US3573137A - Apparatus for making nonwoven fabrics - Google Patents

Abstract

APPARATUS FOR THE CONTINUOUS PRODUCTION OF NONWOVEN FABRIC WHICH INCORPORATES A SUPPORTED, CONTINUOUS BELT TYPE FEEDER AND DRIVE MECHANISM FOR ADVANCING A PLURALITY OF WRAP STANDS ALONG A HORIZONTAL PATH IN A LONGITUDINAL DIRECTION, WITH A DANCER ROLL MECHANISM INCORPORATED THEREIN FOR TENSION CNTROL THEREOF, AND A FILL STAND APPLYING DEVICE DISPOSED FOR ROTATION ABOUT THE WARP STRANDS AS THE WARP STRANDS ARE MOVED ALONG THE FEEDER MECHANISM.

D R A W I N G

Description

M 30, 1971 BASCOM ET AL 3,573,137

APPARATUS FOR MAKING NONWOVEN FABRICS Original Filed 001:. 31, 1966 4 Sheets-Sheet 1 a-n-n-vx-q-e-u-ami Wk HULL/1% H. @4560! JON/V J GREG/ Mmmh 30, 1.971 BASCQM ET AL 3,573,137

APPARATUS FOR MAKING NONWOVEN FABRICS Original Filed Oct. 51, 1966 4 Sheets-Sheet 2 52 J'l'l'g. 8., n5 0 9. v

U .fw 66 3 L A m M O C S A B a H APPARATUS FOR MAKING NONWOVEN FABRICS Original Filed Oct. 31, 1966 4 Sheets-Sheet 3 HULL/5' N. 845606! JON/V J- 51750] U 371 BASQQM ET AL 3,573,137

APPARATUS FOR MAKING NONWOVEN FABRICS Original Filed Oct. 31. 1966 4 Sheets-Sheet 4 HOLLIS H. BASCOM JOHN J. GRECI United States Patent 3,573,137 APPARATUS FOR MAKING NONWOVEN FABRICS Hollis H. Ilascom and John J. Greci, Livermore, Califi, assignors to Green Corporation, Livermore, Calif. Original application Oct. 31, 1966, Ser. No. 590,910. Divided and this application Apr. 16, 1969, Ser. No. 835,842

Int. Cl. 1331c 1/00, 1/08; B65h 81/00 US. Cl. 156-428 12 Claims ABSTRACT OF THE DISCLOSURE Apparatus for the continuous production of nonwoven fabric which incorporates a supported, continuous belt type feeder and drive mechanism for advancing a plurality of warp strands along a horizontal path in a longitudinal direction, with a dancer roll mechanism incorporated therein for tension control thereof, and a fill strand applying device disposed for rotation about the warp strands as the warp strands are moved along the feeder mechanism.

This is a division of application Ser. No. 590,910, filed Oct. 31, 1966.

This invention relates to nonwoven fabrics and particularly relates to techniques and apparatus for obtaining precise strand positioning with low adhesive content in the completed fabric.

The present invention relates to improvements in the process and apparatus disclosed in the copending United States application of Hollis H. Bascom, Ser. No. 281,421, filed May 20, 1963, which matured into U.S. Pat. No. 3,391,043 on July 2, 1968 and in the copending United States application of Hollis H. Bascom, John J. Greci and Richard G. Jenkins, Ser. No. 365,318, filed May 6, 1964 which matured into US. Pat. No. 3,391,039 on July 2, 1968.

As described in the two above noted applications the general process to which this invention relates is one in which a number of warp strands are moved, under a controlled tension, along the cylindrical surface of a stationary cylindrical support while one or more fill strands are wound about the warp strands. The fill strands are taken from thread packages mounted on a drum which is rotatable about the cylindrical support and the longitudinally moving warp strands. A magazine containing a liquid binder is also mounted on the drum. A metering tip extends radially inwardly from each magazine and into close proximity to the juncture of the fill strand and the warp strand. A separate magazine is provided for each fill strand, and each fill strand is guided through its associated magazine to apply binder to the fill strand. As the fill strand package and its associated magazine are rotated about the warp strand the fill strand is successively engaged under tension with the warp strand. Because the warp strands are moving horizontally, the fill strand forms a helix on the warp strand. The tube of fabric thus formed is cut, after the binder has set, along a line parallel to the warp strands. The fabric is then opened to a flat sheet and wound upon a storage roll.

