 of a fabric in layer 420. The base sheet 410 will ordinarily be a permeable sheet such as a fabric sheet bonded with yarn that it will not interfere with the flow of gas through the movable forming surface 62. The permeable material will be applied from a roller 416 passing under an applicator roll 418 on the movable formed surface 62. If it is desired to improve the strength of the woven layers 420, this can be etched either ultrasonically or at elevated temperature so that the thermoplastic melt blown fibers are flattened in the film-like structure in the etched areas. This type of film structure works to keep the wood fibers m rigidly in place in the engraved areas. Thus, in the illustrative apparatus of Figure 6, the layered fabric 420 passed through an ultrasonic engraving station having an ultrasonic calendering head 422 vibrating against an anvil roller with pattern 424. The conditions of recording (for example, pressure, velocity, energy input) as well as etching pattern can be selected to provide the desired tissue characteristics. A desired intermittent pattern with the area of tissue occupied by the engraved areas after passing through the engraving pressure point, from about 5 to about 50 percent of the surface area of the tissue, even though the particular recording conditions for any given material will depend on the composition of the material. It is also known to carry out engraving by the use of heated engraving rolls with patr. In addition, to improve the strength of the fabric, the etching process also improves the appearance of the fabric. It is also possible to apply a top sheet 430 to the fabric 420 layers. The top sheet can already be either a permeable sheet, a waterproof layer, or other absorbent material. The upper sheet 430 is applied from a low roller 432 or applicator roll 434. It may also be desirable to apply either a carrier or a lower sheet 440 beneath the layered fabric 420. This carrier or lower sheet may be particularly desirable if a sheet is not used. trainer as it will help in the handling of tissue and can later be discarded. Therefore, it can be readily appreciated that the present invention uniquely provides a variety of fabrics having one or more layers. It can also be easily appreciated that such fabrics may also have a single layer that contains particles or that includes multiple layers having one or more layers. or more layers containing particles in a variety of multi-layered configurations The composition of a layer having meltblown fibers and wood fibers, and the composition of a layer having meltblown fiber, wood fibers and particles can be varied over a wide range. The forming gas of the meltblown fibers and the wood fibers in the manner described herein results in a fabric commonly called a coform. This coform fabric can vary between about 10 percent of blown fibers with melting and about 90 percent of wood fibers, and about 90 percent of fibers blown with melting and about 10 percent of wood fibers. Generally, there is a surfactant that It is added to the tissue to help in wetting the polymer.
A wide variety of thermoplastic fiber forming polymers are useful in the formation of meltblown fibrins so that fabrics can be formed with different physical properties by the appropriate selection of polymers or combinations thereof. Among the many useful thermoplastic fiber-forming polymers, polyolefins such as polypropylene and polyethylene, polyamides, polyesters such as polyethylene terephthalate, and thermoplastic elastomers such as polyurethanes are anticipated to find widespread use in the process. preparation of the tissues described here.
The basic fiber blown in the coform can be any fiber that improves absorbency and another property coform. Suitable basic fibers include polyester fibers, nylon fibers, cotton fibers and mader fibers. The preferred fiber is a wood fiber since the wood fibers formed from pulp are of a desired size, low cos and high absorbency.
By "particle", "particle" "particulate" particulate "is meant that the particulate material is generally in the form of discrete units.The particles may comprise granules, powders, or spheres.Therefore, the particles may have any form desired particle that can allow a part of each heated particle to penetrate slightly into one or more fibers blown with solidifying fusions according to the present invention The desired particle shapes include, for example, cubic, rod-like, polyhedral, spherical or hemispherical, rounded or rounded, angular, irregular, etc. The shapes that have larger size ratio / smaller size grand like needles, fibers and leaflets are also contemplated for use here. The particles of desired shape can be coated ( coated with gel, coated with protein and the like having a particulate core, a solid porous core, solid core, a nucleus or semi-solid, a liquid core, semiliquid core, a gaseous core, a semi-solid core combinations thereof) or coated (solid porous, semi-solid solid and the like). It should be noted that more than one kind of particles can be used in some fabrics of the invention, either in mixture or in different layers. The use of "particle" "particles" can also describe an agglomeration comprising more than one particle, particulate or the like.
