US2648876A - Method and machine for producing unwoven fabrics - Google Patents

Description

Aug- 18, 1953 J. PHILLIPS ErAL 2,648,876

METHOD AND MACHINE FOR PRODUCING UNWOVEN FABRICS l INVENTOR JOE PHILLIPS j VERNA LPAYNE BYKW? 19d/1% LM ATORNEY 4 Sheets-Sheet 2- Aug. 18, 1953 J. PHILLIPS ErAL METHOD AND MACHINE FOR PRODUCING UNWOVN FABRICS Filed Sept. 19, 1950 m m Y mor, ,kvwmmllll .,vo. /M fw mm. w: omomg N: .0 ...m mml @Q i@ O NQ mw Aug. 18, 195.13 J. PHILLIPS Afr-ALl 256485876;

METHOD AND MACHINE FoR PRODUCING uNwovEN FABRICS `4 sheets-sheet s Filed Sep'.. 19, 1950 INVENTOR JOE Pr-HLLIPS VEQNA vl.. PAYNE BY #MMU ATTORNEY METHOD AND MACHINE FOR PRoDUcI-.NG uNwovEN FABRICS Filed sept. 19, -1950 Aug. 18, 1953 J. PHILLIPS ErAL 4 Sheets-Sheet 4 wb Ow NNL INVENTOR JOE PHILLIPS VERNA L. PAYNE BY a4/maag M@ )L www ATTORNEY Patented Aug. 18, 1953 UNITED STATES PATENT OFFICE METHOD AND MACHINE FOR PRODUCING UNWOVEN FABRICS Application September 19, 1950, Serial No. 185,590 v 6 Claims.

This invention relates to a method and machine for producing unwoven fabrics, of .uniform texture and strength in all directions, composed of bers deposited in random relationship.

In U. S. Patents Nos. 2,477,675 and 2,478,148, both issued August 2, 1949, to Wilson et al., are disclosed a method and machine for producing unwoven fabrics, which yield an eminently satisfactory product. While these inventions achieve a high rate of fabric production compared to prior art methods and machines, the capacity of a single machine is yet limited, and it is found that extremely heavy or thick fabrics cannot be made without some slight loss of textural uniformity. These limitations are inherently involved With the critical dimensional characteristics of the fiber transfer duct, which have been found essential to successful operation.

It has now been found that the production rate of the prior inventions, and the maximum limit of fabric thickness which may be satisfactorily produced, may be materially increased by employing a high speed air stream to doi and entrain the fibers from a fiber carrying supply instrumentality, the air stream travelling initially tangentially to and in the same direction as the liber carrying instrumentality, and at a Velocity bearing a xed minimum relationship to the velocity of the supply instrumentality. Additionally, it has been found that by so entraining the fibers, and by the provision of novel flow -control means in and beyond the transfer duct, the dimensional requirements of the transfer duct may be rendered less critical, permitting employment of ducts of varying configuration without sacrice of uniformity in the resulting product.

It is an object of the present invention, accordingly, to provide a simplified method and machine adapted to produce unwoven fabrics at extremely high rate.

It is a further object of the invention to provide a method and machine adapted to .produce heavy or thick unwoven fabrics of outstanding uniformity.

Another object is to provide in a machine of the type described controllable and differential adjustment means adapted to maintain smooth and uniform the flow of air through the fiber transfer duct and liber receiving member.

Still another object is to provide in a machine of the type described novel liber transfer duct structure, adapted to maintain a smooth, unform flow of air therethrough, without dead air spaces, turbulence or other factors detrimental to formation of a uniform fabric.

Yet another object is to provide in a machine for producing unwoven fabrics by deposit of fibers through a transfer duct onto a foraminous receiving member, means adapted to effectively seal the trailing edge of said duct relative to said receiving member without impairing the surface of the fiber produced.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention and the novel features thereof may best be made clear from the following description and the accompanying drawings, in which:

Figure l is a side elevational view of an exemplary machine according to the present invention, including a carding machine, a ber transfer duct and a foraminous fiber receiving member;

Figure 2 is a side elevational View of further elements of the machine of Figure 1, including a dip tank employed to apply bonding material to the fabric produced;

Figure 3 is a partial plan view of the machine, taken on the line 3-3 of Figure 1;

Figure 4 is an enlarged sectional View taken on the line 4 4 of Figure 3, showing details of the fiber transfer duct, the fiber receiving screen and related elements, and

Figure 5 is a sectional View taken on the line 5-5 of Figure 4, showing details of the air stream control means incorporated in the throat of the air conduit downstream of the ber receiving member.

