U.S. patent application number 11/437353 was filed with the patent office on 2006-12-14 for papermachine fabric.
Invention is credited to Arved Westerkamp.
Application Number | 20060278361 11/437353 |
Document ID | / |
Family ID | 36754089 |
Filed Date | 2006-12-14 |
United States Patent
Application |
20060278361 |
Kind Code |
A1 |
Westerkamp; Arved |
December 14, 2006 |
Papermachine fabric
Abstract
The invention relates to a papermachine fabric having a batt
structure extending over the entire width of the fabric, the batt
structure comprising at least one ultrathin elongated fiber batt
which extends over a part width of the fabric and has a thickness
of 0.3 mm or less.
Inventors: |
Westerkamp; Arved;
(Dettingen/Ems, DE) |
Correspondence
Address: |
VOITH FABRICS
3040 BLACK CREEK ROAD
P.O. BOX 1411
WILSON
NC
27893
US
|
Family ID: |
36754089 |
Appl. No.: |
11/437353 |
Filed: |
May 19, 2006 |
Current U.S.
Class: |
162/348 ;
162/358.1; 162/358.4; 162/900; 162/901; 162/902; 162/903; 442/320;
442/334 |
Current CPC
Class: |
Y10T 442/608 20150401;
D21F 1/0036 20130101; Y10T 442/50 20150401; D21F 7/083
20130101 |
Class at
Publication: |
162/348 ;
162/358.1; 162/358.4; 162/900; 162/901; 162/902; 162/903; 442/320;
442/334 |
International
Class: |
D21F 1/00 20060101
D21F001/00; D21F 7/08 20060101 D21F007/08; D04H 1/08 20060101
D04H001/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2005 |
DE |
10 2005 023 390.2 |
Claims
1. A papermachine fabric comprising: a batt structure, wherein the
batt structure comprises at least one ultrathin elongated batt
section that extends over part of a width of the fabric, the
ultrathin batt structure having a thickness of greater than 0 mm
and less than approximately 0.3 mm.
2. The papermachine fabric of claim 1, wherein the thickness of the
ultrathin batt section is greater than 0 mm and less that at least
one of 0.25 mm, 0.15 mm and 0.1 mm.
3. The papermachine fabric of claim 1, wherein the ultrathin batt
section comprises fibers with a titer in the range from
approximately 1 to approximately 150 dtex.
4. The papermachine fabric of claim 1, wherein a plurality of
ultrathin batt sections are adjoined in a width extent.
5. The papermachine fabric of claim 1, wherein a plurality of
ultrathin batt sections are not adjoined in their width extent when
arranged beside one another in one plane.
6. The papermachine fabric of claim 1, further comprising a second
ultrathin batt section, wherein the at least one ultrathin fiber
batt section differs from the second ultrathin batt section by at
least one of permeability, liquid storage volume, compressibility
and density.
7. The papermachine fabric of claim 6, wherein the at least one
ultrathin batt section has the same thickness as the second
ultrathin batt section.
8. The papermachine fabric of claim 6, wherein the at least one
ultrathin batt section has a different thickness than the second
ultrathin batt section.
9. The papermachine fabric of claim 1, wherein a first ultrathin
batt section comprises fibers with a different titer than a second
ultrathin batt section.
10. The papermachine fabric of claim 1, wherein the batt structure
comprises a plurality of ultrathin fiber batts which are arranged
flatly on one another.
11. The papermachine fabric of claim 10, wherein the ultrathin
fiber batts are joined flatly to one another.
12. The papermachine fabric of claim 10, wherein the ultrathin
fiber batts are joined to one another by at least one of adhesive
bonding, fusing and cross-linking.
13. The papermachine fabric of claim 1, wherein the fabric
comprises a carrier structure which is joined to at least one of
the ultrathin fiber batts.
14. The papermachine fabric of claim 13, wherein a first part of
the carrier structure is arranged between a first ultrathin fiber
batt and a second ultrathin fiber batt.
15. The papermachine fabric of claim 14, wherein the carrier
structure is joined flatly on both sides to the first and second
ultrathin fiber batts.
16. The papermachine fabric of claim 13, wherein the carrier
structure comprises an ultrathin carrier layer with a thickness of
0.3 mm or less.