A wide variety of particles capable of slightly penetrating one or more fibers blown with solidifying fusions in accordance with the present invention have utility in a three dimensional array in which they can interact with (eg react chemically physically, or be physically contact and modify them). modified by) a medium to which the particles are exposed Including among the variety of particles that have utility in the present invention are the superabsorbents. The superabsorbent material suitable for incorporation into various embodiments of the present invention may be any superabsorbent which will maintain its particulate integrity during the meltblowing process and exhibit storage, handling and resistance to gel blocking properties. Typical of such absorbent materials are water insoluble hydrocolloid particles derived from starches that will swell but not dissolve when exposed to water. Also suitable for various embodiments of the invention are those absorbers formed polyacrylamides cross-linked and hydrolyzed polyacrylates, acrylic polymers on their copolymers. Such materials, when crosslinked slightly insoluble, and when dried are solids that can be heated and blown in a gas stream, and maintain integrity when they impact on one or more of the solidifying meltblown fibers.
Also included within the spirit scope of the present invention are particles suitable to be used to control odor frequently emanating from absorbent articles used for the absorption of body fluids such as menstrual fluids, blood, urine and other excreta. Suitable ol controlling particles include activated carbon, sodium bicarbonate, chitin, deodorant materials such as clay, diatomaceous earth, zeolites and potassium permanganate complexes with active alumina, used alone.
Several embodiments of the present invention also contemplate including particles to control odors carried in the air or carried in the vapor, as well as include particulate material to slowly release a masking ol. The vibration of the masking odor can be achieved by using a superabsorbent material that slowly releases a built-in odor, similar to that of the mechanism p, in which the superabsorbents slowly release moisture. With one example, fragrances that are released over time, use a fragrance absorbed on a surface of silica particles, can be incorporated into the blown tissue c fusion. Other deodorants and masking odors, also known in the art, which can be incorporated in the form of particles in the tissue include the maladates commonly known as chemical masking agents.
The amount of particles included in the meltblown fabric may depend on the particular use to be made of the fabric. In the present invention, the particles can be added in any amount from a very small to a higher range which can be the amount that remains in the tissue without causing the tissue to lose its integrity or the particles undesirably falling out of the tissue during handling. The particles may be about 0.1 about 80 percent, by weight, of the layer containing the particles. Generally, it is desired that the coform of any particular layer varies between about 90 percent by weight wood fibers and about 50 percent by weight of wood fibr and between about 10 percent by weight of melt blown fibr and about 50 percent. Percent by weight blown fibers with melting for high absorbenc properties and good handling.
In order to achieve a particular combination of tissue properties, there are a number of variables in primary and secondary environments that can be controlled together with the composition and the basis weight of the tissue. The parameters of processes are susceptible to be controlled in the primary current are the gas temperature which is desirable in the range of about 315 ° C to about 372 ° C within the ducts of the forming matrix; the volume of gas, which desirably in the range of about 250 to about 4 cubic skin per minute (about 118 to about 215 cubic centimeters per second) within the forming matrix ducts; the polymer extrusion cup, which is desirably in the range of about 0.25 grams per hole per minute; the temperature of the polymer and the proportion of gas to polymer (mass flow cups) which is desirably in the range of about 10: 1 to about 100: 1. The variables that can be controlled in a secondary stream are the gas flow rate and the speed of the defibrillating rod; the velocity of the gas which is desirably in the range of about 3,000 to about 15,000 feet per minute (about 15 to about 76 meters per second) and basic fiber size which is typically in the order of about 3 millimeters of length. The variables that can be controlled in a tertiary stream include the gas temperature which is typically in the range of about 130 to about 390 ° F around 54 to about 200 ° C and desirably from about 150 to about 30. ° (at around 65 to around 150 ° C); the volume of gas, which is desirably in the range of about 5 to about 20 cubic feet per minute (about 2400 to about 95,000 cubic centimeters per second); and the particle size which is typically around 10 to about 35 microns in diameter. To minimize the possibility that the meltblown fibers will break with the particle impact, it is desirable that the impact force (eg speed and mass of the particle) be no greater than tensile strength (e.g. the maximum stress that a meltblown fiber can withstand before it breaks or separates, measured in strength per unit of a cross-sectional area of the original melt blown fiber) a blown fiber with individual melting. If desired, the additional gas streams can be similarly adapted for use with the present invention.
