JP4030525B2 - Apparatus, method and system for air opening of fiber tows and opened fiber tow web made thereby - Google Patents

Description

Detailed Description of the Invention

System capable of inventions minute field This invention that "tows opening" of the resulting fiber is used to opening a tow of fibers to have a useful shape to the manufacture of the absorbent structure In particular, it relates to an air opening jet device and a method for use in such a system and the products formed by such a system.

Background of the Invention Many types of filaments, fibers and yarns (collectively “fibers”) are sold as “tows”, where a plurality of such fibers are used in packaging systems such as cocoons (such as The tow is compressed together, optionally by crimping, by methods known to those skilled in the art to maximize the content of the tow sold by the cocoon and delivered to the tow user. Prior to use, such users generally “open” such tows and separate the compressed fibers by a greater distance than that in the compressed state. Many methods and devices for opening tows are known and described in the literature. Examples include US Pat. Nos. 3,282,768, 3523059, 3099594, 4522616, 2794480, 3032829, 5591297 and 5203757, the teachings of which are incorporated herein by reference. While such devices find use in a variety of applications, such devices typically contain “opened” tows that are substantially circular in cross-section, such as tobacco filters or writing instrument fluid reservoirs. Make tow, which is used to make. However, rectangular shapes are preferred for other applications; for example, in absorbent structures intended for use in personal care products such as diapers, bandages, sanitary pads and similar absorbent products. . For such use, shapes having a substantially rectangular cross section are preferred. Representative examples of these various types of products are disclosed in US Pat. Nos. 4,289,130, 5117235 and 5928452, US Statutory Invention Registration H1565, and PCT International Publication No. WO 99/30661.

  In a system of the type described above, it is also possible to use an air jet that opens a tow and forms it into a rectangular shape for use with a tobacco filter rod or the like, as disclosed in U.S. Pat. Nos. 4,468,845 and 4,435,239. Are known. One of the notable advantages that has emerged with these systems is the fact that the air opening jets employed in these systems are designed to operate at very low air pressure (eg 3 psi or less), which is usually It eliminates the need for expensive air compression and plumbing capital investment associated with air opening or “blooming” systems. This low-pressure air moves the tow through an air opening jet, during which the tow is opened, then the tow opened there is decelerated through the bastle device and stagnates in the bastle device to achieve the desired opening and toe density. obtain. This tow deceleration and stagnation is achieved by an adjustable tension device for engaging the tow, in particular a flat, non-perforated "tension" plate pivotally mounted in one of its ends in the bustle device And by relatively complex mechanical devices for adjusting the movement of the swivel tension plate towards and away from the toe, whereby the tension plate can change the tension applied to the tow can get.

Summary of Invention According to one aspect of the present invention, an air opening jet device opens a thin, relatively wide tow of fiber filaments held together by crimping, and opens the opened tow. For example, provided for use in a system for forming a predetermined shape suitable for use as an absorbent structure for a personal care product. The air opening jet device includes a housing having an inlet opening for receiving a partially opened tow and having a shape substantially corresponding to the shape of the partially opened tow. The housing also has an outlet opening (through which the tow exits the housing), the outlet opening having a shape approximately corresponding to a predetermined shape.

  An air jet is formed in the housing adjacent to its inlet opening to create a venturi that moves the tow through an air opening jet device, which also opens the tow, and a source of compressed air communicates with the air jet to drive the tow. Supplying carrier air to move through the air opening jet device.

  A forming chamber is provided in the housing and downstream of the air jet, which includes a cross-sectional area that gradually increases in the direction of tow flow and corresponds to a predetermined shape, wherein the air jet is disposed in the housing. The tow is fully opened to substantially fill the forming chamber as it moves through it.

  A storage chamber is located in the housing downstream of the forming chamber, which allows the opened tow to accumulate in the storage chamber and be pulled out of the housing at various flow rates through the housing outlet opening in a predetermined shape. And is arranged as follows. The storage chamber includes at least one perforated plate disposed in the tow path through which carrier air moves to engage the tow with the perforated plate and at least some transport air is passed through the perforated plate.

  Allow at least a portion of the carrier air to pass through the perforated plate and force the tow to frictionally engage the perforated plate with sufficient force to suppress tow movement through the storage chamber, allowing the tow to accumulate in the storage chamber. A control valve is provided to maintain the flow of carrier air at the expected level.

  In a preferred embodiment of the present invention, the storage chamber can include a second perforated plate spaced from the first perforated plate described above, and the tow moves between the perforated plates and both perforated plates. Is forced to engage them by the carrier air passing through them. Finally, in a preferred embodiment of the present invention, the predetermined shape of the outlet opening of the housing is a rectangle.

  Another aspect of the present invention provides an apparatus and method whereby one or more air opening jets of the type described above open a multi-tow and use it as an absorbent structure, for example for personal care products. Can be used to form a composite multi-toe band of a predetermined shape suitable for. In this type of system, instead of a single tow delivered to the inlet end of the air opening jet device, two separate and separate tows are used at the inlet end of the single air opening jet or the separated air opening. Delivered to a jet where it is combined into a composite multi-toe band there or downstream.

