WO2000052263A1

WO2000052263A1 - Transfer fabric

Info

Publication number: WO2000052263A1
Application number: PCT/US2000/004910
Authority: WO
Inventors: Volker Ostermayer; Norbert Reuther; Hans-Peter Breuer
Original assignee: Geschmay Corp.
Priority date: 1999-03-01
Filing date: 2000-02-25
Publication date: 2000-09-08
Also published as: AU3379600A

Abstract

A transfer fabric (14) for use in the press section of a papermaking machine which includes a forming section and a dryer section. The transfer fabric (14) is adapted to receive paper (P) delivered from the forming section and to transport the paper (P) through the press section. The support surface (29) of the transfer fabric (14) is constructed to hold the paper (P) during transport through the press section and to release the paper upon reaching the dryer section. The transfer fabric (14) comprises a base fabric (20) formed of interlaced longitudinal and transverse continuous filament yarns having fibers interspersed throughout. A latex coating is dispersed evenly throughout the base fabric (20) coating the yarns and fibers and forming the support surface (29) and the running surface (28) with non-uniform peaks (30) and valleys (32). The transfer fabric (14) as constructed has a first porosity in an uncompressed condition which creates a first paper holding intensity and a second porosity in an uncompressed condition which creates a second and greater paper holding intensity. The construction allows the transfer fabric (14) to hold the paper (P) with the first intensity when in an uncompressed condition during movement to and from the press rolls and to hold the paper (P) with the second intensity when compressed during movement through said press rolls. The first intensity is sufficient to hold the paper (P) and yet release the paper (P) to the vacuum roll (18) without stretching while the second intensity is sufficient to pull the paper (P) away from the press roll while maintaining contact with the transfer fabric (14).

Description

TRANSFER FABRIC

Background of the Invention

The present invention relates to the transfer of a paper sheet between sections,

or between elements of a section, such as the individual presses in a press section of the

paper machine on which it is being manufactured. Specifically, the present invention is a

transfer fabric designed both to carry a paper sheet through a portion of a paper machine,

so as to eliminate open draws, wherein the paper sheet receives no support from a carrier

and is susceptible to breakage, from the machine, and to release the sheet readily to another

fabric or belt at some desired point. The prior art is replete with proposals for elkninating so-called open draws from

paper machines. By definition, an open draw is one in which a paper sheet passes without

support from one component of a paper machine to another over a distance which is greater

than the length of the cellulose fibers in the sheet. All such proposals for eliminating open

draws have as their object the removal of a major cause of unscheduled machine shut-down,

the breakage of the sheet at such a point where it is temporarily unsupported by a felt or

other sheet carrier. When disturbances in the normally stable flow of paper stock occur,

the likelihood of such breakage is quite strong where the unsupported sheet is being

transferred from one point to another within the press section, or from the final press in the

press section to the dryer section. At such points, the sheet usually is at least 50% water,

and, as a consequence is weak and readily broken. At present, then, an open draw will

place a limitation on the maximum speed at which the paper machine may be run. The prior art proposals for eliminating open draws include some form of transfer

fabric to carry and support the paper sheet between components of the paper machine. In

so doing, the transfer fabric may have to carry out several of the following separate

functions:

a) to take the paper sheet from a press roll or press fabric (felt);

b) to carry the paper sheet into a press nip;

c) to work cooperatively with a press felt in the press nip to dewater the

paper sheet;

d) to carry the paper sheet out of the press nip;

e) to repeat functions b) through d) as necessary where the transfer fabric

carries the paper sheet through more than one press; and,

f) to transfer the paper sheet to another fabric or belt, such as , for example ,

a dryer fabric.

In general, and referring to the various functions of a transfer fabric identified

above, where the transfer fabric removes the paper sheet from a press roll, a procedure

rarely used in practice, it must overcome the strong adhesion the paper sheet will normally

have for the roll, which may be very smooth. In the in-going side of a press nip, the paper

is squeezed until it becomes fully saturated, at which point water will start to move out from

the sheet into the water receptor, the press felt. As a consequence, there will always be a

water film, perhaps partly broken, at the interface between the roll surface and the paper

sheet. This film has to be broken before the paper sheet may be reliably transferred from

the roll to the transfer fabric. In the press nip, the transfer fabric must work cooperatively with a press felt to

dewater and to density the paper sheet. As a consequence, the surface topography and

compression properties of the transfer fabric are critical for producing a paper sheet with

a smooth, mark-free surface. Because, as is well known to those skilled in the art, even a

high quality, well-broken- in press fabric may provide a very non-uniform pressure distribution in the nip, a transfer fabric having a smoother and harder paper-side surface

than the press felt will provide a more uniform pressure distribution to the paper sheet being

dewatered, and will impart a smoother surface to the sheet.