The ratio between the primary secondary currents can also be controlled and it is generally desired that in the proportion of the gas velocities in the primary and secondary currents they are in the range of about 5: 1 around 10: 1. The angle between the secondary primary currents at their melting point can also be varied eg it is generally desired to have two currents that come together perpendicular to one another. Similarly, the particular point at which the two streams are fused, in relation to the matrix point of the forming matrix in the upward direction, the mobile forming surface in the downward direction can be varied.
The relationship between a primary current and a tertiary current can also be controlled, and it is generally assumed that the proportion of gas volumes in a primary stream and a tertiary stream are in the range of about 12: 1 to about 90: 1, depending on the size and mass of the particles. The angle between a primary current and a tertiary current at the melting point can also be varied, but it is generally necessary to have two currents that come together perpendicular to one another. Similarly, the particular point where the two streams are fused, in relation to the matrix point of the forming matrix in the upward direction and the mobile forming surface in the downward direction can be varied.
A tertiary stream having heated particles can be fused into a primary stream that has blown fibers with fusion between the matrix tip of the forming die and the moving forming surface, as long as the heated particles can penetrate into the skin of one more of the fibers. blown fibers with fusion with impact. Therefore depending on the polymer, as well as the meltblowing method conditions, the melting point is typically about 0 to about 2 inches (about millimeters to about 51 millimeters) below the die tip. Desirably, the melting point is about 0. to about 1 inch (about 13 to about 2 millimeters) below the die tip. In order to minimize the amount of waste heat lost by the particles to the environment with the outlet from the feeder duct of a particle supply unit, it is desired that the particles s displace by a distance of about 0 to about an inch (about 100%). 0 to about 25 millimeters) when exiting the feeder duct and merging with a primary stream It is even more desired that the particles move by a distance of 0 to about 0.5 inches (about 0 about 13 millimeters) when leaving the feeder duct merge with a primary current.
The invention has been described with the formation of coform tissues. It is also within the invention to form successive meltblown fabrics formed with gas, which do not contain additional wood fibers or other basic fibers in which the first layer is without a particle while the second or another successive layer contains particle. It is also within the present invention to form melt blown fabric formed of single layer gas, which contains wood fibers and other additional basic fibers, which single layer includes particles. For example, forming apparatus as illustrated in FIG. 1 is capable of forming blown fabrics with single layer melting with both the first meltblowing unit 30 and the shredder unit 152 of the second meltblowing unit. They are not operated. The phrases "meltblown layer", "ho blown with melt" as used herein, mean a meltblown layer formed with gas from entangled meltblown fibers that do not contain basic fibers while the term "coform" is a layer as previously described, it contains basic fibers in addition to meltblown fibers. Typically the gas used in the formation of melt blown layers formed with gas is air. Consequently, the process is sometimes referred to as a process of air-forming or air-forming which, in turn, typically produces one or more layers formed with air.
In an alternate embodiment, a cap tissue can be formed by the apparatus illustrated in the drawings of FIGS. 1, 2 and 6 but not operating the pulper sheet shredding apparatus. In another alternate embodiment, a structure of one or more coheorm layers in coherent integral combination, or more cap of blown with fusion is also possible. The desired coform layers on the meltblowing layers for most purposes since the coform layers are superior in absorbency. The formation of various meltblown and co-melt cap combinations is within the invention as is the placement of particles in any meltblown layer or a coform layer.
A fabric containing particles of the present invention finds uses in a variety of fields, depending of course on the particles used. The tissue particularly suitable for use in absorbent articles such as shields, perineals and incontinent undergarments, bed rods, parallels, women's hygiene products and body wraps such as those for wounds.
