IE40284B1 - Paper sheets and processes for their manufacture - Google Patents

Abstract

A low-density, soft, bulky and absorbent paper sheet exhibiting a diamond-shaped pattern in its surface after creping, said paper being characterized by having a cross-directional stretch of from about 3.5 percent to about 6 percent, as well as improved softness, surface feel and drape, said paper sheet being particularly suitable for use in tissue, toweling and sanitary products. The aforesaid paper sheets are produced by impressing a dot-dash knuckle pattern, wherein the long axis of the dash impressions is aligned parallel to the machine direction of papermaking, using the back side of a monofilament, polymeric fiber, semi-twill fabric of selected coarseness, the knuckle imprint area of which constitutes between about 20 percent and about 50 percent of the total fabric surface area, as measured in the plane of the knuckles, on an uncompacted paper web at selected fiber consistencies, induced by thermal predrying, prior to final drying and creping. [US3905863A]

Description

40284 In a Fourdri.ni.ur |>aper machine, paper stock is fed onl.o a l.i-nvul.l Liik endless holt th.it. is supported and driven by rolls assoc i.atcd with tin? machine and which servos as I.In; papcr-making surface of the machine. Fourdrinier belts are commonly formed from a length of woven Fourdrinier fabric with its ends .joined together in a seam to provide an endless holt. Fourdrinier fabrics of this type generally comprise a plurality of spaced longitudinal warp filaments and a plurality of spaced transverse woof or weft filaments which have boon woven together on a suitable loom. It should be noted that the warp filaments of the fabric are, for purposes of Lhis specification, defined as those which run parallel to the; machine direction of papermaking and non-woven web manufacturing machines to form a continuous carrier belt; woof or weft filaments are, for purposes of this specification, defined as those which run in the cross-machine direction.

While both warp and woof filaments in fabrics can he made up of a multiplicity of fibres, the present invention is concerned with warp and woof fiLaments comprised of one 10 2 8 1 fibre, i.e. monofilaments. Kxamples of monofilament, polymeria fibre fabrics are inoi.sl. welt carrier fabrics woven, I'or example, from pol yamiile, vinyl, acrylic and polyester fibres e.g. nylon, ami I.lio.se sold under the re tj» J fctTftl Trade Marks "Orion", "Dacron", and "Trevira", and Trade tark "Saran.Wh LI e a number «> I* different weaves have been proposed for Kourdr in let- fabrics, t.wo such weaves which find extensive use today are tin; so-called "plain" weaves and the "twill" (sometimes also called "long crimp") weave. £11 the plain weave, each weft rilament passes successively under one warp filament and then over the next warp filament whereas in the I will weave each weft I'i lament, passes over two warp filaments, mirier t he next warp filaincul , and I lien over t in- next, two warp filament* in a repealed pattern.

Ilritish Paleiil. Specif icat ion No. |,()73,()61 describes and claims a process for the manufacture of a soft, bulky and absorbent paper sheet which comprises the steps of (I) forming an tiiicompacfrd paper web having a basis weight of 5 40 lbs. per 300l> .square feet, (2) support ing said uncoinpaetcd paper web on an imprint.ing fabric having 2<> to til) meshes per inch, said imprint, ing fabric beinu formed from filaments having a diameter of O.OO.S to O.Oi! inches, ( .?) thermally pro-drying said uncoinpacted paper web to a fibre consistency of 30'/> to >SU5£, while support.ed by said imprint Ing fabric, (4) imprinting the knuckle pattern of .sai.il imprinting fabric in the pre-dried uiicorr.pacted paper web at a knuckle pressure of 1OOO psi to 12,()()0 psi and (5) finally drying the paper sheet so formed.

The paper sheet s produced by I lie above process exliihil similar properl i es to paper sliei-l .s which are produced by using 40284 a plain weave Imprinting fabric having filaments of approximately the same diameter when the twill fabric is installed so that its conventional "face" side is used to imprint the iincompactud paper- web. This is due to the fact that the con-5 volitional "face" side of the twill fabric, assuming the fabric has uniform knuckle heights on its web contacting side, will produce a dot-dash pattern wherein the long axis of the dash impressions is aligned parallel to the cross-machine direction and the long axis of the dot impressions is aligned parallel to 10 the machine direction. The dash impressions result from each weft filament passing in a repeated pattern under one warp filament and then over the next two warp filaments, while the dot impressions result from each warp filament passing in a repeated pattern over one weft filament and then under the next I •» «wo weft filaments on the conventional face side of the fabric.

When paper sheets imprinted by the conventional face side of a twill fabric are doctored from the drying drum, the dot-dash knuckle impressions are aligned essentially between the ci'epiitg folds. The resulting creping folds are, therefore, 20 substantially uninterrupted across the sheet's surface.

If, on the other hand, the "back" side of a mono- \ fiLament twill fabric is used to imprint an uncompacted paper web, and assuming that the fabric has uniform knuckle heights on its wob-contacting side, a dot-dash pattern is produced 2S where the long axis of the dash impressions is aligned parallel to the machine direction of the paper machine and the long axis of the dot impressions is aligned parallel to the cross-machine direction. The dash impressions result from each warp filament passing in a repeated pattern under one weft filament 30 and then over the next two weft filaments, while the dot Impres- - 4 - J 0 2 S 1 .sinus ri'su I I from each weft filament |>assiiig ill a repeated pattern iivit kin- warp I'i 1.-iiiicnl. anil I.Im-ii under I.he next, two warp I'i laments on tho hack siili: of" tho Fabric.

Paper sheets imprinted with the back side of a con-*> volitional twill fabric, unlike paper sheets imprinted with either a plain weave fabric or a conventional face side of a twill fabric, exhibit a staguercd pattern after creping.

According to the present invention, a process for the manufai lure of a soft, bulky and absorbent, paper sheet having ll> a uniform basis weight, of from 5 to 4^ lbs. per ;}000 square foot is provided, I lie proeess rompr i s i ng (a) forming an nucoiii-paeled paper wcl»: (l>) support ing I lie iuieonip.'iel ed paper welt on I lie hack side of a monofilament, syn l.het. i.c po L ymei-ic twill fabric which has from 20 to (>() meshes per inch measured in IS both the machine and cross-machine directions, a knuckle Imprint. area on i I s hack side of be! ween 2() and SO',S of its I dI a I surface area as measured in I.he plane of I.he knuckles, anil which is formed from synthetic polymeric mono I'i laments having a diameter of from I). DOS to 0.25 inches; (c) thermally 20 pro-dry Lug t he uiiconi|x»ct.od paper web to a fibre cons i.stcncy of from .30 to (d) causing tho hack side of the fabric to imprint, a dot-dash knuckle pattern on the web such t.hat. the long axis of the dash impressions is aligned parallel to the machine direct.ion of the prc-dried web; and (c) drying 2 5 and croping the thus formed paper sheet.

