Patent Description:
One important process step in the manufacture of many items is the transporting of material along a manufacturing pathway. In the specific case of manufacturing absorbent articles in a continuous process, materials and article components that form part of the produced absorbent articles move along different conveyer systems in the manufacturing process. Processing steps such as bonding steps or application of absorbent material or the like may happen along the manufacturing process to produce the absorbent articles. In some instances, the materials and article components may be transferred between adjacent conveyer systems within the manufacturing process. The hand-off from one conveyer system to the next can be a source of production errors or malfunctions. For instance, the materials and article components may become wrinkled, an edge of the materials or article components may be become folded over, or, particularly in high speed manufacturing processes, air may get under a leading edge of an article component, causing the component to flip, become skewed, or even fly off of the conveyer system. Accordingly, improved conveyer systems for safely and consistently transferring materials and article components between conveyer systems within a manufacturing process are desired. <CIT> discloses a vacuum conveyor with a vacuum roller according to the preamble of claim <NUM>.

The disclosure is directed to several alternative designs and methods of for conveying material.

The present invention provides a vacuum conveyer system as claimed in claim <NUM>.

The system may further comprise a single vacuum source which supplies a vacuum to both the first discrete vacuum chamber and the second discrete vacuum chamber, or the system may further comprise a first vacuum source which supplies a vacuum to the first discrete vacuum chamber and a second vacuum source which supplies a vacuum to the second discrete vacuum chamber.

The second discrete vacuum chamber may be external to the first discrete vacuum chamber.

The first box end may comprise an inlet end of the vacuum conveyer system.

The second discrete vacuum chamber may be free of obstructions.

A cross-sectional area of a region bounded by the recess may comprise between <NUM>% and <NUM>% of a cross-sectional area of a portion of the dead shaft not comprising the recess.

The live roll may comprise a plurality of apertures to allow airflow into the second discrete vacuum chamber, and the apertures may be chamfered.

The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of aspects of the disclosure.

The aspects of the disclosure may be further understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the disclosure. Additionally, while the aspects of the disclosure are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.

The present disclosure is generally directed towards several alternative designs and methods of for conveying material. In some high speed manufacturing processes, moving materials and article components from one conveyer system to another conveyer system can introduce undesired movement of the materials and article components, from slight skewing of the materials and components with respect to desired positions all the way to complete dislodgment of the materials and components from the conveyer system. Generally, conveyer systems employ vacuum pressure to help keep materials and article components in position on the conveyer as the materials and components move within the system. However, this vacuum pressure can be difficult to localize at front and/or rear ends of conveying systems, thereby making the transition from one conveying system to another conveying system a source of manufacturing problems. The present disclosure relates to vacuum conveying systems with improved abilities for retaining materials and article components on the conveying systems and along the desired conveying paths as the materials and components transition from one conveying system to another conveying system.

When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. Many modifications and variations of the present disclosure can be made without departing from the scope defined in the appended claims. Therefore, the exemplary embodiments described above should not be used to limit the scope of the invention.

The term "nonwoven" refers herein to materials and webs of material which are formed without the aid of a textile weaving or knitting process. The materials and webs of materials can have a structure of individual fibers, filaments, or threads (collectively referred to as "fibers") which can be interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven materials or webs can be formed from many processes such as, but not limited to, meltblowing processes, spunbonding processes, carded web processes, etc..

The term "spunbond" refers herein to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine capillaries of a spinnerette having a circular or other configuration, with the diameter of the extruded filaments then being rapidly reduced by a conventional process such as, for example, eductive drawing, and processes that are described in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>, <CIT>, <CIT>, and <CIT> Spunbond fibers are generally continuous and often have average deniers larger than about <NUM>, and in an embodiment, between about <NUM>, <NUM> and <NUM> and about <NUM>, <NUM> and <NUM>. Spunbond fibers are generally not tacky when they are deposited on a collecting surface.

The term "superabsorbent" refers herein to a water-swellable, water-insoluble organic or inorganic material capable, under the most favorable conditions, of absorbing at least about <NUM> times its weight and, in an embodiment, at least about <NUM> times its weight, in an aqueous solution containing <NUM> weight percent sodium chloride. The superabsorbent materials (SAM) can be natural, synthetic and modified natural polymers and materials. In addition, the SAM can be inorganic materials, such as silica gels, or organic compounds, such as cross-linked polymers.