  In this system, the first gathering device receives a first tow from a tow trough having a predetermined denier unit per filament, spreads the filament in the first tow into the first tow band, and the first tow band is predetermined. It has a width and has an exit end for discharging from there. The second gathering device receives a second tow from a second tow bar having a predetermined denier unit per filament different from the predetermined denier of the first tow and spreads the filament in the second tow into a second tow band. The second tow band is provided with an outlet end for discharging from the second tow band with a predetermined width. The first and second tow bands are then simultaneously introduced into the inlet end of the air opening jet device and moved there through for opening and forming as described above for a single tow. The first and second tow bands can also be introduced into two separate air opening jet devices.

  Each of the first and second assembly devices preferably receives a first or second tow, respectively, and a tow banding jet for spreading the tow into a band shape, and the first and second banding jets and air opening respectively. It includes at least one pair, preferably multiple pairs of delivery rolls, disposed between the jet device (s).

  In one contemplated embodiment of this system, the width of one outlet end of the first or second banding device is smaller than the other so that it is discharged from the outlet end of the air jet opening device (s). The multi-toe band has one tow band that is wider than the other. It is preferred that the tow band having a large width has a smaller denier per filament than the denier per filament of the other tow band. In addition, the system can include a surfactant applicator provided upstream of the air opening jet inlet to apply the surfactant to the small width tow band, and the system binds to the large width tow band A binder applicator provided upstream of the inlet of the air opening jet for applying the agent may be included. It is also possible to individually change the speed at which the two tow bands are delivered to the inlet of the air opening jet device, and to control the bloom of the two tow bands individually.

  In accordance with a further aspect of the present invention, there is provided a novel fibrous web that is preferably but not necessarily made by the system apparatus and methodology described above, wherein the webs are essentially each of which the filaments are not aligned with respect to each other. Including first and second tows with multi-continuous fiber filaments opened. In one embodiment, the filaments of the first and second tows are intermingled with each other within at least a portion of the web, eg, essentially each other through the web or along the interface between the first and second tows. Can be mixed together. In an alternative embodiment, the first and second tows are generally layered with respect to each other at least within a portion of the web. The first and second tow filaments can be of different denier per filament, which can provide enhanced web performance compared to a comparative web made from a single tow of the same average denier per filament. It was found. Additional components can be incorporated into the web, such as a superabsorbent polymer to enhance the liquid acquisition and absorption capabilities of the web. It is further contemplated that at least one filament of the first and second tows can include a meltable bicomponent fiber for bonding the first and second tow filaments together.

DETAILED DESCRIPTION OF THE INVENTION The phrase “fiber” as used herein refers to filaments, fibers or yarns of all materials such as cellulose acetate and triacetate, polyester, polyamide, polyolefin and similar polymeric materials.

  The phrase “tow” as used herein is intended to facilitate the transport of multiple fibers within a manufacturing facility, for example, to maximize the content of the packaging system in which such tow is sold and delivered, or from one point to another. This means a plurality of fibers optionally compressed together by “crimping” by methods known to those skilled in the art, and such lexical terms themselves are used and understood in the literature.

  As used herein, the terms “rectangular” and “substantially rectangular” are understood to mean structures with a roughly rectangular cross-section, possibly with a few defects, for example round corners and slight bends or depressions along the sides. It should be.

  The fibers that make up the tow are polyester, polyamide, cellulose acetate and triacetate (collectively “acetate” tow), polypropylene oxide, polyethylene sulfide, liquid crystalline polymer that can be formed into fibers, polyamide, silk, wool, cotton, It can be made from any natural or synthetic material, or mixtures and / or blends thereof, including rayon, polyolefins, polyacrylates, polymethacrylates, and similar materials that can be formed into fibers. Such fibers may or may not have a “finisher” applied to them, depending on their use. In general, external finishes are applied to such fibers to facilitate transport, but "internal" finishes contained in the materials used to form the fibers can also be used, Such fibers are included within the scope of this invention. In addition, the tow fibers can be of any denier, tex, diameter, or other cross-sectional dimension suitable for making cross-sections or tows.

  The phrases “banded jet” and “air banded jet” are used to indicate a first tow opening device that utilizes air to spread the tow in a direction perpendicular to the direction of movement. “Banded jets” are also different and distinct from “opening jets” or “air opening jets” described herein.

  While the present invention can have a wide range of tow opening applications, it has been found to be particularly useful for opening tows made from acetate fibers, polyester fibers, polyolefin fibers and polyamide fibers, and mixtures thereof. It was issued. For example, acetate tow can consist of about 2500 to about 25000 fibers with about 1 to about 10, preferably about 3 to about 6 individual denier. The total denier of the entire tow, which is a collection of about 2500 to about 25000 fibers, is thus about 2500 to about 250,000. Acetate tow is generally from about 10,000 to about 20,000 fibers of about 3 to about 6 individual deniers, giving a tow having a total denier of about 30000 to about 120,000.

  The tow fibers should be distributed uniformly or substantially uniformly across the width / cross section of the crimped tow fiber bundle or band. This uniform fiber distribution is important for the process of opening the tow into a rectangular or substantially rectangular shape, and a more even distribution of fibers makes it easier to create a rectangular or substantially rectangular opened tow. It will be. Crimped tows with various widths / cross-sections, eg, from about 25 mm (millimeters) to about 75 mm, preferably from about 40 mm to about 60 mm, and from about 1 mm to about 7 mm in height or thickness A tow, preferably about 2 mm to about 5 mm, symbolically having dimensions of about 50 mm wide and about 3 mm thick, can be used according to the present invention.

  As mentioned above, an external finish can be applied to each fiber in the tow, such finish being from about 0.3% to about 5%, preferably from about 0.5% to about 5% by weight of the fiber bundle. The amount is 2.0%.

