Patent Application
20160375458
The present invention relates to equipment and methods for depositing a fluid or a plurality of fluids onto a substrate. More particularly, the invention relates to equipment and methods for dosing fluids on moving substrates.
Manufacturers of consumer goods often apply absorbents in solid forms to their products. To date, manufacturers have mostly relied on the use of drums and vacuum to deliver solid absorbents to the product. To date, absorbent precursors in a fluid state are not handled in a manner that allows for precise delivery to a substrate in a controlled manner accounting for shear while having precise fluid flow control. Manufacturers may use moving rolls having primarily axial fluid flow and/or primarily circumferential fluid flow which results in uneven fluid distribution and lack of fluid reaching parts of the rolls. In addition, such designs limit the number and sizes of fluid channels that may be incorporated into the device and limit the location of the fluid orifices stemming from those channels in a way that undermines precision. Alternatively manufacturers use printing plates and flat surfaces, which result in slower processing or imprecision when running at high rates as the printing plate may not be able to keep up with the moving substrate.
Known devices also suffer from imprecise registration, overlaying and blending of fluids. Because a single device is often used for a single fluid, registration, overlaying and blending between multiple fluids requires the use of more than one device. The inherent imprecision in each known device results in imprecision when trying to register (etc.) their respective fluids. Indeed, because the inability to control fluid flow and application and other factors in each device, known devices often are not able to precisely register fluids with other fluids or product features such as embossments or sealing areas.
Further, manufacturers are faced with higher production costs and resources due their inability to separately control different fluids in one printing device.
Therefore, there is a need for a controllable and/or customizable apparatus for depositing fluid(s) that permits more precise fluid deposition. Further still, there is a need for an efficient process for, and decreased manufacturing costs associated with, depositing one or more fluids on a substrate.
A method for delivering a High Internal Phase Emulsion to a substrate. The method includes providing a rotating roll, The rotating roll has a central longitudinal axis, wherein the rotating roll rotates about the central longitudinal axis, an exterior surface defining an interior region and substantially surrounding the central longitudinal axis, and a vascular network configured for transporting the one or more fluids in a predetermined path from the interior region to the exterior surface of the rotating roll. The method further includes providing a High Internal Phase Emulsion to the rotating roll vascular network. The method further includes contacting a substrate with the rotating roll and contacting the substrate with the High Internal Phase Emulsion.
A method for delivering a High Internal Phase Emulsion to a substrate. The method includes providing a rotating roll, The rotating roll has a central longitudinal axis, wherein the rotating roll rotates about the central longitudinal axis, an exterior surface defining an interior region and substantially surrounding the central longitudinal axis, and a vascular network configured for transporting the one or more fluids in a predetermined path from the interior region to the exterior surface of the rotating roll. The method further includes providing a High Internal Phase Emulsion to the rotating roll vascular network. The method further includes contacting a substrate with the rotating roll and contacting the substrate with the High Internal Phase Emulsion. The substrate can contact the rotating roll, the emulsion, or both simultaneously before contacting the other provided that the substrate contacts the High Internal Phase Emulsion prior to the High Internal Phase Emulsion vertically protruding from the surface of the rotating roll at a height of greater than 0.1 mm.
As used herein, the “aspect ratio” of a shape is the ratio of the length of the longest dimension or diameter of the shape, in any direction, that intersects the shape's midpoint and length of the shortest dimension or diameter of the shape, in any direction, that intersects the shape's midpoint.
“Vascular network” as used herein means a network of channels that carry fluid from an entry, such as an inlet, to one or more exits. The channels include one or more main arteries, one or more capillaries, and/or one or more sub-capillaries. In the vascular network, each channel may be in fluid communication with another channel. In general, the entry may be at or near the main artery, and the main artery may be in direct fluid communication (i.e., without intermediate channels) with a capillary. Likewise, a capillary may be in direct fluid communication with a main artery, another capillary, and/or a sub-capillary, and/or a fluid exit (all of which are discussed more fully below). Capillaries may extend from a main artery and connect with a sub-capillary or divide into a series of sub-capillaries. In one embodiment, the cross-sectional area of a main artery is larger than that of a capillary to which the main artery is connected. In another embodiment, the cross-sectional area of a capillary is larger than that of a sub-capillary to which the capillary is connected. In some respects, the vascular network of the present invention is analogous to a biological vascular network. However, the vascular network of the present invention is not a biological system.
In an embodiment, one path from the entry to an exit is substantially radial. In other words, the vascular network carries a fluid in a substantially radial direction.
“Radial” or “radially” as used herein refers to the direction of radii in a circular, spherical, cylindrical or similar shaped object. In other words, if an element is described as extending radially herein, that element extends from an inner portion (including the center) of an object outward to an external portion, including the perimeter or outer boundary or surface of that object. Radial and radially as used herein are distinguished from circumferentially, wherein an element so described would extend about the center of a spherical, cylindrical or similar shaped object such that the element would mimic the circumference or perimeter of the object. Likewise, radial and radially is distinguished from axially, wherein an element so described would extend in a direction parallel or substantially parallel to the longitudinal axis of the object.
Elements described as extending “substantially radially” or being “substantially radial” may have axial or circumferential components. However, a substantially radial element as described herein means that the element has a radial vector greater than its axial or circumferential vectors. Visually, in the aggregate, a substantially radial element (which may be a tree 23 or a fluid path 48) extends in a radial direction more than it extends in an axial or circumferential manner.
“Fluid” as used herein means a substance, as a liquid or gas, that is capable of flowing and that changes its shape at a steady rate when acted upon by a force tending to change its shape. Exemplary fluids suitable for use with the present disclosure includes inks; dyes; emulsions such as oil and water emulsions; high internal phase emulsions; monomers and polymers; polyacrilic acids; chemical fluids such as alcohols; softening agents; cleaning agents; dermatological solutions; wetness indicators; adhesives; botanical compounds (e.g., described in U.S. Patent Publication No. US 2006/0008514); skin benefit agents; medicinal agents; lotions; fabric care agents; dishwashing agents; carpet care agents; surface care agents; hair care agents; air care agents; actives comprising a surfactant selected from the group consisting of: anionic surfactants, cationic surfactants, nonionic surfactants, zwitterionic surfactants, and amphoteric surfactants; antioxidants; UV agents; dispersants; disintegrants; antimicrobial agents; antibacterial agents; oxidizing agents; reducing agents; handling/release agents; perfume agents; perfumes; scents; oils; waxes; emulsifiers; dissolvable films; edible dissolvable films containing drugs, pharmaceuticals and/or flavorants. Suitable drug substances can be selected from a variety of known classes of drugs including, for example, analgesics, anti-inflammatory agents, anthelmintics, antiarrhythmic agents, antibiotics (including penicillin), anticoagulants, antidepressants, antidiabetic agents, antipileptics, antihistamines, antihypertensive agents, antimuscarinic agents, antimycobacterial agents, antineoplastic agents, immunosuppressants, antithyroid agents, antiviral agents, anxiolytic sedatives (hypnotics and neuroleptics), astringents, beta-adrenoceptor blocking agents, blood products and substitutes, cardiac inotropic agents, corticosteroids, cough suppressants (expectorants and mucolytics), diagnostic agents, diuretics, dopaminergics (antiparkinsonian agents), haemostatics, immunological agents, lipid regulating agents, muscle relaxants, parasympathomimetics, parathyroid calcitonin and biphosphonates, prostaglandins, radiopharmaceutical, sex hormones (including steroids), anti-allergic agents, stimulants and anorexics, sympathomimetics, thyroid agents, PDE IV inhibitors, NK3 inhibitors, CSBP/RK/p38 inhibitors, antipsychotics, vasodilators and xanthines; and combinations thereof.
“Register” as used herein means to spatially align an article, including but not limited to a fluid, with another article, such as another fluid, or with a particular area or feature of a substrate.
“Overlay” as used herein means to place a fluid on top of another fluid. For example, a blue fluid may overlay a yellow fluid, producing a green image.
“Operative relationship” as used herein in reference to fluid transmission between two articles (e.g., a roll and a substrate) means that the articles are disposed such that the fluid is transmitted through actual contact between the articles, close proximity of the articles and/or other suitable means for the fluid to be deposited.
“Paper product,” as used herein, refers to any formed, fibrous structure product, traditionally, but not necessarily, comprising cellulose fibers. In one embodiment, the paper products of the present invention include sanitary tissue products. A paper product may be made by a process comprising the steps of forming an aqueous papermaking furnish, depositing this furnish on a foraminous surface, such as a Fourdrinier wire, and removing the water from the furnish (e.g., by gravity or vacuum-assisted drainage), forming an embryonic web, transferring the embryonic web from the forming surface to a transfer surface traveling at a lower speed than the forming surface. The web is then transferred to a fabric upon which it is dried to a final dryness after which it is wound upon a reel. Paper products may be through-air-dried.
“Product feature” as used herein means structural or design features that are applied to or formed on a substrate prior to or after use of the apparatuses or methods described herein. Product features may include, for example, embossments, wet-formed textures, addition of fibers such as by flocking, apertures, perforations, printing, registration marks and/or other fluid deposits.
“Micro-reservoir” as used herein means a structure having a void volume capable of collecting and/or holding less than about 1000 mm3, or less than 512 mm3, or less than 125 mm3, or less than 75 mm3, or less than 64 mm3, or less than 50 mm3 of one or more fluids and supplying the fluids to one or more exits. In one nonlimiting example, the micro-reservoir operates as a reverse funnel, being smaller in the area where fluid enters the micro-reservoir than the area where the fluid leaves the micro-reservoir. The micro-reservoir can serve as a single fluid supply region for one or fluid exits or sleeve exits (both types of exits described in more detail below), minimizing the number of channels required to supply a given number of exits. In addition, the micro-reservoir may be disposed under an exterior surface or a sleeve.
“Sanitary tissue product” as used herein means one or more fibrous structures, converted or not, that is useful as a wiping implement for post-urinary and post-bowel movement cleaning (bath tissue), for otorhinolaryngological discharges (facial tissue and/or disposable handkerchiefs), and multi-functional absorbent and cleaning uses (absorbent towels and/or wipes). Sanitary tissue products used in the present invention may be single or multi-ply.
