NO124605B - - Google Patents

Description

that different groups of filaments are grasped, respectively released, and that the filaments are fixed in their displaced positions by the application of heat and/or by the use of a binder.

In French patent document 1,317,477 and in Canadian patent document 674,101, a method is described for the production of a fuse of frilly filaments, which is particularly intended for the production of cigarette filter pieces, but which can also be used for the production of a so-called non-woven cloth mat in the form of a thin web of ruffled filaments in which the adjacent filament ruffles collide in such a way as to ensure that the web hangs together.

The known method consists in starting from a skein of crimped plastic filaments and arranging this in the form of a band and then subjecting the band to a longitudinal alternating displacement of. the ripples. This longitudinal displacement of the filaments, which is carried out by means of helical felt-coated rollers, can be combined with a displacement of one half of the fuse in the direction of one end of the roller and displacement of the other half in the direction of the other end.

US patent 2,908,045 relates to processing a flat fuse that is pulled from a bale. This treatment should eliminate any incorrect twisting of the fuse and straighten the curved edges by an even application of a softener or binder to all the filaments in the fuse. The transformation of the fuse into ribbon, which is carried out with the help of an air current, can be followed by a spreading of the fuse in the lateral direction, but this patent document does not indicate a method with the aim of producing an alternating displacement of the individual filament corrugations.

According to Belgian patent document 623,040, it is proposed to provide a cloth formed from non-woven, dispersed threads,

which are bonded together and exhibit uniform thickness, by allowing a bundle of threads to pass through an opening zone, the threads being held tight enough to prevent the filaments from mixing, by spreading the individual filaments in the threads in this zone electrostatically, while the filaments in the bundle which leaving the opening zone are kept firmly spaced from each other by applying a binder composition to

the uniformly spaced filament bundles and by providing curing of the binder.

Since the filaments leaving the opening zone are held apart, it is clear that the resulting bundle does not have the same cohesion in the lateral direction prior to the application of the binder.

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The purpose of the present invention is to produce a method where the transparent and porous tape has a cohesion before the application of heat and/or the application of the binder which is better than the cohesion in known products with the same weight per surface unit, and which is sufficient for processing

of the tape, while this is particularly thin and light.

The invention is characterized by the fact that the opened fuse is spread out to increase the width by using means which cause a force evenly distributed over the entire width of the fuse which seeks to separate the individual filaments from each other, without canceling the entanglement or overlapping of the filaments' ripples.

The combination of the opening of the cup arcs and the subsequent spreading of the opened fuse produces a light, transparent tape that has substantial cohesion due to the displacement of the individual filament cup arcs, but is also bulky and light, so that it is suitable for manufacturing of bulky, light products, such as cushion materials.

This process of displacing the mug arcs is carried out by means of a plurality of pairs of rollers, one roller in each pair having a smooth surface while the other is provided with grooves over its entire circumference, the alternating grooves and ridges running obliquely or helically in opposite directions from the center towards mutually opposite ends of the roller, When the fuse passes between

the two rolls in each given pair, some of the filaments are gripped between the tops of the ridges on the grooved roll and the outer circumferential surface of the opposite smooth roll, while other filaments which at that time lie flush with the spaces between the ridges on the grooved roll roller is not caught between this and the smooth roller. Generally speaking, only one roller in each pair is driven positively, while the other is pressed springily against it and set into rotation by the fuse passing between the rollers.

The opened fuse is then subjected to a spread which transforms the fuse into a continuous band of greater width and with remarkable smoothness. density. Preferably, the opened fuse is spread out to from 1.5 to 6 or more times its original width. The manufactured tape can be of a width of 2 meters or more, but for most purposes a width of up to 1 meter is sufficient.

The spreading operation is preferably carried out by passing the opened fuse through an air spreader in which the flat fuse is passed through a passage of low height while streams of air or other suitable gas are directed at the fuse across its entire width and escape through the inlet and outlet of the fuse. In this way it is possible to spread the fuse easily and very evenly in large widths to produce tapes of particular voluminousness, for example tapes containing less than 240, for example 40, filaments per centimeter of width, and where its average cavity per filament is significantly larger than the diameter of the filaments.

The spreading operation can also be achieved with a device comprising at least one and preferably a plurality of curved rods which extend across the direction of movement of the opened fuse, and are arranged so that the fuse can be stretched over them under relatively low tension. This stretch causes pressure to be exerted against the flat web of the fuse as it is pressed into a curved shape by the curved rods, so that the filaments are spread apart as they pass over the rods.

The average cavity per filament is the mean space between the filaments in the band measured along a line in the plane of the band perpendicular to the general direction of the filaments in the band, this space being calculated on the assumption that all the filaments are placed in a single plane without any filaments crossing other filaments . In this description, it has been calculated based on a knowledge of an average diameter of the filaments (Dp), the width (w) of the largely conventional band, and the number of filaments (n) in this

width, according to the formula: average cavities per

In the preferred embodiments of the invention, there are intermediate cavities per filament a plurality of times (eg 5, 10 or more times) the mean filament diameter.

Publications that describe the use of such air diffusers and that provide data from which the average cavity per filament in the product can be calculated, suggests that the maximum possible separation with the treated fuses was of a negative value, that is, the number of filaments times their diameter was greater than the width of the spread product. In contrast to this, it is possible with the method according to the invention to produce average webs in which the average cavity per filament is well over 10 times the diameter of the filaments and where the filaments are largely evenly distributed over the entire width of the web.

Of the different ways to spread out the opened fuse, air spread is preferred. It has been found that even at high spreading rates, the tape produced by air spreading is a generally uniform, high quality product. When the spreader arrangement with curved bars is used instead of the air spreaders, in comparison the quality of the product is not as good and the allowable operating speed is slightly lower. If the fuse band splits during spreading with the curved rods, the splitting will thus become more pronounced as the process progresses. In contrast, air diffusion has a self-healing or self-correcting effect, so that any splitting is not continued, but instead tends to close. The use of a divergent band system for spreading will similarly produce a lower quality product than is obtained when air spreading is used.

