US3168414A - Process and apparatus for wet-treating fibrous materials - Google Patents

Description

Feb. 2, 1965 Filed March 7, 1962 H. FLEI PROCESS AND APPARA FIBROUS SSNER FOR WET-TREATING ERIALS 2 Sheets-Sheet 1 Heinz 'FLEISS'NER av inventor.

5 AGENT Feb. 2, 1965 H. FLEISSNER 3,168,414

PROCESS AND APPARATUS FOR WET-TREATING FIBROUS MATERIALS Filed March 7, 1962 2 Sheets-Sheet 2 I WEB -A DVANCING MECHN/SM 27 26a I" ,1, f

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' Heinz FLEISSNER 1 INVENTOR.

BY AGENT United States Patent 3,l$,- il4 ERQCESS AND APPARATUS FGR WET-TREATENG FEBRUUS MATERKAL Heinz Fleissner, Egelshaeh, Germany, assignor to Firms Fleissner Gamhl l, Egeisbaeh, near Eh'anlrfurt arn Main, Germany, a company of Germany Filed Mar. 7, 1962, Ser. No. 178,133 Qlairns priority, application Germany, Mar. 13, 1961, F 33,407 7 Qlaims. (ill. 117-102) My present invention relates to a process and an apparatus for wet-treating fibrous materials in web form, the web being passed through a bath containing the liquid treatment agent. More particularly, the invention is applicable to the sizing or glazing of webs of loosely coherent textile fibers which may be subdivided into ribbons or slivers destined for slubbing after the treated material has dried.

In a continuous process in which the drying operation is speeded up by a spreading of the slivers on a moving conveyor surface(e.g. as described in commonly assi ned copending application Ser. No. 172,064, filed February 7, 1962, by lohann Fleissner), the output rate of the overall system is largely determined by the operating speed of the wet-treating plant. This speed i limited inter alia by the relative fragility of the fibrous mass which tends to be weakened or even partly disintegrated by a too abrupt separation of the fibers from the liquid. Thus, the relative motion between fibers and liquid at the point where the web breaks the water line gives rise to disruptive forces; on the other hand, a withdrawal of heavily wetted fibers from the bath with subsequent runoff of the entrained liquid leads to the formation of water pockets along the web which tend to wash out some of the fibers.

It is, therefore, the general object of my present invention to provide an improved process for lessening the.

impact upon the fiber web of the transition from its immersed into its partially dried state, whereby such transition can be accelerated, as "well as an apparatus for carrying out the process.

I have found, in accordance with this invention, that the preservation of the fibrous structure is facilitated if the web i maintained in contact with a surrounding boundary layer or laminar shell of liquid for as long a time as possible and, in particular, during the squeezing of excess liquid from the material. Hence a primary feature of my invention resides in a process wherein'the web is squeezed, preferably in a plurality of successive stages, below the bath level and this squeezing operation is immediately followed by a withdrawal of the web from the bath and a further squeeze-drying of the fibers outside the bath.

A very effective method of squeezing the fibers within the bath involves the successive passage of the web between several roller pairs whose line of contact lies below or substantially at the bath level, at least one roller of each pair having a grooved periphery so as to exert pressure upon the web at axially spaced locations which are relatively staggered in axial direction for successive pairs; the rollers thus form channels through whicha part of the li uid may pass without substantial motion relative to the Web whereby the aforementioned boundary layer is at least partly preserved. It has also been found advantageous to perforate one of the rollers so that the squeezed-out liquid can move out in a direction perpendicular to the Web surface, i.e. again without substantial relative motion along that surface. Moreover, one of the coasting rollers of the last squeezing stage may have a projecting surface along which the web i guided out of the bath on its path to a further roller pair serving to squeeze out most of the residual liquid, this guiding surface having, of course, the same peripheral speed as the web so that relative motion between the web and the liquid adhering to the roller is minimized. It will also be advantageous to let the web rise from the treating bath (or from the aforementioned guiding surface) at a very small angle so as to reduce the flow of liquid along the web on its way to the final squeezing stage outside the bath; this is best accomplished if the rollers for the 10 final squeeze are positioned beyond the treatment vessel above a receptacle for the extracted liquid, the recep- "tacle being provided with circulation means such as'a pump for maintaining the liquid level therein substantially below that of the bath and, preferably, returning the excess to the treatment vessel.

Generally, the peripheral grooves of the submerged rollers may extend, over 360 or less, along closed annular zones or may form part of a continuous channel of, say, helicoidal configuration. They may be cut or milled into the roller surface or may be formed between annular or helical ridges laminated onto that surface. Coacting rollers may be of identical or complementary configuration though it is also possible to use a grooved roller in contact with a roller having a continuous surface. A single roller may, according to a more specific feature of the invention, cooperate with several wholly or partly submerged rollers oftsmaller diameters to form therewith the successive underwater squeezing stages, this roller being thus common to the several roller pairs previously referred to.

