US3314841A - Method and apparatus for manufacturing compound non-woven textile structures - Google Patents

Description

April 18, E957 B. ROMANIN 3,314,841

METHOD AND APPARATUS FOR MANUFACTURING COMPOUND NON-WOVEN TEXTILE STRUCTURES Filed April l2, 1963 3 Sheets-Sheet l M L/a M TM@ 1M/ B. ROMANIN 3,314,841 METHOD AND APPAR G 3 Sheets-Sheet 2 I N VEN TOR. Kean/0 aMA/v/A/ BYZQKQ Ma @W vApril 18, 1967 B. ROMANIN 3,314,841 METHOD AND APPARATUS FOR MANUFACTURING COMPOUND NON-WOVEN TEXTILE STRUCTURES Filed April l2, 1963 5 Sheets-Sheet 5 INVENTOR. m//va i@ 0M A /L/ /A/ above; as well as to inorganic United States Patent Otlce 3,314,841 METHOD AND APPARATUS FOR MANUFACTUR- NG CUMPOUND NON-WGVEN TEXTILE STRUC- URES Bruno Romanin, 8 Via Vincenzo Monti, Milan, italy Filed Apr. 12, 1963, Ser. No. 275,787 laims priority, application Italy, Jan. 25, 1958, 598,602/58; Apr. 16, 1962, 22,524/62; llan. 16, 1963, 30,920/63 18 Claims. (Cl. 156-179) This invention relates to an improvement in the processes and apparatus for the commercial manufacturing of textiles of the so called non-woven type, wherein all More particularly, men-ts in the processes rics of the particular type as disclosed arrangement in the direction of fabric may be called, in their whole, the Warp of the fabric, by analogy with the arrangement of Warp yarns as present in a loom woven fabric.

undulations of the other yarns (which may be called, by analogy, though improperly, weft yarns) is such as to of warp yarns. are tightly and parallely spaced, and preferably two groups of weft yarns, showing like undulation amplitudes but oppositely directed, are present in the fabrics according to the invention. Consequently,

By suitably bonding all warp and weft yarns with one another at the intersections of threads with picks, it benon-extensibility in a that olf the straight warp yarns.

Yarns of any nature may be utilized for the manufacturing of said non-woven fabrics. Recourse may be made e.g. to yarns obtained from cotton, hemp, jute, wool, or other short natural fibres, from silk wastes, from artificial or man-made short libres, as viscose staple, viscose acetate, polyamide, polyester, acryl-, polyvinyl alcohol-, PVC- and vinyl-copolymer libres, or olen fibres (eg.

filaments, man-made filaments, obtained from same plastics as stated yarns, e.g. glass yarns.

3,3l4,84l Patented Apr. 18, 1967 Thus, since no limitations exist in the use of yarns of every kind, and/or previously submitted to whatever processing steps which might be required. or desirable, as for instance a stretching, twisting, setting or other treatmerits, it is to be understood that the term yarns, as used in the following description and in the appended claims, must be construed as covering, in its broadest sense, all possible kinds of textile filaments and yarns.

It is likewise possible to have recourse to many different purpose in question.

The association Vof said non-woven :fabrics with films or sheets of different nature is also foreseen. Thus, re-

sacks, bags, tarpaulins or the like, as well as for waterproof coverings and laminations. However, such laminated fabrics might show, in some cases, an excessive stiffness, or more exactly they cannot be submitted to complex bendngs, or to a simultaneous bending in opposite direction. In addition, they are not much able to fwithstand shocks and irregular stresses of both transitory and permanent nature.

An essential feature of the ed examples, taken with the accompanying drawings, wherein:

FIG. 1 is a diagrammatic, ment for the manufacturing a non-woven fabric of the above stated 3 nique, the zone wherein the non-woven made.

FIG. 3 diagrammatically shows the operating machine components by which the fabric is made, in a crosssectional view taken on the line 3-3 of FIG. 2.

FIG. 4 shows, similarly to FIG. l, an equipment for the manufacturing of fabric, in a variant design for the making of a fabric wherein the components thereof are bonded by means of films that are laminated on either sides of same fabric.

FIG. 5 shows, similarly to FIG. 3, the zone in which the fabric is being formed on a machine of the type as diagrammatically shown in FIG. 4.