Ily I.he process of this invent.ion, low density, soft., hulk and absorbent, crcpcd paper sheets are prepared. These are characterised by having a cross-directional stretch of from 2 to h, preferably from ."?. ■> to 6, percent., as woLl as .10 improved softness, surface fool and drape compared with the - S - 4 0 2 8 '1 l>rlor art. The so paper sheets are particularly suitable for use as tissues, towels or sanitary products.

Wo have found that the desirable characteristics of the product become more pronounced as the knuckle imprint 5 area of the back side of the twill fabric is increased. This Increase can be achieved by the abrasion techniques disclosed in U.S. Patent Specification No. 3»573»164- In order to maximise the beneficial effects of abrading the knuckle surfaces on l.lio back Mich* of a twill imprinting fabric, we have found ID it desirable to obtain a twill fabric having uniform knuckle hoights and minimum free area (i.e. the plan area of the fabric unocciipi od by fibres) on its hack si tie prior to abrading. Uniform knuckle heights permit, a greater increase In kmtckle imprint area while minimising the danger of abrading IS completely through any particular filament. In addition, if tho knuckle heights are uniform prior to abrasion, the resulting Imprint pattern will be more uniformly consistent after the abrasion.

Because the fabric is subjected to elevated tempera-20 tures during use, it is desirable to make it dimensionally heat stable before abrading it. If this is not done, the uniform imprinting surface produced by carefully weaving the fabric and abrading the web contacting surface of the fabric prior to use will tend to warp as the temperature of the 25 fabric becomes elevated, thereby losing most of the benefits to be obtained by such careful pretreatment.

British Patent Specification No. 1,224,048 disclosed a process for preparing a dimensionally heat stable, plain weave, monofilament, polymeric fibre fabric having uniform .10 knuckle heights and minimum free area on each side of the - (> - <1 0 2 8 J Fabric. A plain weave fabric is prepared by selected polymeric warp monof1laments having relatively high heat-induccd .shrinkage potential <111(1 then determining an initial warp monofilament spacing in the Loom. Polymeric wool* mono Pi la-5 incuts having relatively low heat indnccd shrinkage potentlaL are then selected mid woven and beaten in the weaving process into a plain weave Fabric having a pre-determined initial caliper. APter the initial weaving, the Fabric knuckles are brought to uniform heights on both sides oF the Fabric and the 10 minimum Free area oF the Fabric is set by a heat shrinkage treatment which maintains the Fabric in warp tension while allowing it to shrink in the? wooF direction. Successive heat t reatinents are repeated until the Fabric does not shrink Further at I.lie I. real, ing temperature, at which point it. is said to be I " I ocked-np", i.e. no further shrinkage will occur it' the fabrir is later .subjected, ill use, to elevated tempera In res equivalent to the t. real, ing temperature.

Tt Is important to note that due to the symmetry of the plain weave, uniform knuckLe heights and minimum free 20 area are achieved simultaneously on both sides of I lie fabric.

This is not. the ease with a t.w i I I weave fabric. If a monofilament, polymeric t.wiLI fabric, is subjected to the heat, treatment process of Dritish Patent Specification No. 1,224,04X I lie kniiek I es on the convent ional face side of (lie fabric w1) will heroine coplanar before I lie kuuekLcs on t .hi? back side of tin* fabric reach a uniform height.. Thus, in order for the knucklcs of the back side of the Fabric to become coplanar, the Fabric must be subjected to Further heat treatment. The additional heat, treatment required to make the knuckle .1(1 height, s on the back side of the fabric uniform I lien causes - 7 - <10 2 8 1 I tho knuckle height.* on the conventional I'acn Hide of tin* fabric to become non-uniform again.

The initial warp filament spacing and caliper of a twill fabric necessary to produce minimum free area and uniform knuckle heights on the back side of the fabric after heat treatment uust therefore be determined experimentally, by trial mid error.

The invention will now be described with reference to the accompanying drawings.

Figure 1 is a plan view of an enlarged portion of a conventional right-hand twill, monofilament, polymeric fibre fabric as viewed from the back side, i.e., that side of the fabric which does not normally contact the web.

Figure 2 is an enlarged cross-sectional view of the t.will fabric illustrated in Figure 1, taken looking in the cross-machine direction (CD) along line 2-2 in Figure 1, and i I I u.st. rut.es the higher relative elevation and the smooth knuckle surfaces of the warp filaments on each side of the fabric.

Figure 3 is an enlarged cross-sectional view of the twill fabric illustrated in Figures 1 and 2, taken looking in the machine direction (MD) along line 3—3 in Figure 1, and illustrates the lower relative elevation and the smooth kuuckle surfaces of the woof or weft filaments.

Figure 4 is a simplified illustration of an enlarged partial plan view of an increped paper sheet which has been imprinted using the conventional face side of a twill fabric such as is shown in Figures 1 to 3. The long axis of the dot impressions formed by the warp filaments is aligned parallel to the machine direction.

Figure 5 is a simplified illustration of an enlarged 1 0 2 SJ part i«l plan \ lew of all incrcped paper .sheet which has been imprinted using I he hark .si tie n|' a (will fabric such .in is shown ill I*ignres I to Tho long axis ol' the dash impress ions formed by I.Ih? warp fi lament.s is a I igniid parallel to tho 5 machine direction.

I'inures (» and 7 correspond to Figures 2 and 3> respectivoly, after tho fabric has been subjected to a heat treatment process sul'ricient to produce uniform knuckle heights on the conventional. face side of the fabric. Ill Figures H and •) correspond to Figures 4 and 5, respectively, after imprinting with a twill fabric such as is i I lust.rat.ed in Figures (> and 7. In Figure 8, using Lhe face side, the long axis of the dash impressions formed by the woof or weft filaments is aligned parallel to the eross-15 machine direction, while the long axis of the dot impressions formed by the warp filaments is aligned |>arallel to the machine direct, ion. In Figure 9, using the back side, the I on*; axis of the dash impressions formed by the warp fila-. inents is al ignod parallel to tin; machine direct ion, lit) Figures 10 and II correspond to Figures <> and 7, respectively, after the fabric has been subjected to a Ileal, t reatment, process sufficient to produce uniform knuckle heights and minimum free area on tho back side of the fabric. It should be noted t.hat. at this point., the knuckle heights on -5 the conventionaI faro side of the fabric a re no longer 1111 i form.

Figures 12 anil 13 correspond to figures 4 and 5, respect ively, afler imprinting with a twill fabric such as i .s illustrated iu Figures 111 and II. The dot impressions are 30 present, in Figure I .3 because I.hi' knuckles on tin; back side of - 9 - 4 0 2 8 1 I li«* fabric nfc of uniform height.

Figures 14 and 15 correspond Lo Figures 10 and 11, respective I y, after the back sides of the fabric has been abraded to increase its knuckle imprint area.

