A dry-formed nonwoven fabric; preferably an air lay web; including a fiber composition which is at least 50%, by weight, wood pulp fiber less than about 0.635 cm (1/4 inch) in length with 25% or more of the fiber composition in the web, by weight, being kraft wood pulp fibers, and under 50%, by weight, reinforcing fibers intermixed with the wood pulp fibers throughout the web structure; an embossment in the web providing a plurality of compressed, densified valley regions and less-dense high loft regions; the web including no more than about 5.1 g/m.sup.2 (3.0 lbs per ream of 2,880 ft..sup.2) of a binder and having a cross machine direction wet tensile strength no lower than about 0.09 Kg/cm (0.5 lbs/inch), and preferably at least 0.107 Kg/cm (0.6 lbs/inch). A higher cross-machine direction wet tensile strength in excess of 0.267 Kg/cm (1.5 lbs/inch) can be established at a binder level less than 8.5 g/m.sup.2 (5 lbs/ream), and preferably at a binder level between 6.8-8.5 g/m.sup.2 (4-5 lbs/ream).

TECHNICAL FIELD 
This invention relates generally to a dry-formed nonwoven fabric, and more 
particularly to a unique air lay web structure employing a blend of wood 
pulp fibers and reinforcing (e.g., textile) fibers. 
BACKGROUND ART 
Air lay web forming technology has developed to the point where it is now 
being used commerically to manufacture a variety of absorbent web 
products. For example, Scott Paper Company has developed an air lay 
process in which wood pulp fibers and textile fibers are blended together 
to manufacture webs for use in impregnated baby wipes, household towels 
and a variety of industrial wipers. These textile fibers enhance web 
strength by reinforcing the structure. In addition, Scott owns a number of 
patents directed to its blended-fiber, air lay technology (e.g., U.S. Pat. 
Nos. 4,134,948; 4,130,915; 4,097,965 and 4,064,600). This list of patents 
does not include all patents directed to Scott's air lay technology; 
however, it is representative of information relevant and material to the 
subject matter of the instant invention. 
Johnson & Johnson also has developed an air lay technology for 
manufacturing absorbent webs from a blend of wood pulp fibers and textile 
fibers. This technology purportedly utilizes the suction bonding technique 
described in U.S. Pat. No. 3,663,348, issued to Liloia et al., to bond the 
webs throughout their thickness, and purportedly is being commercially 
utilized to manufacture the facing sheet of Johnson & Johnson's disposable 
diaper product. This technology also may have been employed at different 
times to manufacture other absorbent web products. 
Karl Kroyer of Denmark has developed an air lay technology employing 100% 
wood pulp fibers in forming air lay webs. In other words, Kroyer's 
technology does not employ textile fibers blended with the wood pulp 
fibers to reinforce the web structure. This technology presently is being 
utilized by American Can Company to commercially manufacture a household 
towel under the Bolt trademark, and purportedly employs the method claimed 
in U.S. Pat. No. 3,669,778, issued to Rasmussen. 
In the commercial products employing blended fiber compositions (i.e., wood 
pulp fibers and textile fiber) relatively large quantities of binder have 
been needed to establish the necessary strength levels; particularly for 
absorbent products encountering rigorous use (e.g., household wipers, 
industrial wipers, etc.). In fact, the prior art technology employed by 
Scott Paper Company to manufacture its household and industrial wipers 
relies upon the use of approximately 8.5-10.2 g/m.sup.2 (5-6 lbs. per ream 
2,880 ft..sup.2) of a cross-linking latex binder to establish a 
cross-direction wet tensile strength that does not fall below 0.107 Kg/cm 
(0.6 lbs. per inch). Although for some applications a lower 
cross-direction wet tensile strength on the order of about 0.089 Kg/cm 
(0.5 lbs./inch) can be tolerated, a high binder level in excess of about 
6.1 g/m.sup.2 (3.6 lbs./ream) would still be needed. 
The need for high binder levels is even more acute in air lay webs formed 
from 100% wood pulp fibers, since no additional strength will be imparted 
to these webs by longer-length textile fibers. For example, the commercial 
use of Kroyer's technology, as is partially reflected in 
earlier-referenced Rasmussen U.S. Pat. No. 3,669,778, to manufacture Bolt 
household towels utilizes in excess of 13.6 g/m.sup.2 (8 lbs./ream) of 
binder to establish a cross-machine direction wet strength level of about 
0.135 kg/cm (0.76 lbs./in). 