  The tow used to practice this invention is a “crimped tow” which is a lexical term commonly used and known to those skilled in the art. Crimping is done at about 5 to about 30 crimps per inch of non-crimp tow, and preferably at about 20 to about 25 crimps per inch of non-crimp tow.

  It should be understood that the present invention can have applications in a variety of tow opening systems, one exemplary system within which the present invention finds particular application is schematically illustrated in FIG. It is shown. The tow 14 can be fed through a conventional guide set (not shown) to initially planarize and orient the tow 14. The tow is then fed into a normal design banded jet 130. The banding jet spreads the tow band uniformly in a direction perpendicular to the tow processing direction. Air banded jets 130 generally used in these preferred embodiments are known in the literature, for example, US Pat. No. 3,226,773, or co-pending US patent application Ser. No. 09/90 filed on Dec. 23, 1998. It can be any air banded jet as described in 21818. These teachings are incorporated herein by reference. The tow 14 is then fed to the pre-tension roller device 40 and compressed between the metal roller 42 and the rubber roller 44 of the tension roller device 40, thus stretching the tow and dealigning and separating the tow fibers. Within the tension roller device 40, the roller pressure, ie the force applied to the tow by the rollers 42 and 44, is from about 1 to about 25 psi, preferably from about 5 to about 15 psi. In the apparatus 40 as shown in FIG. 1, the metal roller is element 42 (top roller) and the rubber roller is 44 (bottom roller).

  After exiting the device 40, the tow is fed to a roller device 60 that includes a drive metal roller 62 and a rubber roller 64. The metal roller 62 has a circular groove or is threaded or is a flat metal roller. During the passage from device 40 to device 60, the tow is stretched, and this stretching is accomplished by traction combined with the nip pressure between rolls 42 and 44. The nip pressure between the rollers of the device 60 is about 1 to about 40 psi, preferably about 20 to about 30 psi.

  After exiting the device 60, the tow 14 is an optional first electrostatic exclusion bar to remove static charges that may be present on the tow 14 and may interfere with subsequent work necessary to form the absorbent structure. 100 is allowed to pass.

  After exiting the device 60, the tow is fed to a roller device 70 that includes a drive metal roller 72 and a rubber roller 74. The metal roller 72 has a circular groove or is threaded, or is a flat metal roller. During the passage from the device 60 to the device 70, the tow is stretched, and this stretching is achieved by driving the metal roller 72 at a faster rotational speed than the drive roll 62. The rotational speed of roll 72 is 20-60 percent faster than roll 62, preferably 30-50 percent faster. Each of the roller devices 40, 60 and 70 are conventional and well known; they include a device for applying pressure to one of the rolls of the device and the two rolls of the device have a predetermined pressure level. Force them to engage each other. While these conventional devices can apply pressure pneumatically, hydraulically or electrically, pneumatic control is preferred. The nip pressure between the rollers of device 70 is from about 1 to about 40 psi, preferably from about 20 to about 30 psi.

  The tow that exits the device 70 will hereinafter be referred to as the tow 14. The grooves or threading of the rollers 64 and 74 are of a design or orientation known to those skilled in the art of towing or opening. The fibers exiting the device 70 are substantially dealigned or opened to be suitable for opening or forming into a further bulky rectangular structure.

  Substantial misalignment or blooming is a distance greater than the distance between the fibers when 90% or more, preferably 95% or more, of the fibers making up the rectangular structure or rectangular tow are removed from the heel 12 with the tow 14 removed. It means that they are separated with a gap.

  After exiting the device 70, the tow 14 may be provided with an optional electrostatic exclusion bar 101 to remove static charges that may be present on the tow 14 and may interfere with subsequent work necessary to form the absorbent structure. Passed through.

  After the antistatic treatment, the tow 14 is sent to an optional liquid addition device 80. The liquid addition device includes a liquid holding tank, a metering pump 84 and a liquid delivery applicator 86 in the device 80 for dispensing liquid onto the tow 14. The liquid application applicator 86 can be a spray nozzle, disk applicator, rotating brush applicator, wicking contact roll and similar devices of ordinary design known to those skilled in the art. Liquids that can be spread on the tow 14 are water; hydrophilic liquids such as alcohols, glycols, dimethyl sulfide, ketones, ethers and similar materials; such as Fiberset 100 or Fiberset 200 (Henkel, Cincinnati, Ohio) Plasticizers; surfactants; and solutions containing plasticizers, surfactants and similar materials known to those skilled in the art. The liquid or solution can be applied to either or both sides of the tow 14 as it passes through the device 86 to additionally transfer the liquid in the absorbent composite structure containing the rectangular tow 14 or Can be applied in specific patterns in several liquids to produce a unique effect for storing.

  After exiting the air opening jet 240, the tow 14 is delivered to an optional device 120 where solid materials such as superabsorbent polymer (SAP), glue, adhesive, fragrance, wood pulp, deodorant. , Fungicides and similar materials can be applied to the tow 14 by an instrument such as a spill supply device manufactured by Solid Flow, Fort Mill, South Carolina. For example, in the preparation of diapers containing SAP, the SAP can be delivered onto the tow 14 vertically downward as a powder or slurry. The low density, open, rectangular tow band structure exiting the air jet 240 allows solid particles to be uniformly distributed within the tow fiber structure. A fiber structure with uniformly distributed solid particles can be rapidly delivered to the next step so that solid particle containment is achieved. Liquid addition from device 80 also enhances solid containment.

