DE1560660A1 - Non-woven fabric - Google Patents

Description

description

XHHIWWiMWH-WIlMWMMWl IHIl if

to the patent application

of the company BiIB ⁵ ISH IiYLON SPIHNEHS KPD., Pontypool / Monmouthshire,

Great Britain

concerning:
"Non-woven fabric"

The priority of filing in Great Britain on July 20, 1963 becomes in Availed.

The invention relates to the manufacture of non-woven fabrics and in particular a method for. Manufacture of non-woven textiles t off e of the bound tape type.

In the manufacture of non-woven fabrics of the bonded type Ribbons A ribbon is formed from loosely related fibers and subjected to a binding treatment in order to make the individual fibers bind »so that to a certain extent dimensional stability and tensile

9 0 9839/1227 ^ΒΑυ ... / 2

strength of the fabric is achieved. The binding organ can, for example be carried out by the fact that the whole band with a natural or artificial resin is impregnated. If the tape contains thermoplastic fibers, the bonding can also be achieved by using Heat, and often also pressure on the belt can be achieved

Regardless of the form of the all-pervading bond the fabric preserved not only stiff and bratt like _t but also has a unangenshne: i stick handle and has few de. · Feature on "normally gewebb-m 'L'extilstoffen come" like a good eaIl and a soft, textile-like handle. The use of non-woven fabrics as a cheap alternative to woven or knitted fabrics is therefore severely limited.

To improve the grip and in the case of such non-woven fabric © to achieve from tied ribbons; it is already proposed been »to tie the barrels in the ribbon only in selected areas» and these areas are referred to as "binding areas". This type of tie is commonly referred to as intermittent or gridded bonding

One method of achieving this intermittent bond is a resin binder applied to the sliver by a pressure roller The surface of this roller is engraved in accordance with a master in such a way that “when it is held in the recesses that receive the binder Binding resin is transferred to the tape that needs «binding pattern printed on it will. The tape is then subjected to a drying process

909839/1227 ... / 3

SAD OFHGiNAL

the Han; essentially in the pattern in which it was printed on the tape. This process is not entirely satisfactory .. On the one hand it is schwiex'ig, a uniform distribution of Harsbinders chiroh the bead of the tape within the designated area in the pattern 'get λχ and diesa difficulty is always great $ when the tape is thicker. Experience has also shown that there is a general tendency, after the pressure has been removed, to diffuse beyond the boundaries of the areas provided in the cough, especially on and close to the surface of the tape o because of the irregular distribution of the resin binder, the finished nonwoven fabric has variable tensile strength, and because of the concentration of the binder on and off the surface of the tape and its diffusion out of the patterned areas, the effect of intermittent winding in improving drape and grip is limited . In addition to the disadvantages associated with this type of intermittent binding, the fabrics produced in this way have other disadvantages. In particular, the resin binder is generally not resistant to washing and dry cleaning, so that the fabrics can only be used in cheap, only one-wetting products . Furthermore, because of the presence of the resin, the fabric is easily flammable

If the tape contains ärmeaktivierbax ^ i.e. thermoplastic fibers, the binder pattern can instead be formed by the Tape is passed under pressure between two rollers, one of which one has a surface provided with a protruding master

909839/1227 /

• •• / 4

"BATH

is ι the rollers are heated so that only one compression subjected fibers are heated. The effective operation of this procedure to make an intermittent bond depends on having a sharp temperature difference between the protruding Maintain pattern areas of the roller and the remainder of the liaise and in practice this cannot easily be achieved.

It became, jCitE · ;; found that a faked bond in baths » the fiber «: nii; contain dielectric losses, can be achieved more easily by dielectric © welding, whereby a patterned Electrode or electrodes can be used.

