DE1435114B - Method for producing a nonwoven fabric - Google Patents

Description

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This invention relates to a method of production bound by a binder so far that the un-

development of fiber nonwovens, which by thermoplastic elongated fibers in a certain relative position point-

Polymer binders are bound and crimped together with a bond strength

Contain fibers. ("Fibers" in the present context means to be, which is sufficient that any through internal

Connection between »fibers and / or threads«.) 5 forces, tensions in the fibers do not

The possibility of the material properties in a relative displacement of the fibers, but fiber nonwovens over a wide range of properties - only in a spectrum taking place between the binding points - can affect different utility properties - fiber curvature. If one assumes to be able to turn off in a similar way, as is the case with such a prepared nonwoven bandage, which is therefore applicable from the conventional fabrics, is in itself io unelonged and temporarily only slightly, but sufficiently known. The most common means of controlling the interconnected fibers is the possible utility value, in addition to the selection of fibers, in particular to increase its volume, and the binding technique is initiated in particular. In particular, the firm now the fibers of the fleece to a spontaneous length binding of the fibers forming the fleece by means of an enlargement, so inevitably a multitude of randomly distributed point-shaped adhesives arises in the fleece interior, an increased pressure, which provides the temporary point bonding is a generally preferred means on the one hand the fibers are improved. Is it still possible to use the non-elongated fibers to achieve an increased tensile strength of the fleece, on the other hand temporary fiber binding to achieve a high degree of flexibility. The use of a thermoplastic agent and the use of thermoplastic binders and their subsequent fiber elongation through the action of heat, activation through heat and pressure, is the most useful means for regulating the quality of the fleece at the softening temperature of the binding agent. In practice, however, this known binding technique is ensured by the fact that at the end of the process the nonwoven is burdened with the difficulty that with the setting of a high binding and thus a high tensile strength, a nonwoven property has a certain target value, but that, in addition, the already optimal, inevitably the change in another fleece properties - flexibility and voluminosity of the starting fleece, which consists of unelonged shaft in undesirably accepted fibers, does not have to be reduced. So is z. B. the increase in the nonwoven tensile strength has even been improved according to the degree of fiber elongation by increasing the proportion of binder. , .- readily possible, but one must thereby possibly The described process can also go abgeweise * undesirable reduction in the flexibility converts in 30 that purchase fiber are taken at the initiation of the. On the other hand, keeping the fleece volume constant, especially when using thermoplastic binding, could be dispensed with, provided that the main focus on the tear resistance is not achieved through the use of a more targeted fleece properties on the high tensile pressure, which, however, in turn strength, but in the voluminosity and resilience is only at the expense of the pliability, especially the yield of the fleece (e.g. for upholstery purposes). Cost of bulkiness could succeed. The solution of the complex and diverse effects of the known standing technical problem in the described processes is achieved according to the invention binding techniques on the spectrum of material in that a nonwoven material is used as the starting material to hinder and complicate the adaptation, which is predominantly or exclusively the Fiber nonwovens to the varied conditions 40 made of self-elongating fibers known per se (cf. the requirement. Belgian patent specification 566 145) in the unelonged addition

It is already known in the fiber nonwoven technology that existed, and that known thermal shrinkage properties of certain fibers for the nonwoven to use plastic binders for the temporary and final binding technique. The realization that both fleece binding are used,
the tendency to shrink certain fibers, as well as the 45 subject matter of the invention is a process for the tendency to elongation of the self-elongating nonwovens containing fiber nonwovens from a starting fiber to intermolecular change processes, which became known with the Belgian patent production of bound and crimped fibers writing 566 145, which is wholly or partially from synthetic, organiin of the fiber substance, the see fibers are made and this is based on an in the invention. 50 gangs fleece distributed thermoplastic polymers

The object on which the invention is based - binders under the action of heat through formation position is solidified in the idea of microphysical, spatially separated binding sites see, which are outlined below: denotes by

Assuming that one is made from unelonged fibers

existing non-woven fabric by means of known binding 55 ^a ) ^the use of a starting non-woven fabric, whose fiber technology through point-like connection of adjacent components to 50 to 100% of fibers that can be used per se and through compression with certain ^th > self-elongatable fibers and / or threads under pressure a certain tensile strength exists in certain ungelängten state which has become the intrinsic flexibility and bulkiness, so must have shaft, that they are at fünfminütlichem it but without any delay the tensile strength of possible 60 heating to a 3O ⁰ C above its Einfriersein, the bulkiness and flexibility of the nonwoven fabric Increase the temperature that is too high by at least if the 3% expand without changing the relative position,

