US3326711A - Method of and apparatus for preparing napped fabric - Google Patents

Description

June 20, 1967' F. T. SPENCER 3,326,711

METHOD OF AND APPARATUSFOR PREPARING NAPPED FABRIC Filed May 2, 1963 2 Sheets-Sheet l *5 I. a j INVENTOR j $08M??? June 20, 1967 F. T.VSPENCER 3,326,711

METHOD OF AND APPARATUS FOR PREPARING NAPPED FABRIC Filed May 2 1965 2 Sheets-Sheet 2 United States Patent 3,326,711 METHOD OF AND APPARATUS FOR PREPARING NAPPED FABRIC Francis T. Spencer, Biddeford, Maine, assignor to West Point-Pepperell, Inc., a corporation of Georgia Filed May 2, 1963, Ser. No. 277,502 20 Claims. (Cl. 117-66) The present application is a continuation-in-part of the pending application for Letters Patent, Ser. No. 157,487, filed by Francis T. Spencer on Dec. 6, 1961 now patent 3,191,258 and relates to an improvement upon the method and apparatus described in said application.

This invention pertains to the manufacture of napped textile fabric, for example blanket fabric, and more especially to a novel method of and apparatus for use in so treating fabric, previously napped by customary procedure, as to increase its loft and to improve its resistance to shedding.

In accordance with the disclosure of said copending application, soft, drapeable blanket cloth of conventional type is so treated as to make the nap layer substantially shed-proof and in such manner that the nap layer retains substantially the same appearance and has a loft substantially as great as when the cloth was first napped.

In accordance with the present invention, even better results are attainable, particularly with reference to increase in the loft of the nap layer and in the production of a fabric which is even more resistant to shedding, and in fact, for the most part, completely shed-proof.

In the practice of the invention, as disclosed in the above named application, under commercial conditions, it has been usual to fold the material immediately after leaving the tentering frame and while still at an elevated temperature, but apparently, because the fiber-coating material at this temperature had not completely set, the result was that the folds, so formed in the fabric, tended to become permanent, thus detracting from the appearance of the fabric when made up into blankets. The pres ent invention provides a procedure and apparatus whereby the formation of such permanent folds is avoided.

Thus objects of the present invention are to provide a napped fabric having improved characteristics as compared .with those resultant from the practice of the method and the employment of the apparatus disclosed in the above named application, in particular, with reference to increase in loft and retention of nap; and further to provide a procedure whereby, after completion of the nap-proofing operation, the resultant fabric, when folded, does not show permanent fold lines.

-In the attainment of the above objects, the present invention provides for agitating the fibers, which constitute the nap layer or layers, desirably 'by nap-agitating means, for example like that disclosed in the above named application, before the fabric is passed through the wetting zone, and, in passing it through the wetting zone, so directing a fluid spray, containing the coating substance, that it is opposed to the direction of advance of the fabric and enters between the raised nap fibers so as to penetrate to the full depth of the latter, all without subjecting the raised nap to pressure, and thereafter proceeding, as in the aforesaid application, to subject the wetted fabric to a second and similar nap-agitating treatment, followed by heating it to concentrate the liquid, but desirably, before folding the fabric, reducing its temperature, for example, by passing it through a cooled chamber or in heat transfer relation to refrigerating means, whereby it is reduced in temperature so that it is no longer sticky or plastic. Thus, when the fabric is folded, it has no tendency to form permanent folds.

Apparatus useful in carrying out the above procedure is illustrated, by way of example, in the annexed drawings and will be described in greater detail in the following description.

In the drawings:

FIG. 1 is a diagrammatic elevation, partly in vertical section, illustrative of apparatus according to the present invention;

FIG. 2 is a fragmentary plan view of the nap-treating part of the apparatus of FIG. 1;

' FIG. 3 is a fragmentary vertical section, to larger scale, on either of the lines 33 of FIG. 2;

FIG. 4 is a fragmentary diagrammatic end elevation, partly in vertical section, to larger scale, illustrating a set of nap-treating rolls of a desirable type;

FIG. 5 is a fragmentary radial section through one of the nap-treating rolls of FIG. 4, to larger scale, illustrating the preferred form of fiber-lifting pin;

FIG. 5a is a diagrammatic section through a piece of napped fabric of conventional type;

FIG. 6 is a diagrammatic section illustrative, by contrast, of the depth of nap resultant from the method of the present application as compared with that produced by the apparatus of the above pending application;

FIG. 7 is a fragmentary diagrammatic edge view of a piece of napped fabric such as produced by the apparatus of the above named pending application, if folded While it is still hot from the heat-treating apparatus; and

FIG. 8 is a similar view showing the results of cooling the material prior to folding, in accordance with the present invention.

