EP0717133A2 - Production and application of a shrinkable and shrinked, permanently deformable textil material made out of hybrid yarn - Google Patents

Abstract

Hybrid yarn (I) consists of at least two sorts of filaments, in which the first type (A) has a max. dry heat shrinkage (DHS) of less than 7.5%, the second type (B) has a max. DHS of more than 10%, and the max. DHS stress is so large that the total shrinkage force of component (B) is sufficient to cause crimping of the low-shrinkage component (A), other types of filament (C) which may be present have max. DHS values of 2-200%, and at least one of the filament types (B) and/or (C) consists of thermoplastic filaments with a m.pt. at least 10 (pref. 20-100, esp. pref. 30-70) degrees C below the m.pt. of the low-shrinkage component. Also claimed is (i) textile sheet (II) consisting of or contg. a proportion of yarn (I) significantly affecting its shrinkage properties; (ii) permanently formable textile sheet (III) contg. (I), in which the low-shrinkage filaments (A) are crimped; (iii) fibre-reinforced mouldings (IV) contg. 20-90 (pref. 35-85, esp. pref. 45-75) wt.% sheet material made of low-shrink filaments embedded in 10-80 (pref. 15-45, esp. pref. 25-55) wt.% of a thermoplastic matrix, 0-70 (pref. 0-50, esp. pref. 0-30) wt.% other fibre components and up to 40 (pref. up to 20, esp. pref. up to 12) wt.% additives etc.; (iv) a process for the prodn. of (I) by swirling filaments (A) (low heat shrinkage), filaments (B) (high shrinkage) and opt. other types of filament (C) in a swirling appts.; (v) a process for the prodn. of textile sheet (II) by interweaving, knitting, laying down or matting yarn (I), opt. with other yarns, in an amt. sufficient to affect the shrinkage of the prod.; (vi) a process for the prodn. of formable sheet (III) by making textile sheet as in (v), and then shrinking it by 3-120% in at least one direction by heating at a temp. below the m.pt. of the lowest melting fibres or by infrared treatment; (vii) a process for the prodn. of moulded prods. (IV) by forming textile sheet at a temp. above the m.pt. of the thermoplastic filaments and below the m.pt. of the low-shrinkage filaments.

Description

The present invention relates to a hybrid yarn containing reinforcing filaments and thermoplastic matrix filaments, and to shrinkable and shrinkable, permanently deformable, e.g. deep-drawable, textile fabrics. Furthermore, the invention relates to the fiber-reinforced thermoplastic molded articles produced by deforming the deformable textile surfaces according to the invention, which, due to the unidirectional or multidirectionally arranged, essentially elongated reinforcing filaments, have a selectively adjustable high strength in one or more directions.

Hybrid yarns made from infusible (e.g. glass or carbon fiber) and meltable fibers (e.g. polyester fiber) are known. For example, patent applications EP-A-0.156.599, EP-A-0.156.600, EP-A-0.351.201 and EP-A-0.378.381 and Japanese publication JP-A-04 / 353,525 relate to hybrid yarns made from non-meltable fibers, eg glass fibers, and thermoplastic, eg polyester fibers.
EP-A-0,551,832 and DE-A-2,920,513 also relate to mixed yarns, which, however, are bonded but previously exist as hybrid yarns. From European patent EP-B-0.325.153 a textile fabric made of polyester yarns with a craquelé effect is known, which partly consists of cold-drawn, more shrinking and partly of warm-drawn, normal-shrinking polyester fibers. With this material, the craquelé effect is brought about by triggering the shrinkage of the higher-shrinking fibers.
EP-B-0,336,507 discloses a method for compacting a textile fabric made of polyester yarns, which partly consists of cold-drawn, more shrinking and partly of warm-drawn, normal-shrinking polyester fibers. With this material, compression is brought about by triggering the shrinkage of the higher-shrinking fibers.

It is also known from hybrid yarns which have a high-melting or infusible filament portion and a thermoplastic lower-melting filament portion to produce fabrics which are heated to above the melting point of the thermoplastic, lower-melting yarn component in fiber-reinforced, rigid thermoplastic sheets, so-called "organic sheets". can be transferred.