“Substrate” as used herein includes products or materials on which indicia or fluids may be deposited, imprinted and/or substantially affixed. Substrates suitable for use and within the intended scope of this disclosure include single or multi-ply fibrous structures, such as paper products like sanitary tissue products. Other materials are also intended to be within the scope of the present invention as long as they do not interfere or counteract any advantage presented by the instant invention. Suitable substrates may include films, foils, polymer sheets, cloth, wovens or nonwovens, paper, cellulose fiber sheets, co-extrusions, laminates, high internal phase emulsion foam materials, and combinations thereof. The properties of a selected material can include, though are not restricted to, combinations or degrees of being: porous, non-porous, microporous, gas or liquid permeable, non-permeable, hydrophilic, hydrophobic, hydroscopic, oleophilic, oleophobic, high critical surface tension, low critical surface tension, surface pre-textured, elastically yieldable, plastically yieldable, electrically conductive, and electrically non-conductive. Such materials can be homogeneous or composition combinations. Additionally, absorbent articles (e.g., diapers and catamenial devices) may serve as suitable substrates. In the context of absorbent articles in the form of diapers, printed web materials may be used to produce components such as backsheets, topsheets, landing zones, fasteners, ears, side panels, absorbent cores, and acquisition layers. Descriptions of absorbent articles and components thereof can be found in U.S. Pat. Nos. 5,569,234; 5,702,551; 5,643,588; 5,674,216; 5,897,545; and 6,120,489; and U.S. Patent Publication Nos. 2010/0300309 and 2010/0089264.
Substrates suitable for the present invention also include products suitable for use as packaging materials. This may include, but not be limited to, polyethylene films, polypropylene films, liner board, paperboard, carton materials, and the like.
The channels 20 may be associated by any suitable means, such as gluing, welding or similar attachment operation or may be integrally formed with one another, or combinations thereof. Further, each point of association between channels 20 may comprise a junction 21. The junction 21 may be formed to provide a smooth transition from one channel 20 to another in order to prevent turbulence. A smooth transition may be achieved for example by rounding the edges of the junction 21 or associating the channels 20 such that they are not aligned end-to-end creating a sharp edge, such as a 90 degree angle. In other words, the channels 20 may be associated away from one or both of their ends. If turbulence is desired, the junction 21 may be provided with more jagged edges. One of skill in the art will recognize how to design the junction 21 to achieve the desired fluid flow.
Still referring to
Importantly, as shown in
As noted above, the vascular network 18 may be disposed with the interior region 16 of the rotating roll 10 and comprise a plurality of channels 20 (i.e., main artery 22, capillaries 24 and/or sub-capillaries 26). The vascular network 18 may comprise a main artery 22. The main artery 22 may comprise an inlet 28, where fluid enters the network 18. The inlet 28 may be disposed at any location suitable for permitting fluid to enter the vascular network 18.
As shown in
Turning to
Still referring to
Both the first capillary 24a and the second capillary 24b may be associated with the main artery 22 at a single junction 21 as shown in
In one embodiment, the first capillary 24a is substantially symmetrical to the second capillary 24b with respect to the main artery 22. In one nonlimiting example, the main artery 22 has a cross-sectional area greater than a cross-sectional area of the first capillary 24a. In another nonlimiting example, the main artery 22 has a cross-sectional area greater than the cross-sectional area of the second capillary 24b. In yet another nonlimiting example, the main artery 22 has a cross-sectional area that is greater than the cross-sectional area of both the first capillary 24a and the second capillary 24b. The cross-sectional areas of the first capillary 24a and the second capillary 24b may be the same or may be different.
The vascular network 18 may also include a plurality of fluid exits 30 which may be disposed on the exterior surface 14 of the rotating roll 10. The first capillary 24a and the second capillary 24b may each be in fluid communication with one or more fluid exits 30. In an embodiment, one or both of the first and second capillaries 24a, 24b may be in fluid communication with the fluid exits 30 through a series of sub-capillaries 26 disposed on one or more branching levels of their respective trees 23. A capillary 24a, 24b may be associated with a sub-capillary 26 or may be associated with a plurality of sub-capillaries 26. Each sub-capillary 26 may associate with another sub-capillary 26a of a subsequent level or may associate with a plurality of sub-capillaries 26a on a subsequent level. In one nonlimiting example, a sub-capillary 26 has a cross-sectional area that is less than the cross-sectional area of a capillary 24 with which the sub-capillary 26 is associated. Likewise, a sub-capillary 26a in the subsequent level may have a cross-sectional area less than that of the sub-capillary 26 from which it extends.
Essentially (as shown in
In one embodiment, each capillary 24 or sub-capillary 26 on a given level has substantially the same length, diameter, volume and/or area. For example, the first capillary 24a and the second capillary 24b will both reside on the starting level and may have substantially the same length, diameter, volume and/or area. Alternatively, the capillaries 24 or sub-capillaries 26 on a given level may vary in length, volume and/or area.
In an embodiment, the channels 20 in the network 18 may be larger closer to the inlet 28 and may become smaller closer to the fluid exits 30. Said differently still, the main artery 22 may be larger in area and/or volume than the capillaries 24 extending from the main artery 22, and those capillaries 24 may be larger in area and/or volume than the sub-capillaries 26 extending therefrom. Reducing the area and/or volume at each level can facilitate the movement of fluid to the exits 30 while maintaining a desired flow rate and/or pressure.
In a further embodiment, as for example in depicted schematically in
The fluid exits 30 may be openings of any size or shape suitable to permit fluid to exit the vascular network 18 in a controlled manner as dictated by the particular fluid being deposited, the substrate on which it is being deposited, and the amount and placement of the fluid on the substrate, all of which can be predetermined by the skilled person. In an embodiment, an even number of fluid exits 30 are disposed on the exterior surface 14. In one nonlimiting example, the fluid exits 30 have an aspect ratio of at least 10. The aspect ratio is typically the ratio between the depth of the exit 30 (in the z-direction) and a dimension or diameter located in the x-y plane of the exit 30 on the surface 14. In another nonlimiting example, the diameter of the longest dimension of the fluid exit 30 on the exterior surface 14 is less than about 20 millimeters, less than about 10 millimeters, less than about 5 millimeters, such as, for example, between 100 microns to 5000 microns, such as, 500 microns or less than about 250 microns or less than about 100 microns or less than about 10 microns. By limiting the area of the fluid exits 30, the flow of fluid and/or the fluid deposition may be controlled more precisely.
Each fluid exit 30 may comprise an entry point 31 and an exit point 32. In one nonlimiting example, the entry point 31 and the exit point 32 are conterminous, that is, the respective capillary 24 or sub-capillary 26 simply ends at an opening on the exterior surface 14 (as shown in
The fluid exits 30 may be arranged in any desired manner, with the only constraint being the physical space. If desired, fluid exits 30 may be placed as close as the physical space allows as shown in
In another nonlimiting example, one or more of the fluid exits 30 comprise a micro-reservoir 39. Fluid may collect within an inner portion 40 of the micro-reservoir 39, hold fluid until eventual deposition on a substrate, and/or supply fluid to one or more fluid exits 30 (or sleeve exits 120 as discussed in more detail below). The micro-reservoir 39 may be in any shape suitable for the collection and/supply of fluid to one or more exits 30, 120. Nonlimiting examples of suitable shapes include cubic, polygonal, prismatic, round or elliptical. In another nonlimiting example, the micro-reservoir 39 is in the shape of an isosceles trapezoid as shown in
As depicted in
The individual fluid exits 30 and/or micro-reservoirs 39 may be designed to comprise different shapes, volumes, widths, depths and/or aspect ratios. In one nonlimiting example, some fluid exits 30 and/or micro-reservoirs 39 may comprise differently radiused portions 33 (such as relieved portions 34 and/or raised portions 35), while others are formed without differently radiused portions 33.
In yet another embodiment, the vascular network 18 may comprise a plurality of main arteries 22 (as shown, for example, in
In the case of multiple main arteries 22, the vascular network 18 may be viewed in sections, each section having one main artery 22. Each section may branch in the same manner (e.g., having the same number of trees 23 with the same levels) or each may branch in a different manner. In one nonlimiting example shown in
Returning to
The vascular network 18 may comprise as many main arteries 22, capillaries 24, sub-capillaries 26 and fluid paths 48 as can fit within the interior region 14. A circumferential or axial design would result in less available space within the roll 10 for channels 20. Thus, in circumferential or axial designed networks, it is more difficult to include a plurality of main arteries 22, capillaries 24 and fluid exits 30. Likewise, the constraints on physical space make it difficult to overlap channels 20 of different sections and thereby put different fluids close to one another on the exterior surface 14.
As noted above, the rotating roll 10 comprises an exterior surface 14 that substantially surrounds its central longitudinal axis 12. In an embodiment, the rotating roll 10 rotates about the central longitudinal axis 12. The rotating speed of the roll 10 can be any speed suitable for the processing being performed. In one nonlimiting example, the roll 10 rotates at a surface speed of 10 ft/minute, or from about 10 ft/minute to about 5000 ft/minute, or at about 500 ft/minute to 3000 ft/minute. The rotating roll 10 may also have an outside diameter suitable for processing needs. In a nonlimiting example, the rotating roll may have an outside diameter about 25 mm or greater, or from about 25 mm to about 900 mm, 150 mm to 510 mm.
It has been found that providing a fluid network as described herein can be effective at maintaining desired flow rates and pressures throughout the entirety of the fluid network, even with relatively small diameter rolls operating at relatively high surface speeds. In one nonlimiting example, a rotating roll 10 with an outer diameter (i.e., the diameter from the central axis 12 to the exterior surface 14) of 150 mm can operate with a surface speed of at least 1000 ft/minute while maintaining uniform flow at all points on the roll surface. In previous tests with a rotating roll having an outer diameter of 150 mm at a speed of 1000 ft/minute and containing an annular fluid micro-reservoir extending at least half the length of the roll, the fluid flow exhibited significant non-uniformity in both axial and circumferential directions. The fluid network 18 of the instant invention overcomes these prior limitations and enables the application of uniform fluid patterns with a wide range of fluids while using a wide range of roll sizes and operating over a wide range of speeds. Moreover, the roll 10 and network 18 of the present invention are capable of depositing fluids in a variety of sizes, including very large and very small patterns, despite the size of the roll 10.
The exterior surface 14 of the roll 10 substantially surrounds the vascular network 18 which is disposed in the interior region 16 of the roll 10. In one embodiment, the roll 10 is in the shape of a cylinder. However, one of skill in the art will readily recognize that the roll 10 may comprise any shape suitable for enclosing the vascular network 18 and rotating as required for the deposition of fluid in accordance with the present disclosure.
The exterior surface 14 comprises one or more fluid exits 30. In addition, the exterior surface 14 may comprise one or more regions.
In one embodiment, the exterior surface 14 of the roll 10 can be multi-radiused (i.e., comprise different elevations at different points). In a nonlimiting example, the fluid exits 30 and/or micro-reservoirs 39 may be designed such that they comprise different depths, widths and/or aspect ratios, causing the surface 14 to be multi-radiused.
In a further embodiment, as shown for example in
The roll 10 may also be temperature-controlled using, for example, heated oils, chilled glycol, mechanical heaters or other technologies known in the art. In one nonlimiting example, sections of the roll 10 are provided at different temperatures. In another nonlimiting example, one or more channels are temperature-controlled. In an embodiment, the roll 10 or the network 18 is controlled so that one or more of fluids may be provide at a temperature between 0° F. and 500° F., such as, for example, between 5 Celsius and 50 Celsius.