Figure 16 is a plan view of an enlarged portion of tho monofilament twill fabric illustrated in Figures 14 and |(>, as viewed from the back side of the fabric. - 10 - <10 2 8 1 of n I will fabric refers tothnt side of the fabric* which, according t.o I.he prior art, would normally come In contact with the | taper web, I.e. the side ol' t.hc (will fabric which would, depending upon ils pa rl i en I ,-i r rumlil ion, produce one S of the imprint- patterns illustrated in l-'igure* 4» N and 12 (assuming 11. is a right-hand twill fabric). The "back" sldo of a twill fabric: is defined as that side which would not normally contact the paper web according* t.o the teachings of I.lie prior art, i.e. t.hc side of the twill fabric whi.eh III would, depending upon i ts particular condition, produce one of the imprint |>attcrns illustrated in l-'igures 5, 9 and 13 (assuming it is a right-hand twill fabric). [n these drawings, the lout; axis of the dash impressions M is a I igned pa r.'i I -Ie| to the machine direction.

IS It. should he noted that although this invention is i I I list, ra ted with reference t.o a right-hand twill fabric, the benefits of tho invention can also be obtained with a left-hand twill fabric.

The twill fabric illustrated in figure I has not —< > been {riven any special ahrad ing I.rral.mcnI.. The imprinting fabric has from 2() to (>0 meshes per inch, measured in both the machine and cross-machine directions, and is formed from synthetic polymeric monofilaments having diameters of from I).(>1)8 In I).()2S inches. 2S Both warp and wool" monofilaments may, hut need not. necessarily be, of the same diameter. The knuckles formed at the cross-over points of the warp filaments I and the woof filaments 2 in figures I and 3 are not eoplauar on either the fare of the bark side of the fabric. As can be seen in .?<> I'ignres 2 and , the warp filaments I are at a higher relative -II- 40284 «;l oval. Ion than t.hc woof f ilament.s 2 on both sides of the fabric. Tliiti is termed, for- the: purposes of this specification, a "warp-high" condition of the fabric.

In Figure 4, the dot impressions 3> which are visible 5 on the surface of the uncreped paper sheet after imprinting, form a pattern corresponding to the knuckles 4 of the warp filaments 1 on the conventional face side of the fabric.

Since the dot impressions 3 are formed by the warp filaments 1, the long axis of the dot impressions is aligned parallel LO to the machine direction. The knuckles 7 formed by the woof filaments 2 on the conventional face side of the fabric do not. form a corresponding impression in tho uncompacted paper web clue to tho fact that they are at a lower relative elevation than the warp filament knuckles 4« 15 The imprint pattern illustrated in Figure 5 differs from the imprint. |>attern illustrated in Figure 4 in two important respects. First, since each warp filament 1 passes over-two woof filaments 2 on the back side of the twill fabric as comfwred to only one woof filament 2 on the face side of the 20 fabric, the; length of the impressions is approximately twice as great when the web is imprinted with the back si^de of the fabric. Secondly, when a paper web imprinted with the pattern illustrated in Figure 5 is removed from the drying drum by incans of a conventional doctor blade, a staggered pattern 25 is imparted to the surface of the paper, whereas when a paper web imprinted with the pattern illustrated in Figure 4 is removed from the drying drum by means of a conventional doctor blade, a regulated crcping pattern results in which the crepe ridges are substantially unbroken across the width 30 of the sheet. This characteristic el il'Terrence in finished - 12 - i <1 0 2 8 4 proline I. appears t.o be duo Lo the fact that, the web illustrated i.u l''i(;iin! 4 is adhered Lo Lhe dryer drum only at interrup-. I.oil intei vaIs, i .i>. by tint dot impressions 3, which are not sufficiently I ong to overlap cach other in the machine direc-S I. ion. Tho |>aper web illustrated in KLftnre 5» oil the other hand, is adhered to the dryer drnni in a continuous fashion, i.e. I>y tin; dash impressions <S, which art! sulTLeienl.ly long to overlap each other in (.lie machine d i reel, ion.

In a preferred embodiment. of the present, i ii von I. Lon , III a monof i I anient., po I ymcr i c I'i hre , twill fabric is prepared by sel i'i'l.ini> warp inonol' i I amen I s having a rclat ively high lic.nl-i nducetl .shrinkage pot.cn I. i a I , i.e. ol* from 11) t.o fflt, and preferably about. UVJ6. After selecting and spacing t.hc warp monofilaments, polymeric woof mono f i I amen t s art; select ed I 5 which have a relatively low heat.-i uduced shrinkage po ten t. i a I i.e. of from 2 to H/,, and preferably about. 4'/'« The lie.it. shrinkage treatment takes advantage of these shrinkage characteristics by subject, ing the initially woven fabric to a series of heat applications as it is strctclied and secured at 2() i t.s ends ill the lengthwise or warp direction, while it is free t.o shrink In (.he woof direct, ion.

The heat shrinkage treatment is conveniently applied t.o the initially woven twill fabric whiLe the fabric is mounted as an endless belt on a finishing tahle such as those 25 conventionally used in finishing metal l-'oii rdr in ier wires.

A conventional wire finishing table consists of two adjustable rolls for supporting, tensioning and driving the wire or fabric to be finished as an endless belt.. The heat, shrinkage can be induced eonven iciitly by an infrared source mounted .11) as a bank above .and across t.lie initially woven fabric. The 4 0 2 8 1 infrared source heats areas of the initially woven fabric as the fabric slowly revolves on the rolls of the wire finishing tabic. Heat is applied to the fabric in successive treatments of from 5 to 40 seconds, preferably about 15 seconds, per 5 treatment. The fabric temperatures during the successive applications of heat approach gradually the softening point of the selected monofilament polymeric fibres. Multiple l>a.«tscs arc used to avoid sudden shrinkage which induces fabric wrinkles. Successive heat treatments are repeated II) until the knuckle heights on the back side of the fabric reach uniformity, and this condition should also correspond Lo minimum free or interstiLial area if the initial warp filament spacing and caliper of the fabric have been properly dcterminc;d. A twill fabric which has been subjected to such IS a heat treatment process, although not "locked-upn as a plane weave fabric- would be, is dimensionally heat stable at the LempcraLurc encountered in the web imprinting process.

The temperature of the fibres in the successive heat treating passes is increased to a maximum temperature immedia-20 l.ely below the .softening point of the selected fibres. For example;, the heat. LrcaLiiig temperature used with "Trevira" I'ihre.s is from 3<>0°F Lo 4tK)°F, preferably about 375°P« For dimensional heat stability, a sufficient number of successive heating treatments or passes is employed to insure 2 5 that the monofilament polymeric fibres making up the fabric structure have been at the highest heat treating temperature for a total time of from 15 to 120 seconds.