  After addition of the solid material by the device 120, the tow 14 is delivered to an optional high speed delivery device 90, including in particular a drive roller 92 and a roller 94. Either or both of these rollers can have a rubber or metal surface for contact with the tow 14. The drive roller 92 controls the overall operation of the process and the speed of the tow 14 as it is delivered to other processes such as diapers or absorbent composite formers. Generally, the driving roller 92 and the driving roller 72 have a surface speed ratio (72/92) of about 1.0: 1.0 to about 3.0: 1.0, preferably 1.8: 1.0 to 2. .2: Operated at a speed such as 1.0.

  The linear speed of the roll 92 is typically controlled by the line speed of the diaper or absorbent composite forming process supplied with a bulky rectangular tow structure.

  In the preferred embodiment, the tow 14 is delivered directly to the diaper or absorbent composite formation process without the use of a delivery high speed device 90. In this embodiment, the diaper or absorbent composite process acts as a delivery or takeoff rate control. The tow band structure with solids and applied liquid is drawn between the air jets 240, sandwiched between rollers or wound around a drive alone roller. A tissue or other web can be introduced to encapsulate the fiber solid structure.

  Additional optional static eliminator bars, elements 102 and 103, can be placed between the air opening jet 240 and the liquid addition device 80 and after the air opening jet 240. The static elimination bars 100, 101, 102, and 103 can easily control the workability of the tow 14 and the shape of the rectangular structure of the tow 14 by limiting static electricity. Additional static exclusion bars can be employed as needed and are recommended when the moisture content of the environment is low. Such additional antistatic bars can be provided not only after the devices 60, 70 and 80, but also between the devices 60 and 40, 40 and 130, and 120 and 90. The preferred embodiment has at least electrostatic exclusion bars 100, 101 and 102.

  The air opening jet 240 of the present invention includes a housing 242 formed with an inlet opening 244 at one of its ends. As best seen in FIG. 7, the inlet opening 244 has a generally rectangular shape that substantially corresponds to the shape of the partially opened tow 14 received within the inlet opening 244 as described above. The housing 242 also includes an outlet opening 246 that has a rectangular shape corresponding to the desired shape of the tow leaving the air opening jet device 240 as best seen in FIG.

  An air jet (generally indicated by reference numeral 248) is formed adjacent the inlet end of the housing 242, which provides a flow of compressed air from the compressed air source 250 and the compressed air source 250 to the air manifold 254. A normal control valve 252 for adjusting is included. Compressed air is delivered through the manifold to the jet orifice 256, which forms a normal jet of air for moving the tow 14 through a central passage 258 in the housing 242 as will be described in more detail herein. As best seen in FIG. 3, the passage 258 has a gradually increasing cross-sectional area in the direction of movement of the tow 14, thus providing a formation chamber 260 downstream of the air jet 248, which is also preferred. Has a substantially rectangular shape corresponding to the rectangular shape of the tow 14.

  A storage chamber 262 is provided downstream of the forming chamber 260 adjacent to the outlet end of the housing 242, and the storage chamber 262 has a larger vertical dimension than the outlet opening 264 of the forming chamber 260, which also preferably has a rectangular shape. The tow 14 that has been formed and passes from the forming chamber 260 into the accumulating chamber 262 can be accumulated in the accumulating chamber 262, and finally at various flow rates and the preferred tow 14 A rectangular shape would allow it to be pulled out of the housing 242 through the outlet opening 246.

  As best seen in FIGS. 3 and 4, a pair of plates 268, each having a number of holes 270, are in the storage chamber 262 and the tow 14 exits the forming chamber 260 and enters the storage chamber 262. It is placed in the route. The plate 268 is fixed in place in the storage chamber 262 by a plurality of bolts 272 that maintain the plate 268 in a fixed position in the storage chamber 262.

  The housing 242 also includes a pair of side plates 274 extending along both sides thereof (see FIG. 7). The housing 242 surrounds the sides of the storage chamber 262 and the formation chamber 260, and each of the side plates 274 is formed with a plurality of holes 276. These holes 276 are provided approximately where the carrier air leaves the formation chamber and enters the storage chamber 262 so that some of the carrier air can be exhausted through the holes 276.

  In operation of the air opening jet device 240, compressed air from the compressed air source 250 flows to the air jet 248 at a flow rate controlled by the control valve 252, and the air jet formed by the orifice 256 forms the tow 14 and the forming chamber 260. Will move through. As the tow 14 is moved through the forming chamber 260 by the carrier air, the carrier air will expand partially opening the tow 14. Thus, it will gradually increase the cross-sectional area in line with the gradually increasing cross-sectional area of the forming chamber 260. When the tow leaves the formation chamber 260 and enters the storage chamber 262, it first opens further to correspond to the vertical distance between the upstream ends of the perforated plate 268 (see FIG. 3), and the tow 14 is in the path of the tow 14. Is engaged with the inner surface of the perforated plate 2.

  Although some of the carrier air can be exhausted through the holes 276 in the side plates 274, a substantial portion of the carrier air moves the tow 14 through the space between the perforated plates 268 and passes outwardly through the holes 270 in the plates 268. . In doing so, air passing outwardly through the holes 270 frictionally engages the tow 14 with the facing inner surface of the perforated plate 268, which creates a braking action on the tow 14, which is the storage chamber of the tow 14. The tow is slowed down to increase the density and accumulate in the accumulation chamber 262 at a density greater than the density that the tow had in the formation chamber 260 and then opened to increase the density. 14 exit the storage chamber 262 through the outlet opening 246 at various flow rates.