Different ways of producing fiber-reinforced thermoplastic semi-finished products have been described in chemical fibers / textile technology 39/91. Volume (1989) pages T185 to T187, T224 to T228 and T236 to T240. The production based on sheet-like textile materials from hybrid yarns is described there as an elegant way, which offers the advantage that the mixing ratio of reinforcement and matrix fibers can be set very precisely and that the textile materials can be easily inserted into press molds due to their drapability (chemical fibers / Textile technology 39th / 91st year (1989), page T186).
As can be seen from page T238 / T239 of this publication, problems arise with the two-dimensional deformation of the textile materials. Since the elasticity of the reinforcement threads is usually negligible, textile surfaces made of conventional hybrid yarns can only be deformed due to their binding.
However, this deformability is usually limited if wrinkles are to be avoided (T239), an experience that has been confirmed by computer simulations.
The way out of pressing the textiles from reinforcing and matrix threads into molds has the disadvantage that a partial compression then occurs, which leads to a displacement and / or crimping of the reinforcing threads combined with a decrease in the reinforcing effect.
Another possibility mentioned in page T239 / T240 to produce three-dimensionally deformed molded parts with undisplaced reinforcing threads would be the production of three-dimensionally woven preforms, but this requires considerable mechanical expenditure, both in the production of the preforms and in the thermoplastic impregnation or coating .

A fundamentally different way of producing fiber-reinforced thermoplastic molded articles is to produce a textile surface which essentially consists only of reinforcing yarns, to insert them as a whole or in the form of smaller sections into molds or to place them on molds, with a melted or in a solution or To disperse the dispersing agent dissolved or dispersed matrix resin and to harden the resin by cooling or evaporation of the solvent or dispersing agent.
This method can also be varied in such a way that the reinforcing textile is impregnated into or onto the mold before it is placed or laid on and / or that the reinforcing textile and a thermoplastic matrix resin are pressed into the desired shape in closed molds under pressure, one Working temperature is selected at which the matrix resin flows and encloses the reinforcing fibers without gaps.
Reinforcing textiles for this technology are known, for example, from German Utility Model 85/21, 108. The material described there consists of superimposed longitudinal and transverse thread layers which are connected to one another by additional longitudinal threads made of thermoplastic material. A similar reinforcement textile material is known from EP-A-0,144,939. This textile reinforcement consists of warp and weft threads, which are wrapped with threads made of thermoplastic material, which cause the reinforcing fibers to be welded together by heating.

Another reinforcing textile material is known from EP-A-0,268,838. This also consists of a layer of longitudinal threads and a layer of transverse threads, which are not interwoven, but one of the thread layers is said to have a significantly higher heat-shrinking capacity than the other. In the material known from this document, the cohesion is achieved by means of auxiliary threads which do not glue the layers of the reinforcing threads but instead fix them loosely to one another so as to be displaceable.

A method known from DE-A-4,042,063 is used to improve the deformability of reinforcing inserts. In this case, length-deformable materials, namely, are provided in the fabric provided as textile reinforcement heat shrinking, auxiliary threads incorporated. The shrinkage is triggered by heating and the textile material is contracted somewhat, so that the reinforcing threads are curled or held in a loose wrap.

DE-A-3,408,769 discloses a method for producing fiber-reinforced molded articles made of thermoplastic material, in which flexible textile structures are used which consist of largely unidirectionally oriented reinforcing fibers and a matrix made up of thermoplastic yarns or fibers. When they are finally shaped, these semi-finished products are deformed by heatable profile nozzles, whereby practically all thermoplastic fibers are melted.

A layered semi-finished product for the production of fiber-reinforced thermoplastic molded articles is known from EP-A-0,369,395. This material consists of a thermoplastic layer in which a multiplicity of spaced parallel reinforcing threads with very low elongation at break is embedded, which have deflections at regular intervals, which form a thread reservoir. When these layered semi-finished products are deformed, the deflections of the reinforcing threads are drawn straight, as a result of which tearing is avoided.