Contrary to expectation, a weaving procedure wherein polymeric; warp and woof monofilaments are merely woven as .10 tightly as possible, to insure; a minimum free area, will not - 14 - •10 2 8 1 result, in .1 fabric with uniform knuckle heights after heat treating or use in web dry ing systems. Polymeric fibers in general exhibit, heat shrinkage, and if such a tight weaving procedure involving initial minimum spacing in both polymcric 5 warp and wool* monofiLaments is attempted, the resulting heat treated and heat, stabilized fabric will exhibit non-uniform knuckle heights. Therefore, in a preferred embodiment of the present invention, an initial warp filament spacing in the loom and an initial caliper of the semi-twill fabric are de-It) lermined experimentally by trial and error to Lake into ■iri'iiuiil. the heal-imimed shrinkage which occurs durini; the above described dimensional heat stabilisation process.

Figure (> represents the condition which results when l.lie warp fi laments I tend to draw themseI ves closer to a 15 straight line due t.o t.hc heat induced shrinkage. The tendency of the warp I" i I amen Is I In assume a lower total ainpl i tilde, due lo the Ilea I-i mill cell .shrinkage, Idi'irs the woof iiionofi lament. s 2 on I lie con v en t i oita I I'acc side of the fabric downwardly and the woof monofilaments 2 on t.lie back side of the 2t> fabric upwardly since the ends of the woof monofilaments are not restrained. This is more clearly illustrated in Figure 7, where the woof monofilaments 2 Lend to wrap themselves more completely about the warp monofilaments I. As a result, the knuckles ^ formed by the woof monofilaments 2 become co-25 planar with t.hc knuckles 4 formed by the warp monofilaments I on I.lie conventional face side of the fabric. It. should he noted that, at this part icular point., t he kmick I es 5 formed hy (he warp monofilaments I remain at a liiylicr relative elevation than the knuckles <> formed by I lie woof monofilaments .It) 2 on flic hack side of t.hc fabric. - 15 - 4 0 2 8 4 In Figure S, tin* knuckle Imprint pattern is similar to that shown In Figure 4, where; the dot impressions 3 formed l>y the knuckles 4 of the warp monofilaments 1 on the conventional face side of the fabric are illustrated, but the dash impressions 9 formed by the knuckles 7 of the woof monofilaments 2 are also present. Because the woof monofilaments 2 art; al Igned |>aral lei to the cross-machine direction, the long axis of the dash impressions ') is also aligned |>arallel Lo tho e inss-iKirh inc; <1L reel, ion.

In Figure 9, as in Figure 5, the long axis of the dash impressions 8 formed by the knuckles 5 of the warp monofilaments 1 is aligned parallel to the machine direction, and (.he cruped paper sheets exhibit a staggered pattern characteristic of |>apei' sheets made in accordance with the present i it vent ion when doctored from th«s dryer drum.

In order Lo obtain uniform knuckle heights and minimum free area on the back side of a twill fabric such as is L1 1 ustraLed in Figures (i and 7, as is desired in a preferred emhod i men I of Lhc prcsenL invention, (.lie heaL treatment process is continued until a condition similar Lo that i I lust.rated In Figures 10 and 11 is achieved.

HeaL—induced shrinkage of Lhe warp monofilamenLs 1, as shown in Figure 10, has produced a lower Lotal amplitude cans Lug Lhe woof monofilaments 2 on the back side of the fabric; to move upwardly and the; woof monofilaments 2 on the (onvcMitional Tare; side of the fabric to move downwardly. As can l>e seen in Figure 11, the woof monofilaments 2 which, unlike; the warp monofilaments L, are not subjected to tension, Lend to wrap themselves more completely about the warp monofilaments | located oil the con vent iona I face side of the fabric:. Simu IL nneously , Lhe woof monof ilamcnts 2 - 16 - <1 0 2 8 I t lend lo "holly" or gradually wrap themselves about the two adjacent warp monofilaments I located on the back side of |.hi». fabric. As a result, the heights of the warp monofilament. knucklcs ■> on the back side of the fabric and the woof •> monofilament knuckles fi on the l>ack side of the fabric he- come uniform, while the heights of tile woof monofilament knncklcs 7 on the conventional, face side of the fabric and the warp monofilament knuckles 4 on the conventional face side of the fabric become non-uniform. If the initial warp II) filament spacing in the loom and the initial caliper or (.hick ncss of the twill fabric have been proper! y determined to tak into account tin? heat-induced shrinkage, the condition illustrated in l-'igures 1.0 and II. should result, i.e., a dimensional I y heat, stabilized l.w l I I fabric having uniform knuckle IS heights as well as miniinitni free area on its hack sine.

In Figure 12, I lie imprinting pattern is basically similar to that shown in l-'igurc N, but the dot Impressions .3 formed by l-he warp monofilament knuckles 4 on the convent iona fact? side of the fabric art; no longer present due to the fact 21) Ilia I. the warp monof i I ament. knuckles 4 •ire at a lower relative elevation tlian the wool" monofilament knuckles 7 on tilt.' conventional face side of flit? fabric. Paper sheets imprinted with l.lit; |>aftcrn illustrated In Figure 12 exhibit, propert ies substantially similar to sheets imprinted with the patterns 2S shown In Figures 4 and 8 after crcping.

In F'igure l.3> the dash impressi tins 8 formed by the warp filament knockles 5 on the hack side of the fabric an; essentially the same as those illustrated in Figure 9, but flit; dot impressions 10 formed by Lhe woof monof i lament. .{(> knuckles b on t.hc hack side of the fabrie are also p.-esenl - 17 <10 2 8-1 dm; t.o the fact that Lhe warp filament knuckles 5 and the wool' filament, knuckles 6 on Lhe back side of the fabric are "I' uniform height. After creping}the paper sheet exhibits a staggered surface appearancc which is characteristic of 5 paper sheets made in accordance with the present invention.

As the knuckle imprint area on the back side of such a monofilament, polymeric fibre, twill fabric is increased, the staggered paLlern becomes more pronounced.

Preferably, the back side of the twill imprinting 10 fabric is subjected to an abrasion treatment in which the knuckle surfaces of the fabric are abraded using, for example, either wet or dry sandpaper having an effective abrasive grain size of from 300 mesh to 500 mesh as the abrasive medium, as disclosed in U.S. Patent Specification No. IS 3>573,164. The abrasive medium can be mounted on drums for application to the fabric knuckle surfaces. The abrading process can be performed while continuously showering the fabric with water or other cleansing and lubricating fluid, for example light oil, to remove abraded particles and facili-20 Late the polishing operation.

The total knuckle imprint area must not be more than 5056 of the total fabric surface area, as measured in Lhe plane of Lhe knuckles. Increasing the knuckle imprint area beyond the 50 percent level greatly increases the dan-25 ger of abrading completely through particular monofilaments and is also likely to have a detrimental effect on the fabric lire.

It is desirable to form a smooth and polished surface on Lhe knuckles on Lhe hack side of Lhe Lwill fabric. 30 To t.his end, Lhe abrading operaLion can be conducted in - 1H - 1 0 2 8 4 several For example, the initial abrasion enn lie carrictl nut. with an abrasive medium having an effective abrasive grain size of about. 300 mesh, and this initial abrading operation ran ho followed by an abrasive polishing S treatment, using a water lubricated wet. sand|>aper having an effeel.ive abrasive grain si/.it of about. 50" inesh. PoLishing abrasives sueli as tale, rouge and eroeus eloth i:an also be iise<l lo polish the knuck I e snrfaees.