<FIG> is a perspective view of vacuum conveyer system <NUM>. Vacuum conveyer system <NUM> may generally comprise vacuum box <NUM>, vacuum nose roll assembly <NUM>, and moveable belt member <NUM>. Moveable belt member <NUM> may be driven by belt motor assembly <NUM>, which can drive belt member <NUM> to move about vacuum box <NUM> and vacuum nose roll assembly <NUM> in machine direction <NUM>.

Vacuum box <NUM> may generally include a hollow interior forming a discrete vacuum box vacuum chamber <NUM> (as depicted in <FIG>), and the hollow interior may be connected to airflow conduit <NUM>. Airflow conduit <NUM>, in turn, may be connected to vacuum source <NUM>. In this way, vacuum source <NUM> can create a pressure differential within vacuum box <NUM> relative to the space outside of vacuum box <NUM>. In some embodiments, vacuum box <NUM> may include a porous top surface, which, in combination with vacuum source <NUM>, creates a suction force at the porous top surface of vacuum box <NUM> as air is pulled into vacuum box <NUM> due to the pressure differential between the inside of vacuum box <NUM> and the outside of vacuum box <NUM>. In other embodiments, vacuum box <NUM> may be enclosed only on three sides while the top is left open. In such embodiments, belt member <NUM> may act as the top surface of vacuum box <NUM>.

Belt member <NUM> may generally be comprised of any number of suitable flexible materials, and in some embodiments may comprise a screen. For example, belt member <NUM> may be comprised of any rubber material having suitable flexible properties enabling belt member <NUM> to bend around vacuum nose roll assembly <NUM>. Alternatively, belt member <NUM> may be comprised of any suitable metal material that has the suitable flexibility. In general, these types of belt or screen members are well-known in the art. One important aspect of belt member <NUM> is that belt member <NUM> includes porous region <NUM>. As mentioned previously, vacuum box <NUM> may be configured with vacuum source <NUM> to create a pressure differential within vacuum box <NUM> relative to the space outside of vacuum box <NUM>. Porous region <NUM> of belt member <NUM> allows air to flow through belt member <NUM> and into vacuum box <NUM> due to the pressure differential, thereby creating a suction force at belt member <NUM>. This suction force helps to maintain the positioning of materials and article components being transported on belt member <NUM>.

Although only depicted in <FIG> in a small region relative to the size of belt member <NUM>, in other contemplated embodiments porous region <NUM> may take on any shape or size. For instance, porous region <NUM> could extend along belt member <NUM> all the way up to the entire length of belt member <NUM>. Additionally, in <FIG>, porous region <NUM> extends approximately along the entire cross-machine direction <NUM> length of belt member <NUM>. However, in other embodiments, porous region <NUM> may only extend along a portion of the cross-machine direction <NUM> length of belt member <NUM>, such as along a cross-machine direction <NUM> length approximately equal to a cross-machine direction <NUM> length of materials or article components to be transported on vacuum conveyer system <NUM>.

Vacuum nose roll assembly <NUM> may be generally disposed adjacent one end of vacuum conveyer system <NUM>. In some embodiments, vacuum nose roll assembly <NUM> may be disposed adjacent an inlet end of system <NUM> where material is brought onto system <NUM>. However, in other embodiments, vacuum nose roll assembly <NUM> may be disposed adjacent an outlet end of system <NUM> where material exits system <NUM>. As will be described in more detail below, vacuum nose roll assembly <NUM> may comprise a discrete nose roll vacuum chamber <NUM> (as seen in <FIG>) which is separate and distinct from vacuum box vacuum chamber <NUM> and not fluidly connected to vacuum box vacuum chamber <NUM>. Vacuum conveyer system <NUM> may further comprise an airflow conduit that is separate from airflow conduit <NUM> and which connects vacuum nose roll assembly <NUM> to a vacuum source. In some contemplated embodiments, system <NUM> may include airflow conduit 112a which connects vacuum nose roll assembly <NUM> to vacuum source <NUM>, the same vacuum source that is connected to airflow conduit <NUM> and vacuum box <NUM>. In other contemplated embodiments, however, system <NUM> may include airflow conduit 112b which connects vacuum nose roll assembly <NUM> to vacuum source <NUM> which is separate from vacuum source <NUM>. In general, vacuum sources <NUM> and/or <NUM> may be vacuum pumps, fans, or any other suitable energy source configured to provide airflow out of vacuum box vacuum chamber <NUM> and nose vacuum chamber <NUM>. Vacuum sources <NUM> and/or <NUM> may be configurable to provide adjustable pressure differentials within vacuum box vacuum chamber <NUM> and/or nose roll vacuum chamber <NUM>. In other embodiments, airflow conduits <NUM> and/or 112a, 112b may include one or more dampers which can be adjusted to provide different pressure differentials within vacuum box vacuum chamber <NUM> and/or nose roll vacuum chamber <NUM>.