As shown in
The use of a plurality of rolls 10 enhances the delivery of fluids to a substrate. As discussed in more detail below, the vascular network 18 of the present invention permits more precise fluid deposition. Thus, the use of multiple rolls 10a, 10b with multiple fluids can create a product that has multiple fluids deposited on the substrate in a controlled manner to deliver an optimized pattern. Further, because multiple fluids can be deposited from one roll 10, a single roll 10 can produce a product that has more than one fluid versus known apparatuses and the combination of a plurality of rolls 10 permits a wide variety of fluid and or pattern combinations to be produced from a limited number of rolls 10.
In another embodiment, the number of fluids in each roll 10 may be changed. For example, one roll 10 may have 8 fluids, another roll 10 may have 4 fluids, and another roll 10 may have 3 fluids. Three rolls 10 are used for illustration purposes herein, but one of skill in the art will recognize that any number of rolls 10, any number of fluids within a roll 10, and any combination and/or order of fluids and other fluids may be used to create desired fluid applications.
In a non-limiting embodiment, the fluid may be an emulsion. The emulsion may be a water in oil emulsion or an oil in water emulsion. The emulsion may be a High Internal Phase emulsion.
The emulsion may be a High Internal Phase Emulsion (HIPE), also referred to as a polyHIPE. To form a HIPE, an aqueous phase and an oil phase are combined in a ratio between about 8:1 and 140:1. In certain embodiments, the aqueous phase to oil phase ratio is between about 10:1 and about 75:1, and in certain other embodiments the aqueous phase to oil phase ratio is between about 13:1 and about 65:1. This is termed the “water-to-oil” or W:0 ratio and can be used to determine the density of the resulting polyHIPE foam. As discussed, the oil phase may contain one or more of monomers, comonomers, photoinitiators, crosslinkers, and emulsifiers, as well as optional components. The water phase will contain water and in certain embodiments one or more components such as electrolyte, initiator, or optional components.
The HIPE can be formed from the combined aqueous and oil phases by subjecting these combined phases to shear agitation in a mixing chamber or mixing zone. The combined aqueous and oil phases are subjected to shear agitation to produce a stable HIPE having aqueous droplets of the desired size. An initiator may be present in the aqueous phase, or an initiator may be introduced during the foam making process, and in certain embodiments, after the HIPE has been formed. The emulsion making process produces a HIPE where the aqueous phase droplets are dispersed to such an extent that the resulting HIPE foam will have the desired structural characteristics. Emulsification of the aqueous and oil phase combination in the mixing zone may involve the use of a mixing or agitation device such as an impeller, by passing the combined aqueous and oil phases through a series of static mixers at a rate necessary to impart the requisite shear, or combinations of both. Once formed, the HIPE can then be withdrawn or pumped from the mixing zone. One method for forming HIPEs using a continuous process is described in U.S. Pat. No. 5,149,720 (DesMarais et al), issued Sep. 22, 1992; U.S. Pat. No. 5,827,909 (DesMarais) issued Oct. 27, 1998; and U.S. Pat. No. 6,369,121 (Catalfamo et al.) issued Apr. 9, 2002.
Following polymerization, the resulting foam pieces are saturated with aqueous phase that needs to be removed to obtain substantially dry foam pieces. In certain embodiments, foam pieces can be squeezed free of most of the aqueous phase by using compression, for example by running the heterogeneous mass comprising the foam pieces through one or more pairs of nip rollers. The nip rollers can be positioned such that they squeeze the aqueous phase out of the foam pieces. The nip rollers can be porous and have a vacuum applied from the inside such that they assist in drawing aqueous phase out of the foam pieces. In certain embodiments, nip rollers can be positioned in pairs, such that a first nip roller is located above a liquid permeable belt, such as a belt having pores or composed of a mesh-like material and a second opposing nip roller facing the first nip roller and located below the liquid permeable belt. One of the pair, for example the first nip roller can be pressurized while the other, for example the second nip roller, can be evacuated, so as to both blow and draw the aqueous phase out the of the foam. The nip rollers may also be heated to assist in removing the aqueous phase. In certain embodiments, nip rollers are only applied to non-rigid foams, that is, foams whose walls would not be destroyed by compressing the foam pieces.
In certain embodiments, in place of or in combination with nip rollers, the aqueous phase may be removed by sending the foam pieces through a drying zone where it is heated, exposed to a vacuum, or a combination of heat and vacuum exposure. Heat can be applied, for example, by running the foam though a forced air oven, IR oven, microwave oven or radiowave oven. The extent to which a foam is dried depends on the application. In certain embodiments, greater than 50% of the aqueous phase is removed. In certain other embodiments greater than 90%, and in still other embodiments greater than 95% of the aqueous phase is removed during the drying process.
In an embodiment, open cell foam is produced from the polymerization of the monomers having a continuous oil phase of a High Internal Phase Emulsion (HIPE). The HIPE may have two phases. One phase is a continuous oil phase having monomers that are polymerized to form a HIPE foam and an emulsifier to help stabilize the HIPE. The oil phase may also include one or more photoinitiators. The monomer component may be present in an amount of from about 80% to about 99%, and in certain embodiments from about 85% to about 95% by weight of the oil phase. The emulsifier component, which is soluble in the oil phase and suitable for forming a stable water-in-oil emulsion may be present in the oil phase in an amount of from about 1% to about 20% by weight of the oil phase. The emulsion may be formed at an emulsification temperature of from about 5° C. to about 130° C. and in certain embodiments from about 50° C. to about 100° C.
In general, the monomers will include from about 20% to about 97% by weight of the oil phase at least one substantially water-insoluble monofunctional alkyl acrylate or alkyl methacrylate. For example, monomers of this type may include C4-C18 alkyl acrylates and C2-C18 methacrylates, such as ethylhexyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, tetradecyl acrylate, benzyl acrylate, nonyl phenyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, and octadecyl methacrylate.
The oil phase may also have from about 2% to about 40%, and in certain embodiments from about 10% to about 30%, by weight of the oil phase, a substantially water-insoluble, polyfunctional crosslinking alkyl acrylate or methacrylate. This crosslinking comonomer, or crosslinker, is added to confer strength and resilience to the resulting HIPE foam. Examples of crosslinking monomers of this type may have monomers containing two or more activated acrylate, methacrylate groups, or combinations thereof. Nonlimiting examples of this group include 1,6-hexanedioldiacrylate, 1,4-butanedioldimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,12-dodecyldimethacrylate, 1,14-tetradecanedioldimethacrylate, ethylene glycol dimethacrylate, neopentyl glycol diacrylate (2,2-dimethylpropanediol diacrylate), hexanediol acrylate methacrylate, glucose pentaacrylate, sorbitan pentaacrylate, and the like. Other examples of crosslinkers contain a mixture of acrylate and methacrylate moieties, such as ethylene glycol acrylate-methacrylate and neopentyl glycol acrylate-methacrylate. The ratio of methacrylate:acrylate group in the mixed crosslinker may be varied from 50:50 to any other ratio as needed.
Any third substantially water-insoluble comonomer may be added to the oil phase in weight percentages of from about 0% to about 15% by weight of the oil phase, in certain embodiments from about 2% to about 8%, to modify properties of the HIPE foams. In certain embodiments, “toughening” monomers may be desired which impart toughness to the resulting HIPE foam. These include monomers such as styrene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene. Without being bound by theory, it is believed that such monomers aid in stabilizing the HIPE during polymerization (also known as “curing”) to provide a more homogeneous and better formed HIPE foam which results in better toughness, tensile strength, abrasion resistance, and the like. Monomers may also be added to confer flame retardancy as disclosed in U.S. Pat. No. 6,160,028 (Dyer) issued Dec. 12, 2000. Monomers may be added to confer color, for example vinyl ferrocene, fluorescent properties, radiation resistance, opacity to radiation, for example lead tetraacrylate, to disperse charge, to reflect incident infrared light, to absorb radio waves, to form a wettable surface on the HIPE foam struts, or for any other desired property in a HIPE foam. In some cases, these additional monomers may slow the overall process of conversion of HIPE to HIPE foam, the tradeoff being necessary if the desired property is to be conferred. Thus, such monomers can be used to slow down the polymerization rate of a HIPE. Examples of monomers of this type can have styrene and vinyl chloride.
The oil phase may further contain an emulsifier used for stabilizing the HIPE. Emulsifiers used in a HIPE can include: (a) sorbitan monoesters of branched C16-C24 fatty acids; linear unsaturated C16-C22 fatty acids; and linear saturated C12-C14 fatty acids, such as sorbitan monooleate, sorbitan monomyristate, and sorbitan monoesters, sorbitan monolaurate diglycerol monooleate (DGMO), polyglycerol monoisostearate (PGMIS), and polyglycerol monomyristate (PGMM); (b) polyglycerol monoesters of -branched C16-C24 fatty acids, linear unsaturated C16-C22 fatty acids, or linear saturated C12-C14 fatty acids, such as diglycerol monooleate (for example diglycerol monoesters of C18:1 fatty acids), diglycerol monomyristate, diglycerol monoisostearate, and diglycerol monoesters; (c) diglycerol monoaliphatic ethers of -branched C16-C24 alcohols, linear unsaturated C16-C22 alcohols, and linear saturated C12-C14 alcohols, and mixtures of these emulsifiers. See U.S. Pat. No. 5,287,207 (Dyer et al.), issued Feb. 7, 1995 and U.S. Pat. No. 5,500,451 (Goldman et al.) issued Mar. 19, 1996. Another emulsifier that may be used is polyglycerol succinate (PGS), which is formed from an alkyl succinate, glycerol, and triglycerol.
Such emulsifiers, and combinations thereof, may be added to the oil phase so that they can have between about 1% and about 20%, in certain embodiments from about 2% to about 15%, and in certain other embodiments from about 3% to about 12% by weight of the oil phase.
In certain embodiments, coemulsifiers may also be used to provide additional control of cell size, cell size distribution, and emulsion stability. Examples of coemulsifiers include phosphatidyl cholines and phosphatidyl choline-containing compositions, aliphatic betaines, long chain C12-C22 dialiphatic quaternary ammonium salts, short chain C1-C4 dialiphatic quaternary ammonium salts, long chain C12-C22 dialkoyl(alkenoyl)-2-hydroxyethyl, short chain C1-C4 dialiphatic quaternary ammonium salts, long chain C12-C22 dialiphatic imidazolinium quaternary ammonium salts, short chain C1-C4 dialiphatic imidazolinium quaternary ammonium salts, long chain C12-C22 monoaliphatic benzyl quaternary ammonium salts, long chain C12-C22 dialkoyl(alkenoyl)-2-aminoethyl, short chain C1-C4 monoaliphatic benzyl quaternary ammonium salts, short chain C1-C4 monohydroxyaliphatic quaternary ammonium salts. In certain embodiments, ditallow dimethyl ammonium methyl sulfate (DTDMAMS) may be used as a coemulsifier.