In a preferred embodiment of the invention, the air spread is carried out in a plurality of steps and in each of these the fuse is spread out to a greater width than in the previous step. In order to obtain the best results, the fuse in any stage is isolated from the influence of the previous stage, for example by bringing the fuse between the stages in firm contact with a surface moving at a controlled speed, for example around and between a pair of driven rollers with a gap between these.

The air diffusers have air discharge slots or other suitable openings in one or both of the parallel walls which extend across the width of the fuse passage. which slits lead from a main protective chamber which is supplied with air at a constant pressure. In a highly efficient construction, there are a number of slits, each extending in a direction transverse to the direction of movement of the fuse and positioned so that all parts of the fuse are exposed to the air flows from these slits. It has surprisingly been found that even when the width of the air spreader is 2.5 meters or more, the fuse is spread out evenly and the outer edges of the fuse, where the resistance to the air would be assumed to be lowest, get mostly the same density as the middle parts of the fuse.

In cross-section, the air release slots are preferably bevelled, as they taper towards their outlets. The taper can be symmetrical about an axis perpendicular to the surface of the web, so that the air is blown straight out over this surface, or the slots can be inclined so that the air exerts a forward or backward force against the traveling fuse.

The air in the main chamber can be under an overpressure of, for example, 0.07 to 0.35 kg per square centimeter, but higher pressure can be used, for example 7 kg per square centimeter, but this is not economically viable. The pressure in the fuse-limiting zone, between the parallel walls, is usually slightly higher than atmospheric pressure. When the air is blown directly against the surface of the strip, the air will usually leave the fuse-limiting zone from both ends of this zone. Surprisingly little air is needed to expand the fuse. Despite the degree of fineness of the tape, the walls in the fuse-limiting zones in the air diffusers do not need to be correspondingly close to each other, and thus very good results have been achieved with a distance of 0.25 cm.

In the earliest stages of the spread of the fuse, the tape exhibits "cross-striping", i.e. there are alternating narrow zones of high filament density and of low fiber density running generally in the longitudinal direction of the fuse, but at a slight angle (for example 2°) to the exact longitudinal direction. The number of such stripes corresponds to the number of protrusions and grooves on the grooved roller that engages the fuse. It has been found that air spreading, rather than accentuating such streaks, largely eliminates them, and that the streaks can be removed by allowing the tape to unload, preferably as a continuously traveling, shallow bay, after leaving the last spreading stage. The ribbon is usually under a slight stretch during its passage through the air spreaders, this stretch being insufficient to remove the crimp in the filaments; when unloading in a bay, the ripple in the filaments increases while the width of the ribbon remains the same. The relieved bands are fairly even, but often have certain areas with visibly varying fiber density; the smoothness of these latter products is, however, much greater than that of the commercially available "smooth" carded tapes of staple fibers produced on the most modern carding machines.

In the tapes according to the invention, all the continuous filaments run in the same general direction, in the longitudinal direction of the tape. However, when one does not look at the entire length of a certain filament, but instead considers the individual ripples in these, it will be seen that most parts of the filament do not run in this general longitudinal direction, but instead in a zig-zag shape back and forth across this general direction. The amplitude of the ripples is such that for a particular filament the part of the ripple on one side (which can be called the "bay" in the ripple) will overlap one or more adjacent filaments, while the part of the ripple on the other side (which can be called the "valley" in the ripple) overlaps one or more of the adjacent filaments on this other side. This overlap helps give the bands their cohesive character. For example, the filaments in the tape can have a ripple whose amplitude (from a center line that runs in the same direction as the filament) is of the approximate order of magnitude 0.2 to 8 mm, this amplitude being measured from the center line to the top of a bay or to the bottom of a valley. Since there can be, for example, a hundred or more filaments per cm. bandwidth, and since the ripples are not flush with each other, it will be

a substantial overlap of filaments in the band.

When one departs from an examination of the ripple and instead examines a slightly larger but still relatively short section of a certain filament containing a majority of ripples, one will find that these sections are not completely parallel to the longitudinal direction of the tape, but form small angles with this , which angles change in direction and magnitude along the filament; generally these angles are less than 20°, although the angle over very short sections, for example 1 cm, can occasionally be greater.

The overlapping of the ripples and the overlapping which is due to the presence of the short angular sections just described contribute to the band holding together, so that despite its great fineness it can easily be treated as a uniform structure. -The degree to which the individual filaments wind as a result of the presence of these undulations and angularly extending short sections is not, however, great; in a typical example, the ratio is . between the straightened lengths of the individual filaments and the lengths of the same filaments in the band less than about 1^:1 and greater than 1.1:1, for example from 1.2:1 to 1.4:1. This ratio can be measured by cutting a measured length of the tape, removing the individual filaments from the cut portion and measuring their lengths while they are under just sufficient tension to remove the shrink seam; the results are then expressed as the ratio between the measured lengths of the individual filaments and the length of tape used.

When specifying denier per filament and total denier, the figures given here with regard to fuses and ribbons are the denier for the filament before crimping. However, with respect to yarn made from the ribbons, the denier stated is based on the actual, unstretched lengths.

Advantageously, the bands are spread out to such an extent that when further spreading is attempted while the length of the band is kept constant, the band will strongly oppose such spreading and return to its former width. If, for example, a curve is drawn with the air pressure in the spreader as the ordinate in relation to the degree of lateral spread of the traveling belt, it is found that no further pressure is needed to achieve spread up to a certain width, after which it is necessary -dige air pressure rises sharply. The band density where this sharp change occurs is referred to herein as "potential band density". This potential tape density will vary according to the type of fuse used and will depend in particular on the degree of intertwining and crossing of the fuse filaments. Generally speaking, the optimal fuses have a potential band density below 34 grams per square meter, often less than 17 grams per square meters. Surprisingly, ribbons of such densities have been shown to be easily handled and to retain their cohesion without splitting or splitting during normal processing or folding.