Liloia et al. U.S. Pat. No. 3,663,348, assigned to Johnson & Johnson, 
suggests the use of low binder levels in air lay web structures. However, 
in order to achieve desired strength levels Liloia et al. appears to 
require the use of reinforcing synthetic fibers having a substantially 
uniform length greater than 1.9 cm (3/4 inches), and a suction bonding 
technique for bonding the entire web throughout its thickness. 
The webs described in the Liloia et al. examples are not embossed, and 
there is absolutely no teaching that any relationship exists between the 
magnitude of embossing pressure and strength. However, such a relationship 
has surprisingly been recognized by applicant, and has been made use of in 
inventing the products covered herein, as will be explained in greater 
detail later in this application. It is significant to note that even 
though specific examples in the Liloia et al. patent suggest the use of 
low binder levels less than 3.4 g/m.sup.2 (2#/ream), commercial products 
purportedly covered by this patent employ considerably higher levels above 
8.5 g/m.sup.2 (5 lbs. per ream) to obtain a CDWT level of about 0.14 kg/cm 
(0.8 lb/in). 
A further patent of interest relating to air-lay fibrous webs including 
blends of wood pulp fibers and longer-length fibers, is U.S. Pat. No. 
2,926,417, issed to Duvall. The webs disclosed in Duvall are primarily 
intended for use as flexible insulation and cushioning felts and are not 
embossed. Duvall definitely does not suggest any relationship between the 
magnitude of embossing pressure and strength; a relationship that need to 
be recognized by applicant in making the instant invention. Duvall 
indicates that to provide sufficient strength in his web to permit it to 
be conveyed through a bonding operation without falling apart, he needs to 
include at least 20% textile-length fibers in the structure. 
Interestingly, the blended fibrous webs of the instant invention can 
include considerably less than 20% textile fibers and still be carried 
through a bonding operation in a reliable manner. 
DISCLOSURE OF INVENTION 
A dry-formed nonwoven fibrous web includes a fiber composition which is at 
least 50%, by weight, wood pulp fibers less than about 0.635 cm (1/4 inch) 
in length, with 25% or more of the fiber composition in the web, by 
weight, being kraft wood pulp fibers, and under 50%, by weight, 
reinforcing fibers intermixed with the wood pulp fibers throughout the 
web; an embossment in the web providing a plurality of compressed, 
densified valley regions and less-dense high loft regions, said web 
including no more than about 5.1 g/m.sup.2 (3.0 lbs./ream of 2,880 sq. 
ft.) of binder and having a cross-machine direction wet tensile strength 
(CDWT) of at least about 0.107 Kg/cm (0.6 lbs. per linear inch). With less 
than 8.5 g/m.sup.2 (5 lbs/ream) of binder a cross-machine direction wet 
tensile strength in excess of 0.267 Kg/cm (1.5 lbs/linear inch), and 
actually in excess of 0.356 Kg/cm (2.0 lbs/linear inch) can be achieved. 
It has been found that for a given blend of wood pulp fibers and textile 
fibers, and for a given quantity of binder (i.e. g/m.sup.2), variations in 
web basis weight in the range of about 51 g/m.sup.2 (30 lbs/ream) to about 
119 g/m.sup.2 (70 lbs/ream) have very little effect on strength levels. In 
addition the Duvall U.S. Pat. (No. 2,926,417) indicates that variations in 
web basis weight in the range of about 340 g/m.sup.2 (200 lbs/ream) to 
about 510 g/m.sup.2 (300 lbs/ream) also have very little effect on 
strength levels. Basis weight will have a greater influence on strength 
(for a given fiber mix and binder level) at lower basis weight levels. The 
particular basis weight level where this becomes significant, and 
therefore needs to be taken into account in determining the quantity of 
binder that is needed to maintain, or establish a particular strength 
level, can be determined quite easily by empirical means. 
Preferably over 50% of the fiber composition in the web, by weight, is 
kraft wood pulp fibers. Preferably these wood pulp fibers are 
predominantly softwood, and are northern kraft wood pulp fibers that 
impart greater strength to the web than coarser southern kraft wood pulp 
fibers. A northeastern kraft wood pulp fiber, such as Pictou, is preferred 
since it is finer than its northwestern counterparts, and provides a 
stronger web construction. Although not desiring to be limited to any 
particular theory, it is believed that the higher strength levels are 
achieved since the finer northeastern kraft wood pulp fibers provide more 
fiber crossover points per unit area that can be bonded together in the 
dry-formed web structure. 