FIG. 6 is a fragmentary plane view of the finished fabric, with the superposed components thereof partly removed.

FIG. 7 shows, in a structurally simplified form, a side view, partly sectioned on vertical planes, of an auxiliary equipment, designed to be installed downstream of the machine whereon the non-woven fabric is manufactured, for the conversion of the same fabric into a laminated structure, wherein the fabric is enclosed between two film-s or sheets, and

FIG. 8 shows, on an enlarged scale and intentionally exagerated, for a the effects that can be obtained, as shown in FIG. 7.

Briefly stating the essential modes of operation to be followed in the manufacturing of the non-woven fabrics in question, and referring particularly to FIG. 1, the fabric, generally indicated with S, is manufactured by bringing into mutual contact, under a condition of substantial coplanarity, a plurality of yarns, which `are fed in groups arranged along as many convergent planes, between oppositely driven members, e.g. the cylinders 11 and 12, between which said yarns are brought into mutual contact along the line or Zone of tangency, or of maximum approach T of said members.

In the simplified embodiment form, e.g. four groups of yarns 13-16--originally straight and parallel-are fed between the cylinders 11 and 12. The course and parallelism -of yarns pertaining to the outer groups 13 and 16 are not changed in the fabric S. The yarns pertaining to inner groups 14 and 15, are, however, alternately displaced in either direction at a point upstream of said inlet or tangency zone T, by means of reciprocating combs 17 and 18, or the like, whereby these yarns are caused to take cyclically variable inclinations, which are reproducible in both directions, at the time of their inlet in the zone T, wherein they come into contact with the adjacent yarns of all other groups.

Since each yarn, from said mutual contact Zone T onward, is obliged to maintain the position taken at the inlet in said zone, in respect of all other yarns present in the textile structure, a net-like weave is obtained. A typical, advantageous form of such net-like weave is fragmentarily shown in the FIG. 2 wherein, for clearness sake, one yarn only, pertaining to each one of groups 14, 15 and 16, is drawn on an enlarged scale in the section upstream of tangency zone T (which is shown in the plane by a dash and dot line), and these same two weft yarns are represented at 14 and 15', with oppositely directed undulations, and a straight Warp yarn at 16', in the textile structure downstream of said Zone.

Obviously, said op-positely directed undulations are obtained by causing the combs 17 and 18 to perform oppositely directed reciprocating motions, e.g. by means of connecting rod systems, eccentric mechanism, as shown in a merely diagrammatic form at 19 in the FIG. 1, or by other equivalent hydraulic, pneumatic or electromagnetic means.

The length of the undulations of each sinusoidal weft yarn (the half-length of an undulation being indicated at L/Z in FIG. 2) is obviously determined by the ratio of fabric is being in proportions better understanding of a detail of the equipment linear speed V (which is imparted to the textile structure by the rolls 11 and 12), to the frequency of reciprocating motions A' and A" that are imparted to shifting devices (eg. the combs 17 and 18) for the weft yarns.

The amplitude or height of the sinusoidal undulations, as well as the angle a of inclination or slope shown by the waves represented by each weft yarn, are a function of the amplitude of said reciprocating motions A and A as imparted to the combs, as well as a function -of the distance D between the transverse line by which the contact zone T is defined (and wherein the yarns are mutually bonded) and the transverse line as defined by the comb teeth 20 (or equivalent means), by which the yarns pertaining to groups 14 and 15 are physically acted upon and cyclically shifted sidewise.

Obviously, by assuming that said combs could act exactly in the tangency or contact Zone T, the cyclic shifting A and A" of said combs might show an amplitude not greater than the amplitude H of the undulations. However, this is obviously impossible, since a given space is required for fitting and driving the combs. Thus, a space D must be left between the contact Zone, and the Zone wherein the weft yarns are cyclically shifted.

The amplitude of reciprocating motion to be imparted to combs may be approximately defined by the equation:

being the approximation due to uncontrollable .phenomena of inertia, adherence and tendency to spontaneous straightening on the part of yarns.