17. The papermachine fabric of claim 16, wherein the ultrathin
carrier layer comprises at least one of a permeable film, a
semipermeable film, an impermeable film, a two-dimensional textile
structure such as a woven fabric or a fine woven fabric, a film
structure, and a warp knit.
18. The papermachine fabric of claim 10, wherein the batt sections
of different ultrathin fiber batts extend parallel to one
another.
19. The papermachine fabric of claim 10, wherein the batt sections
of different ultrathin fiber batts extend perpendicular in relation
to one another.
20. The papermachine fabric of claim 1, wherein the papermachine
fabric is one of a forming fabric, a press felt, a dryer fabric,
and a transfer belt.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C.
.sctn. 119 of German Patent Application No. 10 2005 023 390.2 filed
on 20 May 2005, the disclosures of which is expressly incorporated
by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a papermachine fabric for use in a
paper, board or tissue machine.
[0004] 2. Description of Background
[0005] In order to reduce the production costs for papermachine
fabrics, the aim of current developments is often to provide
modularly constructed papermachine fabrics.
[0006] One possibility for the modular construction of papermachine
fabrics consists in providing carrier or reinforcing structures
which are built up from basic elements that are prefabricated and
joined to one another, such as threads and/or flat structures such
as films or the like.
[0007] In the production of papermachine fabrics, use is currently
made of batt structures having fiber batts with thicknesses in the
region of 1.0 mm or more (measured in accordance with EN ISO 5084),
batt structures being employed both in the production of press
felts and in other papermachine fabrics such as forming fabrics or
transfer belts.
[0008] As a result of using the relatively thick fiber batts,
limits are placed on the variability in the production of the batt
structures. For example, for a customer-specific adaptation of the
fabrics to conditions in the paper machine of the customer and/or
to the paper grade produced by the customer and so on, batt
structures are provided individually, with thickness graduations of
the batt structures which are often fine. In the case of the known
fiber batts, this often requires individual production of the fiber
batts specifically for the respective customer requirements, which
often makes the costs for the production of such fabrics
expensive.
BRIEF SUMMARY OF THE INVENTION
[0009] The object of the present invention is to propose a
papermachine fabric having a batt structure whose properties can be
adapted simply to the respective customer-specific requirements and
which, moreover, can be produced more cost-effectively than the
papermachine fabrics with a batt structure known from the prior
art.
[0010] According to the invention, a papermachine fabric having a
batt structure extending over the entire width of the fabric is
proposed, in which the batt structure comprises at least one
ultrathin batt section which, in its entire width, extends over
part of the width of the fabric and has a thickness of 0.3 mm or
less, measured in accordance with EN ISO 5084.
[0011] As a result of providing at least one ultrathin batt section
which extends over part of the width of the batt structure and has
a thickness of 0.3 mm or less, it is possible to build up the batt
structure from one or more of the ultrathin and cost-effectively
prefabricated batt sections in accordance with the specific
requirements on the fabric, irrespective of its overall thickness
and overall width.
[0012] Furthermore, it is conceivable, for example, for the
ultrathin batt layer to be incorporated into a conventional batt
layer, extending over only part of the width of the batt structure,
in order to provide a dewatering performance over the aforesaid
part width that is different from the remainder of the papermachine
fabric. It is thus possible, with the at least one ultrathin batt
layer, to influence one or more properties of a batt structure, for
example a conventional structure, locally over a part width of the
papermachine fabric without the planarity and thus the marking
behavior of the batt structure being influenced notably as a result
on account of the ultrathin thickness of the batt section.
[0013] On account of the very low thickness of the ultrathin batt
section, this can, for example, simply be integrated locally into
an existing batt structure without affecting the thickness of the
latter substantially.
[0014] The ultrathin batt section is preferably formed in such a
way that the latter is different from the remaining batt structure
in at least one property. The property can be, for example, the
permeability, the liquid storage volume or compressibility.
Possible ways of influencing the at least one property of the
ultrathin batt section consist, for example, in the fact that this
is to be compacted more highly, so that this comprises other fibers
or that this is coated.
[0015] The ultrathin batt section has, for example, a width of 1.5
m or less.
[0016] Furthermore, it is possible to form at least one or more
ultrathin fiber batts with a batt structure from the ultrathin batt
sections. A preferred embodiment of the invention therefore
provides for at least one ultrathin fiber batt extending over the
entire width of the fabric to be formed by a plurality of ultrathin
batt sections adjoining one another in their width extent. It is
thus possible to build up an ultrathin fiber batt of any desired
width modularly by placing prefabricated batt sections laterally
beside one another.