Referring to the drawings, the numeral 10 (FIGS. 1 and 2) designates the frame or casing of the apparatus, this casing comprising vertical side walls 10a and 1017 (FIG. 2) spaced apart a distance exceeding the width of the fabric F to be treated, and which support bearings for transversely extending shafts 14, 15, 14a and 15a.

The bearings for the shafts 14 and 15, which are located near the left-hand end of the frame, as viewed in FIG. 4, are vertically adjustable in guideways 16 and 17 (FIG. 1), carried by the side walls 10a and 10b of the frame or casing. Adjusting screws 18 and 19 are provided whereby these bearings may be moved up and down relatively to the casing or frame. As illustrated in FIGS. 2 and 3, each of the shafts 14 and 15 has fixed thereto, near one end, a drum 21 and 22 respectively, designed for engagement by means operative to oppose the free rotation of these shafts. As here shown, a belt B (FIG. 3) is fixed at one end to a bracket 23 (FIGS. 2 and 3), carried by the frame, and passes beneath the drum 21 and over the drum 22, and with its free end connected to a weight W In the same way, a similar belt B is anchored at one end, 24, to the frame and passes beneath the drum 22 and then over the drum 21, and is provided at its free end with a weight W These belts or brake-bands B or B may be of leather, or other suitable material and, by their frictional engagement with the drums 21 and 22, prevent these drums from turning freely.

Shafts 14a and 15a are located near the right-hand end of the frame, as viewed in FIG. 1, and carry drums 21a and 22a (similar to the drums 20 and 21 respectively), whose free rotation is resisted by friction brake-bands or belts B and B like those above-described. Other means for opposing free rotation of the shafts 14, 15, 14a and 1511 might be substituted, for example electromagnetic force.

The fabric F (FIG. 1), which is to be treated, is received from a suitable source (not shown), it being understood that this fabric, which may, for example, be a blanket fabric having a body portion of customary weave structure, has been napped according to any usual or conventional method and by the use of any desired type of napping machine. The dry and freshly napped fabric first passes beneath a nap-treating roll R (FIG. 2), fixed to the shaft 14a, and then over a similar nap-treating roll R (FIG. 2) fixed to the shaft 1512. From the roll R the fabric advances, free from contact with any part of the apparatus, until it reaches the nap-treating roll R fixed to the .shaft 14, beneath which the fabric passes, then passing over and in contact with the fabric-treating roll R After leaving the roll R the fabric enters a tentering frame T, which may be of any conventional type, comprising, as usual, endless chains C and C which are so guided as to provide parallel, horizontal runs, and which are provided with pins, hooks or the equivalent which engage the selvage edges of the fabric F, and which are so arranged as to tension the fabric transversely while drawing it along from the source of supply, the pull exerted by these chains being the only force requisite for advancing the fabric and for rotating the treating rolls R R R and R It may be noted that after leaving the roll R the fabric, except for its margins, does not contact any mechanical part until it leaves the tentering frame. By adjustment of the bearings for rolls R R R and R the pressure of the treating rolls against the moving fabric may be varied. A casing or oven K (FIG. 1) houses the tentering frame and, within this casing, there is provided means (not here shown) for subjecting the moving fabric to heat. This may be sup-plied by coils through which a heating medium circulates, or by infrared lamps or the like, the particular mode of applying heat forming no part of the present invention. As the fabric leaves the oven K, its surface temperature is of the order of 285 F. (plus or minus two or three degrees).

In accordance with a preferred procedure, the fabric F, after leaving the tentering frame T, will continue to advance without interruption while its temperature is reduced at least as low as 200 F., desirably hastening the cooling by directing fine sprays of water against its opposite faces. While the cloth may be supported, while cooling, upon a long travelling slat apron or the like, it is preferred, in order to avoid crushing the nap, to support it by its edges only, for instance, by means of tenters T T T or the like, which may, for example, comprise continuations of the chains of the tenter frame T. The cooled cloth is delivered to customary folding mechanism (not shown, but whose position is generally designated by the character D), which delivers it in folds onto a truck or into a suitable container. While air cooling at ambient temperature, with or without water spraying, is acceptable, the cooling may be hastened, thus minimizing the dimensions of the requisite apparatus, by subjecting the cloth to artificial refrigeration as by passing it through a chamber in close proximity to cooling coils. Such an arrangement is diagrammatically suggested in FIG. 1, where the cloth F, after leaving the delivery end of the tenter frame T, is caused to pass through a cooling chamber M in a plurality of hoirzontal runs X, Y and Z, respectively, while supported at its opposite edges by tenter chains or the like (not shown). In this arrangement, the uppermost run X of the fabric is sprayed with cool water by the atomizing nozzles N. Since the cloth is advanced by the tenter chains, the nap is not crushed, the guide rolls G being merely required to change the direction of the cloth so that, in passing over these guide rolls, it is subjected to but little pressure. Between the runs Y and Z, refrigerating coils E are arranged, and the lengths of the runs X, Y and Z are such that, by the time the fabric reaches the folding device D, the fiber-coating material has cooled and set and is no longer sticky nor plastic, so that, when the fabric is deposited in folds, as in a suitable receptacle A, it shows little if any tendency to retain the folds so formed.