Referring to the drawings, particularly Figures l and 2, an exemplary embodiment of the present invention comprises a frame I0, and suitably supported thereon a liber attenuating and carrying instrumentality such as card cylinder I2. A ber transfer duct I4 extends outwardly from the peripheral surface of the card cylinder, to a foraminous ber receiving member exemplified by endless flexible screen I6. The unwoven fabric formed on the exible screen is conducted through dip tank I8, and thence over a vacuum cylinder 20 to suitable drying or baking apparatus, not shown.

The fiber attenuating and carrying instrumentality is supplied from a ber lap or similar source, fed thereto by feed rollers, a conventional taker-in, or other common means (not shown), the mechanism illustrated in Patent No. 2,478,148 being entirely satisfactory. The feed lap is attenuated into individual fibers by card cylinder' I2, and the fibers are carried about the periphery thereof, in the clockwise direction as shown, to

the inlet end of transfer duct I4. As best shown in Figure 4, the transfer duct comprises side plates 22, top plate 24 and bottom plate 26. The edges of side plates 22 adjacent the card cylinder are disposed as closely as possible thereto without contacting the cylinder. The edge of top plate 24 adjacent the card is considerably spaced therefrom, defining an elongated air inlet 23 between the top plate and the card. As shown in Figures 3 and 4, the inlet 28 isV partially closed by an adjustable gate 30, from which extends a plurality of transversely spaced bolts 32, which in turn extend through suitable apertures provided therefor in a rigid bracket 34 xedto the upper surface of the transfer duct top plate. rIhe bolts 32 are individually adjustable relative to bracket 34, and in the example shown are threaded whereby each may be individually xed relative to the bracket by means of lock nuts 35. The gate 30 may be constructed of metal, rubber, leather or the like, but must be suficiently ilexible so that it may be differentially adjusted relative to the card along the length of the air inlet. Obviously, the gate 30 may be composed of individual segments, if desired, although a continuous, flexible gate member hasv been found to function with outstanding effectiveness. The edge of bottom plate 26 adjacent the card cylinder is slightly spaced therefrom to define therewith an auxiliary air inlet 38, for reasons presently apparent.

The outlet end of transfer duct I4 is disposed adjacent a vertical night of the flexible screen i6, which is guided and supported by a plurality of rolls 40 rotatably mounted on the machine frame. The side and bottom plates of the transfer duct are effectively sealed against the screen by deformable seal members 2, which may be constructed of rubber or leather, and the top plate 24 is effectively sealed thereagainst by a seal roll f4, and a seal strip 46 disposed between the seal roll and the upwardly turned end flange t8 of the top plate.

The machine is driven from any suitable source of power (not shown) through reduction gear box 5D. From the gear box, one take-off shaft 52 is suitably connected in driving relationship through idler shaft 54 to drive pulley 56 of the card. By means of a second take-off shaft 58, the gear box is drivingly engaged, by suitable chains and sprockets, through idler shaft B9 to the shaft G2 of one of the rolls 40 supporting screen i6. By means of chain 64, shaft S2 is engaged in driving relationship to shafts 56 and 6B of other rolls 140, whereby the screen IB is positively and evenly driven at a speed coordinated with that of the card.

The shaft l!) of seal rollv 154 is slidably supported in bearings l2, and is spring biased against screen I6, adjusting bolts 'I4 being provided to vary the spring pressure. At one end of shaft lll, a sprocket 'I6 is mounted thereon, which is engaged to chain 64, whereby the seal roll is positively driven at a predetermined speed relative to that of the flexible screen. A separating roll 18 is rotatably mounted immediately above the. top horizontal flight of the screen, and is suitably driven from shaft 66, as by chain 8. A screen cleaning brush 82 is rotatably mounted, as by bearings Bt, adjacent the outer surface of the ber receiving screen, immediately below its point of entry into the transfer duct, and is suitably driven from the machine drive, as by means of chain 86 engaged to idler shaft 54.