[0017] Because the ultrathin batt sections are so thin, moreover,
no requirements are placed on the accuracy when the batt sections
are placed laterally beside one another, for example during
winding. Thus, because of the ultrathin formation of the batt
sections, it is no problem for many applications if the batt
sections overlap partly when they are placed laterally beside one
another.
[0018] A plurality of such ultrathin fiber batts can then be joined
flatly to one another in order to form at least one part of the
batt structure. In this way, the batt structure can be built up
simply and cost-effectively from the prefabricated ultrathin batt
sections virtually in any desired thickness graduation and with
virtually any desired properties in accordance with the customer
requirements.
[0019] By using still thinner ultrathin batt sections, still finer
thickness graduations of the batt structure can be achieved.
Moreover, by means of such still thinner ultrathin batt sections,
the property of the batt structure can be influenced locally
without influencing the thickness of the remaining batt structure
noticeably, for example with regard to the tendency to marking. It
has proven to be advantageous if, in this connection, the ultrathin
batt section has a thickness of 0.25 mm or less, preferably a
thickness of 0.15 mm or less or a thickness of 0.1 mm or less,
measured in accordance with EN ISO 5084.
[0020] If a 3 mm thick batt structure is built up from ultrathin
fiber batts with a layer thickness of 0.15 mm, then this is formed
of 20 ultrathin fiber batts arranged above one another. From this,
the potential of the flexible possible configuration for the
adaptation of the papermachine fabric to the customer-specific
requirements by the use of the ultrathin fiber batts emerges
directly if these are compared with fiber batts according to the
prior art, which have thicknesses of 1 mm or more.
[0021] The fibers which are suitable for an ultrathin batt section
have a titer in the range from 1 to 150 dtex which, for example in
the case of polyamide 6 (PA6), corresponds to a filament diameter
in the range between 0.0106 mm and 0.1296 mm.
[0022] The fibers of the ultrathin batt section comprise, for
example, mineral and/or leonic fibers, such as rock fibers, glass
fibers, metal fibers, and/or fibers made of polymer materials, such
as polyamide, polypropylene, polyester, ethyl vinyl acetate,
polyethylene, polyurethane and their modifications, and/or
cellulosic fibers, such as viscose, acetate or mixtures of the
same.
[0023] For the purpose of further individual influencing of the
property profile along the width extent of the papermachine fabric
according to the invention, it is also possible for the batt
structure to comprise a plurality of ultrathin batt sections which
do not adjoin one another in their width extent arranged beside one
another in one plane. This means that the batt structure can have a
plurality of ultrathin batt sections which do not adjoin one
another in a specific plane over its width. This is the case, for
example, when an ultrathin fiber batt is in each case arranged only
in the two edge regions of the batt structure.
[0024] Of course, the ultrathin fiber batt can also be built up
from ultrathin batt sections which differ in their properties in
order to create a property profile that is locally different in the
width of the fabric. A preferred refinement of the invention
accordingly provides for the ultrathin fiber batt to have at least
one ultrathin batt section which differs in at least one property
from the remaining ultrathin batt sections of the ultrathin fiber
batt. For example, the following properties are suitable:
permeability, liquid storage volume, compressibility, density.
[0025] In this case, it is both possible for the ultrathin batt
sections of an ultrathin fiber batt to have the same thickness or
for at least one of the ultrathin batt sections of the ultrathin
fiber batt to have a different thickness than the remaining
ultrathin batt sections of the ultrathin fiber batt. In the
last-named case, it is also conceivable for a plurality of
ultrathin batt sections to be arranged above one another and
jointly to have a height which corresponds to the height of the
adjacent ultrathin batt sections of the same ultrathin fiber batt
adjacent to the former. In this way, it is possible to form an
ultrathin fiber batt having a uniform height.
[0026] In order to set different properties over its width in the
ultrathin fiber batt, it is also conceivable for at least one of
the ultrathin batt sections of the ultrathin fiber batt to comprise
fibers with a different titer than the remaining ultrathin batt
sections of the ultrathin fiber batt.