Further, a transfer fabric with suitable compression properties can in effect

lengthen the press nip to increase the time and the paper sheet is exposed to pressure and

to allow more time for water to leave the paper sheet under a given press load. In addition, a transfer fabric which is substantially impermeable to water and air will contribute to the

dryness of the paper sheet by eliminating the possibility of re-wet after the press nip, as may

occur when a conventional press felt carries the paper sheet out of the nip.

Clearly, a transfer fabric must be designed with the understanding that it will

work cooperatively in the nip with a press felt as a functional pair in order to provide high

dewatering efficiency and high paper quality.

Referring again to the various transfer fabric functions identified above, the

transfer fabric should carry the paper sheet out of the press nip. That is to say, more

precisely , the paper sheet should adhere to the surface of the transfer fabric upon exiting the

nip, as opposed to following the press fabric out of the nip and then moving over to the

transfer fabric after the nip. Not only does the latter permit re-wet while the paper sheet remains in contact with the press fabric, but the moving of the paper sheet over to the

transfer fabric after leaving the press nip would also constitute an open draw, the very

problem the transfer fabric is intended to eliminate. Such a situation can lead to blistering

or some other deformation of the paper sheet. A good adhesion of the sheet to the transfer

fabric on the exit side of the nip is even more important in press configuration where the

belt is run in the top position and the sheet is to be transferred on the underside of the belt.

As before, the paper-side surface and in fact the entire transfer fabric should be neither

water-absorbent nor water-permeable at the nip, so that re-wet of the paper sheet by the transfer fabric may be avoided.

Where the transfer fabric carries the paper sheet through more than one press,

the stability of the transfer fabric will become an important factor. The speed of

consecutive presses in a press section can never be absolutely synchronized, and, normally,

will increase somewhat downstream in the section. Under such conditions, the transfer

fabric must be able to carry the paper sheet without blowing, blistering, or drop off. In

addition, the transfer fabric itself must be of a durable design, capable of enduring the

backside wear and high shear forces, which would attend its use through more than one

press, without rapid degradation.

The final function of the transfer fabric is to effect a correct transfer of the paper

sheet to the next section of the paper machine. In many applications, this will be a transfer

to the first fabric in the dryer section. It is preferred that this first fabric should be of a

design suitable for both paper drying and for the closed transfer of the paper sheet. A typical dryer fabric in the first drying position may be a woven, all-polyester

mono filament fabric. Fabrics used in first drying positions normally have a low air-

permeability and a smooth, fine paper side. Hence, the surface to which the transfer fabric

is to transfer the paper sheet may initially consist of smooth, hydrophobic monofilament

knuckles.

The transfer from the transfer fabric to the first dryer fabric should be carried

out with as low a contact pressure as possible in order to avoid the marking of the paper

sheet by the knuckles. Since the dryer fabric is air-permeable, vacuum may be used to assist the transfer of the paper sheet from the transfer fabric. In order to avoid the marking

of the paper sheet by the knuckles of the first dryer fabric, the vacuum level used at the

transfer point must be as low as possible. It follows, then, that the transfer fabric must

readily release the paper sheet at the transfer point so that the vacuum level required may

be kept at a minimum level.

Summary of the Invention

In view of the preceding discussion, it may be understood that a successful

transfer fabric must be able to carry out several different functions as it carries a paper sheet

from place to place in a paper machine. Correspondingly, the behavior of the transfer

fabric must change in response to the conditions under which it is placed at different

locations in the machine. The most critical of these functions are: a) to remove the paper sheet from a

press fabric without causing sheet instability problems; b) to cooperate with a press fabric in one or more press nips to ensure optimal dewatering and high quality of the paper sheet;

and, c) to transfer the paper sheet in a closed draw from one press in the press section to

a sheet-receiving fabric or belt in the next press, or presses, in the press section, or to a

dryer pick-up fabric in the dryer section.