It has been found that when mats are made from a number of layers of the tapes, the mats are made from such tapes whose actual tape density is less than 34 grams per square meter great strength and can be processed much more easily without the risk of the layers changing, than mats of the same total weight made from bands of higher densities. In addition, the mats made up of the low density bands are thicker and less yielding. unit weight than mats made from high-density tape. In general, it is most desirable to use a tape whose actual density is less than 4/3, preferably less than 6/5, times the potential tape density. The mats made by superimposing successive layers of the lightweight bands are far more cohesive than mats made by similarly laying carded bands of staple fibers on top of each other.

The tapes can be laminated to other tape materials such as woven textile fabric, or a knitted fabric such as a tricot fabric or a non-woven staple fiber tape, or some other types of carrier material, for example sponge rubber, leather, paper or plastic threads.

The tapes, and in particular those produced using air spreaders, are particularly suitable for lamination into lightweight paper, for example by gluing, with a suitable adhesive such as polyvinyl acetate, with a single thickness of such tape to a single thickness of the paper . The reinforcement achieved by the tape with this application is very effective while not significantly increasing the price of the paper, and the side of the laminate where the tape is located feels comfortable. For example, a ribbon of 5 filament denier cellulose acetate filaments weighing 3.5 grams per square meter and contains 32 filaments per cm width is applied with adhesive to a layer of filter paper.

The tapes can be formed into mats of any desired thickness by placing one layer of the tape on top of another, for example by loosely folding, linearly overlapping, or crossing the tape or by winding the tape up on itself, for example on a round mandrel or on an endless belt. For example, the belt can be passed in a continuous working step after the relief step onto a traveling endless belt, so that it "passes around the belt and on this is built up as a layer of several layers during a corresponding number of cycles of the belt's movement. Without interrupting the movement of one of the belts, the deposited layers can be cut through (for example, along a line just opposite the line where the belt is applied to the belt) and the resulting layer mat can be pulled off the belt while a new cycle of application and abduction begins. In the second method, a plurality of bands can be brought to a zone where they are combined with each other, one above the other. The mats may be needle treated across the planes of the component bands or may be otherwise treated to bind the filaments in the mats more firmly together, if desired. Mats formed from lightweight bands can be used to fill, for example, cushions, carpets, seats, upholstery, insulation or sanitary napkins without needling or other bonding treatment.

During needling, the mat is usually passed through a needle chair equipped with the usual spiked needles which go back and forth perpendicular to the main surface of the mat and serve to guide portions of the filaments from each horizontal band upwards or downwards, so that these portions filter together with filaments in neighboring bands. The mat can be passed through the needle chair several times and turned over after each pass. Due to the ripple in the filaments, these can be stretched significantly into neighboring layers without exerting any contraction effect on the entire mat; in practice, it has been observed that the width of the mat can actually increase as a result of the needle treatment. The needle chairs that are used can be those used in practice for needle treatment of staple fiber mats.

The ribbons, and especially those made with air diffusion, are particularly suitable for the production of yarn. It is relatively easy to divide the tape into a number of narrow tapes, each of which contains the desired number of filaments. Thus, when the filaments are of cellulose acetate or other thermoplastic material, the division can be carried out with a series of heated threads each extending perpendicularly or at any suitable angle to the main plane of the tape and which are spaced apart across the width of the tape. With, for example, a tape containing 50 five-denier cellulose acetate filaments per cm width, 640 denier yarn can be obtained by placing the heated strands 2.5 cm apart and, if desired, twisting the cut bands to give them a more rounded shape; for example, a twist of up to 4 turns per cm, depending on the size of the yarn and the desired final weight. As mentioned above, there are portions of the filaments which cross other filaments and which are arranged at small angles, both to the left and to the right, to the general direction of the filaments in the spread band. The heated threads will of course cut through these filaments, so that the resulting yarn will have single filament ends, which gives part of the effect of a staple fiber yarn. Due to the fact that the frizzy filaments in the band are out of alignment with each other, the yarns produced in this way are very voluminous. When the bands are made of filaments of high tensile strength, for example tensile strength above 2 grams per denier, as is the case with filaments of terephthalate esters, it is advantageous to use devices other than heated threads for the cutting. Thus, a number of anvil rollers of a known type can be used, which comprise rotating cutting discs mounted alternately on parallel axes with the sides of the discs in close contact and with a scissor-like effect on the filaments passing between the rollers. For example, a band that per cm width has 340 filaments of polyethylene terephthalate of 3 filament denier are fed to anvil rollers placed side by side to cut the tape into strips each of a width of 2.5 cm and the strips can be wound up, for example on a ring spinner which introduces on a " to 1 turn per cm, producing a hairy, voluminous and very strong 2660 denier yarn.The anvil roll arrangement can also be used to slit ribbons of weaker fibers, giving a product free from the localized meltdown zones that can form occurs when heated wires are used on thermoplastic filaments such as cellulose acetate.

The tapes can easily be converted into porous textiles such as "scrim fabrics" quickly and without the need to form yarn beforehand or to knit, crochet, weave or otherwise form systematic yarn formations. This can be achieved in a very highly efficient way by feeding portions of filaments to places that are separated in the lateral and longitudinal direction of the tape, so that a pattern is transferred to the tape in which there are separated openings (that is, areas that do not contain any filaments, or where the filament density is much less than the average filament density of the tape) and dense areas, in which the filament density is generally significantly higher than the average filament density of the tape. This pattern in the tape is fixed or hardened, so that it becomes more or less permanent, in any suitable way, as will be explained hereinafter.

One way to introduce the pattern is to pass the tape under tension over a heated drum with a plurality of spaced projections. The tension in the belt pushes the filaments into the spaces between the protrusions, leaving openings in the belt where the protrusions protrude through the belt, while the heat from the roll fixes the filaments into their new shapes. It has been found that this patterning operation can be carried out at high speed, particularly because the belts according to the invention can easily be subjected to work steps under the high belt tensions that usually occur in such high-speed operations.