Prior application Ser. No. 365,318 (now U.S. Pat. No. 3,391,039) noted above, described a process improve ment in which a moving sheet was interposed between the warp strands and the support to keep the binder out of contact with the support to prevent build up of binder on the support. The sheet was separated from the fabric at the outlet end of drive rollers which engaged the fabric to pull the fabric along the support. As pointed out in application Ser. No. 365,318 (now US. Pat. No. 3,391,039) the moving sheet, in addition to keeping binder Patented Mar. 30, 1971 'ice off of the support, helped to carry low thread count materials and provided a certain degree of stabilization during the time that the binder or adhesive was setting.

Maintaining the junctures between the warp and fill strands in a stabilized condition during the time that the binder is drying is always an important consideration in making nonwoven fabrics by the general process described above. It becomes critical with fragile fabrics having fine yarn or low thread counts. With such fabrics it has been found necessary to eliminate even the relatively small driving stresses introduced to the fabric by the octagonal arrangement of drive rolls described in the above noted application Ser. No. 365,318 (now US. Pat. No. 3,391,039).

It is therefore a primary object of the present invention to transport the fabric along the support by a conveyor belt which substantially eliminates drive stresses in the fabric during the time the fabric is being formed and during the time the binder is setting-up.

In accordance with the present invention a conveyor belt is formed to a tube shape as it moves toward the cylindrical support and the fabric is carried on the conveyor belt, and is transported along the support, solely by the action of the conveyor belt. The conveyor belt is separated from the fabric at the time the fabric is cut and changed from the tube form to a flat sheet. One or more drive rollers engage the conveyor belt after the belt and the fabric have been separated to pull the belt without any contact between the drive rollers and the fabric itself.

As will be described in greater detail below, the con veyor belt is also preferably provided with a release medium which may be in the form of a coating or in the form of a separate film for insuring easy separation of the conveyor belt from the fabric.

Another important object of the present invention is to supply binder to the magazine while the magazine is rotating so that the process does not have to be stopped when the magazine runs low of binder. This object is achieved by connecting a ring for rotation with the magazine. The ring has flanges at each end which extend radially in to provide a channel or trough within the ring. The interior of the ring is connected to the interior of the magazine. When liquid binder or adhesive is pumped into this trough in the bottom part of the rotating ring, the centrifugal force distributes the binder about the circumference of the ring and through the interconnecting conduit to the interior of the magazine.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by-way of illustration, show preferred embodiments of the present invention and the principles thereof and what are now considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a side elevation view of apparatus for forming nonwoven fabric constructed in accordance with one embodiment of the present invention;

FIG. 2 is a fragmentary plan view of a guide arrangement for insuring accurate positioning of the warp strands in the apparatus shown in FIG. 1;

FIG. 3 is a fragmentary side elevation view of separator mechanism for separating the conveyor belt from the fabric at the time the fabric is cut and opened from a tubular web to a fiat sheet;

FIG. 4 is an end elevation view taken along the line and in the direction indicated by the arrows 4-4 in FIG. 3;

FIG. 5 is a fragmentary side elevation view showing details of the manner in which the conveyor belt is formed to a tube shape;

FIG. 6 is an end elevation view taken along the line and in the direction indicated by the arrows 6-6 in FIG. 5;

FIG. 7 is an enlarged view of the conveyor belt drive arrangement of the machine shown in FIG. 1;

FIG. 8 is a fragmentary end elevation view of one form of outlet tip construction which can be used with a magazine of the apparatus shown in FIG. *1;