The surface of the transfer fabric must have a topography or sculptured effect

on a microscale providing a degree of uneveness which decreases, or smooths out, as the

belt compresses under the levels of compression to which it is typically subjected in a press

nip, but which restores itself as the belt expands after exit from a press nip, to carry out

these functions. In other words, the surface topography of the transfer fabric must have a

pressure-responsive, recoverable degree of roughness, so that, when under compression in

a press nip, the degree of roughness will decrease, thereby enabling a thin continuous water film to be formed between the transfer fabric and a paper sheet to bond the paper sheet to

the transfer fabric upon exit from the press nip, and so that, when the original topography

is recovered after exit from the nip, the paper sheet may be released by the transfer fabric,

perhaps with the assistance of a minimum amount of vacuum, to a permeable fabric such

as a dryer pick-up fabric. At the same time, the transfer fabric must have the necessary

compression and hardness properties to produce a mark-free paper.

In addition to having a surface topography with a pressure-responsive,

recoverable degree of roughness, a successful transfer fabric must also have an optimal

combination of the following additional functional properties : 1) surface energy, which will

determine the interaction of the surface of the transfer fabric with water; 2) limited

permeability to air or water; 3) compressional properties, both for the surface of the belt and for its structures as a whole; 4) hardness; 5) modulus; 6) durability; and, 7) chemical, thermal and abrasion resistance.

The present invention is a transfer fabric for a papermaking, boardmaking, or

similar machine having a caliper including a surface topography with the requisite pressure-

responsive recoverable degree along with an optimal combination of the above noted

additional functional properties. The pressure-responsive, recoverable degree of caliper

remains a characteristic of the transfer fabric throughout its entire lifetime on the

papermaking or boardmaking machine so that the transfer fabric will be capable of carrying

out its intended function for that time.

The transfer fabric may be characterized as having a homogeneous coating throughout which creates a well-defined topography and a well-defined surface energy on

its support surface, such a surface being favorable for taking a paper sheet from a press roll or press fabric, and carrying it into a press nip, where it cooperates with a press fabric.

The transfer fabric may be further characterized as having a sheet-facing

surface, optimally only slightly permeable to water and air, with a pressure-responsive

microscale topography. Under pressure, the microscale degree of roughness of this surface

decreases, and the permeability disappears making the surface much smoother and allowing

a thin, continuous film of water to be built up between the paper sheet and that surface.

Such a thin, continuous film of water provides much stronger adhesive forces between the

paper sheet and transfer fabric than those between the paper sheet and the press felt, so that

the paper sheet may consistently and reliably follow the transfer fabric when leaving the

press nip. Even where the press fabric, by reason of structural expansion, creates a light vacuum at the outgoing side of the press nip, the energy required to overcome the adhesive

forces arising from the water film between the transfer fabric and paper sheet is greater than

that required to overcome any adhesion the paper sheet may have for the press felt. In addition, the caliper regain of the paper sheet upon exit from a press nip is normally much

slower than that of the press fabric. As a consequence, when a light vacuum arises in both

the expanding press fabric and expanding paper sheet upon exit from the press nip, the latter

holds its vacuum for a longer period of time and sticks to the transfer fabric by virtue of the

thin, continuous water film disposed therebetween. As a consequence, the paper sheet will follow the transfer fabric.

Despite the strong adhesion the paper sheet has for the surface of the transfer

fabric at the nip exit, the material composition of the paper side of the belt and its surface

characteristics provide it with the necessary release properties to successfully transfer the

paper sheet to another fabric or belt. These release properties are a direct consequence of

the use of an appropriate polymer coating, and the slight permeability of the transfer fabric.

The slightly permeable belt, having a very low permeability to air and water,

and having a polymer coating in accordance with the present invention, will be able to carry

out the functions of the present invention quite well so long as it has an air permeability of

less than 5 cubic feet per square foot per minute, when measured according to the procedure

set forth in "Standard Test Method for Air Permeability of Textile Fabrics, ASTM D 737-

75 , American Society of Testing and Materials , re-approved 1980. Such a low permeability

in a saturated belt structure allows the transfer function of the belt in the course of use on a paper machine to function uniformly as the pores allow for the uniform cleaning of paper

fines and other materials.

The mechanism by which the water film is broken up during the span between the press nip and the point where the paper sheet is to be transferred to another carrier is

thought to be primarily a function of the pressure-responsive microscale surface topography

of the coating on the paper side of the transfer fabric. In this regard, in order to break up

the water film, the recovered degree of sculpture of the surface topography of the transfer

fabric should be at least equal to the minimum caliper of the water film.