By varying the shape and spacing of the protrusions, the pattern and character of the resulting band can be changed. Thus, for example, projections which are pyramidal or conical can be used, as the projections preferably taper towards their outer parts, so that the tape is more easily penetrated and the filaments are spread out to form the openings in the tape. An arrangement of square pyramid projections can be used to produce a band with substantially square openings, rather closely resembling a square woven open weave textile fabric. Similarly, an arrangement of cone-shaped protrusions may be used to form a belt in which the holes are round or oval, while the use of a drum with a web laying surface with elongated protrusions, such as may be achieved by wrapping the drum with a rigidly woven metal wire cloth, will give elongated holes or slits.

The openings in the band can be produced in a different way than by contact with fixed, penetrating elements. For example, the strip can be passed through a zone in which a patterned series of spaced nozzles with a suitable medium (for example air or water) are directed at the strip to tear the parts of the filaments that come into contact with the jets towards the spaces between the jets, for example by to pass the tape around a perforated drum and to blow air through the perforations in the drum.

The number and size of the openings can be varied as desired. For example, there may be approximately 2 to 20 openings per square centimeter, while the diameter of the openings can be within the size range of 0.25 to 0.8 cm.

The fixing of the pattern in the tape can be carried out with the help of heat. Preferably, sufficient heat input is used to cause the fibers to stick together. However, when the tape contains such types of thermoplastic filaments which can be heat-set to a permanently bent state, such as polyethylene terephthalate, a patterned structure can be obtained by such heat-setting without bonding to the surface. In order to promote the same abundant bing on the surface, especially for filaments with a relatively high softening temperature, the tape can be treated to bring its filaments to a potential adhesive state, for example by applying to the tape a heat-activatable adhesive or a plasticizer that serves to lower the filament softening temperature - the surfaces. Such treatment is preferably carried out before the patterning step, but can also be carried out simultaneously with or after this step.

It is an advantage to leave the openings staggered so that the filaments which normally run in the longitudinal direction of the tape can be distributed evenly around the holes, and the deviation from the filament direction

ge produced by the openings being formed can be largely the same for all filaments.

When it comes to the production of porous textile fabrics, the degree of opacity of the filaments can be controlled as desired. When a limited amount of plasticizer or other binder is used, and the processing draft is controlled so that the degree of crimp is not pulled out of the filaments during the patterning step, there will only be contact between the filaments at discrete locations, due to the crimp being out of alignment, and the filaments will only are stapled together at such separate locations. For example, a ribbon of shrunk cellulose acetate filaments may be coated with a plasticizer such as triacetin, and the patterning and sintering may take place at 160 to 165°C.

Porous textile fabrics made as described above can be used for such items as bandages, towels, filters, nappies, sanitary pillow covers and dusters.

The adhesive, softener or other binding agent can be applied by means of rapidly rotating disks mounted with their axes parallel to the direction in which the belt moves, and with the disks themselves in a plane perpendicular to the plane of the belt. The edges of these rotating discs are continuously tilted into a bath of binder, and then by centrifugal action throw a very fine stream of small drops of the binder evenly over the surface of the bands. This jet, unlike the jet from ordinary spray guns, is not associated with any significant air draft and does not blow the thin band away from its proper path; as a result, it provides a more even and controlled application of the binder. It will be understood that the same method of application can be used when the tape carrying the binder is to be used for lamination, as explained above. In addition, a composite textile fabric can be produced by gluing a porous fabric, made as described above, in a lightweight band to provide a dimensionally stable lightweight structure with a soft surface, since such products are suitable for, for example, sanitary covers, bandages or decorative fabrics. Thus, the imperforate tape can be treated with a binding agent such as a plasticizer and then brought into close contact with, possibly under pressure, the perforated fabric and heated to cause the tape to stick to the textile fabrics. Optionally, the binder can only be applied to the textile fabric or to both the tape and the textile fabric, or the binder can only be applied to separate areas.

The invention will be explained in more detail with special reference to fuses whose filaments are of polyethylene terephthalate or of cellulose acetate (with the usual acetyl content, for example 54 to 55% calculated as acetic acid). It will be understood that it falls within the scope of the invention to use other fuses, such as fuses made from other polyesters (for example the polyesters of terephthalic acid and other glycols such as dimethylolcyclohexane), linear superpolyamides (for example "nylx>n 6" or "nylon 6.6"), polyacrylonitrile and copolymers of acrylonitrile, olefin polymers and copolymers, for example isotactic polypropylene, other organic derivatives of cellulose such as esters and/or ethers of cellulose, for example cellulose propionate and cellulose acetate propionate or similar, highly esterified cellulose containing less than 0.29 free hydroxyl groups per anhydroglycose unit such as cellulose triacetate, rayon (regenerated cellulose). The number of filaments in the output fuse can vary widely and can be as high as 1,000,000, with one denier per filament as high as 25, for example 1 to 20. The number of ripples per cm of fuse can go as high as about 30, but for most end products to be described herein 1 to 20, preferably 1 to 8 ripples per cm in the starting fuse has been found sufficient.

Various embodiments of the invention will now "be described in more detail with reference to the accompanying drawings, where: Fig. 1 shows a schematic illustration of a type of apparatus which can be used to convert a crimped continuous filament wick into the form of a continuous spread wide band Fig. 1a shows a view along the line 1a-1a of Fig. 1 and illustrates details of a portion of the fuse opening means and means for bringing the ripple out of alignment in the apparatus of Fig. 1. Fig. 1b shows a view laid along the line 1b-1b in Fig. 1 and illustrates in perspective the spreading means in the apparatus according to Fig. 1. Figs. 2 and 2a show schematic illustrations of apparatus for applying a binder to tape formed in the apparatus according to Fig. 1 Fig. 3 shows a schematic illustration of an apparatus for producing a quilted or corrugated product from a tape to which a binder has been applied. Fig. 4 shows a plan view of a tape to which it has been added a binder in the form of separate spots or small areas. Fig. 4a shows a section of a schematic illustration of a type of application device and binder that can be used in the apparatus according to figures 2 and 3 to produce the tape shown in fig. 4.

Fig. 5 shows a schematic illustration of another device

to process a tape as produced by the apparatus of fig. 1, so that it is divided into a number of strips.