  It is important that the tow 14 exiting through the exit opening 246 has a desired and uniform density through the generally rectangular shape of the tow 14, and the present invention is unique and provides for proper control of the exiting tow 14 density. Provides a highly desirable method. In particular, it will be apparent that the flow rate of the carrier air will determine the deceleration or braking action applied to the tow 14 passing between the perforated plates 268. If the carrier air flow rate is increased, the carrier air passing outwardly through the holes 270 in the plate 268 causes the tow 14 to engage the plate 268 with greater force, thereby reducing the deceleration applied to the tow 14. Or the braking action will increase. Conversely, if the carrier air flow rate is reduced, the braking action applied to the tow 14 will be smaller.

  Accordingly, a virtually infinite adjustment of the braking action is obtained in the present invention by simple means of operating the control valve 252 to provide a flow of carrier air that will provide the desired braking action on the tow 14. , Thereby controlling the density of the tow 14 leaving the housing 242.

It will be appreciated that the actual flow rate of the carrier air will vary from application to application depending on many factors, but in a prototype operation of the present invention, an air pressure of about 40 psi is 20 cm wide and 2.5 cm wide. It has been found to provide the desired density of tow 14 consisting of 0.004 g / cm ³ exiting through an outlet opening with a height.

  8, 12 and 16 schematically illustrate three alternative tow opening systems that use the air opening jet device 240 of the present invention in a unique manner. More specifically, FIG. 8 shows a system in which a plurality of tow bands are supplied to the inlet of the air jet opening device 240. In FIG. 8, individual elements identical to those described above in connection with FIG. 1 are identified by the same reference numerals and two tow bands 14A and 14B are shown, depending on the desired end product. It will be understood that more than one tow band can be used.

  As best seen in FIG. 8, two tow bands 14A and 14B are fed from the tow troughs into normal banded jets 130A and 130B, respectively. Banded jets are described in more detail here. After tow bands 14A and 14B have been processed by air banded jets 130A and 130B, both tow bands 14A and 14B are pre-formed of metal roller 42 and rubber roller 44, all as described above in connection with FIG. It is sent out to the nip of the tension roller device 40. After the combined tow band leaves the pre-tension roller device 40, it is fed through the same series of elements described in connection with FIG.

  FIG. 9 schematically shows in cross section the resulting final product exiting from the air opening jet 240 in the system of FIG. 8, where the air banded jets 130A and 130B have individual tow bands 14A and 14B of the same width. In addition, they are set so as to be stacked and aligned accurately in the lateral direction with respect to each other. Prior to the air opening jet 240, the pretension roller device 40 and the roller devices 60, 70 effectively create a significant degree of initial intermixing of the tow band 14A and 14B filaments, followed by the air opening jet 240. Effectively, the individual filaments in the two tow bands 14A and 14B are substantially completely intermixed with each other so that the individual filaments in the tow bands 14A and 14B are essentially in the transverse direction as shown schematically in FIG. A composite web that blends with each other throughout the range and through the entire thickness of the web.

  However, in the system shown in FIG. 8, the bandwidth of each individual tow band 14A and 14B is individually controlled by manipulating conventional air banded jets 130A and 130B to change the width of tow bands 14A and 14B. The tow band is simultaneously delivered to the air opening jet 240 to provide a unique product, an example of which is shown in FIG. Thus, if desired, tow bands 14A and 14B can be supplied from a tow trough through conventional guide elements (not shown) that first flatten and orient tow bands 14A and 14B in a manner well known in the art. When 14A and 14B reach the air banded jets 130A and 130B, the tow band is spread in a direction perpendicular to the direction of tow band movement, thereby opening the two tow bands 14A and 14B within the banded jets 130A and 130B. be able to. Further, the width of the tow bands 14A and 14B can be varied by the air banded jets 130A and 130B so that the final product delivered from the air opening jet 240 can have a particular desired composite tow structure. As an example of such a composite tow structure, FIG. 10 is set so that the air banded jet 130A delivers a narrow tow band 14A that is centered in a stacked relationship with respect to the large and wide tow band 14B delivered by the air banded jet 130B. Figure 9 shows in cross section the final product exiting from the air opening jet 240 of the system of Figure 8; In the same manner as described above, the roller devices 40, 60 and 70 followed by the air opening jet 240 can effectively mix the individual filaments of the tow bands 14A and 14B to form a composite web. While the central longitudinal region of the web has two tow bands 14A and 14B filaments that are mixed substantially through, the outer edge region of the composite web is wide as shown schematically in FIG. The entire tow band 14B filament will be substantially entirely composed.

  FIG. 11 schematically shows the intimate mixing of the tow 14A and 14B filaments, characterized by the fact that the respective filaments of the tow are essentially indistinguishable from each other and shows the crimpability of the tow filament. FIG. 11 is a schematic view of a longitudinal section taken through either the composite tow web of FIG. 9 or 10 along section line 11-11. Of course, as will be appreciated by those skilled in the art, many other composite multi-tow web product modifications such as those of the processing system of FIG. 8 and those of FIGS. 12 and 16 will be described in more detail below. It can be made as a result of other possible alternative processing systems of the present invention.