Preferably the fibrous web of this invention is manufactured by an air lay 
web forming process of the type described and claimed in U.S. Pat. No. 
3,862,472, issued to Henry J. Norton and Brian E. Boehmer, and assigned to 
Scott Paper Company. The process preferably is carried out with a fiber 
blending device of the type described in either U.S. Pat. No. 4,064,600 or 
U.S. Pat. No. 4,130,915, both issued to Gotchel, et al. and assigned to 
Scott Paper Company. After the initial web of blended wood pulp fibers and 
longer-length reinforcing fibers is formed it is embossed in accordance 
with unique aspects of this invention; is thereafter bonded through the 
application of a spray binder to both surfaces of the web and is 
subsequently cured. 
The embossing operation is carried out between a steel roll containing the 
desired embossing patern etched into it, and an opposed rubber covered 
roll against which the web is pressed. By embossing at a pressures of 
approximately 24.11 kg/cm (135 lbs. per linear inch) or higher Scott Paper 
Company has been able to reduce the amount of binder applied to the web by 
more than one-half the amount previously employed, while still maintaining 
desired minimum cross direction wet strength levels. In fact this can be 
achieved in a web construction in which secondary, or manufacturers waste 
textile fibers are employed as reinforcing fibers, as opposed to uniform 
length synthetic fibers of the type required for use in the Liloia et al. 
web construction. In addition, these minimum CDWT levels can be achieved 
in web constructions which are not bonded throughout their entire 
thickness; at least in the high loft regions. 
To further emphasize the significance of this invention, a prior art air 
lay web construction employing southern Kraft wood pulp fibers blended 
with secondary textile-length fibers required the use of approximately 
10.2 g/m.sup.2 (6 lbs. per ream) of a cross-linking binder to achieve a 
CDWT level of no less than about 0.107 Kg/cm (0.6 lbs./in.). In the 
instant invention this minimum CDWT level, as well as higher CDWT levels 
in excess of 0.179 Kg/cm (1 lbs./in.) can be established at a binder level 
of no more than bout 5.1 g/m.sup.2 (3 lbs. per ream). This invention is 
made possible by applicant's recognition that an increase in embossing 
pressure, at least in the range of from about 17.86 Kg/cm (100 pli) to at 
least about 107 Kg/cm (600 pli), has a significant effect in increasing 
the strength of webs formed from a blend of wood pulp fibers and longer 
reinforcing fibers. This was quite surprising to discover since a similar 
effect has not been encountered in air lay web structures in which the 
fiber composition is 100% wood pulp. In fact, FIG. 3 of 
earlier-referred-to Rasmussen U.S. Pat. No. 3,669,778, along with the 
textual material, teaches that very little increase in strength can be 
expected by embossing a 100% wood pulp air lay web at pressures in excess 
of 17 Kg/cm (95 pli).

BEST MODE FOR CARRYING OUT THE INVENTION 
The sole FIGURE in this application illustrates the interrelationships 
among fiber mix (i.e., percentage, by weight, of wood pulp 
fibers/percentage, by weight, of reinforcing textile fibers), adhesive 
level, strength level and embossing pressure. The data plotted in the 
FIGURE is set forth in TABLE 1. 
In all samples the wood pulp was Pictou northeast kraft-approximately 85% 
softwood/15% hardwood. 
The textile fiber was manufacture's waste polyester, sold under designation 
1280A by Leigh Company of Spartansburg, South Carolina. This fiber has an 
average length of about 1.9 cm (3/4 inches), and has a random length 
distribution that was not classified in any way prior to being deposited 
into the air-laid web construction. 
The binder was Reichhold 97460, a self-crosslinking styrene-butadiene 
latex; purchased as a emulsion containing about 45% solids. The emulsion 
was diluted to 14-20% solids for spray application. 
The average moisture level, by weight, of the air-laid mat immediately 
after embossing was greater than 15% and less than 30%. 