Fig. 6 shows a schematic illustration of an apparatus which can be used for folding, i.e. linear layering or transverse laying of the tape produced with the apparatus according to fig. 1. Fig. 7 shows a schematic illustration of an apparatus which can be used to laminate the tape produced with the apparatus according to fig. 1 together with one or more additional bands of arbitrary material. Figs. 8 and 9 show schematic illustrations of an apparatus which can be used for needle treatment or needle treatment of a tape produced with the apparatus according to fig. 1.

Fig. 9a shows a diagram laid out along the line 9a-9a in the figures

8 and 9.

Fig. 10 shows a schematic illustration of an apparatus which can be used to divide a tape into sections of any desired length. Fig. 11 shows a schematic illustration of an apparatus for laminating to each other a plurality of tapes processed with the apparatus according to fig. 6. Fig. 12 shows a schematic illustration of an apparatus for laminating to each other a quilted or corrugated tape and a pair of flat tapes. Fig. 13 shows a schematic representation on a larger scale of part of the laminated material produced with the apparatus according to fig. 12. Fig. 14 illustrates a method for producing "scrim fabric" from a band. Fig. 15 shows details of the surface of a roller for use in perforating a band for the manufacture of a "scrim fabric".

In fig. 1, a continuous strand of filament or skein 10 is taken from a bale 11 and fed across a guide 12 through a ribbon nozzle 13. In this nozzle (which may be omitted if desired) the skein is subjected to the action of compressed air, whereby the normally rope-like skein is converted into a relatively narrow flat band. When it leaves the nozzle 13, the fuse 10 is subjected to the action of a fuse opening device 14 which contains two pairs of parallel and equally extending steel rollers 15 and 16 arranged in tandem, the fuse being guided between them. As clearly shown in fig. 1a, the roller 15 in each pair is provided with two sets of obliquely extending elevations and grooves 15a and 15b which extend helically in opposite directions around the roller from its center and towards its two opposite ends. The roller 16 in each pair has a smooth surface and has a sleeve of rubber or similar elastic material on its outer surface.

Although fig. 1 shows only two pairs of such rollers 15 and 16, it will be understood that in practice only one pair or as many as three or more pairs of rollers can be used, depending on the physical properties of the filament sliver being processed.

After leaving the device 14, which opens the fuse and brings the ripples in the individual filaments out of alignment to form a smooth coherent band, the fuse 10 is passed under a tension of less than 4.5 kg over a spreading device 17 in which the width of the band is substantially increased to the desired size. The spreading device 17 which is used in the apparatus according to fig. 1 is shown schematically in fig. 1b and comprises a plurality of upwardly curved or curved bars 17a to 17e of successively greater length, supported at their opposite ends by a pair of elongate divergent frame members 17'. For obvious reasons, the spreading device 17 is positioned so that the shortest rod 17a, whose length is approximately equal to the width of the opened fuse, is closest to the outlet end of the fuse opening device 14. When the fuse band is passed across and in contact with the rods 17a to 17e, its width is substantially increased so that the final band 10' can be as wide as 2 meters or wider.

As indicated above, the tape may be subjected to one or more of a number of different finishing treatments intended to prepare it for its final use in the manufacture of a large number of different end products. Both the nature and the complexity of the final processing will of course depend on the type of filaments that are processed, the physical properties desired in the final products to be produced, and the properties (mechanical and/or chemical) of the aids, materials and devices used to carry out such finishing lines. gives.

In order to stabilize it without resorting to auxiliary tape materials, the tape 10' in fig. 1 passed through an application device 18 (fig. 2 and 2a) in which a binder is applied to the tape, The means for applying the binder to the tape may comprise either a spray system or a bath or a roller system, and may be designed so that the binder is applied to either on one or both surfaces of the traveling belt. It will be readily understood that the binder can be a plasticizer or a solvent for thermoplastic materials of which the filaments are composed, or a suitable adhesive composition suitable for the thermoplastic

material. For example, for the cellulose acetate filament, a plasticizer can be used, for example triethyl citrate, dimethoxyethyl phthalate, methyl phthalate-ethyl glycolate and glycerol triacetate (triacetin) or a solvent, for example acetone, while chloral hydrate and various synthetic polymer emulsions are very effective for polyester filaments.

To enable maximum production rates to be achieved, the binder should be of the fast-setting or fast-drying type. In this connection, after leaving the device 18, the tape can be passed through a heating drying chamber 19 (see fig. 2), or (see fig. 2a) it can be passed over an open air framework 20 (if the binder is of the air drying type), before it is taken to the recording location 21. The total amount of binder applied to each tape unit can be, for example, from 2 to 200$ of the dry basis weight of the tape, and is preferably limited to between 5 and 100$. The base weight of the tape will depend mainly

of the original characteristics, i.e. total deniers and deniers per filament, at the output fuse and the degree of opening and spreading of this. For all practical purposes, the speed of movement from the bale 11 to the pick-up location 21 during any treatment will be determined in accordance with and limited only by the requirements of the binder application device<q>g drying devices.

As shown in Figures 2 and 2a, the stabilized ribbon 10'' of filaments in its flat state can be wound up on a roll pending further use. In such a case, it may be found advisable to wind the stabilized filament material together with a tape of non-adhesive or insulating paper or the like to prevent the windings of the tape from sticking to each other during storage. Optionally, the stabilized filament material can, of course, immediately after it has left the drying zone 19 or 20, be taken up in the form required for the production of the final end product. The tape 10'• can be advantageously used for the production of such products as air filters and liquid filters in industry, bale wrapping and textile fabrics that can be shaped and calendered,' in which a high degree of tensile strength and ability to retain shape are important properties.

When a more voluminous material is desired, it can be used

way of treating the tape 10' which is illustrated in fig. 3. I

in this arrangement, the belt 10' is fed by feed rollers into a packing box 22, and at the entrance of this the belt is acted upon by any suitable type of opposing folding means, for example a pair of alternately reciprocating rods 23, a star wheel fold (not shown) or similar. The original planar band is consequently transformed into a quilted or corrugated structure 24, which when it passes through the packing box is compressed until it comes out as a substantially more voluminous band 24' which is suitable for use as wadding or cushions in a large number of products . If the outlet section 22' in the packing case is heated, the tape can

10' is thereby stabilized in its quilted form 24' by causing the filaments to be either fixed or fused to each other at their crossing points. If the tape had previously passed through a binder application device 18 (indicated by dashed lines in fig. 3), then the heating section 22' will act to stabilize the tape 24' in the same way as the heating dryer 19 shown in fig. 2. It will be understood that a plurality of bands 10' can be fed simultaneously into the packing box 22.