The presence of distinct vacuum box vacuum chamber <NUM> and nose roll vacuum chamber <NUM> allows for greater control of the pressure differentials within each chamber <NUM>, <NUM>. This greater control may help to ensure that transported materials and article components maintain their position as they travel a path through a manufacturing process, both along a vacuum conveyer system such as system <NUM> and during transitions between adjacent conveyer systems.

<FIG> is a perspective view of the vacuum conveyer system of <FIG> with belt member <NUM> removed. As can be seen in <FIG>, airflow conduit 112a (or 112b) connecting vacuum nose roll assembly <NUM> to one of vacuum sources <NUM>, <NUM> may further connect to airflow conduit <NUM> which extends at least partially through vacuum box vacuum chamber <NUM>. Although shown vacuum box vacuum chamber <NUM> is depicted as a single chamber, in other embodiments vacuum box vacuum chamber <NUM> may comprise two or more vacuum chambers with additional airflow conduits connecting each vacuum chamber to a vacuum source (or the same vacuum source in some embodiments). In still other contemplated embodiments, vacuum chamber <NUM> may comprise any suitable number of chambers, such as between <NUM> chamber and <NUM> chambers.

As described previously, vacuum conveyer system <NUM> may be suitable for transporting materials and article components used in the manufacture of absorbent articles. Example materials that vacuum conveyer system <NUM> may transport include webs constructed of any of a variety of materials, such as synthetic fibers (for example, polyester or polypropylene fibers), natural fibers (for example, wood or cotton fibers), a combination of natural and synthetic fibers, porous foams, reticulated foams, apertured plastic films, or the like. Such materials may be in the form of various woven and non-woven fabrics which can include spunbond fabric, meltblown fabric, coform fabric, carded web, bonded-carded web, bicomponent spunbond fabric, spunlace, or the like, as well as combinations thereof.

Vacuum conveyer system <NUM> may also be suitable for transporting absorbent article components such as absorbent cores. Exemplary absorbent cores may be comprised generally of pulp fluff, SAM, or pulp fluff combined with SAM. Vacuum conveyer system <NUM> may be particularly useful in transporting materials and article components that are thin and flexible, for example absorbent cores that are equal to or greater than <NUM>% of SAM by weight.

It should be understood that although the examples used herein describing materials that may be transported by vacuum conveyer system <NUM> include materials and articles used in the production of absorbent articles, these specific uses do not limit vacuum conveyer system <NUM> in anyway. Rather, vacuum conveyer system <NUM> may be suitable for transporting any suitable material, component, or product.

In order to successfully transport such materials and article components, for instance ensuring the materials and article components maintain their positions as they travel throughout the manufacturing process, vacuum source <NUM> (and possibly <NUM>) may be configured to provide specific pressure differentials within vacuum box vacuum chamber <NUM> and nose roll vacuum chamber <NUM> (as seen in <FIG>). In some embodiments, vacuum source <NUM> (and possibly <NUM>) may be fans rated at between about <NUM>,<NUM> cubic feet per minute (CFM) and about <NUM>,<NUM> CFM. Such vacuum source(s) may be able to create pressures of between about <NUM> inch of water (<NUM> kPa) and about <NUM> inches water (<NUM> kPa) within vacuum box vacuum chamber <NUM> and within nose roll vacuum chamber <NUM>. In other embodiments, vacuum source <NUM> (and/or <NUM>) may be able to create pressure of between about <NUM> inch of water (<NUM> kPa) and about <NUM> inches of water (<NUM> kPa) within vacuum box vacuum chamber <NUM> and within nose roll vacuum chamber <NUM>.