From the point of view of production technology, those semi-finished products are most advantageous which have a textile character, ie which are drapable, and which contain both the reinforcing fibers and the matrix material. Those that have a precisely defined weight ratio of reinforcing fibers to matrix material would be particularly advantageous. The previously known drapable semi-finished products, which have a defined ratio of reinforcing fibers and matrix material, can indeed be placed in compression molds and pressed into shaped bodies, but often do not have the ideal arrangement and extension of the reinforcing fibers after the deformation because of the compression during pressing.
Reinforcing inserts, such as those known from DE-A-4,042,063, are indeed three-dimensionally deformable, for example by deep drawing, with the desired arrangement and stretching of the reinforcing fibers generally being achieved can, but must be embedded in the matrix material in an additional step.
Deep-drawable fiber-reinforced semi-finished products, such as those known from EP-A-0,369,395, are difficult to produce because of the complicated wave-like arrangement of the reinforcing yarns.

It has now been found that the disadvantages of the prior art can largely be overcome by a sheet-like semifinished product which has a textile character, either shrinkable (semifinished product I) or shrunk and permanently deformable, for example deep-drawn, (semifinished product II) and both contains the reinforcing fibers as well as the matrix material in a defined weight ratio.
Such an advantageous semi-finished product can be produced by weaving, knitting or knitting, but also by cross-laying or other known processes for the production of sheet-like textiles on known machines, starting from a hybrid yarn which is an object of this invention.

For the purposes of this invention and in the following description, the terms "fibers", "fiber materials", "fiber components" and terms composed with these terms also mean "filaments", "filament materials", filament components "and terms combined therewith "Fiber or filament components" are not to be understood as meaning the components of the fibers or filaments, but rather the fibrous or filament components of the hybrid yarns, semi-finished products and fiber-reinforced thermoplastic molded articles according to the invention.

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die erste Sorte (A) von Filamenten ein Trockenhitze-Schrumpfmaximum von unter 7,5%

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die zweite Sorte (B) von Filamenten ein Trockenhitze-Schrumpfmaximum über 10% aufweist und

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ihr Trockenhitze-Schrumpfspannungsmaximum so groß ist, daß die Gesamt-Schrumpfkraft des Anteils der zweiten Sorte von Filamenten ausreicht, eine Kräuselung der vorhandenen, geringer schrumpfenden Filamente zu erzwingen,

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die gegebenenfalls anwesenden, weiteren Filamentsorten (C) Trockenhitze-Schrumpfmaxima im Bereich von 2 bis 200% aufweisen

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und wobei mindestens eine der Filamentsorten (B) und/oder (C) des Hybridgarns ein Thermoplastfilament ist, dessen Schmelzpunkt mindestens 10°C, vorzugsweise 20 bis 100°C, insbesondere 30 bis 70°C unter dem Schmelzpunkt der niedriger schrumpfenden Komponente des Hybridgarns liegt.

The hybrid yarn according to the invention is characterized in that it consists of at least two types of filaments, at least one type (A) having a lower heat shrinkage and at least one type (B) having a higher heat shrinkage than the other filaments of the hybrid yarn, wherein

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the first type (A) of filaments has a dry heat shrinkage maximum of less than 7.5%

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the second type (B) of filaments has a dry heat shrinkage maximum of over 10% and

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its dry heat shrinkage tension maximum is so large that the total shrinkage force of the portion of the second type of filaments is sufficient to force the existing, less shrinking filaments to crimp,

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the additional filament types (C) which may be present have dry heat shrinkage maxima in the range from 2 to 200%

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and wherein at least one of the filament types (B) and / or (C) of the hybrid yarn is a thermoplastic filament, the melting point of which is at least 10 ° C., preferably 20 to 100 ° C., in particular 30 to 70 ° C. below the melting point of the lower-shrinking component of the hybrid yarn lies.

The filaments are expediently intermingled with one another. This has the advantage that the hybrid yarn can be processed more easily into flat structures on conventional machines because of the improved thread closure, e.g. can be woven or knitted and that in the production of fiber-reinforced thermoplastic molded articles from the sheet-like textile material, because of the intimate mixture of the reinforcing and matrix fibers, very short flow paths of the molten matrix material and an excellent gapless embedding of the reinforcing filaments in the thermoplastic matrix result. The degree of swirling is expediently at an opening length, measured with an ITEMAT needle test device (according to US Pat. No. 2,985,995), of <200 mm, preferably in the range from 5 to 100 mm, in particular in the range from 10 to 30 mm.