For certain areas of use, it has been found desirable to apply the binder in the device 18 only to parts of the total surface of the band 10'. In order to achieve this, the application means in the device 18 can comprise (see fig. 4a) a system of application rollers 25 and 26

between which the tape is passed. The roller 25 has a smooth surface, while the roller 26 which interacts with it is of the intaglio type and is in the illustrative example provided with a plurality of protrusions 26a of any desired shape, here circular cross-section, and distribution. The binder 27 is applied to the roller 26 from a reservoir 27a with a set of transfer rollers 28. The nonwoven, oriented continuous filament fabric produced in this way is given schematically in fig. 4, in which it can be seen that the binder is distributed over the tape in the form of a plurality of spaced spots or circular areas 27' arranged in a plurality of mutually perpendicular rows and columns. The spots or regions 27' in any given row or column are offset with respect to the spots or regions in the following row or column, and each of two neighboring spots or regions in each row extends across the filament orientation so that they slightly overlap the loci. for the side boundaries of the patches or regions in the intermediate column which extend longitudinally in relation to the filament orientation.

The new fleece-like fabric of continuous filaments produced by this "flecklebing" technique has excellent textile properties such as soft grip, flexibility or drape, and the three-dimensional appearance or pile properties of woven fabrics. Since the binder is only applied to a fraction of the entire surface area of the original tape 10', the fabric becomes dimensionally stable while still being completely flexible in all directions. Very soft fleeces of this kind are particularly advantageous for the production of a large number of hygienic products such as surgical tampons, disposable tablecloths, towels, diapers and the like, as well as for a large number of other products, for example linings of caskets, cigarette filter material and special fabric for curtains.

As discussed earlier, the dry basis weight of any webbing 10' depends primarily on the original total denier, denier per filament, the degree of ripple, the degree of opening and the degree of spread of the output fuse. With a fuse of given total denier, denier per filament and number of ripples per cm, the lowest possible band density can thus only be achieved by spreading the fuse to the maximum possible. In order to produce bands of substantially smaller width, but with the same density from the same fuse, the band 10' can be divided into narrower bands 29, for example as shown in fig. 5. Such a device preferably comprises a housing 30 made of plastic or similar insulating material, through which the band 10' is passed. The outlet opening for the belt 10' is delimited by an elongated slot 30a dimensioned so that it allows free passage for the belt. Rigidly attached to the housing 30, for example by being embedded in the plastic material therein, along the top and bottom of the slot 30a are two sets of small metal rods or plates 31 and 32. These elements are arranged in vertical pairs and are connected by suitable means ( not shown) arranged to apply electrostatic potentials of the order of 100,000 volts or higher to the respective pair of plates 31 and 32. The electrostatic fields thus generated across the slot 30a collect the filaments into the desired plurality of relatively narrow bands 29. Dispersed filaments between the bands 29 can be eliminated by placing suitable rotating knives (not shown) placed near the slot 30a.

Each of the bands 29 thus formed can be worked up and subjected to a final treatment as described herein with regard to the band 10', for example application of a binder. Due to their reduced dimensions, however, the bands 29 are very easy to convert into other products. For example, these bands can be twisted to form ropes. If desired, the twine can be hardened or fixed either by applying a binder, or if the filaments are made of heat-curable materials, by a heat-hardening treatment. The ribbons can also be converted into yarn, either with zero twist or with a normal twist of up to 20 turns per cm, which yarns, as a result of the presence of the ripples, have a stretch property that is beneficial in many different garments. Especially the yarns with a low twist form an excellent voluminous carpet yarn when it has sawtooth ripples.

In another embodiment of the invention, the belt 10' can be fed to a folding device or overlapping device 33 (see Fig. 6) mounted for movement back and forth over the upper run of an endless conveyor belt 34 on a table 35. The device 33 can be moved back and forth extends the table 35 either in a direction parallel to the direction of movement of the conveyor belt 34, as indicated by the double-headed arrow A, or in a direction transverse to the direction of movement of the conveyor belt, i.e. at an angle of up to 90° to this, as indicated by the double-headed arrow B. In each case, suitable means are provided to control the speed of movement of the device 33 in relation to the forward speed of the conveyor belt 34. By means of such an arrangement, the belt 10' is deposited on the upper run of the conveyor belt in the form of a continuous multi-layer belt structure 36. If the device 33 moves parallel to the conveyor belt 34, all the filaments in each layer are oriented in b the longitudinal direction of the breath and consequently linear in the direction of the belt's advance, while if the device 33 moves across the conveyor belt, the filaments in each layer are oriented at an oblique angle to the direction of advancement of the belt and of course at an oblique angle to the filaments in the subsequent layers. The number of teams per length unit belt 36 or the angle for the transverse lapping will be determined by the relative movement speeds of the conveyor belt 34 and the laying device 33, and by the angle between the direction of such advancement and the direction of the recording belt's movement.

The multi-layer tape 36 which leaves the apparatus according to fig. 6, regardless of whether it is of the linearly overlapping or transversely overlapping type, will be subjected to further treatments to make it suitable for use in the manufacture of special end products. Thus, the multilayer tape 36 can immediately be taken up in any suitable form, for example on a roll, for the actual product manufacturing operation. If a linear overlapped band 36 is to be formed into a roll, it can of course, for obvious reasons, only be rolled up longitudinally, that is to say about an axis perpendicular to the filament orientation. A transversely overlapped band, on the other hand, as a result of the interlocking laying of the layers therein, can be rolled up either in the width direction or in the length direction. Loosely wound ribbons of this kind, that is, ribbons that have not become

treated for external dimensional stabilization, has been found to be particularly suitable for relatively static products, such as filling in, for example, pillows, duvets, carpets and furniture, insulating cotton wool and sanitary napkins.