It can therefore be readily appreciated that, to attain the maximum production capacity on equipments designed for the manufacturing of textile structures according to the invention, it is essential that the distance D be reduced to the minimum compatible with the structural and dimensional requirements of said equipments, since the limiting amplitude with reciprocating member motion depends, by equality of undulation height H, on such reduction. It must be kept in mind that the number of yarn crossings, and thus the number of bonding points, and the maximum inclination a of the wave curves, is defined by said height, and that the angle a is important to the purposes of attaining high strengths of the textile structure in a direction perpendicular to the warp, since positions closer to transverse ones are taken by the weft yarns.

Moreover, a decrease of the amplitude of comb reciprocating motions is highly important to the purposes of a reduction of stresses to which the weft yarns are subjected while the structure is being formed. In fact, by equality of frequency of operating cycle of weft laying devices, a decrease in the amplitude of their motions results in lower linear speeds of yarn side shifting, and in lower positive and negative acceleration values in the shifting motions.

It is essential that, from the tangency Zone T onward, all weft and warp yarn of which the net-like weave is composed, shall remain mutually stationary whereby they must be bonded in the arrangement taken by them. Such mutual bond can be advantageously brought about simultaneously to formation the net-like weave, by feeding to contact zone T film or sheet materials, that are in turn to be brought into contact with the yarns of the net-like weave.

By the use of suitable bonding agents, preferably previously applied to film or sheet materials, and/or by taking advantage of the inherent or aroused (e.g., by heating) adhesive properties of film or sheet materials, and/ or of the yarns, all weft and warp yarns can be directly bonded with one another and set in the positions taken when forming the net-like weave.

An equipment designed for the manufacturing, in only one step, of textile structures of the above stated type, and laminated on both sides with film or sheet materials, e.g., with plastics films, is shown in the FIGS. 4 and 5, in

il a manner similar to that of FIGS. l and 3. 21 and 22, unwound from the rolls 23 and 24, are fed,

are designed to form, in the resulting industrial product S, both faces of the fabric, with net-like weave proper and bonded therebetween.

FIGURES 4 and 5, only one manner similar to that of the textile structure S (see FIG. 2) is shown enclosed and bonded between the two layers 21 and 22 in the finished structure S.

tween the components of the structure.

Therefore, it can be readily appreciated how a nonwoven textile structure having one side, or preferably both sides, laminated with a sheet material, can be manufactured in practically a single manufacturing step,

films or sheets are bonded thereto.

It has been surprisingly found that, by the method as by iirstly making the net-like weave as stated above, and then associating it with films or sheets materials.

Such :advantageous and novel features and properties strength, particularly in the direction coinciding with that of Warp yarns.

In fact, it has been found that the non-woven textile product-s, as manufactured under the conditions that are diagrammatically shown in the FIG. 4, i.e. wherein the tion-impacts, as well as to conform themselves to jutting and irregularly shaped parts, or the like.

The wide application possibilities offered by such lada given direction (and particularly, in the longitudinal direction), that can be attained by the use of a suitable number, yand/ or count, and/or nature of warp yarns.

' and the like, having a great recauses, can be similarly It can reasonably be assumed that such exceptional and unforeseeable properties of the non-woven textile structures as manufactured according to the present improve- Moreover, by having recourse to suitable, transparent or dull film or sheet materials, having a proper consistency, e.g. of the artificial leather type, single, or multicolored artificial fabrics or the like, for the lining of at least turing of bags and suitcases or trunks, eg. of motor cars, or the like, are produced. The presence of the net-like weave in such products allows them to .be utilized for the manufacturing of outfits, coverings, or the like, with joints which can -be either welded (owing to the and 15', are crossed. Each across more than fifteen (in the by each of which 20 warp yarns 16 weft yarn, on turn, runs are crossed, in both directions, by each warp yarn, within each undulation of weft yarns.

By selecting,

undulation is kept within values of the order of about 70 mms., and maintaining the abovestated crossings.

Moreover, by selecting suitable undulation lengths, eg. such that the value L/Z be of about 75 mms. (as shown), the angle a will be kept within the limit of 60 deg. Finally, by selecting suitable rotary elements 11 and 12, drirven in opposite direction, having a diameter e.g. in the range of 120 to 150 mms., according to machine sizes, and by the use of suitably designed shifting combs 17 and 1S (e.g. as shown in FIGS. 3 and 5), the distance D between the line whereon the weft yarns are laterally shifted (as defined by the teeth 2()` of combs) and the line T, whereon the yarns are brought into mutual contact, and the netlike weave is practically formed, can be reduced to 30u10 mms.