Interiorly of the fiber receiving screen, andv in general alignment with the transfer duct, is disposed an exhaust duct 88, which converges into an elongated throat Q0, which in turn merges into a downwardly curved and inwardly converging section 92, which communicates with an outwardly extending duct portion 94 terminating in a downwardly extending duct portion Qt. ln the throat of exhaust duct 88 is provided means for differentially varying the opening thereof across the width of the throat. As shown in Figures 3, 4 and 5, a plurality of flexible leaf plates 98 may be employed, one end of each plate being fixed to the duct adjacent its open end facing the screen, the other end of each plate extending rearwardly into the throat. Below the throat end of each plate, an adjusting screw it is threadably mounted in a support bracket 02 extending transversely below the duct, each adjusting screw extending through the duct into contact with the lower surface of the free end of the leaf plate thereabove. It will be readily understood that by means of the individual adjusting screws, the leaf plates may be individually adjusted, as illustrated in Figure 5, whereby the throat opening may be differentially varied as required across the width thereof.

As seen in Figure 2, the dip tank 8 is disposed adjacent the rear vertical flight of the flexible screen. The dip tank may contain a quantity of fluid binder lt. Rotatably supported above the tank and extending below the surface of the. binder Hill is an immersion drum it. An endless wire cloth IEB or equivalent pressure member is maintained in contact with the lower portion of the immersion drum, the wire cloth extending about drive roll llt, the immersion drum, idler rolls H2, and thence below the submerged guide bar Hfl to the drive roll. As illustrated in Figure 2, the drive roll HEI may be driven by means of chain H6 from the shaft S8, and the wire cloth H18 and immersion drum driven thereby. Intermediate the idler rolls H2 is mounted the suction cylinder 2r?, provided with a series of apertures or a slot i253 in the upper surface thereof.

The operation of the apparatus and the method of the invention will now be described in detail. As previously indicated, the card l is supplied from a suitable source such as a fiber lap, and functions in the conventional manner to attenuate the fibers. The attenuated bers are carried about the surface of the card to the inlet end of the ber transfer duct. A high Velocity air stream is caused to flow through the duct from the inlet end thereof to the foraminous fiber receiving member. In the example shown, the air stream is induced by means of an exhaust fan (not shown) connected to the downwardly extending duct portion 9S, whereby a flow of air is induced through the transfer duct, the flexible screen, and the exhaust duct throat, air entering the transfer duct primarily through air inlet 28.

It isobviously essential that the air stream entering the air inlet effectively doff the fibers from the card cylinder surface adjacent thereto, and it is equally essential that the fibers so entrained be c-onveyed through the duct to the fiber receiving member by a uniform and evenly flowing air stream, so that the bers are deposited on the liber receiving member in random distribution and in uniform manner and quantity across the width thereof. It has been found that this can be most effectively accomplished byemploying a high velocity air stream, which, as"

-indicated'by arrow 124, 'Figure 4, initially moves tangentially to the surface of the card cylinder,

and then moves longitudinally of the transfer duct. The lmost critical "factor of satisfactory operation has been found to be the velocity of "the air stream lentering inlet 28 relative to the peripheral velocity of the card cylinder or other ber carrying supply instrumentality. It has been found that if a minimum velocity fratio vof at least four to one/is maintained, a highly satisfactory fabric may be produced-at high production rate. An air velocity ranging up to --six or `Vseven or more times the peripheral vvelocity of the supply instrumentality may be employed with excellent results, but a velocityratio ofless than four to one is found to result in transfer duct turbulence, balling up of the 'bers and other'factorsfresulting in a non-uniform or otherwise unsatisfactory product.