  Another alternative processing system using a unique air opening jet 240 is shown in FIG. 12, again using the same reference numerals to the extent that the elements shown in FIG. 12 are identical to those in FIG. Details need not be restated here. In this system, tow bands 14A and 14B are fed to individual air banded jets 130 from the tow trough (as shown in FIG. 8) in the same manner as described above in connection with FIG. However, in the system shown in FIG. 12, the tow bands 14A and 14B each have all the elements acting on the single tow band 14 of FIG. 1, ie, a separate pre-tension roller device 40, a separate roller device 60, 70, And each is individually processed through a separate liquid addition device 80. Since the two tow bands 14A and 14B are individually machined by various machining elements as shown in FIG. 12, the system effectively controls the width of the two tow bands 14A and 14B, and the delivery speed and respectively Can be used to individually control the blooms of the tow bands 14A, 14B. In addition, since the liquid addition is applied individually to the tow bands 14A and 14B by the elements 80, 84 and 86 described in connection with FIG. 1 above, different additives can be applied to either or both of the tow bands 14A and 14B. Each tow element can have a separate effect, such as being able to be applied or without additives, changing the superabsorbent polymer containment, solid adhesion, or fluid distribution enhancing properties of the respective tow bands 14A and 14B. Can be given. Alternatively or additionally, the additive can also be applied to the composite tow web obtained downstream of the air opening jet 240.

  In contrast to the system of FIG. 8, the use of separate pretension roller devices 40, roller devices 60, 70 and liquid addition device 80 for each of the two respective tow bands 14A and 14B of the system of FIG. Any intermixing of tow bands 14A and 14B prior to delivery to fiber jet 240 is prevented. Thus, in the composite tow web exiting the air opening jet 240, the individual filaments of the two tow bands 14A and 14B are intermixed only through the action of the air opening jet 240, and thus the composite made by the system of FIG. Intermixed to a lesser extent than the web. More specifically, the composite tow web produced by the system of FIG. 12 has three distinct distinct tow regions across the thickness of the composite web: adjacent to one outward face of the composite web. A first region predominantly composed of air-opened and unaligned filaments of tow band 14A is both open and unaligned substantially mixed with respect to each other across the center of the tow web thickness. Gradually coalesced into an intermediate region composed of filaments of tow bands 14A and 14B, the intermediate region being predominantly composed of the unfolded and unaligned filaments of the toe band 14B on the opposite outward face of the composite tow web. Gradually merge into the third zone. These three regions are shown schematically in cross-section by the composite tow web of FIGS. 13 and 14, which shows one embodiment of the composite tow web made by the system of FIG. 14A and 14B are of the same width and are stacked laterally aligned with each other, and FIG. 14 shows an alternative embodiment of a composite tow similar to that of FIG. 10, where the tow 14A is a wide tow. 14B is of a narrow lateral size placed in the center in a stacked relationship.

  FIG. 15 schematically shows three regions of the composite tow web of FIGS. 13 and 14 in a longitudinal section similar to that of FIG. In contrast to the composite tow web made by the system of FIG. 8, the composite tow web space made by the system of FIG. 12 is only in the region of the interface between the tow bands 14A and 14B when delivered into the air opening jet 240. Each filament of the individual tow bands 14A, 14B is predominantly substantially mixed with each other.

  The ability to use multiple individually controlled and / or processed tow bands in combination with the air opening jet 240 provides an opportunity to make a wide range of products with structures and compositions that can be adapted to specific functions. It will be understood that For example, a composite tow web structure can be made that is particularly suitable for acting as an element of an absorbent disposable device such as a disposable diaper. An example composite tow structure as shown in FIG. 10 or 14 is suitable for this particular application and has a high denier per filament (DPF), eg, 6-8 DPF and a total denier between 12000 and 20000. It will consist of a tow band 14A. The tow band 14A is oriented in the center of the composite structure as shown in FIG. 10 or 14, so it will be in contact with or in close proximity to the first fluid attack zone of the absorbent disposable device. The high DPF of tow band 14A will provide improved fluid acquisition when hydrated due to its high strength and resistance to crushing. In a typical example, the banded jet 130A of FIG. 8 or the banded jet 130 applied to the tow band 14A of FIG. 12 would limit the width of the tow band 14A to approximately 80 mm. If the system of FIG. 12 is used, the liquid applied to the tow band 14A via the liquid application device 80 will be a surfactant that will enhance fluid treatment within the fluid acquisition structure. On the other hand, the tow band 14B has a low DPF with a total denier between 30000-40000, eg 2-3, and the tow band 14B is oriented at the bottom of the composite structure so that it is the main core body of the absorbent disposable device. It will be. The low DPF tow band structure will provide high density, large fiber surface contact area and improved superabsorbent polymer containment for a large number of individual fibers. Thus, for example, 2.0 DPF / 40000 total denier tow band 14B will have approximately 20000 separate fibers, while 6.0 DPF / 15000 total denier tow band 14A will have only about 2500 separate fibers. . Preferably, the banded jet 130B will limit the width of the tow band 14B to 150 mm, which would be the full inlet width of the air opening jet 240. Thus, the composite tow structure exiting the air opening jet 240 will have a shape as schematically illustrated in FIG. Finally, if the system shown in FIG. 12 is used, the liquid applied to tow band 14A via device 80 is preferably superabsorbent polymer containment and / or solid deposit or containment within the structure of tow band 14B. It may be a binder such as a plasticizer, water, or water-based adhesive that reinforces.