The hybrid yarn according to the invention expediently has a total denier from 100 to 24000 dtex, preferably from 150 to 18000 dtex, in particular from 200 to 10000 dtex.

The proportion of the less shrinking filaments (A) is 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight,
the proportion of the higher shrinking filaments (B) 10 to 80, preferably 15 to 45, in particular 25 to 55% by weight and the proportion of further fiber components 0 to 70, preferably 0 to 50, in particular 0 to 30% by weight of the invention Hybrid yarn.

The proportion of thermoplastic fiber, the melting point of which is at least 10 ° C. lower than the melting point of the slightly shrinking fiber, is 10 to 80, preferably 15 to 45, in particular 20 to 40% by weight of the hybrid yarn according to the invention.

In order to ensure sufficient deep-drawing ability, the maximum dry heat shrinkage difference ΔS _MAX between the less shrinking (A) and the higher shrinking (B) type of filament is more than 2.5% points, for example 2.5 to 90% points, preferably 5 to 75% points, especially 10-60% points. For lower demands on deformability, for example deep drawing, lower values of the dry heat shrinkage difference can also be selected.

Advantageously, the less shrinking filaments (A) which form the reinforcing filaments in the end product, ie the fiber-reinforced three-dimensional thermoplastic molded body, have a dry heat shrinkage maximum of less than 3%.
These less shrinking filaments (A) expediently have an initial modulus of over 600 cN / tex, preferably from 800 to 25000 cN / tex, in particular from 2000 to 20,000 cN / tex, a fineness-related maximum tensile strength of over 60 cN / tex, preferably from 80 to 220 cN / tex, in particular from 100 to 200 cN / tex and a maximum tensile force elongation of 0.01 to 20%, preferably from 0.1 to 7.0%, in particular from 1.0 to 5.0%.

In the interest of a typical textile character with good drapability, the less shrinking filaments (A) have individual titers of 0.1 to 20 dtex, preferably 0.4 to 16 dtex, in particular 0.8 to 10 dtex.
In cases where drapability is not important, reinforcement filaments with individual titers greater than 20 dtex can also be used.

The less shrinking filaments (A) are either inorganic filaments, or filaments made of so-called high-performance polymers or pre-shrunk and / or fixed organic filaments made of other organic polymers suitable for producing high-strength filaments.

Examples of inorganic filaments are glass filaments, carbon filaments filaments made of metals or metal alloys such as steel, aluminum or tungsten; Non-metals such as boron; or metal or non-metal oxides, carbides or nitrides, such as aluminum oxide, zirconium oxide, boron nitride, boron carbide or silicon carbide; Ceramic filaments, filaments made of slag, stone or quartz.
Preferred as inorganic, less shrinking filaments (A) are metal, glass, ceramic or carbon filaments, in particular glass filaments.

Glass filaments used as less shrinking filaments (A) preferably have titers from 0.15 to 3.5 dtex, in particular from 0.25 to 1.5 dtex.

Filaments made of high-performance polymers in the sense of this invention are filaments made of polymers which, without or with only slight stretching, possibly after a heat treatment after the spinning process, provide filaments with a very high initial modulus and very high tensile strength (= moisture-related maximum tensile strength). Such filaments are described in detail in Ullmann's Encyclopedia of Industrial Chemistry, 5th edition (1989), volume A13, pages 1 to 21 and volume 21, pages 449 to 456. They consist, for example, of liquid-crystalline polyesters (LCP), poly (bis- benzimidazo-benzophenanthroline) (BBB), poly (amide imides) (PAI), polybenzimidazole (PBI), poly (p-phenylene benzobisoxazole) (PBO), poly (p-phenylene benzo bisthiazole) (PBT), Polyether ketone (PEK), polyether ether ketone (PEEK), polyether ether ketone ketone (PEEKK), polyetherimides (PEI), polyether sulfone (PESU), polyimides (PI), aramids such as poly- (m-phenylene-isophthalamide) (PMIA), poly- (m- phenylene terephthalamide) (PMTA), poly (p-phenylene isophthalamide) (PPIA), poly (p-phenylene pyromellitimide) (PPPI), poly (p-phenylene) (PPP), poly (phenylene sulfide) (PPS), poly (p-phenylene terephthalamide) (PPTA) or polysulfone (PSU).