FIG. 9 is a side elevation view, in somewhat diagrammatic form, of an arrangement which can be used for maintaining a continuous feed of binder to the magazines of the apparatus shown in FIG. 1;

FIG. 10 is a fragmentary enlarged side elevation view, partly in cross section, of a ring construction used for supplying binder to the magazine of the apparatus shown in FIG. 1;

FIG. 11 is a fragmentary side elevation view of a fill strand delivery arrangement which incorporates an easily removable magazine;

FIG. 12 is a fragmentary end elevational view showing how the magazine of FIG. 11 may preferably be oriented to minimize stressing the fill strand 'while achieving the desired positioning of binder on the fill strand;

FIG. 13 is a fragmentary top plan view of the support showing how the support is formed with helically disposed slots for injecting air under pressure between the conveyor belt and the support; and

FIG. 14 is a fragmentary top plan view showing how canted guide rollers are mounted to alternately engage and release the side margins of the belt to tighten the belt and to keep the belt from wandering sideways.

In FIG. 1 apparatus for forming nonwoven fabric constructed in accordance with one embodiment of the present invention is indicated generally by the reference numeral 21. The apparatus 21 is, as noted above, of the general kind disclosed in detail in copending United States applications Ser. Nos. 281,421 filed May 20, 1963 (now US. Pat. No. 3,391,043) and 365,318 filed May 6, '1964 (now US. Pat. No. 3,391,039) and assigned to the same assignee as the present invention. Reference is made to those applications for details of the parts of the structure not described in detail below.

Briefly, the apparatus 21 includes One or more creel and tension carts (not shown in FIG. 1) for imparting a measured tension to a plurality of warp strands WS. The warp strands are lead through guide means, an eye board 22 and one or more reed guides 23 and 24, and through a constricting ring 26 to the outer surface of a cylindrical support or mandrel 27.

One or more fill strand packages 28 are mounted on a drum 29, which is in turn mounted for rotation within a support 31 and is rotated by a motor 32. The fill strands F8 are led from the packages into a magazine 33 which contains a liquid binder. The magazine is only partly filled with the liquid binder, for reasons that will be described in detail below, and the fill strand is trained through the binder and then through a binder metering and positioning tip 34. The outlet of the tip 34 is located close to the support 27 and, because the warp strands are continuously moving along the support, the fill strand traces a helical path as it successively engages the warp strands during rotation of the drum 29 about the warp strand.

The apparatus 21 preferably includes a heater, not visible in FIG. 1, for heating the binder to dry and set the binder while the engaged warp and fill strands are being carried along the support 27.

As thus far described the apparatus 21 and mode of operation are basically like that disclosed in prior appli- 4 cation Ser. No. 365,318 (now U.S. Pat. No. 3,391,039).

In the present invention the fabric is transported through the apparatus 21 by a conveyor belt 36 rather than by any drive means which could impose stresses on the fabric tending to disrupt the bonds between the warp and fill strands during the time these bonds are setting up.

As best shown in FIGS. 5 and 6, the conveyor belt is converted from a flat belt to a tube shape by a former 37 located in front of a support 27. It is quite important that the belt be made to conform quite closely to the surface of the cylindrical support 27, since any wrinkles would cause a corresponding disruption in the spacing of the strands of the fabric. The belt should be sufficiently resilient to stretch to shape, but it cannot be compressed without wrinkles. It is also quite important that there be no concavity in the upper surface of the belt since any concavity in that part of the belt would prevent the cylindrical support from providing the desired support function. There is a natural tendency of the belt to sag at the top during the time that it is being converted from a flat belt to a tube shape and, in the process, is being flexed in two directions. As illustrated in FIGS. 5 and 6 a roller 38 positioned in the manner illustrated provides effective support for the top part of the tube at this critical point in the formation of the tube. The roller also is a preferred means of support at this point because it minimizes drag.