As has been discussed above, the primary mechanism by which the present

transfer fabric releases the paper sheet at a desired point is thought to be its pressure-

responsive, recoverable surface topography, since the strength of the adhesive bond formed

between the surfaces of the transfer fabric and the paper sheet depends upon the actual

interfacial contact area and surface roughness of each.

The water film between the paper sheet and transfer fabric will tend to fill the

low spots in the belt surface. As the pressure distribution changes in the interface between

sheet and belt during expansion after exit from the sculptured effect of the nip, the belt will

increase, after having been compressed to a substantially smooth condition in the nip. The

increase of sculptured effect causes the water film to break. The work necessary to

counteract the adhesion of the paper sheet to the transfer fabric and to separate the two from

one another depends upon surface tension, which decreases with increasing water film

thickness. Where there are low spots in the surface of the transfer fabric, the thickness of the water film will be increased. This reduces the adhesion of the paper sheet to the transfer

fabric at such locations and promotes sheet release.

It is also possible that air may be trapped in low spots on the surface of the

transfer fabric as the transfer fabric, paper sheet, and press fabric are entering the nip. As the paper sheet is compressed in the nip, the air is compressed into such low spots. In the

outgoing part of the nip, this compressed air expands, exerting a pressure which helps to

break the water film.

The transfer fabric of the invention comprises a base fabric formed of interlaced continuous filament yarns with fibers being interdispersed evenly among the yarns

throughout. A water base latex coating is dispersed throughout the base fabric coating all

external services of the yarns and fibers and forming support and running surfaces with non-

uniform valleys and peaks throughout. The transfer fabric so constructed has an

uncompressed porosity of between 2.5 and 3.5 CFM and a compressed porosity of 0 CFM.

The paper holding intensity of the suppoπ surface is directly proportional to the porosity,

the holding intensity being greatest when the fabric is compressed and less when

uncompressed. This is primarily achieved by the existence of the peaks and valleys. Peaks

diverge to about 0.066 mm substantially equally from a median plane when the fabric is

uncompressed to being substantially eliminated creating a substantially planar suppoπ surface when compressed.

The transfer fabric of the invention may be formed which have a cross-section

which is one of round, oval, rectangular, triangular, and star shaped. These yarns may be

formed of one of PA, PPS, PE, PET, PEEK, PPA, PCTA, and PU or a combination thereof. The latex coating is preferably formed of one of nylon, PU, PET, PP and PE or

a combination thereof.

A specific embodiment of the present invention will now be described in more

complete detail, with reference frequently being made to the figures identified as set forth

below.

Description of the Drawings

The construction designed to carry out the invention will hereinafter be

described, together with other features thereof.

The invention will be more readily understood from a reading of the following

specification and by reference to the accompanying drawings forming a part thereof,

wherein an example of the invention is shown and wherein:

Figure 1 is a diagrammatic view of a press section in a papermaking machine;

Figure 2 is a sectional perspective view of the transfer fabric of the invention;

Figure 3 is a sectional side view of the press fabric, press felt, and paper in the

nip of the press rolls;

Figure 4 is a sectional side view of the combination of Figure 3 showing the

paper leaving the nip of the press rolls and transfer fabric as it approaches the vacuum roll;

Figure 5 is a diagrammatic view showing height and depth of the sculpture of

the surface of the transfer fabric; and,

Figure 6 is a diagrammatic view of a coating method forming the fabric of the

invention. Description of a Preferred Embodiment

Turning now to the drawings, Figure 1 is a representative arrangement of the

press section of a papermaking machine. As shown, the paper sheet P is delivered from the

forming section onto the press felt 12 and carried into engagement with the transfer fabric

14. From this point the paper sheet is sandwiched between the fabrics 12 and 14 as it is

carried through the press rolls where the fluid in the paper is forced out and almost totally

carried off by the press felt 12. After paper P moves past press rolls 16, it is held on the

transfer fabric and carried to the dryer section. Here vacuum roll 18 acts to transfer the paper from the transfer fabric to the dryer section. The dryer section comprises the final

phase of the paper forming process.

There are three phases in this process where the proper function of the transfer fabric is essential.

The first phase is where the press felt and transfer fabric come together. Here,

the surface of the transfer fabric must be such as to take control of the paper sheet and hold

it firmly as the paper is carried into the nip of press rolls 16. This is accomplished by the

fact that the surface of the transfer fabric is less porous than that of the felt and as the wet

paper engages with the surface of the transfer fabric a capillary effect takes place and

secures the paper in place.