Attachment points the length of the nonwoven fibers in general b) and the use of 3 to 50 percent by weight, is enlarged. Accordingly, an additional one, based on the finished weight of the fleece, would be one per se Valuable means for the adjustment of the fleece own 65 known thermoplastic binder, its Shank found if it succeeds in the following process optimal bonding temperature in the range of to trigger: an optimal elongation temperature of the Fasermate fiber structure consisting of unelonged fibers (Starting fleece) is initially located temporarily rials, and that

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c) esters the fleece during heating to control, such as polyethylene terephthalate, polyhexahydro-

of the volume clamped or in a form p-xylylene terephthalate and similar polymers that

is being held. by reacting terephthalic acid with ethylene

glycol or similar glycols are produced

5 are preferred for the method according to the invention. Polyamides are also suitable for this purpose are so-called “fibrids” * that are unsuitable, especially poly- (p-xylylene azelaic acid amide). rigid, purely synthetic polymer particles, which for example consist of further self-elongatable fibers Formation of paper-like structures are capable. Fibrids from polyurethanes, polyacrylonitrile, polyolefins, such as particles used in the practice of this invention include polypropylene and other polyadic data. Polyester turns are in detail in the IO fibers are the preferred according to the invention, self-Belgian U.S. Patent 564,206. The tensile elongatable fibers.

initial strength modulus is the normalized cutting. It is usually desirable to use nonwovens continuously

voltage at 100% elongation and strength ^it is ously to produce by means of extrapolation, in which, for example, the usual

polishing the first straight piece of tension papermaking machines and other similar ones

Elongation curve according to ASTM test D-885-64 is 15 apparatus, such as carding, aerodynamically acting

it's correct. Fleece forming machines and other equivalent devices

The new method allows in simpler and more simple ways that can be used. Railways that are faster Way the production of new fiber nonwovens contain elongatable (endless) threads, can be reduced Manufacture with high tensile strength, tear resistance, drapable processes in which by means of electrostatir strength, suppleness, softness and density or shear charges the formation of the nonwoven Voluminosity and also excellent equal structure is steered, as it is for example in the moderation. The new nonwovens can be described on British patent specification 932 482, wherein Areas used that previously woven the threads during or after web formation Were reserved for fabrics. For example, can be relaxed from, then spontaneously when heated be able to stretch them women's dresses, suits, costumes, coats, 25.

Sweaters and the like can be produced. On the other hand, usable staple fibers are short staple fibers,

according to the invention, such fiber nonwovens are also produced which are 6.4 mm or shorter; but it is often desirable

due to their properties, such as with longer ^ fibers, such as staple fibers of 76 mm

Bulky, resilience and rebound-length to work. The distribution and deposit

speed, are suitable as upholstery inserts. 3 ° such fibers in a flat product

The synthetic, organic, polymeric fibers produced by the use of foaming-dispersing agents are preferably polyester fibers, in particular those made of polyethylene terephthalate or when working with viscous liquids. In the case of an embodiment which is particularly preferred in connection with shorter fibers, the described aqueous dispersion process is facilitated. Binder in the form of polyester filaments before, the 35, by using longer fibers, the softening point will be at least 20 ⁰ C under DER tensile and tear strength of the inventive hergejenigen temperature lowest among the most easily c'er nonwoven fabrics increases,
softening non-binder fibers that melt. The web is heated to effect the elongation of the fibers, the binder has a tensile strength and the fusing of the binder with the fibers initial modulus between 0.002 and 25 g / den when the 40 at their crossing points. The measurement is made in film form. If the binding agent structure is prevented from being in the form of fibrids by clamping, the binding agent should assume a considerably larger surface area. The tensile elongation, preferably measured in fiber form, should be hindered to such an extent that an initial strength modulus of less than 0.9 g / denier than 5% linear growth of the nonwoven fabric is shown. The binding agent can also be prevented from a suspen 45 in any direction. This will be applied vorsion, which preferably brings about the copoly, in that the dry web merisate of an aliphatic ester of acrylic acid perforated between two grids or similar and of up to 5% acrylic acid is pressed in a quantity of structures. Stretch during pressing contains less than 10 weight percent solids. In a particularly preferred embodiment, the fibers or threads curl in the 5 ° thickness direction of the nonwoven fabric, whereby the heating end product causing the fiber elongation is provided with additional volume and a textile step while the fibers are given a grip similar to embossing. The clamping can also be pressed flat. by other means, such as pressing between flat or

The individual fiber components of the after the pre-curved surface, a curved upper

related method of this invention produced fiber surface and a grating as well as by others in the

Nonwovens have a high degree of lateral freedom and flexibility known from the molding technology and vacuum drawing technology

in the three dimensions, making them a high level of methods.