Erfindungsgeinäss is thus a method Srur Preparation not made of woven fabrics of the type of bound bands available in which the fiber tape is bonded in a scoring chance subordinates Kister of spaced apart Bindebereichon clutch dielectric welding, wherein the band contains at least 3 ^ parsers are $ which has a dielectric loss in the frequency used during dielectric welding

In dielectric welding, the sliver is placed between two electrodes over which a high-frequency alternating current is applied. Under these conditions, if the frequency of the alternating current is chosen so that corresponding vibrations are excited in the molecular structure of the fibers, which show the dielectric loss / generate heat in these fibers. The amount of heat generated is therefore _s is determined depending on the physical properties of the fibers through the turn, v / IE to the applied AC voltage to react, the frequency of the

909839/1227

applied alternating current »and the electric field strength * Me ua oen Fibers Amount of heat developed in the unit of time »represented by H» can be expressed by a formula as follows

H - K f E ²

In this equation:
Not a constant
£ the applied frequency
E the electric field strength in the fibers Ig the dielectric constant of the material tg <£ the loss factor in the fibers,

Polyamides have a loss factor of 0.02 to 0.03 at 6506 relajtirer Humidity and 71 MHz. This value increases with the relative humidity to about 0.1. more information about the meaning of the loss factor in dielectric welding, the book "Fibers, Plastics and Rub * bera "by W, J, Hoff, pages 322 to 323 * Butterworths Scientific Publications I956 included.

The fetgi part of the formula is called the dielectric loss and is a characteristic of fibers that changes with the frequency of the applied voltage and also with temperature fluctuations being affected.

AIa consequences dsr in them during the application of the high-frequency alternating current The fibers exhibiting dielectric loss are activated, i.e. they are made adhesive, so that the heat generated is generated they benaohaarta fibers in the sliver ausammeribiaden.

9 0 9839/1227 ... / 6

bad original

The fibers that cause the dielectric loss for the welding process show the frequency used are called weldable fibers

Here and in the following, the term "fibers" is intended to mean both continuous threads and staple fibers or other short fibers.

A dielectric bond of the tape in a given master of mutually distant bonding areas is achieved by sending at least one electrode provided with a pattern. For best results, both the lower and upper electrodes are patterned, with one electrode being a kind of mirror image of the other. The electrode or electrodes can have a baralline line pattern _t that is either parallel or at right angles to the longitudinal axis of the piping tape ψ so that an imitation corduroy results. Instead, the ifa.i: r can also take the form of 45 zigzag lines separated from one another or of resolved equilateral triangles.

Other Muaterarten that are suitable for use in connection with the invention can Seohsecke *, triangles _# pike corner, parallelogram, "combinations of various polygons or Bhombenfarmen be mentioned.

The electrodes can be in the form of flat plates or either or both can be in the form of a roller. The electrodes can form a pair of cooperating migratory surfaces that define the area between them.

909839/1227 -. * ·· / ⁷

Crossing _a piece of fabric o Roller electrodes are particularly suitable for this purpose. Instead, the fiber ribbon may be continuously between the electrodes hiiidurcligaführt V7erden ₉ or it may be retained during the dielectric welding Sans.

She mentions “The pattern should be chosen so that the welds are sufficient are close together to ensure that every paser in the band is tied at least once along its length «Preferably the distance should between the welds must be less than half the length of the shortest fiber in the tape.

The tape that is subjected to the high frequency alternating current can be in in any way, and that in a special case The chosen method depends to a very large extent on the length of the fibers from j if other than continuous threads are used. Staple fibers » are continuous filaments and ribbons made from continuous filamentary yarns all suitable for edging in the invention

Staple fiber tapes can be made, for example, by a wool or cotton wool card or a Garnettmachine can be produced, whereby a The result is a tape in which the staple fibers are predominantly oriented in one direction can be used by itself, but in general it is necessary and desirable to superimpose a number of such bands, around a tape of sufficient thickness and uniformity for the intended use End use to build on «When building such a band you can alternate Layers γοη carding belts are arranged so that their