Each of the rolls R R R and R comprises a cylindrical core which is covered with a layer of fabric L (FIGS. 4 and 5), having teeth or pins P projecting therefrom. This fabric, with its teeth or pins may, for example, be generally similar to conventional napper roll cloth.

As here shown (FIG. 5), the cloth L has pins P provided with bends whose included angle is approximately However, it is contemplated that teeth or pins of other types may be found useful. Desirably, the pins P are of such length that they penetrate approximately to the full depth of the nap layer. The shafts 14, 15 and 14a and 15a turn in their bearings simply in response to the pull exerted by the advancing fabric and, except as their rotation is retarded by the friction of belts B and B As shown in FIGS. 1 and 4, the freshly napped fabric F passes beneath the treating roll R and over the treating roll R then beneath treating roll R and over treating roll R and from the latter enters between the chains C and C of the tentering frame, where its margins are engaged by the pins of the tentering chains, which draw the fabric along in spite of the frictional drag imposed by the belts B and B As the fabric passes from the treating roll R to the treating roll R its upper and lower surfaces are sprayed with the selected treating material delivered by banks of spray heads S. Thus, both surfaces of the napped fabric are wetted with the treating material, it being assumed that the fabric is napped on both sides. If the fabric were napped upon one side only, then the supply of treating material would be cut off from the spray heads which are located at the unnapped side of the fabric.

As shown in FIG. 1, that surface of the fabric P which is treated by the roll R does not contact the roll R so that the latter does not flatten the nap raised by the roll R The nap which was first raised by roll R is again treated by roll R which tends still further to lift the nap, but nothing except the teeth of the rolls contacs this napped surface until after the nap treatment has been concluded since, in passing through the tentering frame, only the marginal edges are contacted by any part of the apparatus. In the same way, that surface of the fabric which is first treated by the roll R does not contact the roll R but is again treated by the roll R which further raises the nap on the last-named surface.

As shown in FIG. 1, the spray nozzles S are directed toward the oncoming fabric and since the treating rolls R and R tend to leave the nap fibers slightly inclined in the forward direction, the spray, directed by the nozzles, readily enters between the nap fibers.

Referring to FIG. 5a, the body of a piece of conventionally napped fabric is diagrammatically indicated at F, and nap fibers Na and Nb are shOWn as projecting from its opposite faces. It has been found experimentally that liquid treating material delivered by spray heads into contact with nap such as is produced by the customary napping apparatus does not ordinarily penetrate very deeply into the nap since, in such napped material, the nap fibers are not by any means straight or parallel and are very closely crowded together, and as the fabric travels along, the spray fails to open up the nap sulficiently for the liquid to penetrate to the roots of the nap fibers.

In accordance with the teaching of the above named pending application, the wet material, after having been sprayed, is treated by toothed rolls R and R such as hereinabove described. By this treatment the nap is opened up and the fibers agitated by the entrance and exit of the teeth or pins P as the fabric approaches and recedes from the rolls and, because of such agitation, the liquid is caused to penetrate the fibers so that the nap is wetted deeply. As the pins recede from the fabric, they tend, by capillary action, or because of some degree of adhesiveness of the treating material, to pull the nap fibers outwardly with them, with the result that, when the fabric leaves the toothed roll, the nap fibers are straighter and more nearly perpendicular to the face of the base fabric, so that, in spite of the force with which the treating material is sprayed onto the napped surface, the fabric leaves the toothed rolls with the nap almost as lofty as when it left the napping machine.

As the result of further experiment, it has been discovered that substantially improved results are attained by the employment of apparatus such as herein disclosed, wherein, before the napped fabric is subjected to the action of the spray nozzles, it is exposed, while dry, to the action of rolls R and R which are substantially like the rolls R and R and which have the effect of opening up the nap and of causing the nap fibers to become straighter and more nearly perpendicular to the face of the body material. Thus, in accordance with the present invention, before the fabric reaches the spray nozzles, the nap fibers have already become predominantly straight and upright so that the droplets of spray easily enter between these fibers and penetrate substantially to the roots of the fibers. Then when the fabric is again treated by the rolls R and R the nap is more thoroughly wetted and its fibers are straighter than though the fibers had not been subjected to the previous treatment. The result is that nearly every individual fiber is coated with the treating material from its tip substantially to its junction with the body fabric but without so wetting the body fabric as to cause the latter to be stiffened or to become impervious as would be the result if the fabric were passed through a bath of the treating material. The thoroughly saturated nap (its individual fibers now being coated with the treating material) passes into the tentering frame without having exposed the wetted and lifted napped fibers to pressure at any point, since the chains of the tentering frame engage the fabric at its margins only. As the material passes through the baking chamber K, it is exposed to a temperature such as to evaporate the liquid carrier for the chemical with which the nap is being treated. Desirably, the temperature in the heating chamber should be approximately 300 F. so that the maximum surface temperature of the fabric as it leaves the chamber would be about 285 F. Among the treating materials,