Degree of drapability and softness, high tensile strength. Embossing improves the fabric-like properties

firmness, small volume and a soft hand characteristics of the product. A pressing in the

obtained in the same area as woven fabrics. ^6o heat between grids causes the

With the expression "self-elongatable", self-elongatable fibers are used here, assuming a three-

Fibers are referred to, which when heated during dimensional configuration on the surface of the

5 minutes to a temperature that is 30 ° C above the nonwoven fabric, resulting from the penetration of

. Freezing temperature of the fibers, spontaneously at least parts of the fibers in the lattice gaps results,

at least 3% (cf. the Belgian patent 65 Such a configuration gives the substance Volumino-

scripture 566 145). Synthetic organic fibers that hold up and contribute to pliability and drapability

spontaneously joins the products under the conditions given above. The material can also be similar

stretch up to 30% or more, e.g. B. from poly to respond to other embossing methods.

Various surface patterns can be embossed. As a result, you can not only create a decorative and achieve a pleasant appearance, but also the physical properties of the nonwoven fabric to steer. So an embossed pattern results from a row running in only one direction, parallel, finer Lines is made up of a nonwoven fabric that is more flexible in one direction than in the other Has direction. With other embossing techniques one can get the feel of the nonwoven fabric and also its acceptability change in the case of printing, dyeing and other post-treatments that result in coloring. The volume of the nonwoven fabric can be controlled during the embossing process. You also need not even to work with a single embossing treatment. If desired, one can use the nonwoven fabric give an overall texture using wire mesh of the type mentioned and then give it in a second embossing treatment using plates, calenders, rotogravure rollers or the like. modify further.

In addition to the self-elongatable fibers and the binder that are used according to the invention, you can also use smaller amounts (less than 47%) of other fibrous materials. So you can Ordinary staple fibers made from any organic synthetic polymer or from cellulose fibers such as rayon, cellulose acetate and the like are added; preferably less than about 15 percent by weight is used, based on the dry weight of the web produced.

The sheets can be made according to conventional papermaking techniques from a loose slurry or suspension of fibers and binders, usually having a solids content of less than 10% (especially less than 5%) ^and preferably less than 1% in water. Liquids other than water can also be used as long as they are inert to the solids.

After making a water-deposited sheet from self-elongatable fibers and binders in accordance with the invention, the sheet is dried at a temperature sufficiently low to avoid any melting of the binder or any stretching of the fibers. Drying the sheet at 100 to 14O ⁰ C is generally sufficient; drying in the range of 100 to 12O ⁰ C is preferred.

The fibers in the web are usually expanded by heating the dry material to 150 to 250 ^° C. for a few minutes, usually less than 10 minutes. It is important that some binder melting (binding of the fibers) occur before the total desired amount of fiber elongation is achieved, and equally important that some elongation occurs before the total amount of binding desired is obtained. Preferably, both expansion and bonding occur simultaneously and this can be easily achieved by choosing an appropriate temperature which depends on the composition of the binder and the fiber. Usually, pressing the web at a temperature between 150 and 200 ° C is sufficient. Naturally, the exact degree of melting and the exact amount of expansion will depend on the temperature and duration of the pressing and the pressure applied. Under extreme press conditions, if a fibrid binder is present, the identity of the fibrid particle is lost and the fibrids are completely melted into the nonwoven fabric.

Particularly desirable nonwovens are those made from a batch of at least 25% of a fibrid binder made from an elastomeric polymer and at least 50% a self-elongatable fiber material that has an elongation of at least 10%.

Other valuable embodiments according to the invention are drapable and flexible, but somewhat more curled and stronger nonwovens made from approaches that are at least 75% of a self-elongatable Fiber with an extensibility of at least 10%. and at least 3 and no more contain than 15 percent by weight of a fibrid binder based on a synthetic polyester.

According to the present invention, pads can be made by subjecting the expansion and bonding treatment in such a way that the fleece fills the mold when heated. You can with one Binder work that responds to heat at the temperature of the expansion stage, so that when Heating and cooling in a mold, the structure adopts the shape of this shape.

Due to its tendency to expand when heated, this fibrous material lies in the finished product in a tortuous non-linear arrangement that gives flexibility, bulkiness and rebound resilience. The cause of the increase in Voluminosity of the fleece during shaping and thus the achievement of the desired bulkiness and the low density of the expanded, shaped structure resides in the elongation of these fibers between bonded ones Crossing points. Furthermore, the heat-activated binder melts under these conditions in contact with the hot mold surfaces, whereby a skin is formed on the molded structure. for any given amount of heat is understandably carried out proportionally in thinner parts of the structure stronger melting or bonding than in thicker parts. Regardless of whether the structure is in a However, essentially all should be binder preferably remain solid in the entire expanded volume of the final structure at the applied stretching heat. The binder preferably contains Fibrids in an amount of not more than 25 percent by weight, based on the finished, elastic Nonwoven fabric. In a typical preferred product according to the invention (as shown in Fig. VI) the edges of the body are compressed and fused together, while the center of the Body has an expanded structure of higher elasticity and can therefore be easily compressed, but immediately assumes the expanded state again. Of course, for certain purposes, some Inner parts of the object (in contrast to the edges) by melting together for remaining in the be held in a compressed state. The invention also includes other objects which some internal parts, a total of at least about 10% of the volume of the object, remain pressed together are and have a higher density, while the outer area is fused and sealed, but is not compressed.