Before describing the drive arrangement for the conveyor belt in greater detail the manner in which the belt and the fabric are separated prior to cutting of the fabric will be reviewed. With reference to FIGS. 3 and 4 it can be seen that the fabric F passes beneath a horizontally extending plate 39 while the side edges of the belt 36 are forced up and are curled away from one another, see FIG. 4, by the combined action of the plate 39 and a plow shaped member 41 just prior to the time that a cutter disc 42 cuts the fabric F along a line parallel to the warp strand. The cutter disc 42 is rotated .by a hardened roll 43 which engages the periphery of the disc and insures that the strands of the fabric passing between the roll 43 and the disc 42 are cleanly cut.

It is important that the edges of the belt 36 be separated to some extent at the time that the fabric is cut to avoid trimming portions off the belt.

With particular reference now to FIG. 7, the conveyor belt 36 is pulled along the support 27 by one or more drive rolls 46. A pressure roll 47 maintains the belt 36 in driving contact with the drive roll 46. The belt 36 is an endless belt and returns to the inlet end of the support 27 by passing over a series of positioning rollers 48.

The fabric F, after being cut by the cutter disc 42 is opened to a flat sheet and is wound upon a storage roll 49. The storage roll 49 is driven by a separate motor, not shown, and the rotation of the storage roll 49 is coordinated with the speed of the conveyor belt 36 to prevent excessive droop of the fabric F while avoiding stressing the fabric. This coordination is provided by a dancer roll 50. The coaction between the dancer roll 50 and the drive for the storage roll 49 is the same as that described for the corresponding elements in the above noted US. Pat. No. 3,391,039 at column 6, lines 723 of that patent. The storage roll 49 is driven by an electric motor under the controls of two mercury level switches which are not shown. The switches sense the level of the dancer roll 50 which indicates the amount of tension in the fabric. Normally one switch will be made to drive the storage roll, through a rheostat control, at a selected take up speed. However, if this take up speed should be too fast, the dancer roll 50 will be pulled upwardly about a pivotal mounting to energize the other switch which causes the storage roll 49 to be driven at a slower speed, through a second rheostat, until the fabric tension again decreases to the point where the storage roll 49 is driven by the energization of the first switch. Thus, the storage roll 49 is driven at a speed fast enough to prevent any undue slack in the fabric, yet excessive tension which could cause distortion is at all times prevented.

The conveyor belt 36 is preferably made from a tough material of high dimensional stability. Mylar polyester film having a thickness between 7 /2 and 10 mils has been found to be a quite satisfactory material for the conveyor belt.

The conveyor belt may be coated with a release film which resists sticking of the binder or adhesive and thus facilitates separation of the belt from the fabric. Alternately, and as illustrated in FIG. 1, a separate release film 51 may be employed. In this event the release film 51 may be carried along the fabric F for some distance after the point at which the belt 36 is separated from the fabric. Doing this lends additional support to the fabric F and provides more time for set up of the bonds between the warp and fill strands. The release film 51 is then returned to the conveyor belt 36 by passing the release film over a series of rollers 52. A polypropylene film has been found to be a very effective release film.

It is important, as indicated above, that the conveyor belt (and release film) be maintained free of wrinkles. To keep the belt tight in a transverse direction and to prevent depressions in the outer surface of the belt a series of guide rollers, inclined at an angle, alternately engage and release the belt 36. These canted guide -rolls 70 are shown in FIG. 14 of the drawings. These guide rollers grab and release the side margins of the belt and release film under the control of limit switches to tighten the belt and to keep the belt from wandering sideways.

The present invention also incorporates means for injecting air under pressure between the conveyor belt and the support 27. The air reduces friction. This is especially important with high shrink fill strands. The support 27 is formed with slots 60, preferably helically disposed as shown in FIG. 13, to distribute the air about the support. Air pressures of 2 to 50 p.s.i. have been found satisfactory.

As the fill strand engages the warp strand in the course of the rotation of the thread package and magazine about the support, the fill strand will tend to pull each individual warp strand, at the moment of engagement, sidewise to a limited extent in the direction of rotation of the rotating drum 29. The present invention uses this pulling tendency to achieve precise lateral positioning of the warp strands.