909839/122 7 · "/ *" ~ ~ *

^ ^Z 'BAD ORIQlNAL

Laser orientation at a certain angle »90 ° for the sake of simplicity, with respect to the intermediate layers. Such crossed ribbons have the advantage that they have approximately the same strength in at least two directions. Continue by cross laying in this way obtain a product with balanced stretchability. Statistical or isotropic staple fiber ribbons, e.g. by laying staple fibers in the air can be obtained. For example, a staple fiber tape that is used for the invention Process is suitable, can be obtained in that continuous threads are fed to a cutter or breaker, which delivers the pasers in a stream of air generated by a fan will. Appropriate guides are provided to guide a suspension of staple fibers in an air stream to a perforated surface on which the fibers are deposited as an interlocking and solid layer, preferably this depositing by suction on the other side of the surface is supported. The perforated surface can have the shape of an endless belt that runs past the place where the fibers are sujefführung, so that a continuous layer of undefined Length is formed. Instead of a running flat screen, a stationary shaped screen can be used for making molded articles be used.

Tapes made from continuous threads can be conveniently pulled off directly produced by a spinning unit (i.e. a polymer extruder), or they can be formed from a package or other storage device for already spun multi-filament or single-filament yarns. The threads (single or multiple) can be formed into a layered band by guiding them onto a Saami surface,

909839/1227 - * ⁰⁹

-9- 156066Q

where they are built up in overlapping layers, the ones being Threads in each layer are predominantly coplanar «parallel or essentially parallel to the collecting surface and to the bottom and top of the so formed band.

Ribbons made from continuous thread yarns »i.e. ribbons» in which the threads as multiple fMen are present, can conveniently in one procedure be put at home, in which freshly spun threads, one or more Pole door components contain "the effect of a turbulent Bochgeschrindigkeitt" fluid jet are exposed to the threads thinned and oriented and mixed together so that a twist-free yarn is formed »that in turn is forwarded by the fluid jet bowegt and on a receiving surface in an arbitrary loop shape o is laid

The ribbon can be composed entirely of fibers »some show dielectric loss at the frequency used for welding (tearable fibers) »if it is only necessary» that the sliver 5ρί contains such fibers and therefore up to zn 95 (£ other fibers may be added, for the sake of simplicity than not activatable fibers should be designated »if it is only necessary» that the fibers cannot be activated under the conditions » among which the weldable fibers show dielectric loss.

Every fiber has a dielectric loss during the welding process The frequency used can be used to carry out the invention

909839/1227 - " ^{/ 1} °" _MA /

BAD ORlGiNAL

Methods are used, although preferably the dielectric loss exhibiting fibers, i.e. the tearable fibers, should not be essentially crystalline or should not recrystallize on cooling after welding. So even if the polyamides, For example, polyhexamethylene adipamide (nylon 66) and polyepsiloncaprolactam (nylon 6) can be used as weldable barrels » so the welded welds obtained are brittle and tend to tend because of spherical crystallization when cooling down after welding Cracks when the fabric is folded. However, this problem can occur can be eliminated if these fibers are spun with suitable crystallization inhibitors.

Suitable weldable fibers in the polyamide series are, for example Copolymers of polyethyleneadipamide and polyepsiloncaprolactam in the 80/20 and 75/25 weight ratios of these copolymers are essentially non-crystalline.

Particularly useful, non-woven fabrics can thereby be obtained that hetero threads are used as weldable fibers. the Heterofldeo consist of at least two components, i.e. a weldable and a non-activatable component are in the same fiber combined, the weldable component forming at least part of the circumferential surface. It goes without saying that here and in the following Speaking of the hetero threads as weldable fibers, that is of course correct only in respect of their weldable components. The expression weldable component should have the meaning that was previously for the

909839/1227

Atisdruck sctareisshare fibers has been explained "

May further hetero threads components except the weldable and non aktiviorbaren component contained ^ although for simplicity df.e Z iEprschung at this point to Zueikomponenten hetero filaments limited sain 30II. In cross-section, the two components are shown as separate 2o2ie_i: dn. Me components can be eB * side by side, or one Lc-isi-nnents can be completely and eccentrically encompassed by the other component T? _{Erden s} d.ho a molded shell "and core" relationship with the component forming the shell being the weldable (heat-activatable) component, or the hetero thread cannot be circular »for example three-lobed, with one or two of the lobes being made by the weldable component. The relative proportions of the two components in the hoter Dfäden can be varied according to the final use _for which the product; is provided.