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The F i g. I shows how the structures according to example

of the invention from thread-like material formed from 6.4 mm long staple fibers, whose fiber denier

be that statistically disordered, e.g. B. in the form of a 3 denier, which according to the working method of the Belgian

relatively thick fleece is present, and see numerous patent 556 145 have been made

Crosshair points by means of a binding agent, 5 and which show a spontaneous elongation of 10 ° / ₀ , if

like the fibrids at 2, is bound. After the picture, immersed it in boiling water for 5 minutes

binding of the fleece and securing the multitude, a fibrid slurry is produced,

These crosshair points will be the length of the by adding 3 parts of the aforementioned fibers with 2 parts

Threads between the crossing points enlarged; Fibrids are stirred in 10,000 parts of water,

the elongated thread is shown in FIG. II shown at 3. io A sheet is deposited from this slurry

F i g. III shows a cross-section of a fleece made from a den. The sheet is removed from the sieve, between

thread-like material 1 that is not stretched and see cotton cloth and a sieve with a sieve opening

brought to a large number of crosshairs of 1.7 mm and 3 minutes at 120 ° C

Fibrid tufts 2 is tied. dries. The dried sheet is then placed between

Fig. IV shows the same structure after 15 sieves with a sieve opening of 0.3 mm brought and

stretching of the threads between the crosshairs by pressing for 1 minute at 205 ° C and 14.1 kg / cm ²

score. This increase in length between the bound print bound. The sheet is then further hardened,

which points results in the formation an expan- by exposed to air for 5 minutes, of 165 ⁰ C.

sion pressure, whereby the structure is washed and drum-

Increases in size experiences a decrease in density. 20 is dried. The fabric obtained has a tensile

F i g. V explains in a plan view a preferred strength of 0.35 g / den, a drape stiffness of

management form, in which the binder at 19.1 mm and a tensile strength (wet) of 0.26 g / den.

Temperature at which the thread-like material The fabric retains its strength well when one

is stretched, responds to warmth. The melting solvent of the chemical-cleaning agents act

leaves this heat-activatable material on the surface 25. Embossing creates a fabric that

of the structure, in which the heat intensity on the creation is similar to the Oxford, an excellent

is strongest, leads to the formation of a thin skin and has this marked degree of whiteness when washing

melted fibrids, which means that the finished structure retains one and Pressen.jut, a medium porosity and

smooth surface ". has a good grip.

F i g. VI explains a shoulder pad 30 in cross section. During the hardening and embossing, the

for garments. This structure is in a flat sheet shape, if desired, a three-dimensional one

produced, in which the original fleece is given at Form.

the expansion of the filaments, and results in the production of the fibrid slurry

its cross-section, which tapers at the edges, was followed by a dispersion of a polymeric acrylic

a graduated density, the compressed 35 acid ester elastomers, the 92 ° / ₀ acrylic acid ethyl

Sections by melting the binder of ester, 6 ° / ₀ acrylic acid methyl ester and 2 ° / ₀ acrylic acid

these points of lesser thickness, at which the heat contained, from a solids content of 46 ° / ₀ , follow-

intensity and the pressure are strongest, in their degree converted into highly stable fibrids

Can be held. On request, this Schmel was: ■

to form thin skins of fused 40 One part of the dispersion, the 100 parts of elasto-

Fibers lead. contained meres, 5 parts of a monomeric bis-

The F i g. VII, VIII and IX are micrographs of diphenylolpropane with a glycidyl ether

one prepared according to the method of Example 5 epoxy equivalent of 175 to 210 and 5 parts butylating

th structure. tes melamine-formaldehyde resin (containing 1 part

Determination of drapability and drapability 45 melamine to 4 to 5 parts of formaldehyde) and 5 parts

stiffness are known means for comparison of titanium dioxide pigment added.