The invention vw'll be described in greater detail with reference to the accompanying drawing in which:

FIG. 1 is a sectional elevational view of a treatment stage of a sizing plant embodying the invention;

FIG. 2 is a view similar to FIG. 1, illustrating a modification;

FIG. 3 is a sectional elevation ofpart of a treatment stage representing another embodiment of the invention;

FIG. 4 is a top view of one of the roller pairs forming 4 fora web 1 of fibrous material which may be subdivided into a plurality of parallel ribbons or slivers as shown in FIGS; 4 and 5( Stage 4 includes a vessel 30, containing a.

treatment liquor 3, which receives the web 1 from a preceding press stage 5 and delivers it to a substantially identical subsequent press stage 5 whence it may be fed to a further immersion stage or to a drying device (e.g. one of the type disclosed in the aforementioned Fleissner application). The press stages 5 and 5 include a pair of coacting, vertically aligned pressure rollers '7, '8 and 7',

8 of which the lower roller 3 or 8' is driven by a motor E7 or 17 to advance the web 1 along its treatment path. This path leadsfrom roller pair I, 8 over a deflecting 'idler roller 18 into the bath 3 at the line of contact between a large tubular roller or drum 2 and a smaller, partlysubmerged roller 6; the periphery of drum 2 is constituted by a cylindrical screen whose perforations enable the liq- T uid pressed from web 1 to enter the interior of the drum and to return by its open sides to the bath. Drum 2 also coaots with a fully submerged roller 60; and with a third roller 6b which contacts it near the water line substantially in the samermanner' as roller 5. The. web 1, after passing for a short distance along the perforated surface of drum a 2, then hugs another deflecting idler. roller 10 and moves on substantially horizontally toward thegap between Patented Feb. 2, 1965 be journaled inmovable bearings, not shown,

for horizontal and/or vertical relative adjustment.

loosely coherent fibrous material, comprising the steps of continuously passing said web through a treatment bath,

In order to maintain the bath level substantially con- I stan-t, a float 19 (indicated schematically) controls a valve 2% on an inlet pipe 21 through which supplemental treatment liquid may be added as needed. Therollers 6, 6a and 6b are peripherally grooved, e.g. as described hereinafter with reference to FIGS. 3-5, for preserving the continuity of the boundary layer of liquid enveloping the web 1 during and immediately after its passage through the bath. V

FIG. 2 shows a partial modification of the treatment stage to and the subsequent press stage 5a. The vessel 38a contains a peripheral dr um' 2 and two coacting grooved rollers 6, do as in the preceding embodiment, yet the roller 61) of FIG. 1 has been replaced by a slightly larger deflecting roller 11 whose projecting upper surface supports the web 1 on its emergence from the bath. The

top of roller 11, shown grooved in substantially the same manner as rollers 6 andda, lies at approrimately the same level as the line of contact between the press rollers 7a, 3a

whereby the web moves toward these rollers along a generally horizontal path with practically no movement of free liquor over its surface. The residual liquor, squeezed from the web 1 by the rollers 7g and 8a,'drips through; a fiber-catching screen into a receptacle 9 whose bottom communicates with that of vessel Boa via a line 22. This line includes a check valve 23'which forms a seat for a ball 14 adapted to float on the treatment. liquor, the valve also including internal ribs 12' on which the ball may come to rest without materially interfering with the outflow of liquid from receptacle 9; ball 14 may be a wooden body, a

hollow metal sphere or the like provided, if desired, with a rubber coating. A piston pump 13 is coupled with a 7 operated continuously,- with variable throttling of the line 22 under the control of float 25. a 1 i In FIGS. Sand 4 I have shown three pairs of coacting rollers 26, 26'; 26a, 26a: 26b, 26b. The upper rollers 26, 26a, 26b are partly and the lower rollers 26', 26a,

26b are fullyimrnersed in the bath 3 to guide the web 1 below its surface until it emerges after partlyembracing' the last upper roller 26b; a further roller pair 27, 28, 0011-. I stituting with the other rollers a guide means for the web,

then squeezes the residual free water from the web, the common axial plane of these latter rollers being shown rollers withinthe bath and above the bath level at a locasqueezingexcess liquid from said material in a plurality of successive stages below/the bath level'at transversely spaced locations which are relatively staggered at different stages, withdrawing said web from the bath immediately after the last squeezing stage, and further squeezedrying the withdrawn web outside the bath. 1

2. An apparatus for wet-treating a web of fibrous mate rial, comprising ,a vessel containing a treatment bath, a plurality of first rollers positioned in said vessel at spaced apart locations in said vessel, cooperating roller means contacting said first rollers along parallel horizontal lines below the bath level for squeezing excess liquid in successive stages from said material, said first rollers being provided at relatively staggered locations with axially spaced peripheral'grooves adapted to receive 'said liquid, a pair of coacting second rollers positioned outside the bath beyond mechanism for advancing said web along said path.