The manner in which this is accomplished can best be explained by reference to FIG. 2.

FIG. 2 is a fragmentary plan view of the reed guide arrangement for establishing the lateral position of the warp strands of the apparatus shown in FIG. '1. The dents 23D and 24D of the reed guides 23 and 24 are arranged in tandem relation, but instead of being arranged exactly coincident, as viewed in the direction of movement of the warp strands, the dents 24D are offset slightly in a circumferential direction (downward as viewed in FIG. 2) so that the dents 24D are slightly laterally offset in a direction opposed to the direction of rotation of the drum '29. As a result, the fill strand FS pulls each warp strand WS into positive engagement with its associated dent 24D on the reed guide 24 to thereby maintain precise and uniform spacing of the warp strands. While two reed guides have been illustrated as the guide elements for the warp strands, the same principal can be utilized with other lateral guide elements. For example, the reed guide 24 could be used with the eyeboard 22 to achieve this same result.

As illustrated in FIG. 1 the warp strands pass through the interior of a constricting ring 26 at the outlet of the reed guide 24. This constricting ring insures that the warp strands are pulled down to the desired radial position with respect to the surface of the support 27. An acetal molded resin ring, such as Delrin resin, has been found quite satisfactory since it is both hard enough to resist wearing down of the surface and yet smooth enough to avoid shredding of the warp strands.

The unstressed fabric transport provided by the conveyor belt makes it feasible to use a binder which is a good film former but which may provide little or no tack or adhesion to the strands themselves. The fill strand in passing through the magazine 33 is immersed in the liquid binder, and as the fill strand passes out the tip 34, the tip wipes the adhesive off the top surface of the strand (as best illustrated in FIG. 8) leaving sufficient adhesive on the underside of the strand to form a filleted film about substantially the entire diameter of each warp strand at the area of engagement of the fill and warp strand. At this time the location of the area of intersection of the warp and fill strands is not at all dependent upon any action of the binder in holding the fill and warp strands together. The belt holds the engaged strands in an absolute position until the film can form the strength to hold the strands in engagement. Thus, the binder can be one which will form cohesive strength after set up and the binder need not be selected for any adhesive qualities. Since the binder forms a film over, under and all the way around the area of intersection, the joint is a high strength joint after the film has set up.

The control of the amount of binder applied to the fill strand is dependent upon a combination of factors. It is dependent upon the centrifugal force developed by rotation of the drum, the outlet diameter of the exit tip, the viscosity of the hinder, the immersion depth of the magazine, that is the length of thread that is immersed, and the wettability of the binder. In this last connection wetting agents can be added to increase the wettability. There does not appear to be any real limitation on the rotational speed. With the apparatus shown in FIG. 1 the binder, in effect, is being moved past the fill strand. As a result, there is very little problem of throwing binder off of the fill strand.

When using a binder which is primarily a film former, that is, one that has little initial adhesive properties, it is important to dry the fabric until the cohesive strength of the set up film is greater than adhesion to the belt. This insures that the binder will pull clean from the belt and release medium and will avoid build up of binder on the belt or on the release medium.

With the form of magazine and exit tip shown in FIG. 8 it has been found desirable to use a bar 56, positioned as shown, to help turn the fill strand FS rather than to rely entirely on contact of the fill strand with the edge of the tip.

The present invention provides means for supplying binder to the magazine while the magazines are being rotated about the support. As a result, it is not necessary to shut down to refill the magazines and magazines of smaller capacity and resulting bulk and weight can be used.

FIG. 9 shows one form of apparatus for supplying binder to the magazines while the magazines are being rotated about the support. A pump 57 pumps liquid binder from a reservoir 58 through a pipe 59 and into a trough or channel formed within a ring 64. The ring 64 is mounted for rotation, by means not shown, with the magazines 33, and conduits 62 connect the interior of the ring with the interior of the magazine. The centrifugal force developed by the rotation of the ring 64 keeps the liquid binder in the radially outer portion of the ring and distributes the binder about the circumference. Rotation at speeds as low as 25 to 30 rpm. will throw the binder to the outside of the ring 61.