Suitable components for the production of the hetero thread can be found in all groups of synthetic fiber-forming materials »with the restriction that one component of the hetero thread must be weldable, ie it must show a dielectric loss at the frequency used in the weld spike. Because of the commercial availability ₉ of the light treatment and the excellent properties are the condensation polymers, for example polyamides and polyesters, and particularly those ^ _t may be the schmelzgaßponnen for use Beie. erfindiittgsgemässen method very suitable "Other Straight threads j vsi-xrendet can be, for example, those who ven based? olyesteraniideii _f Pol.ysulfononideiij polyesters, polyolefins? anes or any combination of these polymers

9 0 9839/1227 * ·· / ¹²

BATH

or contain them, the only significant limitation therein lies »that the components of the hetero thread are sufficiently compatible, to resist fibrillation.,

Examples iait suitable Eetero threads in which both components are fiber-forming Polymers aind can be found in the following table:

Weldable component. Component that cannot be activated

Poly-omega-aminoundscanons, acid, polyhexamethylene adiposide

Copolymer of polyhexamethylene adipaBiid polyhexamethylene adipaBiid and poly-epailon-caprolactam in various Shares

Copolymer of polyhexaethylene adipamide polyhexamethylene adipamide and Polyhexanie jhylen ^ iibacaniid in different Proportions by weight

Terpolymer made of polyhexamethylene adipamide / polyhexamethylene adipaniid poly-epsilon-caprolactam / polyhexamethylene "
sebacamid in various proportions

A number of methods are available by which the heterofilaments can be made. They can be produced, for example, by the methods described in British patents 579 081, 580 764 and 980 94I, which describe a spinning together of the polymers from the melt ₉ from the plasticizing melt or a hass or dry spinning, so that they have a uniform appearance form. Suitable methods and devices for use in the production of hetero threads _f in which the components are side by side by melting

909839/1227 ~ · - ·· /! 3

spinnen * are described, for example, in patent applications 27 350/61 and 29 295/62. »Before or during spinning, pigments» plasticizers,! dyes ₉ moth repellants, fire retardants, fillers, abrasives and / or light stabilizers can be added. In particular, it may be desirable to the spinning solution or to add otherwise the schseissbaren component of the hetero yarn suitable substances for lowering the softening point, for example, plasticizers, soft resins, and the like · * Suitable plasticizers for this purpose are, for example, dibutyl tartrate, Xthylphthalat and A * thylglycollat _o Examples of suitable Soft resins are polyvinyl acetate, ester rubber, coumarone hara and the alkyd resins with lower molecular weights.

Up heterofilaments can be welded with others and / or not activated Fibers can be mixed if desired.

As non-activatable: fibers, all fibers can be used, .the are not activated at the frequency used. Examples are . non-thermoplastic fibers such as cotton, wool, rayon, fibers made from polymers based on acrylonitrile, for example acrilan (registered trademark) or other synthetic fibers that contain a show dielectric loss (but not at the frequency used) like the polyhydrocarbons, for example polyethylene and polypropylene. .- ■ - ·. . - ...-'-_.- ■, -,. .

The method according to the invention will now be based on the following examples on sand will be explained in more detail, which, however, does not fall within the scope of the invention should restrict.

, .- '* 9 0 9839/1227

BATH ORIGINAL

example 1

A Msügo:> t: .a (2 ^I! ) Long staple fibers with a denier of 6 made of hetero: ·: -d.il, made from the same weight of folyhexamethylene adipamide and a commendable 8O / 2O copolymer of polyhaxamethylene adipaaid and poly-epsilDT: - i! aprolaotam (Bylon 66 // 66/6), in which the corn, ponent strings lie side by side, was mixed with an equal {Jewichtmengo of 38 β® (1 1/2 ") long cotton fibers.