Textile fabrics. These expressions are in detail in The mixed material was on a mixer

U.S. Patent 3,117,055. of the Waring type, who found a 5 ° / _o solution

The voluminosity of a textile fabric is determined by sodium sulfate in hot water (75 ⁰ C) besides

by placing a square piece of material containing 50 0.01% of an organic quaternary ammonium salt

of uniform thickness, its dimensions, contained as a wetting agent. The mixer was during

including its thickness, measure and then run its volume of additive at full speed. It

men calculated. Measurement of the thickness of the sample yielded a fibrid slurry

follows by means of a conventional thickness meter for The compounded elastomer mixture can also

Textiles, such as an Arnes measuring device (manufacturer is 55 without conversion into fibrids as a binding agent

B. C. Ames Company, Waltham, Massachusetts.

V. St. A.). The sample is then weighed and the elastomer mixture can be pressed with an equal

Voluminosity as volume / weight unit. Volume of a 5% ^egg *> aqueous sodium sulfate solution

The tensile strength will be diluted using a and applied from an immersion bath.

Instron type tester in conventional 60. . .

Way on a 2.54 cm strip of the nonwoven fabric Example 2

definitely. For the purposes of this invention, a fiber suspension is prepared by

Tensile strength at room temperature and at a relative 10 000 parts of water with 3 parts of the self-elongatable

tive humidity of the environment of 65%. The polyester fiber according to Example 1 (staple length 6.4 mm,

Ratio of tensile strength combined textile fabric to its fiber titer 65 3 denier) and washed with a 5 ° / _o

Drape stiffness is a valuable means of solving polyethylene oxide-ether-fatty alcohol as

like the fiber nonwovens according to the invention are thoroughly mixed with surface-active agent

conventional fabrics, felts and papers. the. Such an amount is added to this fiber suspension

a slurry of fibrids made of an elastomer (of butadiene and styrene in the ratio of 45:55) is added so that 2 parts of fibrids are obtained in suspension form.

This suspension is then poured into the head container in a sheet form about 20 x 20 cm in size and a sheet is deposited on a sieve with a sieve opening of 0.15 mm. Excess water is squeezed off by placing the leaf, still on the sieve, between absorbent towels and rolling it with a steel pin. The sheet is then removed from the sieve and placed between sieves with a sieve opening of 0.3 mm, which in turn are placed between paper mache boards and ^{dried in a press for 10 minutes at 150 ° C. and 6.7 kg / cm 2} pressure. After this pressing, the non-woven sheet is in the form of a fabric which has a fabric texture due to the impression of the screens that were in contact with it during the pressing. The sheet is tested for its physical properties, a tensile strength of 0.18 g / denier and a tear strength of 13.5 g / g / m ^{2 being} obtained. The drape stiffness is 20.21 mm. When washing this sheet in a synthetic detergent and then dried at 8O ⁰ C, the strength of a tensile strength of 0.43 g / denier and tear strength of 15.5 g / g / m ² is increased, while the drape stiffness slightly to 18 , Decreases by 34 mm.

Nonwovens produced according to this procedure are suitable for clothing purposes. A nonwoven fabric weighing 85 grams per square meter, made from a water separated sheet on a Fourdrinier machine, is placed between screens with a screen opening of 0.25 mm, which are mounted on stainless steel plates, between the plates entered a press and held in this 5 minutes at 140 ⁰ C and 9.49 kg / cm ² pressure. The pressed material has a clear weave pattern that is similar to that of Oxford cloth. Dress skirts are made from this fabric, which is easy to sew.

As above, but using sieves with a sieve opening of 0.3 mm instead of sieves with A second nonwoven fabric weighing 153 g per square meter is produced using a sieve opening of 0.25 mm. This non-woven fabric is embossed in the same manner as above and then with a yellow-brown disperse dye colored. A windbreaker and trousers are made from this material.

A third nonwoven fabric weighing 186 g square meter is produced and subjected to screen printing without prior embossing. The printed fabric is then cut into pieces and between mm sieve with a sieve opening of about 0.7, which are mounted on stainless steel plates, shaped in a press for 5 minutes at 14O ⁰ C and 9.49 kg / cm ² Pressure . The pressed fabric is boiled in an aqueous solution of a synthetic detergent, dried, lightly brushed, sheared and subjected to a semi-decade.

In general, all of these nonwovens are found to be in the full broad range of square meter weights be handled in the manner indicated in normal textile treatments similar to woolen fabrics be able.

B eis ρ ie 1 3 ⁶ p

40 parts of a 20 percent by weight solution of a copolyester, consisting of 80 percent by weight of polyethylene terephthalate and 20 percent by weight of polyethylene isophthalate in dimethylformamide, are added in a steady stream to a mixture of 30 parts of water and 370 parts of dimethylformamide, which is operated at approximately 14,000 rpm Waring type mixer is cooled ^{to below 5 ° C.} When the polymer solution is added to the cold precipitating solution, the polymer is caused to precipitate and copolyester fibrids are formed. The fibrids are filtered off and washed with water until they are free of organic liquids.