[0027] If the batt structure has a plurality of ultrathin fiber
batts, the property profile over the width of the papermachine
fabric can further be set individually by at least one ultrathin
batt section of an ultrathin fiber batt differing in at least one
of the following properties from an ultrathin batt section of
another ultrathin fiber batt. For example, the following properties
are suitable: permeability, liquid storage volume, compressibility,
density.
[0028] The ultrathin fiber batts are preferably joined to one
another with one of the following methods, on their own or in
combination: mechanical joining methods such as needling, chemical
joining methods such as adhesive bonding, fusing, chemical
cross-linking. In this connection, it is for example conceivable
for what are known as hot-melt fibers which have a lower melting
point than the remaining fibers of the fiber batt to be
incorporated in ultrathin fiber batts to be joined to one another.
In order to join the fiber batts, the fiber batts are subjected to
the action of heat in order to melt the hot-melt fibers or, in the
case of the lower melting-point sheaths, their sheaths, and thus to
fuse the ultrathin fiber batts at least partly to one another.
[0029] In order to provide adequate dimensional stability of the
papermachine fabric according to the invention, it is necessary for
the latter to comprise a carrier structure which is joined directly
or indirectly to at least one of the ultrathin fiber batts.
[0030] In this case, the carrier structure can be arranged on one
side with the batt strontium or within the batt structure.
According to a further refinement of the invention, provision is
made for at least part of the carrier structure to be arranged
between two of the ultrathin fiber batts. The carrier structure
preferably comprises an ultrathin carrier layer with a thickness of
0.3 mm or less, the ultrathin carrier layer being able to comprise,
on their own or in combination: a permeable or semipermeable or
impermeable film, a two-dimensional textile structure such as a
woven fabric or a fine woven fabric, a film structure, a warp
knit.
[0031] In practical terms, therefore, a semipermeable film which is
joined two-dimensionally to the ultrathin fiber batts can therefore
be arranged, for example, at least partly between two ultrathin
fiber batts.
[0032] Suitable films are, for example, a film marketed by DuPont
under the trademark Mylar.
[0033] The fine woven fabric is preferably one having 50 or more
warp and/or weft threads per cm. The woven fabric is a woven
structure known from the papermachine fabric sector.
[0034] If the batt structure has a plurality of ultrathin fiber
batts, then it is both possible for the batt sections of different
layers to extend parallel to one another or for the batt sections
of different layers to extend crossed in relation to one another.
In the first-named case, the ultrathin fiber batts can be produced
by spiral winding of one or more ultrathin batt strips which, in
the wound state, form the various batt sections extending over a
part width of the fabric and adjoining one another in their width
extent. In the second-named case, the ultrathin batt strip layers
can be wound layer by layer crossing one another.
[0035] Depending on the configuration of the batt structure, the
papermachine fabric according to the invention can be a forming
fabric or press felt or a dryer fabric or a transfer belt.
[0036] These and other features and advantages of this invention
are described in or are apparent from the following detailed
description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The preferred embodiments of the present inventions is
further described in the detailed description which follows, in
reference to the noted plurality of drawings by way of non-limiting
examples of exemplary embodiments of the present invention, in
which like reference numerals represent similar parts throughout
the several views of the drawings, and wherein:
[0038] FIG. 1 shows a cross section of the first embodiment of a
fabric according to the invention,
[0039] FIG. 2 shows a cross section of the second embodiment of a
fabric according to the invention,
[0040] FIG. 3 shows a cross section of the third embodiment of a
fabric according to the invention, and
[0041] FIG. 4 shows in plan view two ultrathin fiber batts arranged
one above the other, which form part of the batt structure of a
fabric according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0042] The particulars shown herein are by way of example and for
purposes of illustrative discussion of the embodiments of the
present invention only and are presented in the cause of providing
what is believed to be the most useful and readily understood
description of the principles and conceptual aspects of the present
invention. In this regard, no attempt is made to show structural
details of the present invention in more detail than is necessary
for the fundamental understanding of the present invention, the
description taken with the drawings making apparent to those
skilled in the art how the several forms of the present invention
may be embodied in practice.
[0043] FIG. 1 shows in cross-section over its entire width a first
embodiment of a papermachine fabric according to the invention,
formed as a dryer fabric 1.
[0044] The dryer fabric 1 has a carrier structure 2 which is formed
by a perforated film 2 having openings 3. In the FIG. 1, above the
perforated film, there is arranged a first ultrathin fiber batt 4,
which is formed by ultrathin batt sections 5a, 5b, 6a, 6b and 7a,
7b.