In some cases it is desirable to provide a continuous circulation of binder in the magazine 33. FIG. 9 shows one form of apparatus that can be used to accomplish such circulation. The magazines 33 are connected by conduits 66 with a second ring 67. The ring 67 is shaped to form a completely enclosed interior except for the open annular area in the surface facing the magazine needed for rotation of the conduit 66 with respect to the ring. A metering orifice may be installed in the conduit 66 to regulate the flow of binder through the conduit and rate at which the binder is circulated through the magazine. The binder, when it enters the ring 67, flows by gravity to the bottom of the ring and is returned to the reservoir 58 by a pipe 68.

FIG. shows another form of ring arrangement for supplying binder to the magazine 33 while the magazine is rotating. In this case, the ring 64 is nestled within the ring 67 and is connected to the magazine by a conduit 62. The binder is again placed in the trough 69 of the ring 64 at the bottom of the ring, in the manner shown in FIG. 9.

The ring 64 in the FIG. 10 form includes an overflow conduit 71, disposed radially inwardly of the conduit 62. When the binder level in the magazine 33 comes up to the conduit 71 flow of binder into the magazine stops, and the excess binder in the ring 64 flows out the conduit 71 and into the return ring 67. The rings 64 and 67 may be made of polypropylene since the binder, even when dry, does not readily adhere to polypropylene.

As noted above, supplying the binder to the magazine while the magazine is rotating makes it feasible to use a relatively small and compact magazine. In accordance with the present invention the magazine 33 may also be made separate from the fill strand supply means 28 (see FIG. 11). As shown in FIG. 11 the magazine 33 may be made from tube stock and fitted with a pair of end caps 71.

The fill strand is led into the magazine through a ceramic eyelet 72 at the liquid center of the magazine, and the warp strand is then passed through the binder B and out through the exit tube 34.

The inlet end of the exit tube 34 extends to the liquid center of the magazine 33 as illustrated in FIG. 11. The level of the liquid binder is maintained below the liquid center so that the binder will be radially beyond the liquid center when the magazine is rotating and will be radially in from the eyelet 72 when the magazine is standing.

Only a portion of the mounting structure for the magazine 33 is illustrated in FIG. 11. The magazine 33 is detachably connected, as by strap, to a plate 73. The plate 73 is connected by means not shown in FIG. 11 to the drum 29. The rotatable ring is also mounted on the plate 73 by a strut 74. This mounting arrangement for the magazine 33 makes it easy to remove and replace the magazine in the event of a malfunction. It also makes it easy to remove the magazine for cleaning, Since the tubular magazines illustrated in FIG. 11 can be relatively small and compact (because of the provision for supplying liquid binder) a substantial number of magazines can be mounted on the plate 73 to make relatively high density and fill strand materials.

FIG. 12 illustrates a preferred orientation of the tubular magazines 33 shown in FIG. 11. The axis of the magazine is angled as illustrated in FIG. 12 so that the magazine and the exit tube extend almost tangential to the circumference of the cylindrical support 27. The inclination of the magazine is just enough below the tangent to produce the desired wiping action of adhesive from the top of the fill strand leaving the tip of the exit tube.

While we have illustrated and described the preferred embodiments of our invention, it is to be understood that these are capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. Apparatus for making nonwoven fabric and comprisa support,

warp strand guide means for guiding a plurality of warp strands continuously in a longitudinal direction over the support,

fill strand means rotatable about the warp strands for engaging a fill strand under tension with the warp strands supported on the support while applying a binder to bond the warp and fill strands together, and

drive means for transporting the warp strands and nonwoven fabric along the support without stressing the fabric, said drive means comprising a drive roller and a conveyor belt interposed between the warp strands and the support and effective to transport the fabric by the friction developed bet-ween the belt and the fabric and the drive roller which engages the belt but does not contact the fabric.