suitable for the purpose of shed-proofing, may be mentioned the thermosetting acrylic polymer known to the trade as Rhoplex K-3 which is made by the firm of Rohm & Haas of Philadelphia, Pa.-this being an aqueous dispersion of acrylic polymers which, when deposited from dispersion in water and heated to a temperature of the order of 285 F., forms a transparent film which is initally sticky and which eventually sets and is no longer sticky. Other useful treating materials appropriate for the purpose are mentioned in Patent No. 3,191,258, above referred to, which issued upon an application of which the present application is a continuation-in-part. It is recommended that, in the practice of the present invention by the apparatus herein disclosed, this dispersion should contain from approximately 5% to 15% (preferably of the chemical and approximately 90% of water. When applied in this dilution and at room temperature the chemical is not appreciably sticky, so that it flows freely. Desirably, the liquid dispersion is applied to the fabric within the range of from 10% to by weight of liquid to cloth. As the water evaporates during the passage of the material through the baking chamber K, the chemical concentrates and gradually forms a sticky coating on the napped fibers, so that adjacent fibers, where they contact, adhere to each other, and then the coating sets to form a permanent bond between the fibers.

The result of the treatment is to produce a lofty nap, substantially 10% deeper than results from the procedure and apparatus described in the aforesaid Spencer applica tion (now Patent No. 3,191,258), and which is almost completely shed-proof.

Desirably, means is provided for removing loose fibers from the treating rolls R and R Thus, for example, as illustrated in FIG. 1, a vacuum nozzle V is associated with each respective roll and connected to a suitable pump (not shown) so as to suck up and carry away loose fibers.

While two rolls, in each set, like the rolls R and R appear to be entirely satisfactory for the purpose of obtaining the desired results, it is contemplated that a larger number of such rolls may be employed, for example, several upper rolls which alternate with lower rolls, thus causing the fabric to follow a sinuous course such that it is first bent in one direction and then in the other, which helps to distribute the liquid among the nap fibers. It is further contemplated that if the fabric be napped upon one side only, one of the treating rolls of a pair may be omitted, although, in the latter case, it may be desirable to provide guide rolls, so arranged as to insure the contact of the fabric with the pins of the treating roll through an arc of substantial extent. In the arrangement here shown the arc is of the order of Treating rolls of the order of four inches in extreme outside diameter, that is to say, the diameter measured from the tips of the pins at diametrically opposite points, have been found useful for the purpose, although it is contemplated that rolls of other size may be used. It may be noted that the tips of the pins are so arranged that their points are directed toward the oncoming fabric, so that, as the advancing fabric turns the rolls against the braking force imposed by the belts B and B the pins are caused to enter deeply into the nap of the oncoming fabric. As the rolls turn, the angle of the pins changes in relation to the plane of the cloth and, as they recede from the fabric, they tend to lift the nap fibers up with them thereby straightening the fibers and leaving them more nearly perpendicular to the body of the fabric, resulting in a smooth and even surface. Not only does the practice of the present invention produce blanket cloth which is even more shedproof than that resultant from the practice of the method of the above named, application (in fact, in many instances having been found to be completely shed-proof), it has the further advantage of providing increased depth of nap, for example a 10% increase as compared with that according to the process of the said pending application. This is illustrated diagrammatically in FIG. 6, where the nap fibers N represent those produced according to the present method, wherein those indicated at N illustrate the comparative depth of the nap fibers resultant from the process of said above application.

If fabric, after having been treated as in the above named application or as herein described, is folded immediately after leaving the tentering frame T and while hot, it tends to form permanent folds or undulations as illustrated at U (FIG. 7). However, by cooling the fabric before folding, such permanent folds are not produced. While it would be possible, by exposing the fabric to ambient temperature for a sufficiently long time, to prevent the formation of such permanent folds, the exigencies of commercial production makes it desirable artifically to cool the material before folding and, as here suggested,

this may be done by passing the hot material, as it leaves a the tentering frame and without interrupting its advance, in long runs through an artificially cooled chamber wherein the temperature is so low that before the material reaches the folding apparatus, the coating material will have set and lost its tackiness and plasticity. Material so treated, when unfolded, is devoid of any permanent folds or undulations as illustrated, for example, in FIG. 8.