The less shrinking filaments (A) are preferably pre-shrunk and / or fixed aramid, polyester, polyacrylonitrile, polypropylene, PEK, PEEK or polyoxymethylene filaments, in particular pre-shrunk and / or fixed aramid filaments or high-modulus polyester filaments.

The shrinkability of the higher shrinking filaments (B) must be at least so great that when their shrinkage is triggered (for example by heating) the reinforcing filaments are crimped, ie assume a corrugated position which, when later deformed, is produced from the hybrid yarn according to the invention Semi-finished product, in which an increase in area occurs, is reversed again, so that the reinforcement filaments in the three-dimensionally deformed, fiber-reinforced thermoplastic molded body (end product) are again essentially in an elongated form.
The higher shrinking filaments (B) expediently have a dry heat shrinkage maximum of over 20%. However, the dry heat shrinkage maximum can also be selected lower for end products with a relatively slight three-dimensional deformation.

As stated above, the more shrinking filaments should pull the reinforcing filaments together so that they are crimped, i.e. form a wavy line. The shrinking force of the more shrinking filaments must do justice to this task.

The higher shrinking filaments (B) therefore expediently have a dry heat shrinkage tension maximum of 0.1 to 3.5 cN / tex, preferably of 0.25 to 2.5 cN / tex.

The higher shrinking filaments (B) have an initial modulus of over 200 cN / tex, preferably from 220 to 650 cN / tex, in particular from 300 to 500 cN / tex, a fineness-related maximum tensile force of over 12 cN / tex, preferably from 40 to 70 cN / tex, especially from 40 to 65 cN / tex
and a maximum tensile strength elongation of 20 to 50%, preferably 15 to 45%, in particular 20 to 35%.

Depending on the required pliability (drapability) of the semi-finished product, they have individual titers of 0.5 to 25 dtex, preferably 0.7 to 15 dtex, in particular 0.8 to 10 dtex.

The higher shrinking filaments (B) are synthetic organic filaments. Insofar as they can be produced with the required dry heat shrinkage maximum and the required dry heat shrinkage stress, they can consist of the high-performance polymers mentioned above. It should only be noted here that the dry heat shrinkage difference ΔS _MAX between the filament types (A) and (B) is achieved, for example filaments (B) made of polyetherimide (PEI).
Other spinnable polymers, such as vinyl polymers such as polyolefins, polyvinyl esters, polyvinyl ethers, polyacrylic and methacrylates, polyvinyl aromatics, polyvinyl halides and a wide variety of copolymers, block and graft polymers, are also suitable as polymer material from which the higher-shrinking filaments (B) are made. Liquid crystal polymers or polymer mixtures.
Special representatives of these groups are polyethylene, polypropylene, polybutene, polypentene, polyvinyl chloride, polymethyl methacrylate, poly- (meth) acrylonitrile, possibly modified polystyrene, or multi-phase plastics such as ABS.
Polyaddition, polycondensation, polyoxidation or cyclization polymers are also suitable. Special representatives of these groups are polyamides, polyurethanes, polyureas, polyimides, polyesters, polyethers, polyhydantoins, polyphenylene oxide, polyphenylene sulfide, polysulfone polycarbonates, and their mixed forms, their mixtures and combinations with one another and with other polymers or polymer precursors, for example polyamide-6, polyamide -6.6, polyethylene terephthalate or bisphenol A polycarbonate.

The higher shrinking filaments (B) are preferably stretched polyester, polyamide or polyetherimide filaments.
Polyester-POY filaments and in particular polyethylene terephthalate filaments are particularly preferred as higher shrinking filaments (B).

It is particularly preferred that the higher shrinking filaments (B) are at the same time the thermoplastic filaments (matrix filaments) whose melting point is at least 10 ° C. below the melting point of the lower shrinking filaments (reinforcing filaments) of the hybrid yarn according to the invention.