The fabrie illustrated in Figures 14, IS •>>i<l lo It' represents a preferred embodiment of tin? present invention, where uniform knuckle heights anil minimum free area were achieved on Lhe haek side of the fahrie prior to LuLliating lhe abrading process. An inhcrciiL advantage associated with obtaining 1111L form knuckle helght.s and minimum free area prior IS to i 11 i t. i a t. i ng the abrading treatment, is in lhe uniform eon-si sl.eiiey of I.In- knuckle imprint. |>at.Lcrii which results after I lie abrading process has been enmp I e Led. This Latter feature is most, clearly ILlustraLed In Figure 16. l-'lgures 14 and 15, taken looking in Lhe cross-machine 20 and machine directions respeclLvely, Illustrate tin: fabric profile which is present.ed Lo an uiicompact.cd paper web when Lhe fabric Is used for Imprinting. The warp filament, knuckles S and the woof filaincnL knuckles (> as shown In Figures 10 anil II have been abraded t.o form tho plaLean-like warp flla--S men I. knuckles 5' and woof filament, knuckles h' . In addition to improving web Lransfer and web drying cliaiact.crisLics, the pi al.eau-1 Ike knuckle surfaces 5 ' and 6" impress .111 iineoin-pacl ed paper web Lo a uniform depl.h, thus produr i ng a more disl inct. imprint |>aLLcrn. ,»0 The moist, paper web, while carried on the Imprinting - I <> - 4 0 2 8 <1 Fabric, is thermally pro-dried. Prior to this pre-drying stop, the um-ompartrd wol) ran l)i; dcwaterod and thus moulded I o mil |*i>rm to the fabric knock 1 e pa I I crn. The pri^dry liif". «*.m 1 hi* achieved by. For example, |ta.ssiiig hot gases, for example 5 air, through tho moisL paper web and the imprinting fabric*. Ono suitable apparatus for pre-drying the moist paper web is disclosed in U.S. Patent Specification No. 3,303,576. Although the means by which thermal pre-drying is accomplished is not critical, it is critical that the relationship of the moist 10 web Lo the imprinting fabric be maintained once established.

Ah in HriLish Patent Specification No. 1»073>063 thermal pro-dry i ng is used t.» of Fee I. a Fibre cons isLcncy in tho moist I viper web, prol'erably of from 30 to 80 percent, and more preferably from 4<> to 80 percent. At fibre consistencies of IS li;ss than 3D percent, the desirably balanced sheet character islics of softness, bulk and absorbency suffer because Lhe sheet and the fibres are too moist, and yielding occurs during the imprinting step.

Fibre consistencies between 30 and 98 percent prior 20 Lo transfer of the web to the drying drum are possible without adversely affecting the tensile strengLh of paper sheets thus produced. Fibre consistencies in the higher end of the range, i.e. above about. 80 percent, are achieved by spraying on the surface of the drying drum, prior to web transfer, an aqueous 25 solution of a polyvinyl alcohol adhesive having a degree of hydrolysis of e.g. 80 to 90 percent and a viscosity, as a 4 perccitL aqueous solution oF more Lhan 20 cenLipoise aL 20°C. From o. S to 2.() pounds of pva (dry basis) is applied per ton oF paper produced (dry basis). 30 The fabric knuckle paLLcrn is imprinted in the moist web - 20 - •10 2 8 J l>y iircssing I.Ik* pro-dried web against. a relatively non-yielding .surface. 'I'lii! wttb may he dried on I.lie (.will fabric, in which rase I.he pro-dried web may be pressed against for example, an unhealed sl.eel roll. AI Lornat i vely the pro-dried web may be *» pressed against a Yankee dryer surface. The imprinting, while carrying the pro-dried wch on (.lie imprinting fabric, results in a |Kiper slieel. having impressed in it.s surface, t.o a depth I»|- at least .?(> percent ol' i l.s niaclii.no gl.iy.ed caliper, the knuckle |>at I orn of I.he imprinting fabric. Machine glazed It) caliper refers to the caliper ol" the paper sheet taken directly from I.he Yankee dryer, before el-oping.

The pressure required For (he imprinting of the imprln-t ing Fabric |>alfcrn is preferably provided by one or more pressure rolls operat ing on I.lie Imprint ing fabric to force the 1 "> knuckles on the fabric into the surface of the pre-ilri eil wel> and lo force the pre-dried web surface imili-r the knixk I os against a Yankee dryer siir-fa«-e.

It should bo nnderstoiid that It is crlt.ical to the pract ice of t.hc present invention that- the imprinting step 21) described above should bit the first substantial overall median i ca I com|>ac t. i on step which the paper web has received during Formation and pre-drying. In the paper sheet produced by l.ho process ol" this invention, the uniform basis weight is from 5 to 4<)» preferably From «) to 25, pounds per .1000 square 2 5 Feet. - 21 - I 0 li 8 I Tin; following Example illustrates the invention: A series «>f Lest runs was made to compare the rhai-.K'l erisL i cs of |>ap<;r sht;c:Ls made as in BriLish Patent Spec i l"i cal ion No. 1,07.1,063 huL using opposite sides of I.in; monofilament, polymeric fibre, twill fabric. Paper machine conditions, with the exception of the imprinting fabric, were maintained constant for the entire series of tests.

Furnish comprising ^0% softwood kraft and 50% hardwood sulphite stock was used Lhroughout the entire series of Lcsls.

An adhesive coat was applied Lo the Yankee dryer surface by utilizing a wire glue roll of approximately 40 mesh turning aL a lineal speed of approximately 9 feet per minute at iLs periphery in an open glue pot and then spraying the glue picked up on the wire mesh glue roll onto the surface of tl>e Yankee dryer drum by means of a series of air jets 4 0 2 8 4 hnml.ini inside I.In.- glue cull ;iimI operaI.ing continuously at a/t air prcssu re o|' 75 p.s. i.g. Tin; ghic uliLi/vd was pureha-si«l under the specification I'cltT Cooper IX from the P('Li;r ('mipiM' Corporation <>|* Cowanda, New York. l'h<? mixture, as 5 applied, contained I |>arl. (jliic anil •)«» |Kicls water. The prc- dcyed and imprinted weh was caused to |>art from the impriiitinc fabric at the pressure nip exit and adhere Lo Lhe Yankee dryer surface hy means ol* Lhe adhesive co.it described above.

The dry ereped sheet was removed from the Yankee ll) dryer by means of a conventional doctor blade so that the I" in i sited product had 12 pi-crcnl. stretch as crepe folds.