The oil phase may comprise a photoinitiator at between about 0.05% and about 10%, and in certain embodiments between about 0.2% and about 10% by weight of the oil phase. Lower amounts of photoinitiator allow light to better penetrate the HIPE foam, which can provide for polymerization deeper into the HIPE foam. However, if polymerization is done in an oxygen-containing environment, there should be enough photoinitiator to initiate the polymerization and overcome oxygen inhibition. Photoinitiators can respond rapidly and efficiently to a light source with the production of radicals, cations, and other species that are capable of initiating a polymerization reaction. The photoinitiators used in the present invention may absorb UV light at wavelengths of about 200 nanometers (nm) to about 800 nm, in certain embodiments about 200 nm to about 350 nm. If the photoinitiator is in the oil phase, suitable types of oil-soluble photoinitiators include benzyl ketals, α-hydroxyalkyl phenones, α-amino alkyl phenones, and acylphospine oxides. Examples of photoinitiators include 2,4,6-[trimethylbenzoyldiphosphine] oxide in combination with 2-hydroxy-2-methyl-1-phenylpropan-1-one (50:50 blend of the two is sold by Ciba Speciality Chemicals, Ludwigshafen, Germany as DAROCUR® 4265); benzyl dimethyl ketal (sold by Ciba Geigy as IRGACURE 651); α-,α-dimethoxy-α-hydroxy acetophenone (sold by Ciba Speciality Chemicals as DAROCUR® 1173); 2-methyl-1-[4-(methyl thio) phenyl]-2-morpholino-propan-1-one (sold by Ciba Speciality Chemicals as IRGACURE® 907); 1-hydroxycyclohexyl-phenyl ketone (sold by Ciba Speciality Chemicals as IRGACURE® 184); bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (sold by Ciba Speciality Chemicals as IRGACURE 819); diethoxyacetophenone, and 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl) ketone (sold by Ciba Speciality Chemicals as IRGACURE® 2959); and Oligo [2-hydroxy-2-methyl-1-[4-(1-methylvinyl) phenyl]propanone] (sold by Lambeth spa, Gallarate, Italy as ESACURE® KIP EM.
The dispersed aqueous phase of a HIPE can have water, and may also have one or more components, such as initiator, photoinitiator, or electrolyte, wherein in certain embodiments, the one or more components are at least partially water soluble.
One component of the aqueous phase may be a water-soluble electrolyte. The water phase may contain from about 0.2% to about 40%, in certain embodiments from about 2% to about 20%, by weight of the aqueous phase of a water-soluble electrolyte. The electrolyte minimizes the tendency of monomers, comonomers, and crosslinkers that are primarily oil soluble to also dissolve in the aqueous phase. Examples of electrolytes include chlorides or sulfates of alkaline earth metals such as calcium or magnesium and chlorides or sulfates of alkali earth metals such as sodium. Such electrolyte can include a buffering agent for the control of pH during the polymerization, including such inorganic counterions as phosphate, borate, and carbonate, and mixtures thereof. Water soluble monomers may also be used in the aqueous phase, examples being acrylic acid and vinyl acetate.
Another component that may be present in the aqueous phase is a water-soluble free-radical initiator. The initiator can be present at up to about 20 mole percent based on the total moles of polymerizable monomers present in the oil phase. In certain embodiments, the initiator is present in an amount of from about 0.001 to about 10 mole percent based on the total moles of polymerizable monomers in the oil phase. Suitable initiators include ammonium persulfate, sodium persulfate, potassium persulfate, 2,2′-azobis(N,N′-dimethyleneisobutyramidine)dihydrochloride, and other suitable azo initiators. In certain embodiments, to reduce the potential for premature polymerization which may clog the emulsification system, addition of the initiator to the monomer phase may be just after or near the end of emulsification.
Photoinitiators present in the aqueous phase may be at least partially water soluble and can have between about 0.05% and about 10%, and in certain embodiments between about 0.2% and about 10% by weight of the aqueous phase. Lower amounts of photoinitiator allow light to better penetrate the HIPE foam, which can provide for polymerization deeper into the HIPE foam. However, if polymerization is done in an oxygen-containing environment, there should be enough photoinitiator to initiate the polymerization and overcome oxygen inhibition. Photoinitiators can respond rapidly and efficiently to a light source with the production of radicals, cations, and other species that are capable of initiating a polymerization reaction. The photoinitiators used in the present invention may absorb UV light at wavelengths of from about 200 nanometers (nm) to about 800 nm, in certain embodiments from about 200 nm to about 350 nm, and in certain embodiments from about 350 nm to about 450 nm. If the photoinitiator is in the aqueous phase, suitable types of water-soluble photoinitiators include benzophenones, benzils, and thioxanthones. Examples of photoinitiators include 2,2′-Azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride; 2,2′-Azobis[2-(2-imidazolin-2-yl)propane]disulfate dehydrate; 2,2′-Azobis(1-imino-1-pyrrolidino-2-ethylpropane)dihydrochloride; 2,2′-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; 2,2′-Azobis(2-methylpropionamidine)dihydrochloride; 2,2′-dicarboxymethoxydibenzalacetone, 4,4′-dicarboxymethoxydibenzalacetone, 4,4′-dicarboxymethoxydibenzalcyclohexanone, 4-dimethylamino-4′-carboxymethoxydibenzalacetone; and 4,4′-disulphoxymethoxydibenzalacetone. Other suitable photoinitiators that can be used in the present invention are listed in U.S. Pat. No. 4,824,765 (Sperry et al.) issued Apr. 25, 1989.
In addition to the previously described components other components may be included in either the aqueous or oil phase of a HIPE. Examples include antioxidants, for example hindered phenolics, hindered amine light stabilizers; plasticizers, for example dioctyl phthalate, dinonyl sebacate; flame retardants, for example halogenated hydrocarbons, phosphates, borates, inorganic salts such as antimony trioxide or ammonium phosphate or magnesium hydroxide; dyes and pigments; fluorescers; filler pieces, for example starch, titanium dioxide, carbon black, or calcium carbonate; fibers; chain transfer agents; odor absorbers, for example activated carbon particulates; dissolved polymers; dissolved oligomers; and the like.
Dependent upon the HIPE chemistry, the HIPE may be delivered through the roll at a temperature between 5 Celsius and 90 Celsius, preferably between 5 Celsius and 70 Celsius, such as, for example, between 15 Celsius and 50 Celsius, such as, 16 Celsius, 17 Celsius, 18 Celsius, 19 Celsius, 20 Celsius, 21 Celsius, 22 Celsius, 23 Celsius, 24 Celsius, 25 Celsius, 26 Celsius, 27 Celsius, 28 Celsius, 29 Celsius, 30 Celsius, 35 Celsius, 40 Celsius, or 45 Celsius.
The fluid may also be a chemical that will react with another chemical in the same roll, such as, for example, a polyol and an isocyanate or a reduction oxidation polymerization reaction wherein one chemical comprises the reducing agent and the second chemical comprises the oxidizing agent such as those described in U.S. Pat. No. 6,323,250 filed on Nov. 14, 2000 with priority to JP patent application 11-328683, filed on Nov. 18, 1999; incorporated herein by reference. The two chemicals may be combined within the roll or at the opening of the roll to the substrate such that they may react upon exiting the roll. Additionally, the polyol and the isocyanate may be combined with a blowing agent prior to entering the roll provided that the materials do not set up to form a solid polyurethane foam prior to exiting the roll.
Turning to
In one nonlimiting example, the sleeve 100 is disposed on the entire exterior surface 14 such that it substantially surrounds the rotating roll 10. Alternatively, the sleeve 100 may be disposed in a surrounding relationship about a portion of the rotating roll 10 to form a sleeve coverage area 105. In such case, one fluid exit 30 may be in operative relationship with the substrate without the fluid passing through the sleeve 100, while another fluid exit 30 can be registered or aligned with a sleeve exit 120. In other words, one of the fluid exits may be outside of the sleeve coverage area 105. In another nonlimiting example, the sleeve 100 is substantially cylindrical. In one embodiment, the sleeve 100 is removable from the roll 10. The sleeve 100 may comprise a central axis 110 and an inner region 130 substantially surrounding the central axis 110. The inner region 130 may comprise a first circumference, C1. The rotating roll 10 may have a second circumference, C2, defined by its exterior surface 14. The first circumference C1 may be larger than the second circumference C2. In a further embodiment depicted in
The sleeve 100 may comprise a metal material. The metal material can have a Rockwell hardness value of about B79. In one nonlimiting example, the metal material is stainless steel. In another nonlimiting example, the outer surface 140 of the sleeve 100 can have a taber abrasion testing factor greater than the taber abrasion testing factor of the exterior surface 14 of the roll 10. Having a greater taber abrasion factor than the exterior surface 14 of the roll 10 and/or having a hardness value of about B79 can protect the roll 10 from exposure to substances that could change its properties, such as UV rays. Further, the hardness and/or taber abrasion of the outer surface 140 allows for harder or sharper items, such as doctor blades to come in contact with the sleeve 100—which may, for example, aid in cleaning. Further still, the sleeve 100 can enhance hygiene. For example, the outer surface 140 may be made of a material that is less likely to attract or retain contaminants (i.e., the outer surface 140 may have a lower coefficient of friction relative to the exterior surface 14 of the roll 10 or may be coated to repel contaminants etc.).
The outer surface 140 of the sleeve 100 may comprise differently radiused portions 33 in the same manner as the roll 10 may comprise differently radiused portions 33. By altering the radius of the outer surface, the sleeve 100 can be customized to provide a wide variety of textural properties such as elasticity or hardness. In one embodiment, the sleeve 100 may have a hardness value up to Shore C60. In another embodiment, the sleeve 100 may comprise a hardness value of at least P&J 150. The sleeve may comprise a hardness value between Shore C60 and P&G 150.