3-. An apparatus according to claim 2 wherein said grooves are part of a helical channel.

4. An apparatus according to claimv 2 wherein said co-operating roller means is a relatively large tubular roller common to said first' rollers and provided with peripheral perforations.

2 5. An apparatus according to claim 4 wherein said second pair of rollers have a generally horizontal plane passing through the line of contact of the secondrollers tangent .to their peripheries and substantially on the level of the top of the last of said first rollers, said path as established bysaid guide means leading substantially horizontally from the top of said last roller to said second pair.

6. An apparatus tor wet-treating a web of fibrous mate- 7 rial, comprising a vessel containing a treatment bath, a

plurality of pairs of meeting rollers positioned in said vessel with a line of contact below the bath level for squeezing excess liquid in successivestages from said material, at least one roller of each pair being provided with axially spaced peripheral grooves axially offset from correspond ing grooves Of an adjacent pair, guide means including said'roll-ers and a further pair of rollers above said path for directing said web along a path between said coacting I tion immediately beyond the last of said pairs, and mechanism for advancing said web along .sm'd path.

7., An apparatus for wet-treating a web of fibrous material, comprising a vessel containing a treatment bath, a l plurality of first rollers positioned in said vessel at spacedinclined to the vertical whereby the elevation of their line of contact above the bath level can be less than the diameter of the lower roller 28 Without requiring this roller? todip into the bath. As best seen in FIG. 4 for the roller 7 26a, all of the immersed rollers are helically grooved to form passages for the boundary layer. 26a, diagrammatically illustrated in FIG. 3; represents any convenh onal drive means for advancingthe web along the guide path established by the rollers.-

In FIG. '5 Ihave shown toners 36a, 36b which as the upper rollers of successive roller pairs submerged or partrection as between therollersfida and 3612; thus, the web" 1 'is alternately squeezed at dilferentlaxial'locations on its passage through-the successive roller pairs.

Modifications of the arrangements describedand illus trated are, of course, possible without departing firom the The mechanism apart locationsin said vessel, cooperating rollermeans I contacting said first rollers along parallel horizontal lines below the bath level for squeezing excess liquid in successive stages from said material, said first rollers being providedlat relatively staggered locations with axially spaced peripheral grooves adapted to receive said liquid,

a pair .ofcoacting second rollers positioned outside the bath beyond said first rollers for further squeeze-drying scope and spirit of the invention as definedin, the appended claims. I Iclaim: f

1. A process for wet-treating a self-supportingiweb of said web,iguide means including said rollers for directing said web along a path between said coacting rollers, said path rising above-the bath level between said first and second rollers, mechanism for advancing said web along saidpath, areceptacle below said pair of second rollers for collecting squeezed-out liquid, and circulating means connected to said receptacle for maintaining the level of collected liquid therein substantially below the bath level and returning the excess to said vessel.

. References (Jilted by the Examiner 'UNITED STATESPATENTS y I 80,780, 8/68 'Iomlinson 6 -22 I (Other references on following page) 5 UNETED STATES PATENTS Stairs 1181 17 Cu-ttniss 117102 X Heinold 118424 X Cave 118-424 X Berger 6844 Brandwoc-d at 211 8-15 6 Borggrave 68--43 6 Voegeli 6843 Mamtius 8-151 Young 117115 X Bloem et a1 118-602 X Pensoluti 8-151.2

RICHARD D. NEVIUS, Primary Examiner.

JOSEPH B. SPENCER, MORRIS WOLK, Examiners.

Claims (1)

1. A PROCESS FOR WET-TREATING A SELF-SUPPORTING WEB OF LOOSELY COHERENT FIBROUS MATERIAL, COMPRISING THE STEPS OF CONTINUOUSLY PASING SAID WEB THROUGH A TREATMENT BATH, SQUEEZING EXCESS LIQUID FROM SAID MATERIAL IN A PLURALITY OF SUCCESSIVE STAGES BELOW THE BATH LEVEL AT TRANSVERSELY SPACED LOCATIONS WHICH ARE RELATIVELY STAGGERED AT DIFFERENT STAGES, WITHDRAWING SAID WEB FROM THE BATH IMMEDI-

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