A novel method of the present invention made the fabric essentially non-dusty. As a result of making the fabric essentially non-pores, the fabric of the present invention can advantageously be cut more economically from a variety of articles having predetermined shapes if particles are undesirably pulled out from the sides of either the fabric or the article chopped up. The ability to cut the fabric allows the manufacturer to produce an absorbent item more efficiently and economically resulting in lower production costs which can be passed on to the consumer. A further advantage of making the fabric essentially non-dusting is that the matrix-cut absorbent articles are not subjected to the additional step and at the cost of adding a peripheral seal to keep the particles in the cut items. In addition, certain tissue incorporations of the present invention have the advantages that the particles will not be present in the body.
As previously noted, depending on the type of particles incorporated herein, the fabric of the present invention has a variety of uses. For example, the material can be used in absorbent articles. Figures 7 and 8 show the incorporation of such an absorbent article. The absorbent article 450 of Figures 7 and 8 is formed with the absorbent material of Figure 3. The absorbent article 450 has a waterproof polymer wrap 454 and a permeable side-by-side member 452. The permeable wrap is adhered to the permeable form by glue lines at points 456 and 450. L ends of the absorbent article can be ultrasonically sealed at points 460 and 462. The coform material layer 80 that does not have a particulate material is exposed to the user body. The absorbent article 450 may be used for absorption of any body exudate. Depending on the type of particulate material used, typical of the absorbent article will include incontinent devices, catamenial devices, diapers or bandages for wounds.
Referring to Figure 19, another embodiment of an absorbent article is shown in Figure 9, there is shown an absorbent article 610 which is designed to be used by a woman to absorb; menstrual body fluids, blood, urine and other excrement. Absorbent article 610 can be a sanitary napkin, a for panties, a panty shield, an incontinent garment or the like. A sanitary pad is designed to absorb a greater amount of fluid than a pant liner than a panty shield. A sanitary napkin is usually larger, wider and thicker than a panty liner may contain a superabsorbent or other type of material, such as swamp moss, which may increase its absorbent capacity. Sanitary napkins can have a length of about 6 to about 13 inches (about 152 about 330 millimeters), a width of about 2 about 5 inches (about 51 to about 1 millimeters) and a thickness of about from 0.25 to about millimeters. The sanitary napkin can have a variety of shapes including rectangular, hourglass, ov or race track.
Pant lining, on the other hand, is relatively thin and small and can, but usually contains a superabsorbent. A lining for panties can have a length of about 127 to about 254 millimeters a width of about 51 to about 76 millimeters and thickness of about 1.3 to about 3.6 millimeters.
Incontinent garments are usually equal to or greater than sanitary napkins. The incontinent pa garments can have a length of around 6 around 33 inches (about 152 to about 8 millimeters) as a width of about 2.5 to about inches (about 64 to about 764 millimeters) and thickness of 19 to about 76 millimeters. Incontinent garments commonly have a rectangular shape or a sand rel.
The absorbent article 610 may include a liquid impermeable cover 612, a liquid impermeable separator 614, and an absorbent 616 positioned therebetween. cover 612 can be formed of a non-woven material, such as a material bonded with yarn. The separator 614 may be in the form of a thin polyethylene film. The cover 612 and separator 614 can be removed, and the function of these d layers can be carried out by other means. For example, the upper surface of the absorbent 616 may serve as the cover, and the adhesive coating of a foam layer may replace the separator.
The absorbent 616 has a face to face surface and a face facing the garment. The absorbent 61 may be a hydrophilic material formed of various types of natural or synthetic fibers, including cellulose fibers, meltblown fibers treated with surfactant, wood fibers, cotton or regenerated cellulose fibers, or a mixture of pulp and other fibers. A desired absorbent material is the particle-containing coform material described herein formed with the forming apparatus of Figure 1. A coform blend of about 70 percent wood fibers with about 30 percent polypropylene melt blown fibers works well.
The absorbent can also contain thermoplastic polymers which can be permanently deformed by the application of heat and pressure. Such materials include polypropylene, nylon, polyethylene, polyesters, etc. Typical such materials are carded and bonded fabrics, fabrics blown with fusion and joined with yarn.