Two separate monofilament, polymeric fibre, twill fabrics were used (luring Lhe I.esL runs. The fabrics were both 31 (machine direcLion) by 28 (cross-machinc direction) IS inesli utilizing warp and woof monof i lamenLs having a diameter of O.45 mm. (about 0.018 inches). One of the fabrics was woven so as Lo presenL iLs back side as a web contacting surface and lhe oLher was woven so as Lo present its conven-tional face side as a web contacting surface. Both of the 20 fabrics, as rei-rivetl, were in a configuration similar Lo that i I Iiist-rated in Figures lO and ll, i.e., the heights of the warp filament knuckles 5 and Liu; woof filament, knuckles (> on lhe back side of each fabric: wen: approx ima Lel.y e«|ua L, while tin: warp filament knuckles 4 were at a lower relaLive eleva-25 Lion I.ban t.lie woof filament knuckles 7 on the conventional fact: side of each fabric.

In order Lo isolate the effect of Lhe imprinting fabrics on finished sheet characteristics, l.lu: fabrics were insl.allcd successively on Lhe same |>apcr machine in Lhe as-;?0 received coudil ion, and paper sheets were produced as in - 2.? - <10 2 8 4 llril ish Patent Specification No. 1,073,063.

Tin: fabric woven so as to present its back side as n web contacting sin-face was found to have an initial knuckle Imprint area of about 21.2 percent, while tho fabric woven 5 so as to present, its convent, ionaI face side as a web ronl.iitiini; surface was found to have a knuckle imprint area of about 23 »4 percent.

Data taken from paper samples made using the imprinting fabric having its back side in contact with tho uncompacted l*> paper web are given in Table I. Data taken from paper samples made using the imprinting fabric having its coiivcnt ional face side in contact with the uncompacted paper web arc given in Table II.

To illustrate the effect of increasing the knuckle imprint area on the web contact ing side of I. In? imprinting fabric.s, each fabric was abraded by l.he Method disclosed in U.S. Patent. Spec i I" i cat- i on No. 3,573. M»4« Tin* knuckle imprint. area on l.he fabric using it.s back side as a web contacting surface was increased Lo approximately 28.4 percent, while Lin: knuckle- imprint area on the fabric utilizing its convent, ional I'ace side as a web contacting surface was increased Lo approximately 34-1 percenL. The LesLs were rcpeat.ed keeping all oLher paper machine conditions unchanged. The results of tesLs performed on sample paper sheets taken 25 during each run are given in Tables III and IV.

Finally, the knuckle imprint area of each fabric was further increased by the abrasion method of U.S. Patent Specification No. 3,573, lf>4 unt.il the fabric using its back 3" side as a web contacting surface achieved a LoLal knuckle imprinL area of 37-3 percenL, while Lhe fabric using its - 24 - 4 028 4 conventional face side as a web contacting surface achieved a tola I kmicklr imprint area ut* 4^.0 percent. The tests were repealed keeping all other paper machine conditions unchanged, 'l'he results of tests performed on sample paper sheets taken 5 during each run are given in Tables V and VI. Data in Tables LLI .iud V are taken from paper sheets made using the twill fabric which presented its back side to the uncompacted paper web, while data lu Tables IV and VI are taken from paper sheets made using the twill fabric which presented its conventional K) fact.' side t.o the uncom|>actcd paper web.

The cal iper of a |>a|>er sheet .it. St) grains per square inch, as tabulated below, is the thickness of t.hat sheet when subjected t.o a compressive load of SO grains per square inch.

Tlie tensile strengths in the machine direction (Ml)) IS and c ross -macli i ne d i reel ion (CD) as tabulated below, are repor ted .is the force ill grams that, a I inch wide sample with a 4 inch span between the tensile tester clamps, cut. in the MD or CI) direction, ran withstand before breaking, as measured on a standard Thw i ng-A I bert Tensile Tester such as is available 21) from the Thw i ng-A I bert Instrument. Company of Philadelphia, I'enusy I van ia.

Tin* percentage stretch data were det.erm ined concurrent I y with the det.erm inat. ion of MD and CD tensile strengths as described above. 25 A Thw ing-A I bert. Hand I e-O-Mefer, catalogue number 211—3, such as is available from l.he Thw i ng-A I bert I lis I. rumen I Company of Philadelphia, Pennsylvania, was used t.o measure a combinat ion of st iffness and sliding frict ion of tho papt.*r samples. A hi.e*h Hand Ie-O-Metor or ll-O-M leading indicates a lack of softness 3D and is, therefore, undesirable. \ lower ll-O-M reading indicates - 25 - 4 0 2 8 4 a sol'lcr sheet. Two 4? incli square paper samples were placed side by side over tho 0.25 inch wide Handle-O-Mei.er slot located beneath Lhe blade of Lhe unit. To determine the machine direction llandlc-O-Meter reading of the sheets* the machine direction of the paper samples was aligned parallel Lo l.he ll.-iudIe-0-Meter blade* To determine the cross-machine di!•«>«*(. ion llandle-O-Meter reading, the machine direction of the sample sheets was aligned perpendicular to the blade of the llandle-O-Meter. Readings taken directly from the standard 50 microampere meter mounted on the Handle-O-Meter are given below.

Fabric handle, as its name implies, is concerned with Lhe feel of the malcrial and so depends on the sense of touch. When Lhe handle of a fabric is judged, the sensations of .sLiffness or limpness, hardness or softness, and roughness or smoothness are all used. Drape has a rather different me-aning and very broadly is Lhe ability of a fabric to assume a graceful appearance in use. Experience in the textile industry has shown that fabric stiffness is a key factor in the .study of hand lit and drape.

One insLrumenL devised by the textile; industry to measure; .stiffness is Lhe; Shirley SLiffness Tester. In order to cumparc Lhe drape; and surface feel properties of paper samples made nl.ili/ine different, sides of a twill imprinting fabric, a Shirley Stiffness Tester was constructed Lo determine the "bending lengLh" of Lhe paper samples, and hence to calculate values fe>r "flexural rigidity" and "bending modulus".

The Shirley Stiffness Tester is described in ASTM Standard Method No 1.188. The horizontal platform of the instrument is suppe>rLed by Lwe» side pieces made of plastic. These s iele- p i i'lirs haver engraved on Lherm index liners at. a standard angle- etf ele-I'l e*<t. i 011 eif 4lJ"* At •• ae:he-«l t.o l.he- i nsl. runetil. is a 4 0 2 8 4 mirror which enables (.lie operator to view both index lines from ;i nmvonirnl position. The scale ol' tho instrument is graduated in crnl. imeLei'.s. Tho si-ale may lx; used as a template I'or rutting the s|M.*trimons to si/.e.

To carry out a lest, a rrrlaiiguIar strip ol* |>apcr, 6 inches liy I inch, is cut to (.lie same size a.s the scale and then both strait; and specimen art* transferred to the platform with lhe specimen iiiiderneath. Both are slowly pushed forward. The si rip ol* |>apcr will comment:)* to droop over the edge of the platform as flit- scale and specimen an- advanced. Movement ol* I lie scale and the specimen is trout i lined until tile tip ol' the specimen viewed in lite mirror cuts both of the index lines. Tin*/ amount, of overhang (X) trail immediately be read off from the scale mark opposite a zero line engraved oil tin.* side of I lie platform.