The second phase is when the paper emerges from the press rolls. As the press

rolls are also not porous, they, along with the transfer fabric, grip the paper. If the paper

continues to adhere to the press roll it will be placed under undue traction, stretched and

marked or even broken. Therefore, the capillary effect of the transfer fabric must be increased in this area so that the paper will be held with the transfer fabric as it passes

through the nip of the press rolls.

Finally, the grip of the paper with the transfer fabric should be reduced prior

to its engagement with the vacuum transfer roll so that it may be drawn from the grip of the

transfer fabric without being stretched or broken.

The transfer fabric 14 shown in Figures 2-4 accomplishes each of these

functions. Transfer fabric 14 comprises a base fabric 20 which may be woven, knitted, or

non-woven. As shown, fabric 20 is woven with yarns 22 extending longitudinally and yarns

24 extending transversely of the machine direction of movement. When woven, the base

fabric may be woven endless or flat and seamed to be endless.

Fabric 20 may be formed as a single layer as multi-layer fabric. When multi¬

layer, the layers may be formed together or united by needling or coating.

Fabric 20 has the fibers of a fiber batt 26 arranged over each outer surface and needled into the base fabric from each side so that the fibers of each fiber batt are evenly

distributed or dispersed throughout fabric 20 forming a felt having substantially identical

outer surfaces, i.e. the running surface and the support surface. Optionally, only a single

fiber batt may be arranged over the support surface of fabric 20. In this instance, needling

will be from only the support surface side dispersing the fibers evenly throughout fabric 20

and forming a support surface as described above. In this second process, the remaining

or running surface will be slightly rougher than the support surface.

Fabric 20 with the fibers needled thereto or felted fabric 20 is formed with a

porosity of between 40-160 CFM. The yarns forming fabric 20 may be continuous filament monofilament or

continuous filament multi-filament yarns. They may have a round, oval, rectangular, star

or other shaped cross-section. They may be formed of any number of synthetic materials such as PA, PPS, PE, PET, PEEK, PPA, PCTA, PU, and combinations thereof to include

minerals.

Felted forming fabric 20 is preferably saturated with a water based latex coating.

The coating as applied penetrates throughout felted fabric 20 so as to coat all internal and

external fiber surfaces. The coating may be applied by way of a coating roll onto a surface

of the fabric which is then moved to a vacuum dryer which causes the latex coating to saturate the fabric and be evenly distributed throughout. After coating the porosity of the

fabric is reduced to about 3.5 CFM. Figure 6 shows an apparatus satisfactory for carrying out this method.

The coating produces sculptured outer surfaces 28 which have randomly arranged peaks 30 and valleys 32 formed thereover (see Figures 3 and 4). One of the

surfaces 28 serves as the paper support surface 29, while the other functions as the roller

surface. There peaks and valleys create substantially equally configurations, as indicated

in Figure 5, which are about 0.066 mm in each direction from a median plane.

Any number of polymers are suitable for use as the coating such as PU, nylon,

PET, PP, PE, and silicone.

Normally, transfer fabric 14 will have a caliper C¹. It is with caliper C¹ the

fabric has a porosity of about 3.5 CFM. The sculptured suppoπ surface 29 is effective to

grip the wet paper delivered from the forming section because of the capillary effect created by the water and the substantially non-porous suppoπ surface. As the transfer fabric is

moved into nip of press rolls 16, transfer fabric 14 is compressed evenly throughout its

thickness producing a reduced caliper C². The compressive action forms the outer surfaces

28 and particularly suppoπ surface 29 when between the nip rolls to be substantially

completely planar with the porosity of the fabric in the area of the nip being reduced to 0 CFM. The restructured or planar suppoπ surface intensifies the capillary action between

the paper and surface 29 causing the paper to be more tightly engaged with or held by

surface 28 during passage through and just after emerging from the nip of the press rolls.

This increased holding or gripping action is sufficient to draw the paper off the press felt

and press roll smoothly and evenly thereby preventing undue stretching as it is carried onto

the drying section.

As the press felt and transfer fabric leave the nip area, fabric 14 expands to

return to substantially caliper C¹ with the peaks and valleys 30, 32 reappearing on support

surface 28. Again, the capillary action between the paper and suppoπ surface is reduced,

bur remains sufficient to maintain the paper evenly positioned over the surface of fabric 14.