The cover 612, the separator 614 and the absorber 616 are sandwiched together to form a pad 616. The pad 616 includes a central portion 620 with the longitudinally extending sides 622 and 62. The sides 622 and 624 may already be either linear or non-linear so that the pad 618 may have several configurations. For example, the pad 618 may have a rectangular shape, a race track, a sand clock or an oval shape.
It should be noted that the pad 618 has uniform thickness. This allows the pad 618 to be cut with matrix during manufacture from a large sheet of laminate material. In addition, pad 618 may optionally obtain appendages as described in United States Patent No. 5,429,630 issued July 4, 1995 to Beal et al. Which is incorporated herein by reference.
The pad 618 may contain a plurality of engraved areas 630. In FIG. 9, the engraved areas 63 are shown in sinusoidal lines formed parallel to the longitudinal ej of the absorbent article 610. The engraving areas may add integrity to the absorbent article 610 by securing the cover to the absorbent 616. The use of the engraved lines gives an indication of waves, or which the consumers may tend to associate with the absorption of the fluid. The engraved areas 630 can be spaced evenly across the width of the absorbent article 610. The engraved areas 63 can also be in the form of dots, flowers or the like.
The engraved lines 630 can be formed by running a laminated material through the fastening point of two rollers, the lower roller being a pressure roller and the upper roller being an engraving roller. The engraving will cause the cover 612 to be pinched in absorbent 616 and will therefore assist the absorbent article 610 to be maintained together.
The pad 618 is formed of a large sheet of a laminated material which includes a cover 612, separator 614 and absorbent 616. The pad 618 can be cut with a matrix of this sheet of material and will have a surface facing the body. 632 and uses the garment facing surface 634. The body facing surface 632 can be formed by the liquid permeable cover 612 and the garment facing surface 634 can be formed by the liquid impervious separator 614.
Referring to Figure 9, the absorbent article 610 further includes the fastening means 63 secured to the garment facing surface 634. The fastening means 636 can be a garment fastening adhesive which provides a means to removably secure pad 618. to the inter-leg part of an interim garment not shown. One garment fastening adhesive which worked well is NS 34-5516 adhesive which is commercially available from National Starch located at 10 Finderne Avenu, Bridgewater, New Jersey 08807. The fastening means 63 may include an adhesive 640 located in the centr part 620. The particular design and configuration of the fastening means 636 may vary.
Referring again to Figure 9, the absorbent article 610 further includes at least one piece of release paper 646 covering the fastening means 636. The release paper 646 and the pad 618 may have coterminous outer peripheries thereby facilitating a cutting operation with matrix during manufacturing. It is also possible to cut the release paper so that it covers all adhesive but has a configuration which lies within the outer periphery of at least a part of the pad 618. For example, the release paper can run at the length of the absorbent article 610, but be narrower than the overall width of absorbent article 610. release paper may also be cut larger than pad 618, for example, having a part lying afue at one end so that the consumer can grasp the release tab and remove it easily from pad 618.
The absorbent article 610 is designed to be cut with a sheet die of a laminate material including the cover 612, the separator 614, the absorbent 616, the fastening means 636 and the release paper 646. The operation of die cutting Allows the manufacturer to produce the absorber 610 efficiently and economically. The lowest production costs can be passed on to the consumer.
Referring to Figure 10, an absorbent article 648, such as a sanitary napkin or a pantiliners liner is shown. The absorbent article 648 is similar construction to that discussed in Figure 9 except that it includes a continuous engraving line 650 formed about 0.4 to about 13 millimeters inward from the outer periphery of the absorbent article 648. The engraved line 6 provides integrity between the cover and the absorbent and advantageous in keeping the article together when it is removed from the crotch portion of an undergarment. absorbent article 648 has a racing track configuration with a longitudinal axis designated X-X and a transversal ej designated Y-Y. The absorbent article 648 also contains a plurality of sinusoidal etched lines 652 l which extend longitudinally through the absorbent article 648 with respect to the longitudinal axis X-X. The engraved lines 652 do not extend beyond the peripheral line 650. When the absorbent article 648 is a sanitary napkin this may have a surface area of less about 30 square inches (about 194 square centimeters). Desirably, when the absorbent article 648 a sanitary napkin, it has a men surface area of about 161 square centimeters. When the absorbent article 648 is a pant liner, the surface area may be less than about 129 square centimeters.