Due to t.hc fact I.Ii.it. |>apcr assumes a permanent set after being subjected to such a stiffness test, four- individual specimens were used to Lest the stiffness of the paper along a given axis, and an average value for the |ki rt. icu | a r axis was then calculated. Samples were cut. both on and across Lite cross-machine direct ion (CD) axis, on and across tilt.- CDt-.t<>° axis, and on and across the Cl)l I Jl" axis. I'roin the data roller-led both on and perpend i eu I a r lo each of I lie three aforementioned axes, an average overhang value was calculated for the particular paper sample.

The bending I ellgl ll (r), for I lie purposes of t hese tests, is defined as the length of |wiper that, will bend under its own weight to a definite extent. It is a measure of the stiffness thai determines draping quality. The calculation is as I'ol I ows: C -Xcin. * I" (W) wlirri! I" (0) - [com 1/2 0 7 8 tan 0] and •v\" - Liu; avuragv uvcrliane value of the particular sampl 5 the alible 0 - 41 i° and therefore f (0) = 0.5» Therefore, th«* above calculation simplifies to: c -\x (O.S) cm.

Flexnal rigidity (U) Is a measure of stiffness associated with handle. It i.s calculated Ln Lhe present case from the ll) eqiiaLinu: C - 0.1b2«> x (basis weight of the particular paper sampl o in pounds per 3,000 sq. ft.) x c^ng. cm. The bending modulus (q), as tabulalcd below, is indepciidcnl of lhe dimensions of Lhe strip lesled and may be IS regarded as lhe "inlrinsic sLiffness" of the material. Therefore, Lhis value may be used Lo compare the stiffness of materials having different thicknesses. For its calculation, the Lhickness or caliper of Lhe |>apcr sample must be measured at a pressure of I pound per square inch: 20 «| - 732 x G ~ g ^kg./sq.cm., where "g" is Lhe thickncss or caliper of Lhe parLicular paper sample;, expressed in mils, when subjecled to a pressure of 1 pound par square Inch.

The resulls of Lests performed on sample paper sheets 25 produced during Lhe runs described above are given below in Lcritis of the heading modulus (q) which relates both to drape and sin-face feel. A lower bending modulus corresponds to Increased drape, and hence Lo Improved surface feel.

The knuckle Lmprinl areas referred Lo below were deter-30 mined by makLng an impression with pressure sensitive paper in - 28 - •10 2 8 1 <*arli ol* I'our arr.i.s on I In? wrl> contact ing surface of the imprinting fabric.

Knl.-iigcil photographs w«ri! taken of each of tho four t imprcM.si.oiiK, anil a "unit-cell." of knuckles, i.e., one repeating |talLciit ol* kiinckles, was enclosed In each photograph. The lotal area of each enclosed unit-cell and l.he tot.nl area o|* l.lie knuckles in.side rarli such unit-cell were then measured, and l.lie re.siill..s wrrv expressed in Lerros of the percentage o|* knuckle area. The average value for the four discrete uiiiL-ci-lls was taken lo he the knuckle imprint area.

The data presented in Lhe following tables clearly show l.he advant ages of the present invention in producing crcped |vi|H*r sheet.s having desirable cross-d i reel iona I sl.rciigl.lt, softness, surface feel and drape. lu I he Tables. I lie sample numbers are for indentifi-eal ion |mii-|m>.scs only.

TABLE I Back side of imprinting fabric contacting web V to 00 Bending Modulus "q". kg./ sq. cm.

Sample No.

Caliper at SO gm/ sq. in., inches.

Knuckle imprint area, percent Basis weight pounds/ 3,000 sq. ft.

Tensile MD, gm./ in.

Tensile CD, gm. in. > Handle-/ 0-Meter MD Handle^ 0-Meter CD Stretch MD* percent Stretch CD, percent 1 0.0106 21.2 15.4 251 224 5.25 3.0 16.5 2.0 10.27 2 0.0104 21.2 16.5 259 170 6.25 2.75 17.0 3.0 10.25 3 0.0106 21.2 15 • 5 325 101 11.25 3.0 1S.0 3.0 10.33 4 0.0105 21.2 15.0 2o5 116 5.5 2.5 19.0 3.0 9.00 5 0.0116 21. 2 15.S 1S1 114 6.25 2.75 19.0 3.0 7.35 6 0.0107 21.2 15.0 251 24$ 10.5 3.0 20.0 2.5 9.OS 7 0.0107 21.2 15.5 219 153 9.5 3.0 16.5 3.0 9.39 IABLE II Conventional face side of imprinting fabric contacting web Caliper Knuckle Basic weight at ;0 gm/ imprint pounds/ Iensile Sample sq. in., area, 3,000 MD, gm. / No. inches percent sq. ft. in.

Iensile Handle- Handle- Stretch Stretch CD, gra. 0-Meter 0-Meter MD, CD, in. MD CD percent percent 'Bending Modulus "q"» kg./ sq. cm. 1 0.0100 23.4 15.? 209 144 7.0 2.0 20.0 3.0 11.33 2 0.0102 23.4 15.5 1 OQ 147 ?.2j 2.0 21.0 2.0 11.04 * S O.OlOo 23-4 15.1 155 130 j.50 2.0 20.5 2.0 5. 60 4 0.0105 23.4 15«3 lo 141 *.25 2.0 20.0 2.0 12.27 5 0.0091 23.4 15.4 3 31 241 11.5 3.0 21.0 2.0 21.60 0 0.0007 23.4 15.2 350 1 °4 10.5 2.5 19.5 3.0 22.01 / 0.0107 23-4 15. 3 200 194 10.5 3.0 22.0 2.5 10.21 o to oc TABLE III Back side of imprinting fabric contacting web Caliper Knuckle at SO gm/ imprint Sample sq. in., area, Mo. inches percent Basis weight pounds/ 3,000 sq. ft.

Tensile MD, gm./ in.

Tensile CD, gm./ in.

Handle-0-Meter MD Handle-0-Meter CD Stretch MD, percent Stretch CD, percent © M oc Bending Modulus "q", kg. / sq. cm. 1 0.0097 2; 4 10.9 275 215 7.0 2.3 18.5 3. 5 10.53 2 0.0105 2S 4 15.7 250 159 5.so 2.0 19.5 3> 5 S.41 3 1 0.0099 25 4 15.2 300 m «i ^ 10.5 2.0 19.0 3.5 11.12 4 0.0105 25 4 14.7 199 153 6.5 2.0 19.0 4.0 5.76 ' 5 0.0105 23 4 15.1 193 150 0. 50 2.0 18.0 3. 5 5-76 6 0.0103 23 4 15.4 209 2oo 10.0 2.5 20.5 3.0 10.50 7 0.0105 25 4 lo.O 275 190 5.3 2.0 20.5 4. 5 B. 37 TABLE IV Conventional face side of imprinting fabric contacting web Sample io.