Where a higher degree of dimensional stability is desired, the overlapping band 36 can be passed through a device of the type denoted by 18 in figures 2 and 2a to apply binder to the band. If desired, the tape can be "spot-glued" as indicated in Figures 4 and 4a. However, it would be readily appreciated that the binder may be applied to the tape 10' prior to the linear overlap or the transverse overlap thereof, to ensure that the filaments are bonded together not only on the outer surfaces of the overlapped tape 36, but also at the contact surfaces between adjacent layers in the band.

In cases where the use of a binder is considered undesirable or unable to give the final end product the desired physical properties, the overlapped tape 36 can be fed into and through a device 37 (Fig. 8) or 38 (Fig. 9) for seam processing and/or needle processing, in which the tape is sewn or needle processed either across at regular intervals, as indicated at 39 in fig. 8, or in a single or multiple zig-zag pattern as described at 40 and 40a in fig. 9. For this type of processing, the band 36 which is fed into the seam device or the needle device is usually first passed through a slack-taking mechanism, shown schematically in figures 8, 9 and 9a, where it consists of a set of three guide rollers 41, 42 and 43 , where the middle roller 42 is mounted for vertical displacement towards and away from the stationary rollers 41 and 43, as indicated by dashed lines in fig. 9a. Movement of the roller 42 from the position shown fully extended makes it possible to take up slack in the belt 36 while the belt is stationary or moving at reduced speed in needle processing or seam processing devices 37 or 38 during the latter's operation. It is understood that the staggered zigzag needle treatment or sewing of the band indicated at 40a in FIG. 9 can be used to achieve a padding effect.

Dimensionally stabilized overlapped bands 36 have been found particularly suitable for the production of products intended for fairly strong movements, for example mop heads, dry and wet bonding, pads for grinding, polishing, cleaning and rubbing, filters for air, gas and liquid, reinforcing tape for other types of relatively weak or unstable tape materials and especially for common non-bonded non-woven fabrics, industrial tapes and carrier tapes, bale wrapping, for outer garments and linings, carpets and paper machine filters. Stabilized bands, however, are not limited to such products, and can be used for static purposes of the kind explained herein in connection with the unstabilized overlapped bands.

The tapes, both of the single-layer type identified by the reference designation 10' and of the multi-layer type identified by the reference designation 36, can be laminated together with one or more layers of identical or different tape material. As shown in fig.

7, the band 10' or 36 can be guided in the direction of the arrow C towards it

a pair of calender rolls 44 and 45 to which another strip material 46 is simultaneously fed from a supply roll 47. In the illustrated embodiment, the strip material 46 is first fed over a guide 48 to an application roll system 49, where a binder is applied to the side that is to come into contact with the belt 10' or 36 by the time it reaches the calender 44-45. For example, the band material 46 can be a woven "scrim fabric", or a tricot fabric or other knitted fabric, or a band of non-woven staple fiber, sponge rubber, leather, paper or a plastic band. At the same time, the band 10' or 36 can be in an unstabilized state or can be stabilized as described above. As the band 10' or 36 and the coated band material 46 together enter the gap in the caiander rolls 44 and 45, they will combine into a unitary laminate structure 50 which can then be wound up for storage or further use in any desired manner.

Where the band material 46 is of the same nature as the band 10' or 36, one or both bands may be of single layer structure, may be linearly or transversely overlapped, and may be stabilized in advance by gluing, needling or sewing, or by lamination steps . Particularly where both bands are of the same type, that is to say both are linearly overlapped or single-layered, it is preferred to laminate them with the filament orientations of neighboring wire sections transversely, for example perpendicularly, in relation to each other.

As mentioned above, the lamination step may comprise more than two bands. This is illustrated schematically in fig. 11, in which three bands X, Y and Z are laminated together. Thus, all three bands can be single-layer bands 10', and can be passed through respective laying devices 51, 52, 53 prior to lamination. For example, the devices 51 and 53 can make linearly overlapped bands, while the device 52 produces a transversely overlapped band, or vice versa. The resulting webs X', Y' and Z<1> may then be fed to a pair of calender rolls 54 and 55 and then to a stream device or needle treatment device 56 which may operate in the manner illustrated in FIG. 8 and 9, as it sews or needle processes in parallel rows or in single or in several zigzag lines, so that different seam patterns or needle patterns are produced as desired, for example a pblstring of the laminate structure. If necessary, the devices 51, 52 and 53 can be application devices for binder either alone or in conjunction with devices for linear overlapping and transverse overlapping as described above. Alternatively, the tapes X and Z can be tapes according to the invention, while the tape Y can be an ordinary non-woven tape of staple fibers or a woven or knitted textile fabric, or the tape Y can be a tape 10' or 36 and the tapes X and Z a woven or knitted fabric of natural or synthetic fibers, such as cotton cheesecloth, nylon fabric or cellulose acetate tricot fabric. In each of the foregoing cases, each of X, Y and Z may be composed of a plurality of ribbons or laminate structures arranged in any desired manner.

Similarly, a laminate structure can be formed with a folded band 24' of the type illustrated in FIG. 3. This is best shown in fig. 13. As before, the glued or unglued tape 10' is fed by means of feed rollers into the packing box 22 through the folded members 23, and at the same time two strips of tape material 46' and 46<1>' are fed into the packing box at the mutually opposite sides of the loosely folded band 24. The band materials 46' and 46'' can be "scrim fabrics" or any of the different materials that have been designated in the foregoing with the reference number 46 in fig. 7. It will therefore be clear that when the tape 24 is advanced through the packing box into the heating section 22' of this latter, it is compressed to

forming the band 24' at the same time as the bands of band material 46' and 46'' are brought into intimate contact with opposite surfaces of this band 24'. Generally speaking, either the tape 10' is pre-passed through a binder applicator 18, or the tapes 46' and 46'' are passed through respective applicator roller systems 49 (the device 18 and the roller systems 49 in Fig. 12 are shown only in symbolic outline to indicate that only one or the other of these is used in any given case) so that a secure bond is achieved between the bands of band material and the band 24' of the heating section 22'.