When the absorbent article is a sanitary napkin, it can have a basis weight of less than about 400 grams per square meter, desirably less than about 300 grams per square meter and more desirably less than about 250 grams per square meter. For pant lining, the basis weight may be less than about 200 grams per square meter, desirably, when the absorbent article is a pant liner, it has a basis weight of less than about 190 grams per square meter; Desirably, less than about 170 grams per square meter, and more desirably less than about 150 grams per square meter. For a panty liner containing particulate material, the particles can be incorporated into melt blown fabric in amounts ranging from about 0.5 to about 30 grams per square meter while the non-woven absorbent has a basis weight of about from around 40 to around 350 grams per square meter.
Examples The following examples describe various embodiments of the invention. Other embodiments within the scope of the claims given herein will be apparent to one skilled in the art of considering the description or practice of the invention as described herein. It is intended that the description along with the examples be considered exemplary only, with the scope and spirit of the invention signified by the claims which follow the examples. The parts, percentages and proportions are by weight less than indicated otherwise.
Example 1 Melt blown method conditions: Polymer conditions Polymer: PRO-FAX® polypropylene (polypropylene homopolymer, homopolymer pellets), class PF-01 commercially available from Himont Incorporated, of Hercul Plaza, Wilmington, Delawere 19894, United States of America.
Polymer temperature at the die tip approximately 265 ° C.
Matrix tip pressure: approximately 8 pounds per square inch over the atmospheric psion.
Separation of air to the ducts of the matrix formation 18 to 20 thousandths of an inch.
Average air temperature to the ducts of the forming matrix: approximately 296 ° C.
Particle conditions Particles: 85% sodium bicarbonate and 15% ABSCENTS® 5000 (ABSCENTS® 5000 is an odor controlling particle commercially available from UOP LLC, 25 East Algonqu Road, PO Box 5017 Des Plains, Illinois 60017, United States America ): The particles have a size range of around 5 around 300 microns in diameter.
Tertiary current outlet temperature approximately 68 ° C.
Volume of tertiary current gas approximately 95,000 cubic centimeters per second.
Pulp / polymer ratio: 70/30 Only coform: 170 grams, per square meter.
The method described above resulted in the ABSCENTS® 5000 particles being incorporated into the meltblown fabric in a predetermined amount of about 2 about 3 grams per square meter.
Example 2 Example 2 used the same conditions of the meltblowing method as in Example 1, except that only the particles present were ABSCENTS® 5000. The particles had a size range of about 300 microns in diameter, the method described aq resulted in the particles being incorporated into the melt blown fabric in a predetermined amount of about 2 about 3 grams per square meter.
Example 3 Example 3 used the same conditions as the meltblowing method as in Example 1, except that only the particles present were ABSCENTES® 3000, an odor controlling particle, commercially available UOP LLC. The particles had a size range of about 5 about 25 microns in diameter. The method described aq resulted in the particles that were incorporated into meltblown fabric in a predetermined amount about 2 about 3 grams per square meter.
Example 4 Melt blown method conditions: polymer conditions: Polymer: ESCORENE Polypropylene (Calse PD 3505G granular resin, commercially available from EXXON Chemica Company, 13501 Katy Freeway, Huston Texas 770791398, United States of America.
Polymer temperature at the die tip approximately 272 ° C.
Matrix tip pressure: approximately 8 pounds per square inch over atmospheric pressure.
Separation of air in the ducts of the forming matrix: 18 to 20 thousandths of an inch.
Average air temperature in the ducts of the forming matrix approximately 299 ° C.
Particle conditions: Particles: sodium bicarbonate. The particles had a size range of around 5 around 30 microns in diameter.
Tertiary current outlet temperature approximately 74 ° C.
Volume of tertiary current gas approximately 95,000 cubic centimeters per second.
Pulp / polymer ratio: 70/30 Coform only: 170 grams per square meter the method described above resulted in the particles being incorporated into the melt blown fabric a predetermined amount of about 2 to about grams per square meter.