In order to lcontrol the high velocity air stream, and maintain'uniformity of flow vacross the Ywidth of and throughout the transfer duct,

differentially adjustable control means-have been provided at the air-inlet and at the 'throat `of the exhaust duct, downstream of the fiber receiving member. Transverse uniformity of the fabric formed mayb-e readily achieved and maintained by differential adjustment of the airsow atthese two points. The uniform and smooth flow of the air stream-through the transfer duct may also'be enhanced, it has been found, by provision of the auxiliary air inlet v38, by means-of which a limited quantity of air is permitted to enter at the bottom of the entry end of the duct. The auxiliary air so -entering serves the primary function of obviating dead airspace in this vicinity, and has been found to very materially reduce anytendency toward `turbulence in the duct.

The employment of a high velocity-air stream, controlled in the manner described, has .been found to ypermit operation ofthe machine at highercapacity than previously obtainable. The fiber :attenuating and carrying instrumentality may be drivenat a speedlimited only by reason of its relationship to the velocity of the ber transfer air stream, and may operate relative to its fiber source atextremely lhigh-draft, wherein correspondingly excellent attenuation of the bers is obtained. For example, the card op- I crates relative to its fiber source most efciently at drafts of four thousand lor more, drafts of five thousand to seventy-five hundred being readily attained with excellent results. The term draft as here employed refers to the numerical relationship between the weight of fibers carried per foot of :ber carrying instrumentality and the weight of fibers per foot of fiber lap fed thereto, or more specifically, the ratio of the latter to the former. Accordingly, by the present invention, not only a high rate of production, but also a high rate of fiber attenuation is made possible. The air stream need not be induced in the manner described, but may be effected in equivalent manner.

As best shown in Figure 4, the entrained ilbers are carried through the transfer duct and deposited upon the upwardly moving foraminous screen to form a lap of fabric |22, the air stream passing on through the flexible screen and the exhaust duct. The formed fabric is compacted somewhat in passage under seal roll ad, and then is conducted over the top horizontal flight of the exible screen. The seal roll 44, especially in the case of thick fabrics, is prone to Wrinkle or otherwise impair the Ysmooth outer lsurface of the formed fabric. It has beenfound that by positively driving the seal roll at rva peripheral velocity slightly exceeding .the velocity of the flexible screen and the lap carried thereon, this effect may be obviated. 'Thelcompacted lap is separated from the flexible screen in passage over the driven separating roll i8, and is `then carried'by the screen to drive roll HG associated with dip tank I8. The `flexible screen It continues its path'about the rolls 40,1and immediately prior to entering the transfer duct .is

cleaned of any adhering `fibers or foreignsubstances by the rapidly rotating'brush 82,

rIt will'be understood that for manyxpurposes lthe fabric so formed may be employed .without further'treatment. For. many purposes, however, it is desirable to strengthen and condense 'the fabric Yby application of binder thereto. This may be conveniently accomplished by the dipping mechanism illustrated, the fabric :passing .onto the cloth ISB, and being conducted thereby around the lower periphery of immersion drum H16, through the fluid binderiiili. The wire cloth being relatively open, the fabric is thoroughly saturated with the binder, and may becompacted by pressure of the wire cloth against the Jdrum.

The saturated fabric is then carried by Vthe :cloth over the rst idler roll H2, `and then over the suction cylinder 20, which induces aflow of .air therethrough and removes excess binder. The impregnated fabric 122 then passes over Lthe second idler roll H2, and Inay be defied vat this point for passage into suitable drying and/or baking mechanism, lif required. Finally, the finished fabric is wound'in rolls kcr Iotherwise collected for shipment.

rlhe transfer duct may be disposed generally normal to the surface of the card, but need Anot be, and may-be disposed-at an acute angle thereto, as shown. The method described above may be employed to form unwovenjfabrics or" vextremely 'heavy thickness, either by slowing the movement of flexible screen it relative to the card, or preferably by so doing and enlarging Ythe downstream end of the transfer duct,`to insure product uniformity. By reason of the .fine control of the high velocity air stream through the duct, effected by the plural differential means describedit'has been found that -the duct may be lmade converging or Ydiverging as best suited -to the width and kthickness 'of `fabric being .pro-

duced, but should be straight, smooth-sided and uninterrupted.