  Of course, it will be understood that the particular composite tow structure described above is only representative of various composite tow structures that can be made using the systems shown in FIGS. For example, in addition to controlling the width of the tow bands 14A and 14B, if the system shown in FIG. 12 is used, the speed of the roller devices 60 and 70 can be controlled to control the delivery speed and the individual tow bands 14A and 14B, respectively. It is also possible to control the bloom separately, thereby changing the characteristics of the tow bands 14A and 14B delivered to the air jet 240. Similarly, other types of filaments can be used to form tow bands 14A and 14B. For example, one of the tow bands is formed from a filament comprising a meltable bicomponent fiber material that can be utilized to bond the tow bands 14A and 14B filaments together by subjecting the composite tow web to subsequent heat treatment. It is also possible to be able to. Of course, many other alternative embodiments will readily occur to those skilled in the art.

  Furthermore, the ability provided by the present invention to selectively bind and intermix different tow bands into a composite tow web is superior to the open tow web made from a single tow band in the resulting tow web or It is also conceivable to be able to have enhanced features, properties and / or performance. To evaluate this possibility, an experiment was performed comparing the composite tow web made by the system of FIG. 8 described above with the opened tow web made from a single tow band using the system of FIG. The results of such experiments are summarized in the tables of FIGS. Each web is treated the same to apply a layer of superabsorbent polymer (SAP), a suitable porous or non-porous adhesive layer, and a tissue outer cover, and from each web is a disposable diaper as described above. An absorbent device was made as used. Two sample devices were made from different composite tow webs made by the system of FIG. 8, and three sample devices were made from a single tow web made by the system of FIG. These devices were then tested to determine their liquid acquisition and absorption capabilities. The various physical properties of the sample device are summarized for comparison purposes in the table of FIG. On the other hand, the test results of such an apparatus are summarized in the table of FIG. Sample devices made with composite tows using the system of FIG. 8 are identified as Samples 6-0601 and 7-0601, while sample devices made from a single tow using the system of FIG. 1 are Samples 2-0601. , 3-0601, and 4-0601.

  As can be seen, sample devices made with composite tow webs achieve superior acquisition and absorption results compared to devices made with single tow webs, even for single tow webs with the same average denier per filament as composite tow webs did. To conclude from these experiments that composite tow webs provide better superabsorbent polymer containment than webs made from a single tow, which conversely indicates that this tow structure has a higher degree of stability Is reasonable.

  Another unique system using the air opening jet 240 of the present invention is shown in FIG. 16, where again like reference numerals identify elements of the same system as those described above in connection with FIG. It is used for. In this system, each of the tow bands 14A, 14B is passed separately through a series of processing steps and then fed to the intake of a separate air opening jet 240. More specifically, as shown in FIG. 16, each tow band 14A and 14B is individually passed through the banded jet 130, then passed through the roller devices 40, 60 and 70 and then through the liquid addition device 80 as described above. Each tow band is then fed to the intake of a separate air opening jet 240.

  The tow bands exiting the air opening jet 240 are then merged and delivered together to the same element downstream of the air opening jet 240 as shown in FIG. When the combined tow band is moved through the high speed delivery roller device 90, a composite multi-tow web is created as schematically shown in FIGS.

  Since the tow bands 14A, 14B are individually opened and processed with separate air opening jets 240 and then merged together, the tow bands 14A, 14B are shown in FIGS. Compared to the multi-tow web shown in 10, 13 and 14, it has a substantially laminated layered relationship with very small fiber entanglement of the two tow bands 14A, 14B.

  Another advantage of the multi-toe web formed by the system of FIG. 16 is that the laminated structure of the web is useful for various types of specific processing. For example, each layer in the product provides a separate and individualized finish at the liquid addition station 80 and, if desired, one or both liquid addition stations 80, or additional processing stations downstream of the air opening jet 240. A desired material (for example, a superabsorbent polymer) can be inserted between the layers formed by the tow bands 14A and 14B.

  Thus, it will be readily appreciated by those skilled in the art that the present invention allows for wide usage and application. Numerous embodiments and adaptations of the present invention other than those described herein, as well as numerous modifications, changes, and equivalent devices will become apparent from the present invention and its foregoing description without departing from the spirit or scope of the invention. Or would be reasonably suggested thereby. Thus, although the present invention has been described in detail herein with reference to preferred embodiments thereof, this disclosure is only illustrative and exemplary of the invention and is for the purpose of providing a complete and possible disclosure of the invention. It should be understood what has been done. The above disclosure is not intended or should be construed as limiting the present invention, or otherwise excludes all such other embodiments, adaptations, modifications, changes and equivalent devices. Rather, the invention is limited only by the claims appended hereto and their equivalents.