This permits obtaining the desired formation of the weft by limiting the amplitude of the comb reciprocations to values of the order of 1Z0-180 mms. Clearly, this permits the obtaining of good throughputs while keeping the stresses, to which both the mechanical components and the yarns are submitted, within absolutely safe limits.

By operating the wefting devices at a speed of about 180-200 cycles per minute, exceptionally high production efficiencies can be attained, since the speed V, at which the material is fed, may attain values of the order of 27-30 linear meters per minute. However, such values could be easily increased, in particular when high strength weft yarns are used. ln practice, the above stated values which, in and by themselves might be considered as indicative of an unusually high production efficiency, can be presently viewed as the practically attainable upper limits, because at speeds even higher, the visual control of evenness and of quality of the production, and in particular of the formation of the net-like weave, would become highly difficult.

On that subject, according to a complemental feature of the invention, in the products of the above-stated type, which are laminated with a dull material on one side (eg. artificial leather, artificial high-grade fabrics or the like), it is recommended that a transparent or pcllucid film be laminated on the opposite side, to allow the visual control of the formation and regularity of the net-like structure.

In some cases it has been ascertained that the direct bonding olf the opposite film or sheet materials in the points corresponding to the spaces left amongst the crossed threads or yarns of the non-woven weave, was interfered with and counteracted, in particular in points irregularly and unforeseeably scattered, by the presence of minute air pockets, -which cannot practically be eliminated when the components are passed between the rolls driven in `opposite directions, and that, after the lamination the manufactured compound material remained trapped therein.

Though, from certain viewpoints, some advantages can be obtained from a spacing of the outer layers between which the net-like weave is enclosed, as e.g. a remarkable decrease of the heat conductivity cocfiicient of the compound structure thus obtained (thereby giving a thermal insulating property to the same) however, in most cases of the applications of this structure, it would be preferable to have both outer layers directly bonded with one another in the greatest possible degree and, in the limit case, in all the spaces left amongst the yarns of the inside net-like weave.

Moreover, the use of polyethylene films would be very advantageous for the manufacturing of such laminated materials, from the viewpoint of costs, and above all to take advantage of the very good physical properties, and in particular of the good resistance to atmospheric agents as shown by said plastic material. Such application is, however, hindered by the well known incompatibility shown by polyethylene films toward all adhesives and solvents heretofore known, which obviously prevent any adhesive bonding of outer films with one another and with the textile components of net-like weave. As already well known, the films of polyethylene, or of equivalent thermoplastic materials, can be joined by heat-welding only, i.e. by heating the films until at least a surface layer thereof is softened and caused to become highly adhesiwe, whereupon same films are joined under the application of a pressure.

According to another feature of the invention, it is also possible to obtain a mutual contact and adhesion of films laminated on both sides of the net-like weave, in practically all points corresponding to the spaces that are left amongst the crossed yarns of same weave, enclosed therebetween, providing moreover the possibility of establishing a firm bond between films of polyethylene or of other plastics that are incompatible with the already known bonding agents by having the films heat welded.

The equipment shown in the FIG. 7 is designed to operate downstream of a manufacturing equipment generally indicated with D, and that corresponds to equipment as shown in FIG. 4, except for the absence of the device by which an adhesive is applied to the components. Such equipment comprises rollers 11 and 12 that are driven in opposite directions, and between which the zone T is left. To such zone, wherein the net-like weave is formed, are fed also the sheets or films 21 and 2'2, which are thus laminated on both sides of said non-woven textile structure. Downstream of said zone T, the laminated material S is delivered.

The example which will be described hereinafter relates to a typical embodiment form of the invention, wherein said laminated material S comprises outer polyethylene films 2,1 and 22, which are then heat welded with one another, thereby enclosing and bonding the inside net-like weave S (see FIG. 8) therebetween, after all gas locks and minute air pockets, possibly yet trapped between said films, downstream of zone T, have been wholly eliminated.