The embossing operation was carried out between an upper pattern roll and a 
lower anvil roll. The upper roll was about a 46 cm (18 inch) diameter, 
fluted heat-transfer roll made of steel. It was internally heated by oil 
flow through internal channels, and the surface temperature of the roll 
was about 22.degree. C. (40.degree. F.) below the average oil temperature. 
Surface temperature of the upper roll was maintained between about 
79.4.degree. C. (175.degree. F.) and 101.degree. C. (215.degree. F.) 
during embossing. The upper roll was engraved with standard Terri pattern 
#201 having about 80% lofted, or raised areas for forming the compressed 
valley regions in the webs of this invention. The spacing between raised 
areas in this pattern is less than the average length of the textile 
fibers, and therefore the textile fibers will interconnect the compressed 
valley regions in the web to become an effective strength imparting 
component of the structure. 
The lower anvil roll was about a 46 cm (18 inch) diameter steel roll, 
covered with a 1.59 cm (5/8 inch) outer layer of rubber having a Shore A 
hardness of 95. 
The upper and lower rolls were brought into contact with each other by 
means of a piston-actuated mechanism. The load plotted in the FIGURE (kg 
per linear centimeter) was calculated by dividing the total load applied 
to the roll by the axial dimension of the roll. 
TABLE I 
__________________________________________________________________________ 
Fiber Mix Adhesive 
Embossing Load 
CDWT (1-ply) 
Basis Weight 
.sup.+ % wood pulp/ 
g/m.sup.2 
Kg/linear cm 
Kg/cm g/m.sup.2 
% textile fibers 
(lbs/ream) 
(lbs./linear inch) 
(lbs./in.) 
(lbs/ream) 
__________________________________________________________________________ 
Curve A 
60/40 6.8-8.5 (4-5) 
35.7 (200) 
.285 (1.60)* 
(67.5) 
" " 71.4 (400) 
.433 (2.43)* 
(71) 
" " 107.2 (600) 
.443 (2.49)* 
(72.5) 
Curve B 
75/25 " 35.7 (200) 
.204 (1.14)* 
(61.1) 
" " 71.4 (400) 
.227 (1.27)* 
(63.2) 
80/20 " 35.7 (200) 
.170 (0.95)* 
(52) 
" " 71.4 (400) 
.234 (1.31)* 
(51.9) 
" " 107.2 (600) 
.246 (1.38)* 
(56.2) 
90/10 " 20.2 (113) 
.163 (0.91)* 
(43.8) 
" " 25.5 (143) 
.152 (0.85)** 
(38.3) 
" " 26.8 (150) 
.146 (0.82)* 
(37.9) 
" " 42.9 (240) 
.179 (1.00)** 
(43.9) 
Curve C 
60/40 1.7-3.1 (1-1.8) 
35.7 (200) 
.082 (0.46)* 
(66.3) 
" " 71.4 (400) 
.113 (0.63)* 
(65.3) 
" " 107.2 (600) 
.120 (0.67)* 
(68.1) 
Curve D 
75/25 " 71.4 (400) 
.134 (0.75)* 
(66.9) 
" " 107.2 (600 ) 
.147 (0.81)* 
(66.3) 
80/20 " 35.7 (200) 
.102 (0.57)* 
(50.4) 
" " 71.4 (400) 
.107 (0.60)* 
(54.8) 
" " 107.2 (600) 
.143 (0.80)* 
(54.2) 
90/10 " 24.1 (135) 
.104 (0.58)* 
(44.8) 
" " 26.8 (150) 
.118 (0.66)*** 
(41.4) 
" " 107.2 (600) 
.141 (0.79)*** 
(38.9) 
__________________________________________________________________________ 
Curves E & F are interpolations from AC and BD, respectively; based on a 
linear relationship existing between strength and increase in adhesive 
load. 
.sup.30 Pictou NE kraft pulp, about 85/15 soft/hardwood 
*Value is a single data point which is an average of tests carried out on 
16 plies by making four determinations; each with a 4ply sample. 
**Value is an average of two data points; each data point being generated 
as indicated above. 
***Value is an average of six data points; each data point being generate 
as indicated above. 