In a further embodiment, the sleeve may have a thickness, T, of greater than 1 mm or greater than 1.5 mm. In yet another embodiment, the sleeve 100 comprises a mesh or screen material. The screen may comprise a thickness, T, of less than about 1.5 mm or less than about 0.5 mm Such screens are commercially available from the Stork Screen Company. As illustrated in
As shown in
As shown in
A sleeve exit 120 may have an aspect ratio of at least 10, or at least 25. The sleeve exit 120 may created in the sleeve 100 by any suitable means. In one nonlimiting example, the sleeve exit 120 is laser drilled into the sleeve 100. A number of shapes may be achieved. In another nonlimiting example, the sleeve exit 120 may be shaped to form a differently radiused portion 33, such as a relieved portion 34 and/or a raised portion 35. In an example of the relieved portion 34, the meeting point 124 can comprise a cross-sectional area smaller than the cross-sectional area of the second side 122, such that a pool of fluid may be provided in the relieved portion 35 and transferred to a substrate 50. One of skill in the art will recognize that the “pool” of fluid may remain a small amount of fluid but may be a higher volume than fluid provided in other configurations of the sleeve exit 120. Any combination of arrangements of sleeve exit 120 designs may be provided. As with the differently radiused portions 33 of the roll 10, one differently radiused portion 33 may comprise both a raised portion 35 and a relieved portion 34. Moreover, the differently radiused portion 33 may comprise one or more sides 37, and the meeting point 124 and/or the release point 125 may be located on a side 37. In one nonlimiting example, a fluid exit 30 and/or reservoir 39 having a differently radiused portion 33 is registered or associated with a sleeve exit 120 having a differently radiused portion 33.
In an embodiment, the sleeve 100 has a thickness, T, of greater than about 1.5 mm, or between about 1.5 mm or about 10 mm, and a sleeve exit 120 has an aspect ratio of greater than about 10. In another embodiment, the sleeve 100 has a thickness, T, of less than about 4 mm, or less than about 2 mm, or less than about 1.5 mm, or less than about 0.5 mm. The cross-sectional area of meeting point 124 of the sleeve exit 120 may be less than about 0.5, or less than about 0.3 or less than about 0.15 times the cross-sectional area of the fluid exit point 32 or reservoir opening 46.
The sleeve exits 120 may be arranged in any desired manner, with the only constraint being the physical space. If desired, the sleeve exits 120 may be placed as close as the physical space allows. In an alternative embodiment, the fluid exits 30 collectively may form a pattern 52 to be deposited on a substrate 50, such as a line or plurality of lines, aesthetic design and/or letters (not shown).
The sleeve 100 may be fitted onto the rotating roll 10 by any suitable means, including but not limited to compression or shrink fit.
It is believed that the design of the vascular network 18 permits optimal control of fluid deposition in multiple ways. First, the ability to separately customize various components of the system (e.g., the diameter of the roll 10, diameters of the channels 20, route and length of the fluid paths 48) allows for various objectives to be achieved with just one roll 10. Essentially, as discussed more completely in the method section below, the designer determines where and at what rate fluid is to be deposited, selects fluid(s) having desirable properties, designs the network 18 to achieve the determined output and objectives (e.g., arranging the trees, designing tree size, etc.) and selects a fluid delivery system (e.g., the channel 20 sizes, junctions 21, feed systems such as pumps at inlet 28, rotary union 230 etc.). Objectives include but are not limited to uniformity in fluid deposition levels or rates despite different exits 30, 120, uniformity in volumetric flow rates despite different channels 20, minimal flow rate and/or pressure fluctuations throughout the network 18, uniformity in pressure drops despite different trees 23, control of shear rates on the fluid, and the capability to apply very precise, small flows of fluid to a substrate 50. Various other objectives could be met as well. Second, the sleeve 100 may be used in conjunction with the vascular network 18 and roll 10 to overcome physical constraints (e.g., available space in the interior region 16). Third, the substantially radial design of the vascular network 18 overcomes challenges associated with rotating rolls 10 used for fluid deposition.
Customization
The following nonlimiting examples highlight the capabilities of the vascular network 18 through customizing various factors:
Minimal flow rate and/or pressure fluctuations may be achieved by, for example, minimizing the differential between the cross-sectional areas of associated channels. For example, the cross-sectional area decreases at each junction 21. In one embodiment, fluid is provided at the inlet 28 at a pressure of less than 10 psi, or less than 5 psi. In a further embodiment, the pressure decreases at each junction 21 by less than 2 psi. Minimizing flow rate and pressure fluctuations also prevents air penetration of the interior region 15 of the roll 10 which could cause fluid flow disruption or even starvation.
To achieve uniform fluid deposition, the fluid paths 48 may also be directed (by use of baffles to slow or direct fluid flow, for example) or configured to have equal path lengths.
Likewise, it is believed the same uniform deposition of fluid can be achieved by having substantially equal area change from the main artery 22 to each fluid exit 30 with which it is in fluid communication. In one nonlimiting example, each capillary 24 or sub-capillary 26 on a given level has substantially the same area, such that the change in area between the main artery 22 and each of the fluid exits 30 is substantially the same despite distinct fluid paths 48.
In another embodiment, substantially the same diameter change can be achieved in two different fluid paths, which would also result in uniform fluid deposition despite the different paths. As shown in
One nonlimiting example of customization of the network 18 involves the use of the following formula when designing each tree 23:
DiameterLevel=DiameterStart*BR̂(−Level/(2+epsilon))
Further to the above, epsilon can be any real number other than −2. The epsilon value may be selected based on shear sensitivity of the fluid, the desired level of uniformity in the fluid flow (i.e., the uniformity between fluid to separate exits), the desired pressure as the fluid exits the network 18 and/or the desired fluid drop or fluctuation within the network 18, the smallest possible orifice that can be formed for the fluid to exit, and physical constraints of the roll 10 such as how large the Diameterstart can be. In one nonlimiting example, epsilon is a real number between 1 and 2. In another nonlimiting example, epsilon is about 1.5 or about 1.6.
By way of example, and as shown in
As another example, as shown in
The skilled person will recognize that there are numerous options available for use in the disclosed formula depending on the desired results. Moreover, each tree 23 can be designed in the same manner (i.e., same values used for each variable) or differently, or each tree 23 can be designed to achieve the same effect despite different values or to achieve different effects. Further, the trees 23 and network 18 can be designed without the use of the formula.
In addition, the design of the fluid exits 30 (including the micro-reservoirs 39) can also contribute to optimization of the vascular network 18. In one embodiment, the area of micro-reservoirs 39 on the exterior surface 14 may vary. The exit length (i.e., the distance from the entry point 31 to the exit point 32) of each micro-reservoir 39 can be adjusted such that the pressure drop of each micro-reservoir is the same. This will result in uniform velocity from the various micro-reservoirs 39 despite their varied areas. Uniform velocity results in the same thickness of fluid being deposited by each exit 30 on each roll 10 rotation.
In yet another embodiment, one or more of the fluid exits 30 are designed to serve as limiting orifices. That is, there is a significantly higher pressure drop through the exits 30 than the pressure drop throughout the rest of the vascular network 18. This design can be achieved, for example, using the above formula where epsilon is −1. The design may resolve or cover imperfections or slight imbalances that exist in the network 18. Essentially, the fluid will still be deposited as desired despite imperfections because of the force with which the fluid is pushed out of the exits 30. This objective may also be achieved by designing one or more of the sleeve exits 120 to serve as limiting orifices (discussed in more detail below).
In yet another embodiment, the velocity at different exits 30 could be different in order to lay down different amounts of fluid. In one such example, the different exits 30 may be the same size or different sizes. The velocity may be varied by lowering the pressure drop at one of the exits 30 (as compared to the pressure drop at another exit 30). Fluid leaving the exit 30 that has the lower pressure drop will have higher velocity and therefore more fluid will be deposited.
Where multiple main arteries are employed as shown for example in
Sleeve as Additional Customization Tool
The sleeve 100 may work in conjunction with the roll 10 and its network 18 to achieve desired effects. Indeed, the sleeve 100 and roll 10 may comprise a sleeve and roll system 160 incorporating any of their respective components as described herein. For instance, the sleeve exits 120 may provide the same optimization as discussed above with respect to the design of fluid exits 30 (e.g., velocity of exiting fluid along different paths, AM tone control). In one nonlimiting example, a sleeve exit 120 may operate as a limiting orifice. In one such example, the sleeve exit 120 is registered or otherwise associated with a fluid exit point 32 at a meeting point 124. As shown in
Turning to
Overcoming Issues
The design of the network 18 compensates for the centripetal/centrifugal forces resulting from the rotation of the roll 10. In networks without substantially radial fluid paths 48, centripetal/centrifugal force can impede the flow of fluids to the desired outlets. Deviation from radial paths can increase negative effects of centripetal/centrifugal force. Here, however, the substantially radial paths minimize deviation from radial flow more than fluid paths that are substantially axial or substantially circumferential. Essentially, the present invention enables operating with high centripetal forces.
It is also believed the radial design permits fluid to flow to exits 30, 120 in a more uniform manner Contrarily, circumferential design may result in certain areas of the network being starved or void of fluid while other areas would have too much fluid. In other words, necessary differences in path lengths from a main artery 22 to a fluid exit 30 in a circumferential design would allow fluid to quickly travel to certain locations within the vascular network 18 while not adequately reaching other locations. The same may be true in an axial design.
The rotating roll 10 and/or the vascular network 18 may be made through the use of stereo lithographic printing (SLA) or other forms of what is commonly known as 3D printing or Additive Manufacturing. In another nonlimiting example, the vascular network 18 is created by casting, such as a process analogous to lost wax printing, or any other means known in the art to create a network of channels 20 with predetermined paths 48. The roll 10 may be comprised of one unitary piece of material. In an alternative nonlimiting example, the roll 10 may be comprised of segments of material joined together. This would allow replacement of just a section of the roll 10 if there was localized damage to the roll 10 and enables fabrication of the roll 10 over a much wider range of machines.
In an embodiment, the rotating roll 10 may be used in conjunction with a backing surface 200 as depicted in
Turning to
In a further embodiment, the rotating roll 10 may be associated with a hygiene system 220. The hygiene system 220 may be any known system or mechanism suitable for the removal of debris and dust. Nonlimiting examples of hygiene systems 220 include vacuums, sprayers, doctor blade, brushes and blowers.
In still another embodiment, the rotating roll 10 may be associated with a rotary union 230. The rotary union 230 may have multiple ports and may supply one or more fluids to the vascular network 18 of a rotating roll 10. By way of nonlimiting example, up to eight individual fluids can be provided to a rotating roll 10. In another nonlimiting example, the rotary union 230 may supply one or more fluids to the vascular networks 18 of a plurality of rolls 10. From the rotary union 230, each fluid can be piped into the interior region 16 of the roll 10, specifically to the inlet 28. One of skill in the art will understand that a conventional multi-port rotary union 230 suitable for use with the present invention can typically be provided with up to forty-four passages and are suitable for use up to 7,500 lbs. per square inch of fluid pressure. A nonlimiting example of a suitable rotary union is described in U.S. patent application Ser. No. 14/038,957 to Conroy.