[0045] The batt sections 6a and 7a and the batt sections 6b and 7b
are in each case arranged flatly on one another and form a first
laminate 8a and a second laminate 8b. The two laminates 8a and 8b
are in each case arranged in the edge region 11a and 11b of the
dryer fabric 1, the ultrathin batt sections 5a and 5b being
arranged in the central region of the dryer fabric 1.
[0046] In order to form the ultrathin fiber batt 4 extending over
the entire width of the fabric 1, the fiber batts 5a and 5b and the
first and the second laminate 8a, 8b are arranged adjoining one
another in their width extent. In FIG. 1, above the first ultrathin
fiber batt 4, there is arranged a second ultrathin fiber batt 9,
which is joined flatly to the first ultrathin fiber batt 4.
[0047] The second ultrathin fiber batt 9 extends over the entire
width of the dryer fabric 1 and is formed by a plurality of
ultrathin batt sections 10a to 10e adjoining one another in their
width extent.
[0048] The first ultrathin fiber batt 4 has a thickness of 0.2 mm,
the batt sections 6a, 6b, 7a, 7b in each case having a thickness of
0.1 mm and the batt sections 5a, 5b having a thickness of 0.2 mm.
Accordingly, the ultrathin batt sections 6a, 6b, 7a, 7b of the
ultrathin fiber batt 4 have a different thickness than the
ultrathin batt sections 5a, 5b.
[0049] The second ultrathin fiber batt 9 has a thickness of 0.1
mm.
[0050] In the ultrathin fiber batt 4, the ultrathin batt sections
6a and 6b have a permeability that is reduced as compared with the
batt sections 7a, 7b, 5a, 5b, in order to prevent fluttering of the
edges in the edge regions 11a and 11b of a paper web carried on the
dryer fabric 1. Furthermore, the ultrathin batt sections 7a, 7b
have a thermal conductivity that is increased as compared with the
ultrathin batt sections 5a, 5b, 6a, 6b, in order to prevent
excessive heating and damage resulting therefrom of the
non-web-carrying edge regions 11a and 11b of the dryer fabric
1.
[0051] The batt sections 6a and 6b are coated with a polymer
coating in order to achieve the lower permeability, the batt
sections 7a and 7b comprising metal fibers.
[0052] FIG. 2 shows in a cross section over its entire width a
second embodiment of a paper machine fabric according to the
invention, formed as a press felt 13.
[0053] The press felt 13 has a carrier structure 14 which is formed
by a woven fabric 14 known in the papermachine fabric sector.
Furthermore, the press felt 13 has a batt structure 21.
[0054] The batt structure 21 has conventional fiber batts 15 and 16
which, in FIG. 2, are arranged above and below the woven fabric 14
and are joined flatly to the latter.
[0055] Furthermore, the batt structure 21 has conventional fiber
batts 19 and 20 and ultrathin batt sections 18a and 18b according
to the invention. The ultrathin batt sections 18a, 18b are in each
case arranged in one of the edge regions 17a and 17b of the press
felt 13, between the fiber batts 16 and 19.
[0056] The two ultrathin batt sections 18a, 18b each have a
thickness of 0.1 mm, whereas the conventional fiber batts 16 and 19
have thicknesses in the range from 1.2 mm to 1.8 mm with thickness
fluctuations of +/-0.1 mm, so that, as a result, the two batt
sections 18a, 18b have no detrimental effect on the planarity of
the paper-side surface 22 of the press felt 13.
[0057] The two ultrathin batt sections 18a, 18b have a reduced
permeability, so that, as a result, the permeability and thus the
dewatering performance of the press felt 13 is reduced in its two
edge regions 17a and 17b as compared with the region in which the
batt sections 18a, 18b do not extend. In this way, an increased
dewatering pressure prevailing in the edge regions 17a, 17b in the
press nip can be compensated for in order to effect more uniform
dewatering over the width of the press felt 13.
[0058] FIG. 3 shows in a cross section over its entire width a
third embodiment of a paper machine fabric according to the
invention, formed as a press felt 24.
[0059] The press felt 24 has a carrier structure 25 which is formed
by a laid scrim having filaments 27 extending in the machine
direction. In FIG. 3, above the carrier structure 25, there is
arranged a batt structure 26 which is joined flatly to the carrier
structure 25.