From a batch of self-expandable fibers of the type described in Example 1 together with the fibrids described above, a nonwoven fabric is produced in accordance with the procedure of Example 2. Since a very effective bond is achieved with this flat material, a small amount of binder gives very satisfactory results. A sheet is made from 92.5% of the spontaneously extensible fibers and 7.5% of the copolyester fibrids. After formation of the sheet of material at 13O ⁰ C. and 3.5 kg / cm ² pressure between screens is dried and 'then fused between the same screen at * 190 ^o C and 0.7 kg / cm ² pressure. The sheet thus obtained has a weight per square meter of 105 g, a thickness of about 0.46 mm, a tensile strength of about 0.47 g / den and a firm but flexible handle which makes it suitable for use as an intermediate lining for a suit.

Using the same fibrids and fibers, but in different proportions, are made other planar structures produced. It turns out that if the amount of these "hard" (non-elastomeric) polyester fibrids to 2% or less no binding effect is obtained, which for Formation of a solid sheet is sufficient.

Example 4

On the device according to FIG. I of British Patent 932 482, sheet-like structures made of polyethylene terephthalate are produced. The threads 1 spun from the spinning nozzle 2 run in the manner shown in this figure over the rod guides 3, 4 and 5 C and then to a suction nozzle 6 which is fed through the inlet 7 with compressed air. The suction nozzle 6 has a thread passage extension 8 which widens outwards at the end 9 (6 °). The triboelectrically charged threads 10, which separate when exiting the nozzle extension, are collected on the receiving element 11, an aluminum plate. The various parts located on the downstream side of the spinneret 2 are earthed via lines 12. The important distances along the grain are:

a = 33.0 cm
b = 43.2 cm
c = 50.8 cm
d = 58.4 cm

e = about 10.2 cm
/ = 121.9 cm
g = 19.1 cm
h = 30.5 cm

The filaments are quenched with air fed 15.2 cm below the spinneret face will. The guide rods 3, 4 and 5 are 2.5 x 2.5 cm in size, have rounded edges and are made by Chromium (III) oxide is formed. The management staff 4, i. H. the working surface of the same is against the grain of the grain offset by 6.4 cm. The entire nozzle arrangement is made of brass.

In operation, polyethylene terephthalate (relative

Viscosity 34) through a 30-hole spinneret (hole diameter 0.178 mm each) with 10 g of polymer (Total amount) spun per minute. The spinning temperature, measured at the spinneret, is 284 ° C. Results:

Table I.

attempt

1
2
3
4th
5
6th

Air pressure (P)

atü

2.8
3.5
4.2
4.9
5.6
6.3

Thread properties

Tear resistance
g / den

2.0

2.4
3.0

3.5

3.5+

3.1

strain Wed % g / den 185 14.5 147 16.2 115 20.0 100 29.9 103 28.0 77.3 26.7

Titer den

10

1.72

1.37

1.15

1.1

1.03

0.97

Flat structures made of threads of this type can be bound with fibrids or with resin dispersions in the manner shown in the preceding examples. In all cases the product obtained are: J-products equivalent to those selbstlängbarer using staple fiber and comparable binding systems are obtained. Such sheet-like products are of value in all embodiments of the present invention.

In all experiments according to Table I, the feasibility of the process as well as the formation of the extensive Gebifdes good. The structures obtained are essentially free of aggregated filaments, i. H., the thread separation after charging is completely satisfactory.

In all of the experiments given above, atmospheric steam at approximately 150 ° C. is fed to the separated threads downstream of the suction nozzles, using an openwork member arranged in a ring with respect to the threads. The threads relax to 20 ° / ₀ or more under crimp. During the later calendering, the threads in the flat structure expand spontaneously, which further contributes to the crimp strength of the individual threads and thus to the properties of the flat J) structure:

The threads can also be relaxed by using a heated gas in the suction nozzle cause. In one such experiment, air at 6.3 atmospheres and 120 ° C has been used, leading to led to similar results.

When repeating this example with the modification that two or three threads the guide rods 3, 4 and 5 go around without touching, a planar structure is collected in which these are less oriented Threads as "binder fiber" are distributed through and through. The subsequent heating leads to Melting these threads, resulting in a structure with greater cohesion.

Example 5

60

Polymeric ethylene terephthalate is injected at 295 ° C. through a 27-hole spinneret (hole diameter per 0.23 mm) spun into threads. The thread material is wound up at 1097 m / min. The thread has in the spun state has a denier of 135 den (15 tex) and a birefringence of 0.0094 and is on Essentially amorphous due to its crystallinity. It is kept at 20 ° C by a conveyor roller Water bath and then passed on to a stretching roller, from which it is stretched (speed on the stretching roller 366 m / min.) and is wound up on a suitable package (stretching ratio 2.80). The birefringence of the drawn thread material is 0.1902. After the stretch it will Filament immersed in water at 70 ° C for 5 seconds, reducing it to 38.3% of its original length shrinks. The thread material obtained is spontaneously expandable; when exposed to boiling water for 5 minutes it will expand 11.6% of its original length. This spontaneously expandable thread is then cut into 6.4 mm stacks.