Other design features can be incorporated into the design of the rotating roll 10 and related apparatuses as well to aid in fluid control, roll assembly, roll maintenance, and cost optimization. By way of non-limiting example, check valves, static mixers, sensors, or gates or other such devices can be provided integral within the rotating roll 10 to control the flow and pressure of fluids being routed throughout the roll 10. In another example, the roll 10 may contain a closed loop fluid recirculation system where a fluid could be routed back to any point inside the roll 10 or to any point external to the roll 10 as a fluid feed tank or an incoming feed line to the roll 10. In another example, as mentioned above, the roll 10 can be fabricated so that the surface 14 of the roll 10 and/or the outer surface 130 of the sleeve 100 is multi-radiused (i.e., has different elevations) surface. In addition to the above disclosure, multi-radiused surface may facilitate cleaning of the roll 10 or sleeve 100, transferring fluid from the surface 14, 130 to a substrate 50, moving the substrate 50 out of plane as in an embossing, activation transformation and the like, and/or achieving different fluid transfer rates and/or different deformation (e.g., embossment) depths. Multi-radiused surfaces may be designed in accordance with teachings provided in U.S. Pat. No. 7,611,582 to McNeil which is incorporated by reference herein. In yet another nonlimiting example, the addition of a light source within or proximate to the rotating roll 10 can be provided to increase visibility of the rotating roll 10 or into the interior region 16 of the rotating roll 10.
Indeed, the rotating roll 10 may be used to perform multiple operations simultaneously and/or in precise registration. For example, a multi-radiused exterior surface 14 in combination with the vascular network 18 permits both embossing and distribution of fluid on a substrate 50 through the same apparatus, namely the rotating roll 10. One of skill in the art will appreciate that various combinations can result including but not limited to simultaneous, dosing, print, and emboss patterns and multiple structural transformations (e.g., embossing and chemical processing).
The rotating roll 10 may also be used in combination with a feedback system 240 such as sensors and computers or other components known in the art. The feedback system 240 can send current state information (e.g., flow rate, fluid amount, add-on rate and location, pressures, fluid or roll velocity, location of product features 51 and/or temperature) so that changes can be made dynamically.
The rotating roll 10 may also be associated with a control mechanism 250 such as a computer or other components known in the art, such that fluid pressure, volume, velocity, add-on rates and locations, fluid or roll temperature, rotational speed, fluid application level, roll surface speed, fluid flow rate, pressure, substrate speed, degree of circumferential roll contact by the substrate, distance between the exterior surface 14, 130 and a backing surface 200, pressure between the rotating roll 10 and the backing surface 200 and combinations thereof, and other operational features discussed herein may be controlled and/or adjusted dynamically. In one embodiment, the control mechanism 250 can separately control features associated with a given tree 23, main artery 22 or section of the roll, including but not limited to fluid application level, fluid application rate, fluid flow rate, pressure, temperature and combinations thereof. In one nonlimiting example, the fluid application rate of each main artery 22 is at least 10% different.
In a further embodiment, the roll 10 can be used in conjunction with a pretreat station 260. The pretreat station 260 may be positioned upstream from the roll 10. Where a plurality of rolls 10 are used, the pretreat station 260 may be positioned upstream from at least one roll 10 and/or downstream from other rolls 10. The pretreat station 260 may comprise a spraying, extruding, printing or other process and/or may be used to treat a substrate 50 with chemicals, fluids, heaters/coolers and/or other treatment processes in preparation for or as a supplement to the fluid deposition provided by the roll 10. In one nonlimiting example, the pretreat station 260 is used to provide water on the substrate 50.
In yet another embodiment, the roll 10 may be used in conjunction with overcoat station 270. The overcoat station 270 may be positioned downstream from the roll 10. Where a plurality of rolls 10 are used, the overcoat station 270 may be positioned downstream from at least one roll 10 and/or upstream from other rolls 10. The overcoat station 270 may comprise a spraying, extruding, printing or other process and/or may be used to treat or coat a substrate 50 with chemicals, fluids, heaters/coolers and/or other treatment processes after fluid deposition is provided by the roll 10. In one nonlimiting example, the overcoat station 270 is used to provide a varnish on the substrate 50.
In an embodiment shown in
The vascular network 18 may be built using stereo lithographic printing as discussed above. The network 18 may be disposed in the rotating roll 10. The rotating roll 10, or a portion of the rotating roll 10, may be substantially surrounded by a sleeve 100. Designing the network 18 may include designing a main artery 22 (having any of the features described herein in relation to main arteries 22) associated with one or more trees 23 (having any of the features described herein in relation to trees 23). Further, designing the network 18 may include selecting the location and/or size of the trees 23 and associating at least one of the trees 23 with a fluid exit 30. One or more of the trees may comprise branching levels as discussed above. In one nonlimiting example, a tree 23 has n levels. The pressure drop in the channels 20 may increase as the branch level increases. In other words, the pressure drop in between channels on level n and level n−1 may be greater than the pressure drop between levels n−1 and n−2. In another nonlimiting example, a tree 23 is designed such that shear rates are maintained at each branch level (i.e., the shear rates are consistent despite the branch level). In one embodiment, a tree 23 is designed using the formula: DiameterLevel=DiameterStart*BR̂(−Level/(2+Epsilon)) (discussed in detail above).
Further still, designing the network 18 may comprise designing and/or fluid exits 30. Fluid exits 30 may comprise any of the features described herein in relation to fluid exits 30. Designing the vascular network 18 may also comprise analyzing the deposit objective, one or more fluid properties, desired pressure and/or diameter changes, shear rates and combinations of these factors.
Selecting the fluid delivery system may comprise selecting or designing channels 20, locations and/or sizes of channels 20, junctions 21, locations and/or sizes of junctions 21, a fluid source (such as a rotary union 230), and/or a pumping mechanism or other means to provide fluid at a desired rate. Further, selecting a fluid delivery system may include selecting desired fluid pressure and/or velocity, which may vary or remain constant during the fluid's travel through the roll 10. The method 300 may also include selecting combinations of these factors.
In another embodiment shown in
The designing step 320′ may comprise any of the aforementioned principles with respect to step 320. Further, step 320′ may comprise designing at least two main arteries 22, each of which being associated with one or more trees 23 and at least one of the trees 23 being associated with a fluid exit 30. Again, the network 18 may be formed using stereo lithographic printing. In addition, the network 18 may be disposed within a rotating roll 10, and the roll 10 may be disposed within or partially within a sleeve 100.
Selecting a fluid delivery system 340′ may comprise the same considerations and steps as indicated above with respect to step 340.
Methods for Depositing a Fluid onto a Substrate
Turning to
In particular, the method 400 may include the steps 410, 420 of providing a fluid and providing a substrate 50. The fluid may be provided from a rotary union 230.
The substrate may include, for example, conventional absorbent materials such as creped cellulose wadding, fluffed cellulose fibers, wood pulp fibers also known as airfelt, and textile fibers. The substrate may also include also be fibers such as, for example, synthetic fibers, thermoplastic particulates or fibers, tricomponent fibers, and bicomponent fibers such as, for example, sheath/core fibers having the following polymer combinations: polyethylene/polypropylene, polyethylvinyl acetate/polypropylene, polyethylene/polyester, polypropylene/polyester, copolyester/polyester, and the like. The substrate may be any combination of the materials listed above and/or a plurality of the materials listed above, alone or in combination.
The substrate may be hydrophobic or hydrophilic. The substrate or portions of the substrate may be treated to be made hydrophobic. The substrate or portions of the substrate may be treated to become hydrophilic.
The constituent fibers of the substrate can be comprised of polymers such as polyethylene, polypropylene, polyester, and blends thereof. The fibers can be spunbound fibers. The fibers can be meltblown fibers. The fibers can comprise cellulose, rayon, cotton, or other natural materials or blends of polymer and natural materials. The fibers can also comprise a super absorbent material such as polyacrylate or any combination of suitable materials. The fibers can be monocomponent, bicomponent, and/or biconstituent, non-round (e.g., capillary channel fibers), and can have major cross-sectional dimensions (e.g., diameter for round fibers) ranging from 0.1-500 microns. The constituent fibers of the nonwoven precursor web may also be a mixture of different fiber types, differing in such features as chemistry (e.g. polyethylene and polypropylene), components (mono- and bi-), denier (micro denier and >20 denier), shape (i.e. capillary and round) and the like. The constituent fibers can range from about 0.1 denier to about 100 denier.
In one aspect, known absorbent web materials in an as-made can be considered as being homogeneous throughout. Being homogeneous, the fluid handling properties of the absorbent web material are not location dependent, but are substantially uniform at any area of the web. Homogeneity can be characterized by density, basis weight, for example, such that the density or basis weight of any particular part of the web is substantially the same as an average density or basis weight for the web. By the apparatus and method of the present invention, homogeneous fibrous absorbent web materials are modified such that they are no longer homogeneous, but are heterogeneous, such that the fluid handling properties of the web material are location dependent. Therefore, for the heterogeneous absorbent materials of the present invention, at discrete locations the density or basis weight of the web may be substantially different than the average density or basis weight for the web. The heterogeneous nature of the absorbent web of the present invention permits the negative aspects of either of permeability or capillarity to be minimized by rendering discrete portions highly permeable and other discrete portions to have high capillarity. Likewise, the tradeoff between permeability and capillarity is managed such that delivering relatively higher permeability can be accomplished without a decrease in capillarity.
The substrate may also include superabsorbent material that imbibe fluids and form hydrogels. These materials are typically capable of absorbing large quantities of body fluids and retaining them under moderate pressures. The substrate can include such materials dispersed in a suitable carrier such as cellulose fibers in the form of fluff or stiffened fibers.
The substrate may include thermoplastic particulates or fibers. The materials, and in particular thermoplastic fibers, can be made from a variety of thermoplastic polymers including polyolefins such as polyethylene (e.g., PULPEX®) and polypropylene, polyesters, copolyesters, and copolymers of any of the foregoing.
Depending upon the desired characteristics, suitable thermoplastic materials include hydrophobic fibers that have been made hydrophilic, such as surfactant-treated or silica-treated thermoplastic fibers derived from, for example, polyolefins such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, and the like. The surface of the hydrophobic thermoplastic fiber can be rendered hydrophilic by treatment with a surfactant, such as a nonionic or anionic surfactant, e.g., by spraying the fiber with a surfactant, by dipping the fiber into a surfactant or by including the surfactant as part of the polymer melt in producing the thermoplastic fiber. Upon melting and resolidification, the surfactant will tend to remain at the surfaces of the thermoplastic fiber. Suitable surfactants include nonionic surfactants such as Brij 76 manufactured by ICI Americas, Inc. of Wilmington, Del., and various surfactants sold under the Pegosperse® trademark by Glyco Chemical, Inc. of Greenwich, Conn. Besides nonionic surfactants, anionic surfactants can also be used. These surfactants can be applied to the thermoplastic fibers at levels of, for example, from about 0.2 to about 1 g. per sq. of centimeter of thermoplastic fiber.
Suitable thermoplastic fibers can be made from a single polymer (monocomponent fibers), or can be made from more than one polymer (e.g., bicomponent fibers). The polymer comprising the sheath often melts at a different, typically lower, temperature than the polymer comprising the core. As a result, these bicomponent fibers provide thermal bonding due to melting of the sheath polymer, while retaining the desirable strength characteristics of the core polymer.