While one desirable embodiment of the invention has herein been disclosed by way of example, it is to be understood that the invention is broadly inclusive of any and all modifications falling within the scope of the appended claims.

I claim:

1. That method of preparing a shed-proof blanket cloth which is soft and drapeable and which comprises a body portion of woven fabric having a layer of nap fibers projecting from one side, at least, of the body fabric and which is substantially the same with respect to appearance, feel and color as when freshly napped, and wherein the nap-forming fibers have the same chemical character istics which they had in the fabric as woven, said method comprising as steps: providing conventional blanket cloth having a layer of nap at one side, at least, such as results from the action of a conventional napping machine and whose constituent fibers slope predominantly in one direction; so mechanically working the nap, while dry, as to open the layer and dispose the individual fibers more nearly perpendicular to the body fabric thereby to facilitate the penetration of fluid deeply into the fiock layer; providing an initially non-sticky bonding liquid of a kind which, when deposited upon the nap fibers and heated to a temperature of the order of 285 F., first forms a transparent film and then sets and is no longer sticky; directing a spray of said non-sticky coating liquid toward the free ends of the fibers of the dry, opened nap thereby to wet indivdiual fibers but without substantially wetting the body fabric, then further mechanically working the fibers, which have been wetted by the spray, thereby to insure penetration of the spray liquid substantially to the full depth of the nap layer while concomitantly applying pull to the fibers such as to dispose them predominantly perpendicular to the body fabric; and then, with out substantially disturbing the fibers, so treating the fabric as to cause the coating material first to become sticky so that adjacent fibers adhere and then to set so as permanently to bond adjacent fibers.

2. The method according to claim 1, further characterized in that, after the second mechanical working of the nap fibers, the fabric is heated until its surface temperature is approximately 285 F. while held under transverse tension until the coating medium has set.

3. The method according to claim 1, wherein, after the coating material has set and before folding the material, the material is cooled until its surface temperature is at least as low as 200 F.,' thereby to eliminate stickiness and plasticity of the material so as to avoid the formation of permanent folds.

4. The method according to claim 1, wherein the nap fibers are predominantly cellulosic, further characterized in that the coating liquid, with which the fibers are wet, is a dilute non-sticky aqueous dispersion of thermosetting acrylic polymer.

5. The method according to claim 4, wherein the acrylic polymer is dispersed in water in the proportion of approximately 10% of the polymer and 90% water.

6. That method of making a conventional napped woven blanket fabric shed-proof which comprises as steps: drawing blanket cloth, freshly napped and while dry, over a toothed rotatable roll thereby turning the roll, and frictionally resisting rotation of the roll thereby causing the teeth of the roll to open the nap and dispose its constituent fibers more nearly at right angles to the body of the cloth; providing an initially non-sticky, water dispersion of a fiber-coating material which, when deposited upon the nap fibers and heated to a temperature of the order of 285 F. first forms a transparent film and then sets and is no longer sticky; directing a spray of said coating material against the open nap thereby wetting the nap layer substantially to its junction with the woven base fabric; drawing the wetted material over a second toothed rotatable roll thereby turning the roll, and so resisting rotation of the roll frictionally that the peripheral speed of the roll is less than the speed of advance of the fabric, thereby causing the teeth of the roll, after entering the nap, to emerge from the latter while lifting the wet nap fibers and concomitantly dispersing the coating material throughout the full thickness of the nap layer but without substantially wetting the woven base fabric; and then, while avoiding the application of pressure to the napped fibers such as would compress them, subjecting the fabric to heat thereby to drive off the liquid carrier and cause the coating material to form a permanent adhesive bond between adjacent fibers.

7. The method according to claim 6, further characterized in providing toothed rolls for working the nap whose teeth are so bent that their tip portions are non-radial with reference to the axis of the roll and wherein the fabric is moved in a direction such, relatively to the rolls,

'8 that the tips of the teeth are opposed to the oncoming fabric whereby the teeth, in emerging from the nap layer, exert a lifting force tending to pull the nap fibers away from the body fabric.

8. The method according to claim 6, wherein, after the coating material has been set by the application of heat, the fabric is advanced through a cool chamber where its temperature is rapidly reduced at least as low as 200 F., and thereafter disposing the fabric in folds.

9. The method according to claim 6, wherein, for setting the coating material, the fabric is heated to have a maximum surface temperature of the order of approximately 285 F.

10. The method according to claim 6, wherein, while the fabric is constantly advanced without interruption, during and following the heat treatment, it is delivered in folds into a suitable receptacle, but, before folding, is cooled to a temperature at least as low as 200 F. thereby preventing the formation of permanent folds.