The progressively fed laminated material S' is passed between the members 3ft and 31, that are driven in opposite directions. At least one of such members, eg. the member 30, consists of a roller whose surface is formed with a plurality of small and thin pins 32 (shown enlarged in the FIG. 8), while the opposite roller 31 is provided with a coating 33 of resilient material, designed to press the laminated material against said pins without damaging either said material or said pins. Thus, the laminated material, after Ihaving been passed between said rollers, will be perforated in a plurality of points, and preferably in such a manner that at least one hole is punched in each space left between the crossed yarns or net-like weave S.

The perforation of films 21 and 22, or also of one of them only, could also be carried out before their feeding to rollers 11 and 12, e.g. by having them passed over a temple roller 30.

Owing to such manifold perforation of laminated material S, all air pockets trapped therein lcan be removed by means of a subsequent calendering or pressing of the material in order to bring the inside surfaces of films 21 and 22, into mutual contact on the whole area of the spaces that are left amongst the components of the netlikeweave S.

After the above operation, the laminated material is passed over a large diameter roll 34 in such a manner as to make a tight contact over a large sector of the surface thereof. Such roll is heated by inner or outer heat radiating means, or by having a hot uid circulated through suitable pipings 35, 0r by other suitable means. To .have the laminated material tightly pressed against the surfaceof roll 34, without however subjecting the material to tension stresses, recourse can be made to the already known implement, consisting of an endless weld band 36, running around rollers 37 and 38, and around a third roller 39, that may serve also to keep the band duly stretched, e.g. by applying to roller 39 a force F, exerted by suitable means, e.g. by a weight 40, or -by a spring, or by hydraulic, pneumatic, or like devices.

of the equipment will depend on the fea- Downstream of the abovedescribed equipment, wheren the laminated material is After the cooling, the laminated material can be wound, e.g. on a beam or bobbin 45 for storage, transport and possible further processing, before its final utilization.

The films 21 and 22 can be heated up to the temperature as required for the welding thereof, also before they are fed to the cylinders 11 and 12, e.g. by having them contacted With other heated cylinders, or 'by infra-red radiators, or the like. In such a case, the welding is performed simultaneously formation of the net-like weave, in the same zone T, after which the cooling implements can be arranged.

What I claim is:

1. An improvement in and to the method for the manufacturing of non-woven textile structures, comprising the steps of feeding at least two groups of originally straight and parallel yarns, along an equal number of converging respected planes, to two members that are driven in opposite directions,

ing laterally reciprocating, along a line transverse to the direction of yarn feed and upstream of the members, at least some of the yarns of at least one group, whereby the thus reciprocated yarns will enter between the members at an angle to the direction of yarn feed, and which angle is continuously varied due to the reciprocation, so that the thus reciprocated yarns will follow a sinusoidal course downstream of the members; the thus reciprocating yarns forming the weft of a net-like weave while those straight warp of the net-like weave; characterized by laterally reciprocating the weft-forming that the weft is laid with weft yarns arranged in symmetrically opposite undul-ations, and in a number such that at least ten warp yarns, and fteen reversely undulated weft yarns, are crossed by each weft yarn.

5. A method according to claim 1, for the manufacturing of non-woven textile structures comprising the step of lfeeding at least one strip of sheet material beween the members in contact with at least one surface of the net-like weave, and effecting adherence between the strip and the net-[like weave at the contact zone.

6. A method according to claim 5, characterized by feeding t-wo strips of sheet material along two respective converging planes to and between the members so that the net-like weave is set in contact with the strips of sheet material.

7. A method according to claim 5, characterized by the step of adhering the yarns forming the net-like weave at least partially to the strips.

8. A method according to claim 7, characterized in that the net-like weave is formed and simultaneously enclosed and pressed between the strips, and adhered to the adjacent surfaces of the latter.

9. A method according to claim 8, characterized by lthe steps of applying thin films of an adhesive agent solution to the inner surfaces of the strips at zones located the inlet zone of the members, and at `a are contacted with the yarns forming the net-like weave. 1t). A method according to claim 6, including the steps of punching a plurality of minute holes in at least one of strip, in order to vent `all air or gas pockets trapped between the strips.

1l. A method according to claim 10, characterized `n that in order to insure the removal of any air pockets.

12. A method according to claim 10, characterized the compound material, wherepressure on the compound structure to force air from between the strips.