1 is a schematic view of a typical tow opening system of the type in which the air opening jet of the present invention can be used. 1 is a perspective view of a preferred embodiment of an air opening jet of the present invention. FIG. 3 is a partial elevational side elevational view showing the air opening jet shown in FIG. 2. FIG. 3 is a plan view of a housing of the air opening jet shown in FIG. 2. It is an end elevation view showing the outlet opening of the housing. FIG. 6 is an elevation view of one of the side plates of the housing. FIG. 6 is an end elevation view of the inlet opening of the housing. It is the schematic of the alternative tow opening system using the air opening jet apparatus by this invention. FIG. 9 is a cross-sectional, or transverse, cross-sectional schematic view of a first embodiment of a composite multi-toe web product formed by the system shown in FIG. FIG. 10 is another schematic view of a cross-section similar to FIG. 9 of a second embodiment of a composite multi-toe web product formed by the system shown in FIG. 8. 11 is an exaggerated schematic view of a longitudinal section taken along line 11-11 of FIGS. 9 and 10 showing the relationship of the filaments of the composite multi-toe web product of FIGS. 9 and 10. FIG. FIG. 6 is a schematic view of yet another alternative tow opening system using an air opening jet device according to the present invention. FIG. 13 is a schematic cross-sectional view of a first embodiment of a composite multi-toe web product formed by the system shown in FIG. FIG. 13 is another schematic cross-sectional view of a second embodiment of a composite multi-toe web product formed by the system of FIG. FIG. 15 is an exaggerated schematic view of the longitudinal section taken along line 15-15 of FIGS. 13 and 14 showing the relationship of the filaments of the composite multi-tow product of FIGS. 13 and 14. FIG. 6 is a schematic view of yet another alternative tow opening system using an air opening jet according to the present invention. FIG. 17 is a cross-sectional schematic view of an exemplary composite multi-toe web product formed by the system shown in FIG. 16. FIG. 18 is an exaggerated schematic view of the longitudinal section taken along line 18-18 of FIG. 17 showing the general relationship of the fibers of the multi-tow product of FIG. 9 is a table summarizing comparative physical data for a sample single tow web product formed by the system shown in FIG. 1 and a sample composite multi-toe web product formed by the system of FIG. 20 is a table summarizing the results of a comparative performance test of the sample web product of FIG.

Claims (27)

A method for producing an absorbent composite from continuous tow, said method comprising the following steps:
Spreading the crimped tow in a direction perpendicular to the direction of movement of the tow by a banded jet;
Dealigning crimped tows;
Forming the dealigned tow into a substantially rectangular cross-section and passing it through an outlet opening having a rectangular shape; and distributing particulates comprising superabsorbent polymer throughout the formed tow.
A method comprising the steps of:   The method of claim 1, further comprising applying a liquid to the shaped tow prior to dispensing the granulate.   The method of claim 1 wherein the toe dealignment is performed by a pair of rollers.   4. The method of claim 3, wherein the toe dealignment is performed by at least two pairs of rollers.   The method of claim 1, wherein forming the dealigned tow is performed by an air jet.   The method of claim 1, wherein the tow consists essentially of a plurality of continuous fibers.   5. The method of claim 4, wherein a pair of rollers operates at a faster rotational speed than the other pair of rollers.   8. The method of claim 7, wherein a pair of rollers operates at a rotational speed that is 20-60% greater than the other pair of rollers.   The method of claim 1, further comprising controlling tow speed through the method.   The method of claim 9, wherein controlling the tow speed is performed by a pair of rollers in which one roller is driven.   The method according to claim 10, wherein a ratio of tow speed during dealignment of the speed control roller to the drive roller is 1.0: 1.0 to 3.0: 1.0.   The method of claim 1, further comprising encapsulating the absorbent composite in a web or tissue. A method for producing an absorbent composite from continuous tow, wherein the composite consists essentially of a plurality of continuous fibers and a superabsorbent polymer distributed throughout, wherein the method comprises: Stage:
Spreading the crimped tow in a direction perpendicular to the direction of movement of the tow by a banded jet;
Dealigning crimped tows;
Forming the dealigned tow into a substantially rectangular cross-section and passing it through an outlet opening having a rectangular shape; and distributing particulates comprising superabsorbent polymer throughout the formed tow.
A method comprising the steps of:   14. The method of claim 13, further comprising applying a liquid to the shaped tow prior to dispensing the granulate.   The method of claim 13 wherein the toe dealignment is performed by a pair of rollers.   The method of claim 15 wherein the toe dealignment is performed by at least two pairs of rollers.   14. The method of claim 13, wherein forming the dealigned tow is performed by an air jet.   17. The method of claim 16, wherein a pair of rollers operates at a faster rotational speed than the other pair of rollers.   14. A method according to claim 13, wherein a pair of rollers operates at a rotational speed 20-60% greater than the other pair of rollers.   14. The method of claim 13, further comprising controlling tow speed through the method.   20. The method of claim 19, wherein controlling the tow speed is performed by a pair of rollers in which one roller is driven.   21. The method according to claim 20, wherein the ratio of tow speed during dealignment of the speed control roller to the drive roller is 1.0: 1.0 to 3.0: 1.0.   14. The method of claim 13, further comprising encapsulating the absorbent composite in a web or tissue. A method for producing an absorbent composite from continuous tow, wherein the composite consists essentially of a plurality of continuous fibers and a superabsorbent polymer distributed throughout, wherein the method comprises: Stage:
Spreading the crimped tow with a banded jet in a direction perpendicular to the direction of movement of the tow;
Dealign the crimped tow with at least two pairs of rollers;
The de-aligned tow is shaped with an air jet into a substantially rectangular cross-section and passed through an outlet opening having a rectangular shape; and the particulate containing the superabsorbent polymer is distributed throughout the shaped tow ,
A method comprising the steps of:   25. The method of claim 24, further comprising applying a liquid to the shaped tow prior to dispensing the granulate.   25. The method of claim 24, wherein the pair of rollers to be dealigned operates at a rotational speed that is 20-60% greater than the other pair of rollers.   25. The method of claim 24, further comprising controlling tow speed through the method.

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