In a separate operation, according to Belgian patent specification 564 206 fibrids are made a copolyester (80 percent by weight polyethylene terephthalate and 20% polyethylene isophthalate), by adding 40 parts by weight of a solution in dimethylformamide containing 20 percent by weight of the polymer in a steady stream 400 parts by weight of an ice-cold mixture of 92.5 parts of dimethylformamide and 7.5 parts of water in one with about 14,000 rev / min. working mixer of the type Waring clogs. This way of working (Shear force precipitation) leads to copolyester fibrids, which are filtered off and washed off with water washes organic liquids free.

Then an aqueous fiber-fibrid slurry (solids content-0 _; 2 ¹ Y ₀ ) is prepared, the 91 parts by weight of the self-elongatable polyester staple fiber, 4 parts by weight of conventional polyester fibers (fiber titer 3 den [0.33 tex], length 6.4 mm ) and 5 parts by weight of the fibrids described above. From this, a 20.3 x 20.3 cm sheet weighing 20 g is deposited on a conventional paper hand scoop with a sieve with a sieve opening of 0.15 mm. The hand-scooped leaf obtained is dried in an air oven at 120 ° C; it is 10mm thick. A micrograph of a section of this structure is shown in FIG. VII. This sheet is then placed in a compression mold, which has the shape of a spherical section with a concave part of 20.3 cm in diameter and a maximum depth of 21 mm, the top plate is flat, while the concave part as a bottom plate in a hydraulic Press is used. The bottom and top plates of the mold are heated to 200 ° C and sprayed with a silicone release agent. The fleece is then placed in the mold and covered with a film made of glass fiber, which is coated with polytetrafluoroethylene resin. The mold lid is put on and the system is placed under a pressure of 704 kg / cm ² at 200 ° C. for 10 minutes. At the end of this period the mold section has reached full temperature and the pressure is relieved.

As a result of this shaping, a shaped body is obtained which has the shape of that described above Has assumed spherical section. The center of the fused product is enlarged by the Expansion based on the presence of the self-elongatable fibers from 10 mm in thickness to 16 mm. the Fibrids on the surface of the shaped body have melted, which is also the case with some internal fibrids the case is. Microscopic examination shows both melted and unmelted Fibrids in the central part of the formed body.

Since the original fleece has a square shape, its corners turn out to be tightly pressed together and roughly film-like. These corners are cut off

cut that the diameter of the remaining molded body that of the diameter of the shape-spherical section is equivalent. The cushion is firm and tight at the edges of this spherical segment compressed, though not stiff. In the middle part, the upholstery is very voluminous and elastic. Because some fibrids are melted inside and others are not, the central part of the Cushion elastic, fluffy and highly flexible. The type of fibrid fusion bond shows in detail the Micrograph according to FIG. VIII, Fig. IX shows in

IO

a photomicrograph a section through the melted bond according to FIG. VIII. The upholstery has an uneven thickness ranging from about 1 mm at the edges to about 16 mm in the highest part is enough, but the amount of weight per unit area of the pad is completely uniform.

Table II shows the composition of a number of similar pads made from various fiber-fibrid mixtures. All of these pads give a more than 30% greater maximum after compression molding Thickness than the original nonwovens.

Table II

sample Self-elongating fiber Conventional
Polyester fiber Polyester fibrids square meters
Weight Maximum thickness after
the compression molding % % % G mm 1 91 4th 5 119 21 2 85 10 5 119 23 3 75 20th 5 119 23 4th 75 20th 5 68 16 " 5 85 10 5 68 * 17th

The composite nonwoven fabric can be molded before deforming be surface-coated with fibrids by placing a thin layer of fibrid on the outer surface of the Fleece is deposited. During the subsequent deformation, the surface obtained in this way becomes the "Waxed" brought, whereby you get a light surface coating that is highly stable and against Resistant to pilling and fraying and prevents fibers from migrating out of the interior of the molding.

The surface coating need not be particularly thick in order to perform its function; h. to to increase the surface stability. A very small amount of fibrid makes a well-fused one Surface. The above examples illustrate coating with a fibrid slurry, man but can also use a fibrid-fiber mixture with a relatively high fibrid content instead.