11. Apparatus for use in the practice of the method of claim 1, comprising, in combination with a tentering frame having elements operative, by engagement with the opposite margins of the fabric to be treated, to hold the latter under transverse tension while exerting pull for traversing the fabric throughout a heating zone and for drawing it off under longitudinal tension from a source of supply, a pair of treating rolls which contact opposite faces, respectively, of the fabric, each of said rolls having a covering of material generally like conventional napper cloth, with the tips of its pins directed toward the oncoming fabric, the pull exerted by said tenter frame elements being the only force for rotating the treating rolls, means for retarding the rotation of each treating roll whereby its surface speed does not exceed the linear speed of the advancing fabric so that its pins enter into the dry nap layer and, in emerging therefrom, tend to dispose the constituent nap fibers more nearly perpendicular to the body of the fabric, means operative to direct sprays of coating material, in liquid form, against the napped surface of the fabric after the latter leaves said treating rolls, a second pair of treating rolls so arranged as to contact the opposite faces, respectively, of the fabric after it has been wetted by the sprayed-on liquid and before it reaches the tentering frame, each of said latter rolls having a covering of 1 material generally similar to conventional napper cloth,

with the tips of its pins directed toward the oncoming fabric, means for retarding the rotation of ,each of said latter treating rolls whereby the surface speed of the roll does not exceed the linear speed of the advancing fabric so that its pins enter into the nap layer and thereby induce deep penetration of the sprayed-on liquid into the nap layer and, in leaving the nap layer, draw the nap fibers upwardly until they are substantially perpendicular to the body of the fabric, and means in association with the tentering frame operative to apply heat to the fabric as the latter is moved along through the tentering frame.

12. Apparatus according to claim 11, wherein the rolls which open the nap layer while the latter is dry and the rolls which disperse the coating liquid throughout the thickness of the wetted nap layer are turned only by engagement of the teeth of the rolls with the advancing fabric, and friction brake means operative to retard free rotation of said rolls.

13. Apparatus according to claim 11, wherein the rolls which open the dry nap layer and the rolls which disperse the liquid throughout the nap layer of the wetted fabric respectively, are so relatively arranged that the fabric extends in an unsupported run from the set of rolls which treats the dry fabric to the set of rolls which treats the wet fabric thereby to avoid compression of the nap layer after it has been treated by the first set of rolls, the second set of rolls being so arranged relatively to the tentering frame that, after being treated by the second set of rolls, the nap fibers are not subjected to compressive stress on their way to the tentering frame.

14. Apparatus according to claim 11, wherein the means for applying the liquid to the nap layer comprises spray nozzles supplied with liquid under pressure and arranged in a row extending widthwise of the fabric and so disposed as forcibly to direct the liquid as a spray toward the advancing ends of the constituent dry fibers composing the opened nap layer.

15. Apparatus acocrding to claim 12, wherein the means for opening the dry layer of nap comprises a toothed roll extending transversely of the run of fabric, said roll being so located relatively to the nap layer and having teeth of such length and contour that, as the dry fabric advances relatively to the roll, the tips of the teeth penetrate said nap layer substatnially to its full depth and then, in retreating, tend to straighten the nap fibers and dispose them in major proportion substantially at right angle to the body fabric.

16. Apparatus for use in preparing a soft, drapeable, shed-proof blanket cloth of the kind wherein a woven body fabric has a layer, coextensive with the body fabric, composed of nap fibers projecting from the body fabric at one side, at least, of the latter, and wherein the body fabric retains substantially the same characteristics as when newly woven, and wherein the nap layer is substantially the same, as respects appearance and feel, as when freshly napped, said apparatus comprising means for supporting the previously napped and dry fabric to form a run wherein its nap layer is exposed, means operative, as the fabric is advanced, to open the nap layer and dispose the constituent nap fibers more nearly parallel to each other and more nearly perpendicular to the body fabric, means for forcibly delivering a spray of an initially non-sticky fiher-coating liquid toward the tips of fibers constituting the opened nap layer whereby the nap layer is wetted to a substantial fraction of its depth, means for advancing the fabric with its incompletely wetted layer of nap exposed, and means operative, as the fabric is advanced, to cause the liquid previously applied as a spray to be dispersed throughout the entire thickness of the nap layer while lifting the constituent nap fibers so that they are predominantly perpendicular to the body fabric, and means for heating the fabric thereby to concentrate and set the coating liquid.

17. Apparatus according to claim 16, comprising means operative artificially to cool the treated fabric after leaving the tentering frame and while it is on its way to folding mechanism.