The mixture was then crimped on a cotton card into a loose sliver weighing about 6 ounces per square yard. The sand was then pressed a dielectric Sehweissmaschine between the two electrodes "in such a way that one side of the tape iimaßr in contact with a fixed electrode stand, over which it moved _f while the other surface of the tape in shelf periodically with a patterned electrode was touched. The alternating frequency applied to me was 73 MSa * Bas Huater on the electrode was in the form of 5 parallel lines extending over the length of the electrode and spaced 6.5 mm apart (0.2%). Through those in the praying threads The heat generated by the high frequency alternating current activates the copolymer component of the heterofadena, that is, it is made adhesive so that it serves to bind adjacent fibers in the sliver parallel lines 0.5 aim (0.02 ") wide had a soft, comfortable feel, good dietary strength, and adequate tensile strength.

... / 15

909839/1227

"BATH

Example 2

The method of Beiapiel _g 1 was repeated except that instead of the 6 Baumwollfansom it uses (2 i / 2 ") long rayon Kunstseidefasera with a denier of 3 mtrden.

The sliver snapped well and resulted in a non-woven fabric » which is characterized by a soft taxi-like handle and good tensile strength was «.

Example 3

A carding tape "consisting of any mixture of 30 ^{parts by weight of 38 mm (i 1/2 H} ) long polyhexamethylene adipamide staple fibers with a denier of 3 per thread and 70 parts by weight of 38 mm (1 1/2 ^M ) long staple fibers of an interpolymer -von 8O / 2O polyhexamethylene adipamide and polyepsiloncaprolactam and a denier of 5 per thread were dielectrically welded using an electrode which was patterned in the form of a resolved 45 zigzag pattern "at a frequency of 73 MHz" The lines of the zigzag master were like this wej / fc apart »that there were 4 pieces per 5 on (2 per inch) across the width of the tape. The resulting nonwoven fabric had a soft hand, good drape, and adequate tensile strength in both the length and width directions

Example 4

A brim abaijil made of 80 parts by weight of 38 mm (1 1/2 ") long staple fibers

909839/1227 '"^

BATH ORIGINAL

made of polyhexamethylene adipamide with a denier of 3 per thread and 70 (1 1/2 ") long staple fibers from one Hetero thread with a denier value of 6 per thread consisting of equal parts of pile; would come from thy lonadipaiaid and any 80/20 copolymer consisted of polylrxraniethylenadipamide and polyepsiloncaprolactam » treated in the manner described in Example 3, so that a non-woven fabric with a softer feel and good strength and maturity revealed.

Example 5

A krempal tape consisting of any mixture of 20 parts by weight of 15 cm (6 ") long staple fibers with a denier of 12 per thread of polyhexamethylene adipamide and 80 parts by weight of a hetero thread of equal parts by weight of polyhexamethylene adipamide and any 80/20 copolymer of polyhexamethylene adipamide and polyepsiloncaprolactamide the two components lying side by side, was fed dielectrically at about the surface of the belt at a distance divided from each other points with electrodes that had a profile in the form of small dissolved equilateral triangles. the Schweisaflächen resultant were about 6 _S 5 mm ( 0.25 ") long and 0.5 mm (0.02") wide. The fabric obtained had a soft handle and good drape.

Example 6

A Krempal tape, made of any mixture; of 30 weight

909839/1227 ° * ° / ¹⁷

BATH

Divide 6 cm (2 1/2 ") long polyvinyl chloride fibers with a denier of 3 and 70 parts by weight 4 cm (1 1/2") long polyhexamethylene adipamide fibers with a denier of J were dielectrically welded using an electrode that had a pattern in the In the form of small dissolved equilateral triangles. The welding surfaces resulting from the activation of the Polyvinylohloridfasern than the sohweissbaren fibers "were about 6.5 mm (0.25") long and 0.5 mm (0 _s 02 "wide); The resulting fabric had a textile-like feel and drape and good tensile strength,

Example 7

A lot of 5 cm (2 ") long, 6 denier staple fiber Hetaro threads from equal parts by weight of polyhexamethylene adipamide and one any 80/20 copolymer of polyhexamethylene adipamide and polyepsiloncaprolactamine where the two components lay side by side « carded on a Baurawollkrempel and the thus formed fiber strands Crossed in the usual way »so that there is a loose sliver weighing about 6 ounces per square yard. This tape then became dielectric according to the technique described in Example 1 welded.