<FIG> is a perspective view of nose roll assembly <NUM> of vacuum conveyer system <NUM>. Nose roll assembly <NUM> generally comprises nose roll <NUM> and nose roll shaft <NUM>. Nose roll <NUM> and nose roll shaft <NUM> are configured in a live-roll-dead-shaft configuration where nose roll shaft <NUM> maintains its rotational position throughout operation of vacuum conveyer system <NUM>, and nose roll <NUM> rotates about nose roll shaft <NUM> during operation of vacuum conveyer system <NUM>.

Nose roll <NUM> generally comprises apertures <NUM>, ridges <NUM>, and smooth areas <NUM>. Apertures <NUM> may allow air to flow through nose roll <NUM> and into nose roll vacuum chamber <NUM> (as seen in <FIG>), as evidenced by airflow paths <NUM>. Ridges <NUM> may cooperate with sealing member <NUM> (as can be further seen in <FIG>) to provide a seal between airflow conduit <NUM> and nose roll <NUM>. Similarly, smooth areas <NUM> may cooperate with sealing members <NUM> in order to provide a seal between airflow conduit <NUM> and nose roll <NUM>.

In at least some embodiments, nose roll assembly <NUM> may further include adjustable inlet plate <NUM>. In these embodiments, adjustable inlet plate <NUM> may cover a portion of airflow conduit <NUM> and may further comprise apertures <NUM>. For example, adjustable inlet plate <NUM> may be a top portion of airflow conduit <NUM>, and apertures <NUM> may allow air to enter airflow conduit <NUM>, as depicted by air flow paths <NUM>, thereby providing a suction force along adjustable inlet plate <NUM>. In this way, vacuum conveyer systems <NUM> that include adjustable inlet plate <NUM> may provide a suction force on materials and article components as they pass over nose roll assembly <NUM> and transition past nose roll assembly <NUM> but before they pass over vacuum box vacuum chamber <NUM>. In at least some embodiments where vacuum conveyer system <NUM> includes adjustable inlet plate <NUM>, adjustable inlet plate <NUM> may be moveable in the direction of arrows <NUM>. Moving adjustable inlet plate <NUM> along a path aligned with arrows <NUM> may adjust both a positioning of the suction force due to the changing of location of apertures <NUM> (and/or opening a gap between nose roll <NUM> and adjustable inlet plate <NUM>) and the level of suction force within airflow conduit <NUM> at adjustable inlet plate <NUM>. In other embodiments, plate <NUM> may be adjustable in a direction different than depicted by arrows <NUM>, for example a direction having any angle with respect to arrows <NUM>. In some of these embodiments, plate <NUM> may comprise a pair of plates with aligned apertures. Moving the top plate of the pair in any direction may un-align the apertures of each of the pair of plates, thereby adjusting the suction strength along plate <NUM>.

<FIG> is a cross-section view of nose roll assembly <NUM> taken as viewed along line <NUM>-<NUM>. As can further be seen in the profile view of <FIG>, vacuum nose roll <NUM> comprises apertures <NUM> and ridges <NUM>. Apertures <NUM> of vacuum nose roll <NUM> may fluidly connect the exterior of vacuum nose roll <NUM> with the interior of vacuum nose roll <NUM> and with airflow conduit <NUM>. As described above, vacuum source <NUM> (and/or <NUM>) may be connected to airflow conduit <NUM>, which connects to air flow conduit <NUM>. Accordingly, when vacuum source <NUM> (and/or <NUM>) is in operation, air may move from the exterior of vacuum nose roll <NUM> to the interior of vacuum nose roll <NUM> through one or more apertures <NUM> and into nose roll vacuum chamber <NUM>, as depicted by arrow <NUM>. Nose roll vacuum chamber <NUM> may be formed by a recess of nose roll shaft <NUM>. The air that entered nose roll vacuum chamber <NUM> may additionally move out of nose roll vacuum chamber <NUM> through one or more additional apertures <NUM> and into airflow conduit <NUM> due to the action of vacuum source <NUM> (and/or <NUM>), as shown by arrow <NUM>. In this manner, vacuum source <NUM> (and/or <NUM>), airflow conduits <NUM>, <NUM>, and nose roll assembly <NUM> may be configured to achieve a suction force at the outer surface of vacuum nose roll <NUM>. In at least some embodiments, apertures <NUM> may have chamfered inner edges <NUM> in order to help create smooth airflow into nose roll vacuum chamber <NUM>. In other embodiments, instead of chamfered inner edges <NUM>, apertures <NUM> may comprise angled walls such that apertures <NUM> widen from as they extend toward nose roll vacuum chamber <NUM>.