Example 5 Example 5 used the same conditions as the meltblowing method as in Example 4, except that the only particles present were ABSCENTES® 5000. The particles had a size range of about 20 about 300 microns in diameter. The method described aq resulted in the particles being incorporated into the meltblown fabric in a predetermined amount of about 2 about 3 grams per square meter.
Example 6 Melt blown method conditions. polymer conditions.
Polymer: Polypropylene (Granules), class PD 348 commercially available from EXXON Chemical Company.
Polymer temperature at the mating tip about 271 ° C.
Matrix tip pressure: approximately pounds per square inch over atmospheric pressure.
Separation of air in the ducts of the forming matrix: 18 to 20 thousandths of an inch.
Average air temperature in the forming die ducts approximately 299 ° C.
Particle conditions: Particles: 85% sodium bicarbonate and 15% ABSCENTS®. The particles had a size range around 5 around 300 microns in diameter.
Tertiary current outlet temperature approximately 155 ° F (approximately 68 ° C).
Gas volume of the tertiary current approximately 20 cubic feet per minute (approximately 95,000 cubic centimeters per second) Pulp / polymer ratio: 70/30 only Coform: 170 grams per square meter The method described above resulted in the particles / ABSCENTS® 5000 being incorporated into the blown-blown fabric in a predetermined amount of about d 2 about 3 grams per square meter.
Example 7 Example 7 used the same meltblowing method conditions of Example 6 except that the ABSCENTS® 5000 particles were present. The particles had a size range of about 2 about 300 microns in diameter. The method described here resulted in the particles being incorporated into the meltblown fabric in a predetermined amount of about d 2 about 3 grams per square meter.
Example 8 Example 8 used the same conditions as the meltblowing method as in Example 6 except that the particles present were ABSCENTS® 3000 from UOP LLC. L particles range in size from about 5 to about microns in diameter. The method described here resulted in the particles being incorporated into the fabric with melt blowing in a predetermined amount of about 2 about 3 grams per square meter.
In view of the above it was found that several advantages of the invention are achieved and other advantageous results obtained.
As various changes can be made to the aforementioned methods and blown fabrics with melting from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings be construed as illustrative and not in a limiting sense. .

Claims (19)

R E I V I N D I C A C I O N S
1. A method for forming a blown fusion fabric, the method comprises: (a) form at least one layer per steps d (i) forming a first primary stream containing meltblown fibers; (ii) forming a first secondary stream comprising basic fibers; (iii) fusing the first primary stream and the first secondary stream so that the first primary stream comprises the entangled basic fibers with the melt blown fibr; Y (iv) then directing the first primary stream comprising the basic fibers entangled with the meltblown fibr on a mobile forming surface to form a first layer comprising the basic fibers entangled with the meltblown fibers; (b) forming at least one contact layer particles by the steps of: (i) forming a first primary stream containing meltblown fibers; (ii) forming a first tertiary stream comprising particles; (iii) fusing the second primary stream and the first tertiary stream so that the second primary stream comprises blown fibers with particle-containing melt; (iv) forming a second secondary stream comprising basic fibers; (v) fusing the second primary stream comprising meltblown fibers containing particles the second secondary stream so that the second primary stream comprises the basic fibers entangled with the meltblown fibers containing particles; Y (vi) then directing the second primary stream comprising the basic fibers entangled with the meltblown fibers containing particles on the first layer on the movable forming surface to form a second layer comprising the basic fibers entangled with the meltblown fibers that contain particles.
2. The method as claimed in clause 1 characterized in that it also comprises forming at least one layer by the additional steps of: (a) forming a third primary stream containing meltblown fibers; (b) forming a third secondary stream comprising basic fibers; (c) fusing the third primary stream and third secondary stream so that the third primary stream comprises the entangled basic fibers with the meltblown fibr; Y (d) then directing the third primary stream comprising the basic fibers entangled with the fibr blown with melt on the second layer on the mobile forming surface to form a third layer comprising the basic fibers entangled with the meltblown fibers.