In many cases it is desired that the three-dimensionally deformed thermoplastic molded articles produced from the hybrid yarns according to the invention via the sheet-like semifinished products should contain auxiliaries and additives such as fillers, stabilizers, matting agents or color pigments. In these cases, it is expedient that at least one of the filament types of the hybrid yarn additionally contains such auxiliaries and additives, in an amount of up to 40% by weight, preferably up to 20% by weight, in particular up to 12% by weight. % of the weight of the fiber components.
The proportion of thermoplastic fiber whose melting point is at least 10 ° C. lower than the melting point of the slightly shrinking fibers, ie the matrix fibers, preferably contains the additional auxiliaries and additives in an amount of up to 40% by weight, preferably up to 20% by weight .-%, in particular up to 12 wt .-% of the weight of the fiber components.
Preferred auxiliaries and additives which may be contained in the thermoplastic fiber content are fillers, stabilizers and / or pigments.

The hybrid yarn described above is shrinkable overall due to the shrinkable fiber type (B) contained therein. If this hybrid yarn is subjected to a heat treatment at a temperature at which the fiber type (B) shrinks, the fibers of the type (A) form a crimp, that is to say they form a series of small or larger arcs, by their unchanged length in the now accommodate shorter yarn lengths.
This shrunk yarn is thus characterized in that the filaments of the type (A) are crimped and the filaments of the type (B) are shrunk. This yarn is also the subject of the present invention.

End products which are produced from the hybrid yarn according to the invention are the fiber-reinforced thermoplastic molded articles. These are made from the hybrid yarn Manufactured via flat textile fabrics (semi-finished products I and II) which, when the reinforcement filaments contained therein are present in a crimped state, are permanently three-dimensionally deformable.

The present invention also relates to textile fabrics (semifinished product I) consisting of or containing a portion of the hybrid yarn according to the invention described above which significantly influences its shrinkage capacity.
The fabrics according to the invention can be woven fabrics, knitted fabrics or knitted fabrics, stabilized scrims or possibly bonded nonwoven fabrics.
The fabric is preferably a knitted or knitted fabric or a stabilized, unidirectional or multidirectional fabric, but in particular a fabric.

In principle, the woven surfaces can have all known fabric constructions such as the plain weave and its derivatives, e.g. Ribbed, panama, barley grain or mock leno weave, twill weave and its multiple derivatives, of which only, for example, herringbone twill, flat twill, braided twill, lattice twill, cross twill, pointed twill, zigzag twill, shadow twill or shadow cross twill are mentioned with floss, or the satin weave with various flaps Length. (Because of the weave designations, see DIN 61101) The density of each of the fabric surfaces is in the range of 10 to 60 threads / cm in warp and weft depending on the application for which the material is intended and the titer of the yarns used in the production. Within this range, the densities of the fabric layers can be different or, preferably, the same.

In a further preferred embodiment of the textile materials according to the invention, the textile surfaces are knitted or knitted.
The knitted textile surfaces can be warp knitted or weft knitted, whereby the constructions can be varied widely by means of handles or floats. (See DIN 62050 and 62056)
A knitted or knitted textile material according to the invention can have right / right, left / left or a right / left stitch structure and their known variants as well as jacquard patterns.
The right / right stitch structure includes, for example, their variants clad, openwork, ribbed, offset, wave, catch or nub as well as the interlock binding right / right / crossed.
The left / left mesh structure also includes, for example, their variants clad, broken, interrupted, offset, translated, catch or pimple. The right / left stitch structure also includes, for example, their variants plated, deposited, perforated, plush, lining, catch or pimple.

The woven or mesh weaves are selected according to the intended use of the textile material according to the invention, whereby purely technical expediency can be decisive, but occasionally also decorative aspects can be taken into account.

As already stated above, these flat structures according to the invention have very good permanent deformability, in particular deep-drawing ability, if the reinforcing filaments contained therein are in a crimped state.
Another object of the present invention is therefore permanently deformable textile fabrics (semi-finished product II) consisting of, or containing a portion of the hybrid yarn of claim 1 which significantly influences their shrinkability, the less shrinking filaments (A) of the hybrid yarn contained therein being crimped.
The less shrinking filaments of the hybrid yarn contained therein are preferably crimped by 5 to 60%, preferably 12 to 48%, in particular 18 to 36%.