Vacuum nose roll <NUM> may comprise both ridges <NUM> and recesses <NUM> and may further be described as having both a minor diameter and a major diameter due to ridges <NUM> and recesses <NUM>. In this manner, vacuum nose roll <NUM> may comprise both surfaces <NUM>, which may be the surface of the minor diameter of vacuum nose roll <NUM>, and surfaces <NUM> which may be the surface of the major diameter of vacuum nose roll <NUM>.

Surfaces <NUM> may be the outer most portion of ridges <NUM>, and ridges <NUM> may interact with sealing member <NUM> in order to form a seal between vacuum nose roll <NUM> and airflow conduit <NUM>. For example, ridges <NUM> and sealing member <NUM> may be configured such that there is a very small-to-no gap between surfaces <NUM> and sealing member <NUM> as ridges <NUM> pass adjacent to sealing member <NUM>. This close fit forms a seal between vacuum nose roll <NUM> and airflow conduit <NUM> to help prevent air entering airflow conduit <NUM> from locations other than through vacuum nose roll <NUM> and nose roll vacuum chamber <NUM>. Locations where air enters airflow conduit <NUM> from locations other than through vacuum nose roll <NUM> and nose roll vacuum chamber <NUM> may be thought of as "leaks". For instance, air entering airflow conduit <NUM> from locations other than through vacuum nose roll <NUM> and nose roll vacuum chamber <NUM> reduces the amount of pressure differential vacuum source <NUM> (and/or <NUM>) may create between nose roll vacuum chamber <NUM> and the exterior of vacuum nose roll <NUM>. This reduced pressure differential equates to a reduced suction force at the surface of vacuum nose roll <NUM>. Additionally, the specific configuration of sealing member <NUM> and of recesses <NUM> and surfaces <NUM> on vacuum nose roll <NUM> as shown in <FIG> is termed a labyrinth seal. In this configuration, as vacuum nose roll <NUM> spins about nose roll shaft <NUM>, air becomes trapped within recesses <NUM> as they pass by sealing member <NUM>. These trapped pockets of air further help to impede any airflow from outside of vacuum nose roll <NUM> into airflow conduit <NUM> from between vacuum nose roll <NUM> and sealing member <NUM> due to the relatively lower pressure within airflow conduit <NUM>.

In order to form an effective labyrinth seal, the specific dimensions of recesses <NUM> and sealing member <NUM> may need to fall within particular boundaries. For instance, sealing member <NUM> has a surface <NUM> which may curve to follow the contour of vacuum nose roll <NUM>. In some embodiments, surface <NUM> of sealing member <NUM> may have a contour length equal to between about <NUM>% and about <NUM>% of the circumference of vacuum nose roll <NUM>. The contour length of surface <NUM> may be the length of surface <NUM> from the top of sealing member <NUM> to the bottom of sealing member <NUM>, as seen in <FIG>, found by following the curvature of the surface <NUM>. Additionally, recesses <NUM> may have a maximum width of between about <NUM> and about <NUM>. In other embodiments, recesses <NUM> may have a width that is equal to portion of a circumferential length of vacuum nose roll <NUM>. In some embodiments, recesses <NUM> may have a maximum width equal to between about <NUM>% and about <NUM>% of the circumference of vacuum nose roll <NUM>. Ridges <NUM> may have a radial height of between about <NUM> and about <NUM>.

In some embodiments, the maximum width of ridges <NUM> may be the same as the maximum width of the recesses <NUM>. However, this is not necessary in all embodiments. For instance, the maximum width of ridges <NUM> may range between about <NUM>% and about <NUM>% of the maximum width of the recesses <NUM> in different embodiments.