18. That method of making shed-proof blanket cloth which is soft and drapeable and which comprises a body portion of woven fabric having a layer of nap fibers projecting from one side, at least, of the body fabric, the nap fibers being predominantly cellulosic, said blanket cloth being substantially the same, with respect to appearance, feel, color and loft, and with the nap fibers as predominantly upstanding as when the cloth was freshly mapped, the nap-forming fibers having the same chemical characteristics which they had in the fabric as woven, the individual fibers comprised in said nap layer being coated with a material which provides a permanent bond whereby adjacent nap fibers are permanently united so as substantially to prevent the shedding of the nap fibers during use of the blanket cloth while the body fabric is substantially free from said coating material, said method comprising as steps: applying force for advancing a conventional woven fabric having a previously formed layer of nap fibers, predominantly cellulosic, at one side, at least, of the body fabric, providing an initially non-sticky liquid comprising a resinous bonding material of a character such as to form a coating for the nap fibers but which does not modify the chemical or physical characteristics of the fibers, and, while retaining, substantially unimpaired, the initial permeability of the woven body fabric, wetting the dry nap-forming fibers of the advancing fabric with said non-sticky liquid, but without substantially wetting the body of the fabric with said liquid; introducing mechanical fiber-erecting elements into the layer of nap fibers while they are wet with the non-sticky liquid; so actuating said erecting elements by the fabric-advancing force as to urge the individual fibers toward perpendicularity with reference to the body of the fabric; and so treating the fabric, without substantially disturbing the erected fibers, as to concentrate the bonding material and cause it first to become sticky and then to set and permanently bond adjacent fibers together, further characterized in so mechanically working the nap, prior to the application of the liquid bonding material and while still dry, as to open the nap layer and straighten out and arrange the individual fibers so that they are disposed nearly at right angles to the body of the fabric, and, in applying the coating material, directing a spray of the coating material toward the free ends of the fibers of the opened nap thereby to Wet individual fibers substantially to their junctions with the woven body fabric.

19. The method according to claim 18 wherein, for causing the coating material to set, the fabric is heated to a temperature of approximately 280 F. and wherein, after the coating material has set and before folding the treated material, the fabric is cooled until its surface temperature is at least as low as 200 F. thereby to eliminate stickiness and elasticity of the material and so avoid the formation of permanent folds when the fabric is folded.

20. The method according to claim 18 further characterized in that for mechanically working the nap while dry the dried nap material is drawn over a toothed rotatable roll whose motion is resisted frictionally so that its peripheral velocity is less than the velocity of the advancing fabric so as to cause the teeth of the roll to open the nap and dispose its fibers nearly at right angles to the body of the cloth.

References Cited UNITED STATES PATENTS 1,311,862 7/1919 Adams 117-11 3,037,262 6/1962 Spencer 117-66 X 3,068,836 12/1962 Spencer 11834 3,191,258 6/1965 Spencer 1177 X 3,236,586 2/1966 Humphreys.

ALFRED L. LEAVITT, Primary Examiner. E. B. LIPSCOMB III, Assistant Examiner.

Claims (2)

1. THAT METHOD OF PREPARING A SHED-PROOF BLANKET CLOTH WHICH IS SOFT AND DRAPEABLE AND WHICH COMPRISES A BODY PORTION OF WOVEN FABRIC HAVING A LAYER OF NAP FIBERS PROJECTING FROM ONE SIDE, AT LEAST, OF THE BODY FABRIC AND WHICH IS SUBSTANTIALLY THE SAME WITH RESPECT TO APPEARANCE, FEEL AND COLOR AS WHEN FRESHLY NAPPED, AND WHEREIN THE NAP-FORMING FIBERS HAVE THE SAME CHEMICAL CHARACTERISTICS WHICH THEY HAD IN THE FABRIC AS WOVEN, SAID METHOD COMPRISING AS STEPS: PROVIDING CONVENTIONAL BLANKET CLOTH HAVING A LAYER OF NAP AT ONE SIDE, AT LEAST, SUCH AS RESULTS FROM THE ACTION OF A CONVENTIONAL NAPPING MACHINE AND WHOSE CONSTITUENT FIBERS SLOPE PREDOMINANTLY IN ONE DIRECTION; SO MECHANICALLY WORKING THE NAP, WHILE DRY, AS TO OPEH THE LAYER AND DISPOSE THE INDIVIDUAL FIBERS MORE NEARLY PERPENDICULAR TO THE BODY FABRIC THEREBY TO FACILITATE THE PENETRATION OF FLUID DEEPLY INTO THE FLOCK LAYER; PROVIDING AN INITIALLY NON-STICKY BONDING LIQUID OF A KIND WHICH, WHEN DEPOSITED UPON THE NAP FIBERS AND HEATED TO A TEMPERATURE OF THE ORDER OF 285*F., FIRST FORMS A TRANSPARENT FILM AND THEN SETS AND IS NO LONGER STICKY; DIRECTING A SPRAY OF SAID NON-STICKY COATING LIQUID TOWARD THE FREE ENDS OF THE FIBERS OF THE DRY, OPENED NAP THEREBY TO WET INDIVIDUAL FIBERS BUT WITHOUT SUBSTANTIALLY WETTING THE BODY FABRIC, THEN FURTHER MECHANICALLY WORKING THE FIBERS, WHICH HAVE BEEN WETTED BY THE SPRAY, THEREBY TO INSURE PENETRATION OF THE SPRAY LIQUID SUBSTANTIALLY TO THE FULL DEPTH OF THE NAP LAYER WHILE CONCOMITANTLY APPLYING PULL TO THE FIBERS SUCH AS TO DISPOSE THEM PREDOMINANTLY PERPENDICULAR TO THE BODY FABRIC; AND THEN, WITHOUT SUBSTANTIALLY DISTURBING THE FIBERS, SO TREATING THE FABRIC AS TO CAUSE THE COATING MATERIAL FIRST TO BECOME STICKY SO THAT ADJACENT FIBERS ADHERE AND THEN TO SET SO AS PERMANENTLY TO BOND ADJACENT FIBERS.