The resulting non-woven fabric, lay over which a series of parallel line-shaped binder areas, wherein the binder of the activation of the weldable Kopolymerkomponenten was obtained of the hetero _s yarn had a good case, and excellent tensile strength "

909839/1227 bad original

Example 6. ·

Heterofilaments consisting of equal parts by weight of polyhexamethylene adipamide and any 80/20 copolymer of poljrhaxamethylene adipamide and polyepsiloncaprolactam, in which the two components work side by side was spun in a continuous manner through openings in a spinneret and then into a bundle at the opening of a suction jet merged. A high-speed air stream acted on the threads in the suction jet one that came in through an inlet in the side wall of the jet «toroidal vortex, the axes of which are essentially perpendicular to the central axis of the threads, presumably have formed inside the nozzle, so that a turbulent zone is created around the threads which had the effect of flinging the threads from side to side and mix them up. The intermingled yarn thus obtained was passed through the air jet emerging from the nozzle is conveyed to a receiving surface, where it is deposited in an arbitrary loop shape, so that a tape made of continuous filamentary yarn weighing about 6 ounces each Square yard was formed. The tape was then dielectrically welded in the manner described in Example 1 and the one thus obtained intermittently bound not woven. Fabric had a soft, comfortable feel and good drape.

The non-woven fabrics according to Examples 7 and & differ of previously available intermittently bonded non-woven fabrics advantageous in that they have a homogeneous character, because the fibers that serve to hold the fabric together (binding fibers) have the same chemical structure as the fibers that make up the material Give structure.

909839/1227 ... / claims

Claims (1)

Claims M =. Process for making a non-woven fabric of bonded tape type? wherein the prepared a fiber tape and the tape in a predetermined pattern of spaced binder areas bound XiXXU ₉ characterized in that the sliver at least 9 $ SGhVTeisGbaye fibers "as _s defined in the description contains and dio bond according to a pattern by dielectric welding as' use TQA at least one? with an electrode provided with a tiuater. =. 2.ο method of claim 1 wherein _{S p} that the sliver in the t? Orm present Onea band aua staple fibers or continuous filaments _t a continuous filament yarn ■ " ο Vexrfahrsz. according to claim 1 »characterized» that the sliver contains at least 2C ^ weldable fibers and optionally existing. Besi: / non-activatable fibers in the sense of the description consists., 4 <. Method according to claim 5 »dadurcli marked that the weldableeii Fibers are derived from hetero threads or take the form of hetero threads habenj, the at least one weldable component and at least contain a non-activatable component ;. Verfahy <m "according to claim 4» characterized in that the welding-'bare un / j öj'.o nS.oht aktiviorbare component of the side Heterofade'ns 909839/122 7 = .. / 20 BAD ORJQlNAL —ESJ— 6. The method according to spoke 4t daduroh characterized in that the echveiss bare component of the hetero thread is arranged as a sheath around a core from the non-activatable component. 7. Method according to claim 4 and 5, characterized in that; that the sohweieetliare component is poly-omega-aminoundecanoic acid » 8 · The method according to claim 4 and 5, characterized in that the Weldable component a copolymer made of polyhexamethylene adipamide and is polyepsilon caprolactam. 9 «Method according to claim 7 and 8, characterized in that the non-activatable component polyhexamethylene adipamide is » MHNG. H. FINCKE DIPL.-IN ©. H. BOH * OiL-ING. S. STABSCK 909839/1227