2. Apparatus as defined in claim 1 including a release film between the conveyor belt and the fabric for preventing contact of the binder with the belt.

3. Apparatus as defined in claim 2 wherein the belt is polyester film and the release film is polypropylene film.

4. Apparatus as defined in claim 1 including guide rollers engageable with the belt at an angle and effective to keep the belt tight in a transverse direction.

5. Apparatus as defined in claim 1 including means for injecting pressurized air between the support and the belt to reduce friction between the belt and support.

6. Apparatus as defined in claim 1 wherein the support is a horizontal cylindrical member, the warp strand guide means form the warp strands into a cylindrical bundle about the support, and including shaping means for shaping the belt to a tube about the support with the side edges of the belt on the underside of the support, said shaping means including a member which engages the inside of the top of the tube in front of the support to press that part of the tube radially out and to thereby insure that there are no concavities in the upper surface of the tube.

7. Apparatus for making nonwoven fabric and comprising,

a support,

warp strand guide means for guiding a plurality of warp strands continuously in a longitudinal direction over the support, fill strand means rotatable about the warp strands for engaging a fill strand under tension with the warp strands supported on the support while applying a binder to bond the warp and fill strands together, and

drive means for transporting the warp strands and fabric along the support,

said warp strand guide means including two guide elements arranged in tandem with the second guide element nearest the support slightly laterally offset with respect to the other guide element in a direction opposed to the direction of movement of rotation of the fill strand so that each warp strand is pulled into positive engagement with its associated second guide element by the force exerted by the fill strand at the area of engagement with the warp strand to thereby maintain precise spacing of the warp strands.

8. Apparatus as defined in claim 7 wherein the support is cylindrical and wherein the warp strand guide means form the warp strands into a cylindrical bundle at the outlet of the tandem guide elements and including an acetal molded resin ring between the guide elements and the support for constricting the bundle of warp strands between the guide element and the support.

9. Apparatus for continuously producing nonwoven fabric of indeterminate length comprising, warp strand means for moving a plurality of warp strands in a longitudinal, horizontal direction under a controlled tension, positioning means for positioning the warp strands in a fixed lateral and vertical position, fill strand means rotatable in an annular path about the horizontally moving warp strands for laying a fill strand on the warp strands in a helix during longitudinal movement of the warp strands, a magazine containing a binder mounted on the fill strand means and rotatable with the fill strand means in said annular path about the horizontally moving Warp strands, said magazine having entrance and exit means for introducing the fill strand into the binder in the magazine as the fill strand passes through the magazine, stationary strand support means for supporting the engaged Warp and fill strands and binder supply means for supplying binder to the magazine while the magazine is rotating, said supply means comprising a ring concentric With the axis of rotation of the magazine and formed with radially extending flanges at each end to provide a trough within the ring, means mounting the ring for rotation with the magazine, a conduit connecting the trough in the ring with the magazine, and means for putting binder in the trough While the ring is rotating at a speed fast enough to keep the binder in the trough by centrifugal action.

10. Apparatus as defined in claim 9 including a second stationary ring encircling the rotatable ring and having a trough for receiving excess binder from the rotatable ring.

11. Apparatus as defined in claim 9 wherein the fill strand means include a rotatable drum and a fill strand 10 package supply means mounted on the drum, a carrier for the rotatable ring and supports connecting the carrier to the drum and wherein the magazine is detachably mounted on the carrier without any connection to the fill strand package supply means so that the magazine can be readily removed and replaced 12. Apparatus as defined in claim 9 wherein the Warp strand means include a conveyor belt interposed between the Warp strands and the support and drive means which engage the belt but which do not engage the fabric whereby the fabric is transported along the support by the friction between the belt and the fabric is not stressed by the drive means.

No references cited.

BENJAMIN A. BORCHELT, Primary Examiner T. H. WEBB, Assistant Examiner US. Cl. XR. 156-426, 429, 171

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