It will thus be seen that there has been provided by this invention a structure in which the various objects hereinbefore set forth, together with many practical advantages, are successfully achieved. As various possible emboidments may be made of the mechanical features of the above invention, all without departing from the scope thereof, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.

We claim:

1. The method of forming a fibrous web which comprises the steps of attenuating a body of bers onto a toothed moving ber carrying instrumentality, removing the fibers from the teeth of said fiber carrying instrumentality by means of an air stream moving substantially tangentially thereto and in the same direction, the velocity of said air stream at the point of ber removal being at least four times the velocity of said fiber carrying instrumentality, passing said air stream and the fibers suspended therein to a foraminous ber receiving member through a confined uninterrupted path, passing said air stream through said foraminous fiber receiving member whereby said bers form a web thereon, and removing the web from said member.

2. The method of forming a fibrous web which comprises the steps of attenuating a body of bers onto a toothed moving fiber carrying instrumentality at a draft of at least four thousand, removing the fibers from the teeth of said liber carrying instrumentality by means of an air stream moving substantially tangentially thereto and in the same direction, the velocity of said air stream at the point of ber removal being at least four times the velocity of said fiber carrying instrumentality, passing said air stream and the iibers suspended therein to a foraminous ber receiving member through a confined uninterrupted path, passing said air stream through said foraminous fiber receiving member whereby said bers form a web thereon, and removing the web from said member.

3. The method of forming a fibrous web which comprises the steps of carding a body of fibers at a draft of at least four thousand, removing the bers from the card by means of an air stream moving substantially tangentially thereto and in the same direction, the velocity of said air stream at the point of fiber removal being at least four times the peripheral velocity of said card, passing said air stream and the bers suspended therein to a foraminous fiber receiving member through a conined uninterrupted path, passing said air stream through said foraminous ber receiving member whereby said iibers form a web thereon, and removing the web from said member. v

4. Apparatus of the class described comprising fiber attenuating means to provide a moving source of ber supply, a ber transfer duct having an uninterrupted passage therethrough and a fiber receiving end in close contact with said ber supply source, an elongated air inlet in the leading edge of said duct, gate means dening said inlet, means for adjusting individual portions of the length of said gate means relative to said source of iiber supply, a foraminous fiber receiving member at the delivery end of said duct,

means for moving said receiving member relative to said duct, means for creating an air stream through said air inlet, duct and ber receiving 8 member to remove fibers from said supply source and transfer them through said duct to said receiving member to form a web thereon, and means for removing said web from said member.

5. Apparatus as defined in claim 4, wherein said air stream creating means includes a second duct downstream of said fiber receiving member in alignment with the delivery end of said transfer duct, and obstructing means in said second duct for differentially adjusting the iow of said air stream across the width thereof.

6. Apparatus of the class described comprising carding means, a fiber transfer duct having an uninterrupted passage therethrough and a fiber receiving end in close contact with said carding means, an elongated air inlet in the leading edge of said duct, gate means defining said air inlet, means for adjusting individual portions of the length of said gate means relative to said carding means, a foraminous fiber receiving member at the other end of said duct, means for moving said receiving member relative to said duct, means for creating an air stream through said air inlet, duct and fiber receiving member to remove fibers from said carding means and transfer them through said duct to said receiving member to form a web thereon, said air stream creating means including a second duct downstream of said fiber receiving member in alignment with the delivery end of said transfer duct, obstructing means in said second duct for differentially adjusting the flow of said air stream across the width thereof, and means for removing said web from said receiving member.

JOE PHILLIPS. VERNA L. PAYNE.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 227,063 Scattergood Apr. 27, 1880 490,271 Crooks Jan. 24, 1893 1,827,183 Bennett Oct. 13, 1931 2,451,915 Buresh Oct. 19, 1948 2,477,675 Wilson et al. Aug. 2, 1949 2,478,148 Wilson et al. Aug. 2, 1949 FOREIGN PATENTS Number Country Date 220,149 Great Britain Aug. 14, 1924 545,638 Great Britain June 5, 1942

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