Comparative comparison

45

Table III illustrates the advantages of the present invention and compares the nonwoven fabrics obtained with other non-woven fabrics and also with conventional fabrics. Samples 4 and 11 of Table III show that curl development by way of self-elongation provides a superior product after formation. The following abbreviations are used in Table III:

SA self-extendable,

"A" polyethylene terephthalate fiber of Example 1,

"C" polyamide fiber of example 3,
F fibrids,

"B" fibrids, made from an elastomeric terpolymer based on ethyl acrylate (Example 2),

ATP1 elastomer according to example 2 added as a dispersion in water (not in fibrid form),

ATP 2 elastomer, added as a solution, obtained by adding an equal volume of space Acetone to the dispersion ATPl,

"Al" modified fiber "A" obtained by expansion same in voluminous form before use, creating a crimped staple fiber with no spontaneous residual extensibility is obtained.

Table III Comparison of fabrics with nonwoven fabrics according to the invention

sample Fabric type Together
settlement square
meter
Weight
G thickness
mm density
g / cm ³ train
firm
speed
g / den Drapery
stiffness
mm train
strength/
Drapery
stiffness nature '. 1
2
3 cotton
wide fabric
Cotton
body
Wool flannel 100 ° / ₀ tree
wool fabric
100% tree
wool fabric
100% wool
tissue 239
288
271 0.254
0.533
0.864 0.59
0.63
0.37 0.74
0.59
0.21 23.1
23.4
15.7 4.13
7.25
3.62 typical fabric
typical fabric
typical fabric

Table III (continued)

sample Fabric type Together
settlement Square-
meter-
Weight
G thickness
mm density
g / cm ³ train
firm
speed
g / den Drapery
stiffness
mm train
strength/
Drapery
stiffness nature 4th not woven,
fibrid-like
bound 60% SA "A"
40% F »B« 119 0.356 0.40 0.32 19.1 1.99 Tissues very much
similar, good ones
Opacity 5 not woven,
fibrid-like
bound 60% SA "A"
40% F »B« 193 0.432 0.53 0.36 24.6 2.82 resembles tissues 6th not woven,
fibrid-like
bound 60 ° / ₀ SA »C«
40% F »B« 119 0.330 0.42 0.25 19.1 1.56 resembles tissues 7th not woven,
fibrid-like
bound 95% SA "A"
5% F "D" 119 0.483 0.28 0.20 24.6 0.790 lies between Ge
weaving and felting 8th not woven,
fibrid-like
bound 60% SA "A"
40% ATPl 122 0.356 0.41 0.39 20.3 2.34 more porous than fibrous
the more bound
Stuff, good own
societies 9 not woven,
resin-bound 60% SA "A"
40% ATP 2 122 0.356 0.41 0.34 20.3 2.04 resembles tissues 10 Wool felt aes
Trade 100% wool
fiber 186 0.991 0.18 0.44 ' 32; 5 "' "" 2.52 typical felt,
voluminous and
stiff 11th not woven,
fibrid-like
bound 60% SA »Al«
40% F »B« 112 0.279 0.47 0.24 29.0 0.93 papery; to
stiff 12th not woven,
fibrid-like
bound 60% »There-
cron «-Sta-
fur fiber
40% F »B« 119 0.241 0.58 0.30 39.6 0.90 papery; to
stiff 13th not woven,
fibrid-like
bound 60% herb
strange
"Dacron"
40% F »B« 112 0.254 0.52 0.26 36.8 0.79 papery; to
stiff 14th Trade pro
dukt, don't
woven »Pellon 920«
(synthetic) 88 0.660 0.16 0.20 41.6 0.422 very stiff and
voluminous 15th Trade pro
dukt, don't
woven "Chicopee"
"Lustron"
Cloth for
decorative
Purposes 78 0.254 0.36 0.41 36.8 0.87 stiff and paper
good 16 Trade pro
dukt, don't
woven »Pellon Polka
dot « 92 0.279 0.38 0.39 67.3 0.53 very stiff 17th Trade pro
dukt, don't
woven »Keybok« der
Chicopee
Mills 88 0.305 0.34 0.19 > 76.2 <0.22 very stiff

Claims (1)

Claim: Process for the production of nonwovens containing bonded and curled fibers from a starting fleece which consists wholly or partly of synthetic, organic fibers and that by means of a ther thermoplastic polymeric binder under the action of heat through the formation of spatially separated Binding sites is solidified, characterized by a) the use of a starting fleece, the fiber component of which is made up to 50 to 100% per se known, self-elongatable fibers and / or 009 545/290 Filaments in ungelängten condition exists, which have the property that they ⁰ C above its glass transition temperature lying extend at least 3% at fiinfminütlichem heating to a 3O
b) and the use of 3 to 50 percent by weight, based on the finished weight of the fleece, of one c) known thermoplastic binder, the optimal binding temperature of which is in the range of the optimal elongation temperature of the fiber material, and that
the fleece is clamped or held in a mold during the heating to control the volume. 1 sheet of drawings