11. APPARATUS FOR USE IN THE PRACTICE OF THE METHOD OF CLAIM 1, COMPRISING, IN COMBINATION WITH A TENTERING FRAME HAVING ELEMENTS OPERATIVE, BY ENGAGEMENT WITH THE OPPOSITE MARGINS OF THE FABRIC TO BE TREATED, TO HOLD THE LATTER UNDER TRANSVERSE TENSION WHILE EXERTING PULL FOR TRAVERSING THE FABRIC THROUGHOUT A HEATING ZONE AND FOR DRAWING IT OFF UNDER LONGITUDINAL TENSION FROM A SOURCE OF SUPPLY, A PAIR OF TREATING ROLLS WHICH CONTACT OPPOSITE FACES, RESPECTIVELY, OF THE FABRIC, EACH OF SAID ROLLS HAVING A COVERING OF MATERIAL GENERALLY LIKE CONVENTIONAL NAPPER CLOTH, WITH THE TIPS OF ITS PINS DIRECTED TOWARD THE ONCOMING FABRIC, THE PULL EXERTED BY SAID TENTER FRAME ELEMENTS BEING THE ONLY FORCE FOR ROTATING THE TREATING ROLLS, MEANS FOR RETARDING THE ROTATION OF EACH TREATING ROLL WHEREBY ITS SURFACE SPEED DOES NOT EXCEED THE LINEAR SPEED OF THE ADVANCING FABRIC SO THAT ITS PINS ENTER INTO THE DRY NAP LAYER AND, IN EMERGING THEREFROM, TEND TO DISPOSE THE CONSTITUENT NAP FIBERS MORE NEARLY PERPENDICULAR TO THE BODY OF THE FABRIC, MEANS OPERATIVE TO DIRECT SPRAYS OF COATING MATERIAL, IN LIQUID FORM, AGAINST THE NAPPED SURFACE OF THE FABRIC AFTER THE LATTER LEAVES SAID TREATING ROLLS, A SECOND PAIR OF TREATING ROLLS SO ARRANGED AS TO CONTACT THE OPPOSITE FACES, RESPECTIVELY, OF THE FABRIC AFTER IT HAS BEEN WETTED BY THE SPRAYED-ON LIQUID AND BEFORE IT REACHES THE TENTERING FRAME, EACH OF SAID LATTER ROLLS HAVING A COVERING OF MATERIAL GENERALLY SIMILAR TO CONVENTIONAL NAPPER CLOTH, WITH THE TIPS OF ITS PINS DIRECTED TOWARD THE ONCOMING FABRIC, MEANS FOR RETARDING THE ROTATION OF EACH OF SAID LATTER TREATING ROLLS WHEREBY THE SURFACE SPEED OF THE ROLL DOES NOT EXCEED THE LINEAR SPEED OF THE ADVANCING FABRIC SO THAT ITS PINS ENTER INTO THE NAP LAYER AND THEREBY INDUCE DEEP PENETRATION OF THE SPRAYED-ON LIQUID INTO THE NAP LAYER AND, IN LEAVING THE NAP LAYER, DRAW THE NAP FIBERS UPWARDLY UNTIL THEY ARE SUBSTANTIALLY PERPENDICULAR TO THE BODY OF THE FABRIC, AND MEANS IN ASSOCIATION WITH THE TENTERING FRAME OPERATIVE TO APPLY HEAT TO THE FABRIC AS THE LATTER IS MOVED ALONG THROUGH THE TENTERING FRAME.

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