Suitable bicomponent fibers for use in the present invention can include sheath/core fibers having the following polymer combinations: polyethylene/polypropylene, polyethylvinyl acetate/polypropylene, polyethylene/polyester, polypropylene/polyester, copolyester/polyester, and the like. Particularly suitable bicomponent thermoplastic fibers for use herein are those having a polypropylene or polyester core, and a lower melting copolyester, polyethylvinyl acetate or polyethylene sheath (e.g., DANAKLON®, CELBOND® or CHISSO® bicomponent fibers). These bicomponent fibers can be concentric or eccentric. As used herein, the terms “concentric” and “eccentric” refer to whether the sheath has a thickness that is even, or uneven, through the cross-sectional area of the bicomponent fiber. Eccentric bicomponent fibers can be desirable in providing more compressive strength at lower fiber thicknesses. Suitable bicomponent fibers for use herein can be either uncrimped (i.e. unbent) or crimped (i.e. bent). Bicomponent fibers can be crimped by typical textile means such as, for example, a stuffer box method or the gear crimp method to achieve a predominantly two-dimensional or “flat” crimp.
The length of bicomponent fibers can vary depending upon the particular properties desired for the fibers and the web formation process. Typically, in an airlaid web, these thermoplastic fibers have a length from about 2 mm to about 12 mm long, or from about 2.5 mm to about 7.5 mm long, or from about 3.0 mm to about 6.0 mm long. The properties-of these thermoplastic fibers can also be adjusted by varying the diameter (caliper) of the fibers. The diameter of these thermoplastic fibers is typically defined in terms of either denier (grams per 9000 meters) or decitex (grams per 10,000 meters). Suitable bicomponent thermoplastic fibers as used in an airlaid making machine can have a decitex in the range from about 1.0 to about 20, or from about 1.4 to about 10, or from about 1.7 to about 7 decitex.
The compressive modulus of these thermoplastic materials, and especially that of the thermoplastic fibers, can also be important. The compressive modulus of thermoplastic fibers is affected not only by their length and diameter, but also by the composition and properties of the polymer or polymers from which they are made, the shape and configuration of the fibers (e.g., concentric or eccentric, crimped or uncrimped), and like factors. Differences in the compressive modulus of these thermoplastic fibers can be used to alter the properties, and especially the density characteristics, of the respective thermally bonded fibrous matrix.
The substrate can also include synthetic fibers that typically do not function as binder fibers but alter the mechanical properties of the fibrous webs. Synthetic fibers include cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orlon), polyvinyl acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, bicomponent fibers, tricomponent fibers, mixtures thereof and the like. These might include, for example, polyester fibers such as polyethylene terephthalate (e.g., DACRON® and KODEL®), high melting crimped polyester fibers (e.g., KODEL® 431 made by Eastman Chemical Co.) hydrophilic nylon (HYDROFIL®), and the like. Suitable fibers can also hydrophilized hydrophobic fibers, such as surfactant-treated or silica-treated thermoplastic fibers derived from, for example, polyolefins such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes and the like. In the case of nonbonding thermoplastic fibers, their length can vary depending upon the particular properties desired for these fibers. Typically they have a length from about 0.3 to 7.5 cm, or from about 0.9 to about 1.5 cm. Suitable nonbonding thermoplastic fibers can have a decitex in the range of about 1.5 to about 35 decitex, or from about 14 to about 20 decitex.
The method 400 may further include the step 430 of providing a rotating roll 10 having any of the features described herein with relation to rotating rolls 10 of the present invention. For example, the rotating roll 10 may comprise a central longitudinal axis 12 and an exterior surface 14 that substantially surrounds the central longitudinal axis 12 and defines an interior region 16. The roll 10 may rotate about the central longitudinal axis 12. In one nonlimiting example, the rotating roll 10 may rotate at a surface speed of greater than about 10 ft/minute, or from about 100 ft/minute to about 3000 ft/minute, or about 1800 ft/minute.
The method 400 may also include the step of providing vascular network 18, having any of the features described herein in relation to a vascular network 18. In one nonlimiting example, the vascular network 18 may be provided separately from the rotating roll 10. The vascular network 18 may be provided to supply the fluid from the interior region 16 to the exterior surface 14 in a predetermined fluid path 48. As described above, the vascular network 18 may comprise a main artery 22, which may have an inlet 28 and be substantially parallel to the central longitudinal axis 12 of the roll 10. In one nonlimiting example, the main artery 22 is spaced at a radial distance, r, from the central longitudinal axis 12. The radial distance, r, is greater than 0. Further, the vascular network 18 may a capillary 24 and a plurality of fluid exits 30. The fluid may enter the vascular network 18 through the inlet 28 and exit the vascular network 18 through the fluid exits 30.
Further still, the vascular network 18 may comprise a first capillary 24a which may be associated with the main artery 22. The cross-sectional area of the main artery 22 may be greater than the cross-sectional area of the first capillary 24a. In an embodiment, the vascular network 18 may comprise a second capillary 24b, which may be associated with the main artery 22. The cross-sectional area of the main artery 22 may be greater than the cross-sectional area of the second capillary 24b. The first capillary 24a and/or the second capillary 24b may be in fluid communication with the main artery 22 and with a fluid exit 30 through a substantially radial fluid path 48 to form a tree 23. In one nonlimiting example, the first capillary 24a and/or the second capillary 24b may be in fluid communication with the main artery 22 and with at least two fluid exits 30 through substantially radial paths 48, forming one or more trees 23. As explained above, the capillary 24 may be associated with and in fluid communication with one or more sub-capillaries 26 disposed between the capillary 24 and a fluid exit 30. Further, any tree 23 within the vascular network 18, may be designed in accordance to the formula: DiameterLevel=DiameterStart*BR̂(−Level/(2+epsilon)), which is explained in more detail above.
In one embodiment, the vascular network 18 comprises both a first capillary 24a and a second capillary 24b and each are in fluid communication with one or more fluid exits 30. As discussed above, a first path length, FP, may comprise the distance between the first capillary 24a and a fluid exit 30 with which it is in fluid communication, and a second path length, SP, may comprise the distance between the second capillary 24b and a fluid exit 30 with which the second capillary 24b is in fluid communication. The method 400 may include equalizing the first and second path lengths, FP, SP. As used herein, “equalizing” means making two values (e.g., distances) substantially equal or within 5% of each other.
In another embodiment, the method may include equalizing diameter changes along different trees 23, such as equalizing a first diameter change with a second diameter change as discussed in detail in previous sections.
Again, the roll 10 and vascular network 18 may include or be associated with any of the features described in the above sections. In one nonlimiting example, the exterior surface 14 of the roll 10, or a portion of the exterior surface 14 of the roll 10, is substantially surrounded by a sleeve 100 having any of the features described herein related to sleeves 100. The sleeve 100 may comprise a sleeve exit 120, which may be registered or otherwise associated with at least one fluid exit 30.
The method 400 may also comprise the step 440 of transporting the fluid to the vascular network 18. In addition, the method 400 may comprise the step 450 of controlling the flow of the fluid to move the fluid at a predetermined flow rate to the fluid exits 30. The fluid flow may be controlled by selecting a particular fluid pressure, a particular fluid volume, a particular fluid viscosity, a particular fluid surface tension, the length of one or more channels 20, the diameter of one or more channels 20, the relative diameters and/or lengths of the channels 20, the roll 10 diameter, temperature of the vascular network 18 or portions of the vascular network 18, temperature of the roll 10 or portions of the roll 10, temperature of a particular fluid and/or combinations thereof. One of skill in the art will recognize that a wide range of predetermined flow rates may be selected and suitable for the present invention. In one nonlimiting example, the fluid may be provided at a pressure of less than 100 psi, such as, for example, less than 90 psi, less than 80 psi, less than 70 psi, less than 60 psi, less than 50 psi, less than 40 psi.
Delivery of a HIPE to a substrate using the rotating rolls may further include an additional step of contacting the substrate to the rotating roll.
The substrate may contact the rotating roll before emulsion is pushed to the surface of the rotating roll. The substrate may contact the rotating roll before emulsion extends beyond the outer surface of the rotating roll. The substrate may contact the rotating roll before emulsion vertically protrudes from the surface of the rotating roll at a height of greater than 0.1 mm, such as, for example, the substrate may contact the rotating roll when the emulsion vertically protrudes from the surface of the rotating roll at a height of 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, and 0.09 mm.
The method 400 may further comprise the step 460 of contacting a substrate 50 with the fluid. In an embodiment, the substrate 50 and fluid exit 30 are in operative relationship. The substrate 50 may contact the fluid at the fluid exit 30. In one nonlimiting example, one or more of the fluid exits 30 may comprise micro-reservoir 39. In one such example, the substrate 50 may contact the fluid at the micro-reservoir 39 or at an opening 46 in the micro-reservoir 39. In another nonlimiting example, a backing surface 200 is provided. The roll 10 may form a nip 205 with a backing surface 200, and the substrate 50 may contact the fluid at the nip 205. In yet another nonlimiting example, the rotating roll 10 comprises a sleeve 100 which substantially surrounds a portion of the exterior surface 14. The sleeve 100 may have a sleeve exit 120 as described above. One or more sleeve exits 120 may be registered or otherwise associated with a fluid exit 30 or with a fluid micro-reservoir 39. The substrate 50 may contact the fluid at the sleeve exit(s) 120 or otherwise be in operative relationship with the sleeve exit(s) 120. Further, the fluid may be registered with a product feature 51 on the substrate.
Delivery of a HIPE to a substrate using the rotating rolls may include contacting the substrate with the HIPE emulsion. The substrate may contact the HIPE emulsion concurrent with the role or after contacting the rotating roll. Without being bound by theory, it has been found that the point of contact between the emulsion and the substrate is critical in that it must occur either after the contact between the substrate and the rotating roll or concurrent with the contact between the substrate and the rotating roll. As the emulsion exits the rotating roll, the amount of shear force placed on the emulsion must be controlled. Having the substrate already in place allows for a reduction in shear force and allows the emulsion to travel into and through the substrate without additional shear forces.
If the emulsion extends from the rotating roll before the substrate and the rotating roll make contact, then the substrate may shear the emulsion as it pushes through the emulsion to make contact with the rotating roll. This additional shear may cause the emulsion to break leading to such potential issues as, without limitation, smearing of emulsion on the rotating roll, destabilizing the emulsion within the substrate, or allowing the emulsion to clog the rotating roll.