3. The method as claimed in clause 1 further characterized in that it comprises forming at least one layer containing additional particles by the steps of: (a) forming a third primary stream containing meltblown fibers; (b) forming a second tertiary stream comprising particles (c) fusing the third primary stream and the second tertiary stream so that the third primary stream comprises blown fibers with particle-containing melt; (d) forming a third secondary stream comprising basic fibers; (e) fusing the third primary stream comprising meltblown fibers containing particles the third secondary stream so that the third primary stream comprises the basic fibers entangled with the melt blown fibers containing particles; Y (f) then directing the third primary stream comprising the basic fibers entangled with the meltblown fibers containing particles on the second layer on the movable forming surface to form a third layer comprising the basic fibers entangled with the meltblown fibers that contain particles.
4. The method as claimed in clause 1 characterized in that the particles are stable with heat.
5. The method as claimed in clause 4 characterized in that the tertiary current comprises particles having a temperature of about 50 about 200 ° C.
6. The method as claimed in clause 4 characterized in that the tertiary current comprises particles having a temperature of about 65 around 150 ° C.
7. The method as claimed in clause 3 characterized in that the particles are heat stable particles.
8. The method as claimed in clause 7 characterized in that each tertiary stream comprises particles having a temperature of about 50 to about 200 ° C.
9. The method as claimed in clause 7 characterized in that each tertiary stream comprises particles having a temperature of about 65 to about 150 ° C.
'10. The method as claimed in clauses 1, 2 or 3 characterized in that the basic fibers are the wood fibers.
11. A method for forming a melt blown fabric, the method comprises forming at least one layer per l steps of: (a) forming a melt blown primary stream of fib; (b) forming a tertiary stream comprising particles; (c) fusing the primary current and the tertiary current so that the primary stream comprises meltblown fiber containing particles; Y (d) then directing the primary stream q comprises melt blown fibers containing particle on a movable forming surface to form a layer comprising the meltblown fibers containing particles.
12. The method as claimed in clause 11 characterized in that the particles are heat stable particle.
13. The method as claimed in clause 12 characterized in that the tertiary stream comprises particles having a temperature of about 50 about 200 ° C.
14. The method as claimed in clause 12 characterized in that the tertiary stream comprises particles having a temperature of about 65 around 150 ° C.
15. A method for forming a co-melt blown fabric, the method comprises forming at least one layer by the steps of: (a) forming a primary stream containing meltblown fibers; (b) forming a tertiary stream comprising particles; (c) fusing the primary current and the tertiary current so that the primary stream comprises meltblown fiber containing particles; r »5 (d) forming a secondary stream comprising stable fibers; (e) fusing the primary stream comprising meltblown fibers containing particles and current 10 secondary so that the primary stream comprises stable fiber entangled with the meltblown fibers containing particles; Y (f) then direct the primary current qu 15 comprises the stable fibers entangled with the meltblown fibers containing particles on a mobile forming surface to form a layer comprising the basic fibers entangled with the melt blown fibers containing particles.
16. The method as claimed in clause 15, characterized in that the particles are heat-stable particles.
17. The method as claimed in clause 16 characterized in that the tertiary stream comprises particles having a temperature of about 50 about 200 ° C.
18. The method as claimed in clause 16 characterized in that the tertiary current comprises particles having a temperature of about 65 around 150 ° C.
19. The method as claimed in clause 15 characterized in that the basic fibers are wood fibers. SUMMARY A method is provided for forming a meltblown knit having meltblown fibers. The particles are heated to a temperature approaching that of the meltblown fibers as they are extruded as a part of any heated particles sticks on the skin of any one or more of the fibers blown with solidifying fusions., that part of any heated particle penetrates one or more solidifying particles. Even when a portion of any particle is embedded in and retained by one or more meltblown fibers, such surface penetration is ultimately desirably light leaving a substantial amount of surface area of any available particles for interaction with any medium at which it is required. A tissue can be exposed.
MXPA/A/2001/006810A 1998-12-31 2001-07-02 Method of forming meltblown webs containing particles MXPA01006810A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US60/114,307 1998-12-31
US09419039 1999-10-15

Publications (1)

Publication Number Publication Date
MXPA01006810A true MXPA01006810A (en) 2002-02-26

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