15. Apparatus for manufacturing compound, nonwoven textile structures including a net-like weave enclosed between strips of sheet material applied to both surfaces of the net-,like weave and `directly bonded to 11 plurality of closely arranged minute holes through at least one of said strips; pressure means operable to exert a pressure on the compound structure; and heating means associated with said pressure means to heat the compound structure to the welding temperature as the strips are pressed into contact with each other.

16. Apparatus as claimed n claim 15, in 'which said pressure means and said heating means comprise a rotary `drtun positioned downstream of the zone at which the compound structure is formed; means for heating the surface of said drum to a temperature sufficient to heat said components to the welding temperature'. an endless revolving band engaged with the drum surface throughout an arcuate extent thereof; and means operable to tension said band to maintain the advancing compound material pressed against the surface of said drum.

117. Apparatus as claimed in claim 15, in which said heating means is positioned upstream of the zone at which the compound structure is formed and is operable to heat the components of the structure to `the welding temperature; and a pair of rotary members rotating in opposed directions, and forming a nip through which the components are fed to form the component structure', said rotary members constituting said pressure means.

18. Apparatus as claimed in claim 1S, including cooling means engagable with the welded structure and positioned downstream of the pressure means and the heating means.

References Cited by the Examiner UNITED STATES PATENTS 1,433,971 10/1922 Roberts 156-87 1,957,732 5/1934 Rowe 156-87 2,189,069 2/1940 Jensen 156-311 X 2,387,631 10/1945 Weir 156-311 X 2,511,703 6/1950 Ettl 156-311 X 2,738,298 3/1956 David et al 161-58 3,095,338 6/1963 Romanin 161-142 EARL M. BERGERT, Primary Examiner. HAROLD ANSHER, Examiner.

Claims (1)

1. AN IMPROVEMENT IN AND TO THE METHODFOR THE MANUFACTURING OF NON-WOVEN TEXTILE STRUCURES, COMPRISING THE STEPS OF FEEDING AT LEAST TWO GROUPS OF ORIGINALLY STRAIGHT AND PARALLEL YARNS, ALONG AN EQUAL NUMBER OF CONVERGING RESPECTED PLANES, TO TWO MEMBERS THAT ARE DRIVEN IN OPPOSITE DIRECTIONS, GRIPPING THE YARNS INTO CONTACT BETWEEN THE MEMBERS TO SET THEM IN THE RELATIVE POSITIONS IN WHICH THEY ENTER BETWEEN THE MEMBERS; CAUSING LATERALLY RECIPROCATING, ALONG A LINE TRANSVERSE TO THE DIRECTION OF YARN FEED AND UPSTREAM OF THE MEMBERS, AT LEAST SOME OF THE YARNS OF AT LEAST ONE GROUP, WHEREBY THE THUS RECIPROCATED YARNS WILL ENTER BETWEEN THE MEMBERS AT AN ANGLE TO THE DIRECTION OF YARN FEED, AND WHICH ANGLE IS CONTINUOUSLY VARIED DUE TO THE RECIPROCATION, SO THAT THE THUS RECIPROCATED YARNS WILL FOLLOW A SINUSOIDAL COURSE DOWNSTREAM OF THE MEMBERS; THE THUS RECIPROCATING YARNS FORMING THE WEFT OF A NET-LIKE WEAVE WHILE THOSE YARNS WHICH ARE NTO RECIPROCATED LATERALLY AND THUS PASS THROUGH THE MEMBERS IN PARALLEL RELATION TO THE DIRECTION OF YARN FEED FORM THE STRAIGHT WARP OF THE NEL-LIKE WEAVE; CHARACTERIZED BY LATERIALLY RECIPROCATING THE WEFT-FORMING YARNS THROUGH A RANGE SUCH THAT THE WEFT IS FORMED WITH UNDULATIONS FOR HEIGHT OF WHICH IS ONLY A FRACTION OF THE OVERALL WIDTH OF WEAVE, AND THAT AT LEAST TEN WARP YARNS ARE CROSSED BY EACH UNDUALATION OF WEFT YARN; THE DISTANCE BETWEEN TEH LINE OF RECIPROCATION AND THE GRIPPING LINE BEING LESS THAN THE AMPLITUDE OF SAID UNDULATIONS.

Images