Finally, as the fabric 14 reaches vacuum drum 18, the vacuum forces of the

drum draw the paper into contact with dryer fabric which carries it into the dryer section.

That transfer fabric 14 has remained its porosity of about 3.5 CFM as it reaches

vacuum drum 18. air may be drawn through the fabric to further assist in releasing the

paper from suppoπ surface 29 without stretching or tearing.

It is noted that caliper C is always larger than caliper C² even though it may

decrease in size between passages through the press rolls. A main advantage of the instant transfer fabric is that it is extremely durable due

to the fact that it is coated throughout rather than having only a coating layer formed over

the support surface. Coating layers become brittle in use, sometimes breaking off damaging

the paper product and shortening wear life of the transfer fabric. Another advantage is that

the sculptured support surface does not require an after treatment but is formed naturally

during the samration process further reducing cost. Finally, the coating operation by

samration is less costly than one in which a doctor blade is employed for coating a layer on a surface.

Claims

What is claimed is:

1. A transfer fabric, for use in the press section of a papermaking machine

having a paper support surface and a running surface, said support surface being operative

to hold paper during transport through said press section with multiple intensities said

transfer fabric comprising:

a base fabric formed of interlaced continuous filament yarns and fibers, said

fibers being interdispersed among said yarns evenly throughout;

a latex coating dispersed throughout said base fabric coating all external surfaces

of said yarns and fibers forming said support and running surfaces with non-uniform valleys

and peaks throughout and said transfer fabric with an uncompressed porosity of between 2.5

and 3.5 CFM and a compressed porosity of 0 CFM.

2. The transfer fabric of claim 1 wherein said yarns forming said base

fabric is woven.

3. The transfer fabric of claim 1 wherein said paper holding intensity of

said suppoπ surface of said transfer fabric when compressed is greater than said paper

holding intensity of said transfer fabric when uncompressed.

4. The transfer fabric of claim 1 wherein said configuration of valleys and

peaks diverge substantially equally from a median plane parallel of said suppoπ surface.

5. The transfer fabric of claim 4 wherein said valleys and peaks have a

maximum extend from said median plane of about 0.066 mm.

6. The transfer fabric of claim 1 wherein at least certain of said yarns

forming said base fabric have a cross-section which is one of round, oval, rectangular, triangular and star shaped.

7. The transfer fabric of claim 1 wherein at least certain of said yarns

forming said base fabric are one of PA, PPS, PE, PET, PEEK, PPA, PCTA, and PU.

8. In combination with a papermaking machine having a forming section,

a press section with press rolls and a dryer section having a vacuum drum, a continuous

transfer fabric adapted, to receive paper on a support surface, delivered from said forming

section and transpoπ said paper through said press section, said suppoπ surface being

adapted to hold said paper during transpoπ through said press section and to release said paper upon reaching said dryer section, said transfer fabric comprising:

a base fabric formed of interlaced longitudinal and transverse continuous

filament yarns having fibers interspersed throughout;

a latex coating dispersed evenly throughout said base fabric coating said yarns

and fibers and forming said suppoπ surface and a running surface opposite said suppoπ

surface with non-uniform peaks and valleys;

said transfer fabric having a first porosity in an uncompressed condition which

creates a first paper holding intensity and a second porosity in a compressed condition which

creates a second and greater paper holding intensity;

said transfer fabric acting to hold said paper with said first intensity when in said

uncompressed condition during movement to and from said press rolls and to hold said

I S paper with said second intensity when in said compressed condition during movement

through said press rolls; whereby,

said paper is held more snugly against said transfer fabric through said press

rolls which maintains said paper evenly disposed over said support surface during transport

through said press section.

9. The combination of claim 8 wherein said first porosity is no more than

3.5 CFM.

10. The combination of claim 8 wherein said second porosity is 0 CFM.

11. The combination of claim 8 wherein said first porosity is sufficient to

allow air to be drawn through said transfer fabric in the area of said vacuum roll.

12. The combination of claim 8 wherein said peaks and valleys diverge from

a median plane parallel with said support surface up to about 0.066 mm.

13. The combination of claim 12 wherein said divergence from said median

plane between said press rolls is 0 mm.

14. The combination of claim 8 wherein said coating comprises one of nylon,

silicone, PU, PET, PP, and PE.

15. The combination of claim 8 wherein said base fabric is multi-layer.

16. The combination of claim 8 wherein said base fabric is woven.