In some further embodiments, nose roll assembly <NUM> may further comprise recesses <NUM> disposed on nose roll shaft <NUM>. Similar to recesses <NUM> and sealing member <NUM>, recesses <NUM> and interior surface <NUM> of vacuum nose roll <NUM> may form a labyrinth seal to prevent air from entering nose roll vacuum chamber <NUM> and/or airflow conduit <NUM> from between vacuum nose roll <NUM> and nose roll shaft <NUM>. In different embodiments, recesses <NUM> may vary in depth between about <NUM> and about <NUM>. Additionally, recesses <NUM> may have a maximum width that ranges from about <NUM> to about <NUM> in different contemplated embodiments.

Nose roll vacuum chamber <NUM> may be formed of a recess within nose roll shaft <NUM>. For example, a portion of nose roll shaft <NUM> not comprising the recess forming nose roll vacuum chamber <NUM> may have a first cross-sectional surface area, which comprises the area bounded by surfaces <NUM> of nose roll shaft <NUM> as shown in <FIG>. Further, nose roll shaft <NUM> may have a second cross-sectional surface area at a portion of nose roll shaft <NUM> comprising the recess forming nose roll vacuum chamber <NUM>. In the example of <FIG>, this second cross-sectional surface area would be the first cross-sectional surface area less the region bounded by dotted line <NUM> defining the recess forming nose roll vacuum chamber <NUM>. In at least some embodiments, the second cross-sectional surface area may be between <NUM>% and <NUM>% of the first cross-sectional surface area. As some illustrative examples, the first cross-sectional surface area may be between about <NUM> in<NUM> (<NUM><NUM>) and about <NUM> in<NUM> (<NUM><NUM>). Accordingly, the second cross-sectional surface area may then be between about <NUM> in<NUM> (<NUM><NUM>) and about <NUM> in<NUM> (<NUM><NUM>). This would put the cross-sectional area of the region forming nose roll vacuum chamber <NUM>, e.g. the region bounded by dotted line <NUM>, between about <NUM>% percent and about <NUM>% of the first cross-sectional area. Using the exemplary area values above, this means the cross-sectional area of the region forming nose roll vacuum chamber <NUM> may be between about <NUM> in<NUM> (<NUM><NUM>) and about <NUM> in<NUM> (<NUM><NUM>). However, it should be understood that these are only exemplary values. In other contemplated embodiments, nose roll <NUM> and nose roll shaft <NUM> may be as large or small as necessary for whatever particular desired application of vacuum conveyer system <NUM>.

In at least some embodiments, nose roll shaft <NUM> may have a further feature where nose roll vacuum chamber <NUM> is substantially free of obstructions. The more open and smooth nose roll vacuum chamber <NUM> is, the less turbulence will be introduced to air entering nose roll vacuum chamber <NUM>. Lower turbulence of air present in nose roll vacuum chamber <NUM> equates to lower levels of pressure able to be achieved by vacuum source <NUM> (and/or <NUM>) given a static amount of vacuum energy supplied by vacuum source <NUM> (and/or <NUM>). Accordingly, if nose roll vacuum chamber <NUM> is substantially free of obstructions, the greater the suction force may be achieved at nose roll surface <NUM> than where nose roll vacuum chamber <NUM> is not substantially free of obstructions. The phrase 'substantially free of obstructions' may be construed to mean there are no portions of nose roll shaft <NUM> or hardware or other members attached to nose roll shaft <NUM> which extend into nose roll vacuum chamber <NUM> an amount greater than about <NUM>.

Claim 1:
A vacuum conveyer system (<NUM>) comprising:
a vacuum box (<NUM>) extending between a first box end and a second box end and comprising a first discrete vacuum chamber (<NUM>);
a nose roll (<NUM>) disposed adjacent to the first box end and comprising a second discrete vacuum chamber (<NUM>); and
a foraminous member (<NUM>) disposed about both of the nose roll and the vacuum box;
characterized in that the nose roll comprises a dead shaft (<NUM>) and a live roll (<NUM>), wherein a recess (<NUM>) within the dead shaft forms the second discrete vacuum chamber,
and wherein the system further comprises: an airflow conduit (<NUM>) disposed adjacent to the live roll; and
a labyrinth seal (<NUM>, <NUM>, <NUM>) connecting the live roll to the airflow conduit (<NUM>).