The most significant fact represented in the FIGURE is that web strength 
(CDWT) can be increased significantly by increasing embossing pressure; at 
least within the range of from about 20 Kg/cm (110 pli) to at least about 
107 Kg/cm (600 pli). This effect is most pronouced at adhesive levels of 
approximately 5.1 g/m.sup.2 (3 lbs./ream) and 6.8-8.5 g/m.sup.2 (4-5 
lbs./ream) (curves A, B, E and F); and is somewhat less pronounced at 
1.7-3.1 Kg/m.sup.2 (1-1.8 lbs./ream) (curves C & D). However, even at 
these low adhesive levels of 1.7-3.1 g/m.sup.2 (1-1.8 lbs/reams) the 
increase in strength resulting from increasing the embossing pressure is a 
significant finding in this invention. 
The relationship between strength and embossing pressure within the 
embossing pressure range of approximately 20 Kg/cm (110 pli) to 107 Kg/cm 
(600 pli) was quite unexpected; particularly in view of the teaching in 
the Rasmussen patent that such a phenomena does not take place in a 100% 
wood pulp fiber web. 
Because of the discovered relationship between strength and embossing 
pressure in air-lay webs formed from blends of wood pulp fibers and 
reinforcing fibers, applicants have been able to establish the same 
minimum CDWT levels at less than one-half the binder level previously 
employed. Alternatively, by using conventinal prior art binder levels 
applicants can achieve twice the CDWT levels previously obtained. 
Significantly, as indicated in the FIGURE, applicants can establish CDWT 
levels no lower than about 0.107 Kg/cm (0.6 lbs/inch) at binder levels of 
5.1 Kg/m.sup.2 (3.0 lbs/ream) and less, e.g. about 1.7-3.1 g/m.sup.2 
(1-1.8 lbs./reams) by suitably increasing the embossing pressure. This is 
true for all of the tested webs having a 60/40 mix (i.e., wood 
pulp/textile fiber) to 90/10 mix. 
Prior to this invention adhesive levels of 8.5-10.2 g/m.sup.2 (5-6 
lbs/ream) were employed in Scott Paper Company's blended fiber air lay 
webs to insure that CDWT levels did not fall below about 0.107 Kg/cm (0.6 
lbs/inch). However, in accordance with this invention applicants can 
employ less than 8.9 g/m.sup.2 (5 lbs/ream) of binder; preferably in the 
6.8-8.5 g/m.sup.2 (4-5 lbs/ream) range, to establish CDWT levels in excess 
of 0.267 Kg/cm (1.5 lbs/linear inch), and actually in excess of 0.356 
Kg/cm (2.0 lbs/linear inch). 
Another extremely significant fact represented in the FIGURE is that merely 
increasing the percentage of textile fibers will not necessarily increase 
web strength (compare curves C and D). Stating this somewhat differently, 
there appears to be a relationship between binder add-on and textile fiber 
composition in establishing web strength. Although curve C is 
representative of webs having a greater percentage of textile fibers than 
the webs represented by curve D, the webs represented by curve C are 
weaker at binder add-on levels of 1.7-3.1 g/m.sup.2 (1-1.8 lbs/ream). 
However, this is not the case at the higher binder levels of 5.1 g/m.sup.2 
(3.0 lbs/ream) and 6.8-8.5 g/m.sup.2 (4-5 lbs/ream), at least in the range 
of about 36-107 Kg/linear centimeter (200-600 pli) embossing pressure. In 
this latter situation compare curve A with curve B, and curve E with curve 
F. 
The precise reasion is not understood for the decrease in strength of webs 
having a 60/40 mix at 1.7-3.1 g/m.sup.2 (1-1.8 lbs/ream) binder add-on 
(curve C), compared to similarly bonded webs having a lower textile fiber 
composition (curve D). Although not wishing to be bound to a specific 
theory, applicants believe that the following may reflect what has taken 
place. The denser the compressed areas of the embossed structure, the 
greater the number of cross-over points that exist to be captured, or 
bound into the structure by a unit amount of binder. The strength of the 
product is directly related to the number of bonded cross-over points that 
are established. Textile fibers are more elastic than damp wood pulp 
fibers, and therefore are inherently less capable of being set in a 
compressed condition than the wood pulp fibers. Because of this resilience 
increasing the textile fiber level will decrease the density in the 
compressed areas of the structure, and thereby provide less cross-over 
points that can be captured by the unit amount of binder. At lower binder 
levels this can actually result in a decrease in web strength, as is 
evidenced by company curve C with curve D. However, when there is 
sufficient binder to bond the textile fibers together in the web 
structure, there will be a strength benefit achieved by increasing the 
percentage of textile fibers relative to the wood pulp fibers. This is 
evidenced by comparing curve A with curve B, and curve C with curve D. 