[0060] The batt structure 26 has ultrathin fiber batts 28, 29, 30,
31 and 32 which are ranged above one another flatly from bottom to
top in FIG. 3.
[0061] In the two edge regions 33a and 33b of the press felt 24,
ultrathin batt sections 35a and 35b are, moreover, arranged between
the two ultra thin fiber batts 30 and 31. Furthermore, two
ultrathin batt sections 36a and 36b adjoining one another in their
width extent are arranged in the central region 34 between the two
fiber batts 31 and 32.
[0062] Each of the ultrathin fiber batts 28, 29, 30, 31 and 32 is
formed by a plurality of ultrathin batt sections adjoining one
another in their width extent, which are not designated
individually in the following text for reasons of clarity.
[0063] The fiber batts 28 to 30 are constructed identically and
comprise fibers having a titer in the range of more than 60 dtex.
The fiber batts 28 to 30 together constitute the equivalent of a
conventional fiber batt having a thickness of about 1 mm thickness,
only with the difference that, according to the invention, the
fiber batts 28 to 30 are formed from prefabricated batt sections
having a thickness of 0.3 mm in each case. Of course, far more
fiber batts can be joined flatly to one another, in accordance with
the customer-specific or application-based requirements.
[0064] The upper side of the ultrathin fiber batt 32 forms the
paper side 37 of the press felt 24 in the embodiment shown in FIG.
3. The ultrathin fiber batt 32 is formed by fibers with a titer of
6 dtex or less and has a thickness of 0.1 mm.
[0065] In order to influence the dewatering performance, the
ultrathin batt sections 35a and 35b are arranged in the edge
regions 33a and 33b of the press felt 24, in between the ultrathin
fiber batts 30 and 31, in each case in the area of the edge regions
33a and 33b. Accordingly, the batt structure comprises a plurality
of ultrathin batt sections 35a, 35b which do not adjoin one another
in their width extent arranged beside one another in one plane.
[0066] Furthermore, in order to reduce the rewetting in the central
region 34 of the press felt 24 between the ultrathin fiber batts 31
and 32, the two ultrathin batt sections 36a and 36b are arranged
beside each other, these extending just over the width of the press
felt 24 in which the two ultrathin batt sections 35a, 35b do not
extend.
[0067] The batt sections 36a, 36b, 35a, 35b have a thickness of 0.1
mm.
[0068] FIG. 4 shows in plan view two ultrathin fiber batts 39 and
40 which are arranged one above the other and which form part of a
batt structure 38 according to the invention.
[0069] The two fiber batts 39 and 40 are produced by winding a batt
strip over two rollers 41 and 42 spaced apart from each other, the
first fiber batt 39 being formed by a plurality of ultrathin batt
sections 43a to 43c adjoining one another in their width extent and
running parallel to one another which, in the illustration of FIG.
4, extend from the roller 41 to the roller 42, running from
below.
[0070] Moreover, the second fiber batt 40 is formed by a plurality
of ultrathin batt sections 44a to 44c adjoining one another in
their width extent and running parallel to one another which, in
the illustration of FIG. 4, extend from the roller 41 to the roller
42 running from above, so that the batt sections 43a to 43c, 44a to
44c of the different ultrathin fiber batts 39 and 40 run crossed in
relation to one another.
[0071] At a later time in the production, the finished batt
structure 38 is cut out of the wound ultrathin fiber batts 39, 40
along the section lines A-A and B-B. According to the invention,
the batt structure 38 comprises a plurality of ultrathin elongated
batt sections 43a to 43c and 44a to 44c, which in each case extend
only over a part width of the batt structure 38 and have a
thickness of 0.3 mm or less.
[0072] While the present invention has been particularly shown and
described with reference to the foregoing preferred embodiments,
those skilled in the art will understand that many variations may
be made therein without departing from the spirit and scope of the
invention as defined in the following claims. This description of
the invention should be understood to include all novel and
non-obvious combinations of elements described herein, and claims
may be presented in this or a later application to any novel and
non-obvious combination of these elements. The foregoing
embodiments are illustrative, and no single feature or element is
essential to all possible combinations that may be claimed in this
or a later application. Where the claims recite "a" or "a first"
element or the equivalent thereof, such claims should be understood
to include incorporation of one or more such elements, neither
requiring nor excluding two or more such elements.
* * * * *