Caliper at SO gm. sq. ine., inches Knuckle imprint area, percent Basis weight pounds/ 3,000 sq. ft.

Tensile MD, gm. ' in.

Tensile CD, gm. in.

Handle-0-Met er MD Handle 0-Meter CD Stretch MD, percent Stretch CD, percent Bending Modulus "q"» ksi. / sq. cm. 1 0.00?o 34.1 15.4 410 241 11.5 2.0 26. S 2.0 19.64 0.00? 7 34.1 15.9 471 295 lo. 5 3-0 26.5 2.0 26.35 3 0.0001 34.1 15.0 330 201 14.5 2.0 24.0 2.5 20.11 4 0.0000 34.1 14.9 291 174 75 2.0 21.5 3.0 20. 5 O.OO03 34.1 15.3 255 196 15«5 2.5 21.5 2.0 18.41 6 O.OO07 34.1 13.5 290 191 12.5 2.0 25.0 2.5 14. -2 / O.OO03 34.1 14.7 203 190 9.5 2.0 24.0 3.0 16.00 IAblt \ Back side of imprinting fabric contacting web Sample No.

Caliper at SO gm/ sq. in., inches Knuckle imprint area, percent Basis weight pounds/ 3,000 sq. ft.

Tensile MD, gm./ in.

Tensile CD, gm. ' in.

Handle-0-Meter MD Handle-0-Meter CD Stretch MD, percent Stretch CD, percent Bending ^ Modulus o "q", kg. / tc sq. cm. 0B 1 0.0092 37.3 15.5 260 133 o.O 2.5 19.2 5.0 3.75 2 0.0099 37. 3 16.4 26* 104 5 • 5 2.0 21.5 5.0 o.07 3 0.0093 37. 3 15.6 333 243 7.0 2.5 20.5 5.5 10.4$ 4 0.0093 37. 3 15.1 271 171 5. 5 2.0 19.5 5.5 6.73 5 0.0099 37. 3 15.9 20o 13o 5.30 2.0 19.5 5.0 o.03 6 0.0107 37. 3 16.1 265 191 9.0 2.5 21.0 5.5 9.25 7 0.0099 37. 3 15.3 259 200 5.5 2.0 20.5 5.5 0. SO TABLE VI Conventional face side of imprinting fabric contacting web Sample No.

Caliper at SO gm/ sq. in., inches Knuckle imprint area percent Basis weight pounds/ 3,000 sq. ft.

Tensile MD, gm./ in.

Tensile CD, gm./ in.

Handle-0-Meter MD Handle-0-Meter CD Stretch MD, percent Stretch CD, percent Bending Modulus "q", kg sq. cm. 1 0.00S5 40.0 15.4 315 216 10.25 2.0 24.0 2.0 26.53 2 0.0087 40.0 14.3 303 209 12.5 2.0 23.5 2.0 22.04 3 0.0088 40.0 14.8 300 223 14.5 2.0 23.0 2.0 20.66 4 0.0091 40.0 14.5 304 213 12.25 2.0 23.0 2.0 15.66

Claims (1)

1. I* I. A I MS 1. A pritrrss lor I lie manufacture ol' .1 sofl , bulky .iiul absorbent |>apcr shoot having a uniform basis wiuglit of from 5 l.i) 40 pounds per 3000 square foot, which comprises 5 (a) forming an uncom|>acLcd |>apor wob; (t>) sii|>|Mirl.ii»(» tho uncompaclcd |>aper wob on the back shle of a monofilament, synthetic polymeric twill fabric which has from 20 to (>0 moshe.s per inch mcasu-roil in both the mai-hino ami cross-machine directions, III a knuckle imprint area on its back side of between 20 anil 511*2 of its lot.-11 surface area as measured in the plane ol* l.lie knuckles, anil which is formed from syulhclic |>olyineric monofilaments having a diameter of from II.IIOS t.o 0.025 inches; 15 («) I he finally pro-drying tin; uncoin|iact oil paper web Lo a fibre cuiisisl ency of from .]() to n.S;H: (d) causing tin* hack side of l.lie fabric to imprint a dot-tlasli knuckle pattern <111 Lhe web such Lhat Lhe long •axis of Lho dash impressions is aligned |>arallcl Lo 2t) l.he machine dircct ioo of t.he pre—dried web; ami (c) ilrying ami crcping lhe thus-formed |>apcr sheet . 2. A process according t.o CI a i in I in which, in step (1), the |>a|>cr sheet, is dried on t.lie (will fabric. 3. A process according lo (Maim I in which, in step 25 (e)» I lie |>aper shoot, is dried on a dryer drum and t.he r.roping is performed by means of a doctor blade. 4- A process according lo any preceding (Maim i 11 which I lie uucompaci ed paper well, prior to the thermal pre-drying, is inou I ded to conform lo t he pattern of t.he twill fabric. .?() 5- A process according to any preceding Claim in which - 15 - <10 2 8 4 lhe .soft, bulky and absorbent paper sheet has a uniform basis weight of flora 9 to 25 pounds per 3000 square feet. 6. A process according to any preceding Claim in which the uncompacted paper web is thermally pre-dryed to a fibre 5 consistency of from 40 to Ho£. 7. A process according to any preceding Claim in which the twill fabric is prepared from warp monofilaments having a heat-induced shrinkage potential of from 10 to 30%. 8. A process according to any preceding Claim in which 10 the twill fabric: is prepared from woof monofilaments having a heal-induced shrinkage j>otential of from 2 to 8£. 9. A process according to any preceding Claim in which the back side of the twill fabric has been abraded using an abrasive medium having an effective abrasive grain size of 15 I'rom 300 to 500 mesh. 10. A process according to claim I substantially as herein described with reference to lhe Example. 11. A soft, bulky and absorbent crepe paper sheet when prepared by a process according to any preceding claim. 20 12. A soft, bulky and absorbent crepe paper sheet which has a uniform basis weight of from 5 to 40 pounds per 3000 square feet; which has, imprinted in its surface, to a depth of at least 30% of its machine glazed caliper, A knuckle pattern of the back side of a twill fabric having 25 from 20 to 60 meshes per inch measured in both the machine and cross-machine directions; which has from 20 to 50^ of Lis .surface compressed in a dot-dash knuckle pattern such thai lhe long axis of the dash impressions in the pattern is aligned parallel to the machine direction during its formation; 30 and which has a cross-directionaI stretch of from 2 to t%. - - •I o 8 l •- 1.1. ' A slii;«;'L SUfiirdl iig l.'o claim 1.2 which has a mi i-1'oitn; liasi s"w<: i e>hL ol' l'ioin«) l.o 2? pound* pii.r -.lOOO square . i 14* .A' -shed. accord i lie l.o claim 12 substantially as !•«•»••?i•• dcscrilx-d wil>li i-cIVi*ciic«« l.o Llii* Kxample. h.R . KKI.I.Y t* CO. ACDNTS l«)R TIIK APPLICANTS.