As a result of discovering the above relationship between strength, the 
percentage of textile fibers in the web and the level of binder in the 
web, applicants have formed lower binder add-on webs having optimum 
strength with small percentages of textile fibers. Thus a more cost 
competitive, higher strength web can be produced, compared to a low-binder 
add-on web in which the percentage of textile fibers is increased in an 
effort to increase strength. In particular applicants can form air-lay 
webs having CDWT levels in excess of 0.09 Kg/cm (0.5 lbs/in.) and even in 
excess of about 0.107 Kg/cm (0.6 lbs./in.), with 1.7-3.1 g/m.sup.2 (1-1.8 
lbs/ream) of binder add-on and a 90/10 mix of wood pulp fibers to textile 
fibers. 
The following Table II sets forth five (5) examples that are illustrative 
of the instant invention, and these examples are not intended to limit the 
scope of coverage. The claims appended hereto define the limits of the 
instant invention. 
TABLE II.sup.++ 
__________________________________________________________________________ 
Adhesive 
Embosser Load 
CDWT Basis Weight 
Mix g/m.sup.2 
Kg/linear cm 
Kg/cm g/m.sup.2 
No. 
Wood.sup.+ 
Textile.sup.+++ 
(lbs/Rm.) 
(lbs/lin. inch) 
(lbs/inch) 
(lbs/Rm.) 
__________________________________________________________________________ 
1* 
90 10 2.04 (1.20) 
24.1 (135) 
.10 (0.58) 
76.21 (44.83) 
2** 
90 10 1.97 (1.16) 
107.2 (600) 
.14 (0.79) 
66.16 (38.92) 
3* 
60 40 2.60 (1.53) 
35.7 (200) 
.08 (0.46) 
112.66 (66.27) 
4* 
60 40 2.60 (1.53) 
71.4 (400) 
.11 (0.63) 
110.93 (65.25) 
5* 
60 40 2.60 (1.53) 
107.2 (600) 
.12 (0.67) 
115.75 (68.09) 
__________________________________________________________________________ 
.sup.+ Pictou = NE Kraft pulp, about 85/15 soft/hard wood 
.sup.++ line speeds: ex. 1-68 meters/minute; ex. 2-70 meters/minute: exs. 
3 through 5-54 meters/minute 
.sup.+++ 1280A manufacturer's polyester waste sold by Leigh Company. 
*Value is a single data point which is an average of tests carried out on 
16 plies making four determinations; each with a 4ply sample. 
**Value is an average of six data points; each being determined as 
indicated above. 
Applicants have found that the desired minimum CDWT can be obtained by 
using secondary or waste reinforcing fibers in the web structure, as 
opposed to using the uniform length synthetic fibers in excess of 1.9 cm 
(3/4 inch) disclosed by Liloia et al. "Secondary textile fibers" or "waste 
fibers" as is used by applicants includes within its scope such fibers as 
cotton thread waste, jute waste, cotton napper waste, reclaimed tire cord 
and wool napper flock. It should be understood that other secondary fibers 
may be employable in this invention. Although these secondary fibers 
generally have less reinforcing capabilities than the uniform length 
synthetic fibers utilized by Liloia et al., these secondary fibers can be 
employed in the instant invention to achieve the desired minimum CDWT 
levels indicated herein. 
The use of lower levels of binder in the web structures of this invention 
provides both a significant cost benefit, and also enhances the ability of 
the web to wipe-up liquids from wet surfaces; particularly when fine 
northeast Kraft wood pulp fibers are employed to aid in establishing the 
desired capillary structure to pick-up and retain the liquids. Moreover, 
since applicants do not saturation bond their webs as is disclosed by 
Liloia et al., interior regions of the web; particularly in high loft 
regions, are generally free of binder, and therefore are highly absorbent. 
The inclusion of binder throughout the thickness of the web is noted by 
Liloia et al as having an adverse effect on absorbent properties. 
Furthermore, the use of low binder levels improves the "hand" of the 
product, reduces streaking (i.e., the leaving of a white film on wiped 
surfaces) and minimizes linting. All of these advantages are obtained 
without sacrificing strength.