The resulting composite fabric, a section of which is shown on a larger scale in fig. 13, is then ready to be taken to any suitable recording location for storage or further processing. It will be understood that in the system according to fig. 12

of course, a plurality of tapes 10' can be fed into the packing box to be laminated between the opposite tapes of tape material 46'

and 46'', or only such a strip of tape material may be used, which is laminated on only one side of the joined tape 24-24', which may be of a single tape 10' or a plurality of such tapes, put together as as described above. The working speed of the folding means 23 and the relative feed rates at which the band 10' and the band or bands 46' or 46'' are delivered to the packing case 22 determine the final basis weight, that is, mass per length unit, in the final laminate.

The laminate structure of the described types is suitable for the production of a large number of different products, among which can be mentioned fabrics for cars, cord fabric for tires, upholstery for furniture and cushions, intermediate linings, insulating wadding, wall panel reinforcement, as well as fabrics for carpets, filters, clothing, packaging materials, laminated textiles, carpets and underlays as well as leather imitations.

A tape W treated in one of the ways described above can be further treated in a manner illustrated in fig. 10

by being fed to a knife or cutting mechanism 57 in which the tape can be cut to suitable lengths. For example, a

such an apparatus comprises a pair of endless belts 58 and 59, the upper course of which lies largely in the same plane and whose adjacent ends are spaced apart, so that a pair of interacting knives or cutting pieces 60 can be moved back and forth between them and 61. The apparatus is preferably associated with an expansion device 62 which is arranged to take up any slack in the tape that is passed through the cutting device, which may come from fabric in the advance movement of the tape during each cutting step.

The following examples are illustrative of preferred embodiments of the invention. As will be seen from these examples, ribbons can be obtained with a weight of from 5 to 35 grams per square meters with the greatest ease. Such bands cover the majority of the areas of use for this, but the invention can be used for the production of both heavier and lighter bands.

Example 1.

A skein of continuous polyester filament with a total denier of 220,000 and one denier per filament of 5.0 was passed through an apparatus for fuse opening and for bringing ripples out of flight, of the kind shown in fig. 1, the apparatus having a first pair of rollers operating at a speed of approximately 19.5 m per minute, and a second pair of rollers operating at a speed of approximately 27 m per minute. The resulting opened fuse was in the form of a band approximately 30 cm wide. The opened fuse was then passed under a tension of approximately 230 grams over a s.predearrangement of the type shown at 17 in fig. 1 and which consisted of two curved bars. The tape produced was of a width of approximately 100 cm and weighed approximately 28 grams per square meters. The strip was taken to a laying device and was therein converted into a multi-layer cross-overlapped structure. This was then wound up to form a pillowcase weighing 366 grams and was found to be characterized by compressibility and elasticity properties that compared favorably with conventional staple fiber pillowcases.

Example 2.

A cellulose acetate wick of continuous filaments with

a total denier of 50,000 and one denier per filament of 3.2 became

worked up into a band of 30 cm width in the manner described

clear ahead. Two parts of the resulting tape were joined,

with the filaments in each layer oriented transversely to the filaments in the other layer. This composite tape was then passed through a spot-gluing apparatus of the type illustrated in fig. 4a, which applied to the filament structure spaced and overlapping cir-

cular areas with triacetin which covered approximately 25% of the total surface area of the textile fabric. The adhesive textile fabric was found to have high strength properties both in the longitudinal and transverse directions and was suitable for use in the manufacture of fabrics, surgical tampons, towels and diapers. Compared to hitherto known spot-glued nonwoven fabrics of staple fibers, the spot-glued nonwoven textile fabric of continuous filaments

ments were found to be free of fiber migration and were also compared favorably with the staple fiber fabrics when it came to such text-

properties such as softness, flexibility, fall and pile.

Example 3.

A ribbon of cellulose acetate containing 240 stre-deniers

filaments per cm bandwidth, which filaments had 3 ripples per cm while the tape had a density of 8.4 g per square meters,

was sprayed with 6$ of its weight of triacetin, as shown at 100 in fig. 14 in the drawings, and then passed under tension over a powered rotating, heated roll 101 which was maintained at a temperature of 163° C. and which had on its surface spaced, square truncated pyramid shaped projections 102 (see Fig. 22),

as there were 15 protrusions per square centimeter, placed in a pattern with staggered rows. A stable, po-

voice textile fabric.

Claims (6)

1. Method for producing a transparent and po- rough bands of continuous, rippled textile filaments, where the filaments mostly lie in the same direction and form a coherent whole in that adjacent filaments overlap each other due to the ripples in the filaments, and due to the filaments' deviations from the main direction, as a skein (10) of continuous, rippled plastic filaments are opened by displacing the filaments' ripples away from adjacent filaments' ripples by passing the fuse between a pair of rollers (15, 16) where at least one of the rollers (15) has a bevelled surface, so that the filaments are gripped between the rollers in areas that alternate with areas where the filaments are not gripped, and where the groups of filaments that are gripped alternate when passing through the rollers, so that different groups of filaments are gripped, respectively released, and that the filaments are fixed in their shifted positions by the application of heat and/ or by using a binder, characterized in that the opened fuse (10) is spread out increasing the width by using means which cause a force evenly distributed over the entire width of the fuse which seeks to separate the individual filaments from each other, without canceling the interweaving or overlapping of the filaments' ripples. 2. Method in accordance with claim 1, characterized in that the opened fuse (10) is spread by, in a manner known per se, directing an air flow through it, while it travels through a defined zone (12). 3. Method in accordance with claim 2, characterized in that the spreading operation is repeated in a subsequently wider zone (17). 4. Method in accordance with claim 3, characterized in that the band (10) is allowed to hang in an unsupported bay before collection. 5. Method in accordance with one of the claims 1-3, k a - (10) characterized in that the opened fuse is spread until its width is increased by a factor of between 1.5 and 6 in 6. Method in accordance with claim 5, characterized in that the spreading is continued until the tape product has a density that is less than 6/5 of the potential tape density.