Delivery of a HIPE to a substrate using the rotating rolls may include pushing emulsion through a portion of the substrate. Once the emulsion is in contact with the substrate, the rotating roll will continue to rotate with the substrate. As the rotating roll rotates with the substrate, additional emulsion is pushed through the rotating roll vascular network and through the substrate in a z or vertical direction through the width of the substrate. Depending upon the desired effect, the emulsion may be pushed through a percentage of the vertical direction of the substrate to create a loaded substrate such as, for example, between 5% and 1,000% of the vertical direction of the substrate, between 10% and 900%, between 20% and 800%, between 30% and 600%, between 40% and 500%, between 50% and 300%, between 100% and 200%, such as, for example, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 200%, 300%, 400%, 500%, 600%, 700%, 800%, or 900%.
In another embodiment, the method 400 may comprise the step of moving the substrate 50 (not shown). The substrate 50 may be moved about the rotating roll 10, or about a portion of the rotating roll 10. The substrate 50 may be driven by any suitable means, including but not limited to a drive motor 210. In one nonlimiting example, the substrate 50 moves at rate of about 10 ft/minute or from about 100 ft/minute to about 3000 ft/minute or at about 2000 ft/minute. In another nonlimiting example, the substrate 50 and the rotating roll 10 move at the same rate. When moved at the same rates, the fluid may be applied in a precise manner, such as in the form of a droplet. In yet another nonlimiting example, the substrate 50 and the rotating roll 10 move at different rates. When the rates of the roll 10 and the substrate 50 are unmatched, the fluid may be smeared on a surface of the substrate 50 or the area or size of a pattern 52 previously applied can be changed.
After the loaded substrate is removed from the roll it moves on to a polymerization stage as described above.
The method may also comprise providing a control mechanism 250 having any of the features described above with respect to the control mechanism 250. In one nonlimiting example, the control mechanism 250 is a computer or other programmable device. In another nonlimiting example, the control mechanism 250 is capable of controlling fluid application level, application rate, roll surface speed, fluid flow rate, pressure, temperature, substrate speed, degree of circumferential roll contact by the substrate, distance between the exterior surface and a backing surface, pressure between the rotating roll and the backing surface and combinations thereof.
In a further embodiment, the vascular network 18 may comprise a plurality of main arteries 22 and a plurality of capillaries 24, such as a plurality of first capillaries 24a. Each capillary 24 is in fluid communication with a main artery 22 and one or more fluid exits 30 through substantially radial fluid paths 48 to form a tree 23. A control mechanism 250 may be used to separately control properties for each tree 23 and/or each main artery 22. The control mechanism 250 can be capable of controlling properties such as fluid application level, application rate, roll surface speed, fluid flow rate, pressure, temperature, substrate speed, degree of circumferential roll contact by the substrate, distance between the exterior surface and a backing surface, pressure between the rotating roll and the backing surface and combinations thereof. In one nonlimiting example, the control mechanism 250 is used to separately control each of the main arteries 22 and their respective trees 23 with respect to fluid application level, fluid application rate, fluid flow rate, pressure, temperature and combinations thereof. In another nonlimiting example, the fluid application rate of fluids in separate main arteries 22 may differ by at least 10%.
Further, the method 400 may comprise equalizing diameter changes of trees 23 stemming from different main arteries as shown in
A sleeve and roll system method 500 may also be employed. The method 500 may comprise the steps of providing a substrate 510, providing a fluid 520, providing a sleeve and roll system 160 having a vascular network 18 (step 530), transporting the fluid to the vascular network 540, controlling the flow of fluid 550, and contacting the substrate 50 with the fluid 560. The steps 510-560 may comprise any of the features in method 400. In addition, the sleeve and roll system 160 may comprise any of the features discussed herein in relation to the sleeve and roll system 160. In one embodiment, the rotating roll 10 is disposed within the inner region 130 of the sleeve 100. The sleeve 100 can have a sleeve exit 120. The vascular network 18 may comprise a tree 22 having a first capillary 24a. The first capillary 24a may be in fluid communication with a main artery 22 and the sleeve exit 120 through a substantially radial path 48. The substantially radial path 48 may end at an exit point 32 of a fluid exit 30. The exit point 32 may be associated with the sleeve exit 120. The tree 23 may be designed by any suitable means, including but not limited to the equation DiameterLevel=DiameterStart*BR̂(−Level/(2+Epsilon)) discussed in detail above. Separately, the tree 23 may further comprise a series of sub-capillaries 26, and the first capillary 24a may be in fluid communication with the sleeve exit 120 through the series of sub-capillaries 26.
In one nonlimiting example, the sleeve 100 has a thickness, T, of greater than about 1.5 mm, or between about 1.5 mm or about 10 mm, and a sleeve exit 120 has an aspect ratio of greater than about 10. In another embodiment, the sleeve 100 has a thickness, T, of less than about 4 mm, or less than about 2 mm, or less than about 1.5 mm, or less than about 0.5 mm. The cross-sectional area of meeting point 124 of the sleeve exit 120 may be less than about 0.5, or less than about 0.3 or less than about 0.15 times the cross-sectional area of the fluid exit point 32 or reservoir opening 46.
Further, the sleeve exit 120 may comprise a supplementary tree 150 as shown in
As with method 400, a backing surface may be provided and used in any of the aforementioned ways. Likewise, as with method 400, method 500 may comprise moving the substrate 50 at speeds matching the surface speed of the roll 10 or at speeds unmatched to the surface speed of the roll 10. Further, a control mechanism 250 may be employed in the same manner as in method 400.
In another embodiment, the step 530 of providing the sleeve and roll system 160 comprises a sleeve substantially surrounding only a portion of the exterior surface 14 of the roll 10 to form a sleeve coverage area 105. The vascular network 18 may comprise a main artery 22, a plurality of capillaries 24 and a plurality of fluid exits 30. Each capillary 24 can be associated with the main artery and in fluid communication with the main artery 22 and one or more fluid exits through substantially radial paths to form a tree 23. An exit point 32 of at least one of the fluid exits 30 is registered or otherwise associated with a sleeve exit 120, and at least one of the fluid exits is disposed outside of the sleeve coverage area 105. The fluid exit 30 disposed outside of the sleeve coverage area 105 is not registered or associated with a sleeve exit 120.
In yet another embodiment, a plurality of rolls 10 may be provided, each roll 10 having a vascular network 18 that operates as described above. One or more of the rolls 10 may be used in conjunction with a sleeve 100. One or more fluids may be provided to each roll 10. One or more main arteries 22 may be provided in each vascular network 18 and/or one or more trees 23 may be provided for each main artery 22. If desired, a control mechanism 250 capable of separately controlling properties associated with each roll 10, each main artery 22 in a roll 10, and/or each tree 23 in a roll 10. The control mechanism 250 can be capable of controlling properties such as fluid application level, application rate, roll surface speed, fluid flow rate, pressure, temperature, substrate speed, degree of circumferential roll contact by the substrate, distance between the exterior surface and a backing surface, pressure between the rotating roll and the backing surface and combinations thereof.
In one nonlimiting example, a backing surface 200 is provided. The backing surface 200 may be used to create a nip 205 or nips 205 with one or more of the rolls 10, and the fluids 13 may contact the substrate 50 at the nip(s) 205. Alternatively, the backing surface 200 does not create a nip 205 but rather is a distance from one or more of the rotating rolls 10. The distance may be substantially equivalent or less than the caliper of the substrate 50. In another alternative embodiment, a plurality of rolls 10 is provided without a backing surface 200. The backing surface 200 may comprise vacuum regions 201.
Using a plurality of rolls 10 allows for a plurality of fluids 13 to be deposited onto a substrate 50. It is believed that the vascular network 18 of the rolls 10 permit better registration, overlaying and blending of fluids than known systems because more than one fluid can be applied using a single roll 10 in an intricate and precisely registered relationship to each other. Each roll 10 is capable of being controlled (due to the design of the vascular network 18) such that a more precise amount of fluid can be more precisely applied at a desired location in a repeatable manner. The plurality of rolls, each having this level of precision, allows for more precise registration, overlaying and blending of the various fluids applied.
Along these lines, a dosing method 600 is also provided and depicted in
In an embodiment, the method 600 includes providing 7 or more fluids and contacting the substrate 50 with 7 or more fluids. The dosing system 70 comprises 6 or fewer rotating rolls 10. The rotating rolls 10 may have any of the features any of the features described above or illustrated in
In one nonlimiting example (illustrated in
In another embodiment, the method 600 includes providing 3 or more fluids in step 620 and contacting the substrate 50 with 3 or more fluids in step 650. The dosing system 70 can comprise one rotating roll 10 having a plurality of fluids disposed therein as shown in
The method 600 may further comprise the step of controlling the flow of the fluid to move the fluid at a predetermined flow rate to the fluid exits 30. The fluid flow may be controlled by selecting a particular fluid pressure, a particular fluid volume, a particular fluid viscosity, a particular fluid surface tension, the length of one or more channels 20, the diameter of one or more channels 20, the relative diameters and/or lengths of the channels 20, the roll 10 diameter, temperature of the vascular network 18 or portions of the vascular network 18, temperature of the roll 10 or portions of the roll 10, temperature of a particular fluid and/or combinations thereof. In addition, the method 600 may comprise registering one or more fluids with a product feature 51. Further, the method 600 may comprise providing an overcoat station 270 positioned downstream of at least one roll 10 and/or providing a pretreat station 260 positioned upstream of at least one roll 10.
One of skill in the art will recognize that any number of rolls 10 and any combination and/or order of fluids may be used to create desired fluid applications. Internal mixers 72 may also be used within a given rotating roll 10 to produce combinations of the fluids within said roll 10.
In embodiments, the above methods 300, 400, 500, 600 may include providing a rotary union 230, such as the rotary union 230 described above, and supplying the fluid(s) from the rotary union 230 to the rotating roll(s) 10.
In other embodiments, the methods 300, 400, 500, 600 may include the registering the fluid with a product feature 51.
In a further nonlimiting example, the rotating roll 10 is part of the converting process of fibrous structures. The roll 10 and additional features described herein may be used in between a winder and unwinds.
One of skill in the art will recognize that the invention may include the negative or reverse of what is shown in the present figures. In other words, the interior region 16 of the rotating roll 10 may be generally solid with the channels 20 of the vascular network 18 being defined by the surfaces of the interior region 16. Alternatively, the interior region 16 could be generally hollow and the channels 20 could be tubular components built within the hollow interior 16 as depicted in the figures.
Applicants have found that the rotating rolls as described above allow for additional controls when working with HIPEs. These additional controls may include a reduced exposure to oxygen throughout the process and dosing step, control over the amount of shear during the dosing step, and the ability to combine more than one HIPE either in the roll or on the substrate. Additionally, the use of the rolls allows for the dosing of multiple combinations to the same substrate in a predetermined pattern. Dosed combinations may include, for example, one or more HIPEs, one or more polyacrilic acids, one or more polyurethane precursors such as polyols and isocyanates, and combinations thereof. The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | |
|---|---|---|---|
| 62185907 | Jun 2015 | US |