The present invention also relates to fiber-reinforced molded parts consisting of 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight of a sheet-like reinforcing material made from low-shrinking filaments, which is embedded in 10 to 80, preferably 15 to 45, especially 25 to 55% by weight of a thermoplastic matrix, 0 to 70, preferably 0 to 50, in particular 0 to 30% by weight of further fiber components and additionally up to 40% by weight, preferably up to 20% by weight, in particular up to to 12% by weight of the weight of the fiber and matrix components of auxiliaries and additives.

Sheet-like reinforcement materials which are embedded in the thermoplastic matrix can consist of sheets of parallel filaments which are arranged unidirectionally or e.g. are multidirectionally aligned and essentially stretched in superimposed layers. However, they can also consist of knitted or knitted fabrics, but preferably of woven fabrics.

Depending on the requirements of the application, the fiber-reinforced molded part according to the invention contains fillers, stabilizers and / or pigments as auxiliaries and additives.
A characteristic of these molded parts is that they are produced by deforming a textile fabric from the hybrid yarn described above, in which the reinforcing filaments are crimped, at a temperature which is above the melting point of the thermoplastic filaments and below the melting point of the less shrinking filaments.
It is important that they are produced by stretching deformation, the reinforcing filaments crimped in the semifinished product being stretched and drawn at least in the region of the deformed parts.

The melting point of the filaments used to produce the hybrid yarn according to the invention was determined in the differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min.
To determine the dry heat shrinkage and the temperature of the maximum dry heat shrinkage of the filaments used, the filament was loaded with a tension of 0.0018 cN / dtex and the shrinkage temperature diagram was recorded. Both values can be taken from the curve shape obtained.
To determine the maximum shrinkage force, a shrinkage force-temperature curve was recorded continuously at a heating rate of 10 ° C / min and with an inlet and outlet speed of the filament in and out of the oven. Both desired values can be taken from the curve.

The determination of the opening length as a measure of the degree of swirling was carried out according to the principle of the hook drop test described in US Pat. No. 2,985,995 using an ITEMAT test device.

• die erste Sorte (A) von Filamenten ein Trockenhitze-Schrumpfmaximum von unter 7,5%
• die zweite Sorte (B) von Filamenten ein Trockenhitze-Schrumpfmaximum über 10% aufweist und
• ein Trockenhitze-Schrumpfspannungsmaximum der höher schrumpfenden Filamente so groß ist, daß die Gesamt-Schrumpfkraft des Anteils der zweiten Sorte von Filamenten ausreicht, eine Kräuselung der eingesetzten, geringer schrumpfenden Filamente zu erzwingen,
• die gegebenenfalls eingesetzten, weiteren Filamentsorten (C) Trockenhitze-Schrumpfmaxima im Bereich von 2 bis 200% aufweisen
• und wobei mindestens eine der Filamentsorten (B) und/oder (C) ein Thermoplastfilament ist, dessen Schmelzpunkt mindestens 10°C, vorzugsweise 20 bis 100°C, insbesondere 30 bis 70°C unter dem Schmelzpunkt der niedriger schrumpfenden Filamente liegt.

Another object of this invention is a method for producing the hybrid yarn according to the invention, which is characterized in that filaments (A) with lower heat shrinkage, filaments (B) with higher heat shrinkage and optionally other types of filament (C) in a interlacing device, which they with an overfeed of 0 to 50% are swirled, whereby

• the first type (A) of filaments has a dry heat shrinkage maximum of less than 7.5%
• the second type (B) of filaments has a dry heat shrinkage maximum of over 10% and
• a dry heat shrinkage stress maximum of the higher shrinking filaments is so large that the total shrinking force of the portion of the second type of filaments is sufficient to force the crimped, lower shrinking filaments to be used,
• the additional filament types (C) which may be used have dry heat shrinkage maxima in the range from 2 to 200%
• and wherein at least one of the filament types (B) and / or (C) is a thermoplastic filament, the melting point of which is at least 10 ° C., preferably 20 to 100 ° C., in particular 30 to 70 ° C. below the melting point of the lower-shrinking filaments.

The swirling is preferably set so that the degree of swirling is at an opening length of less than 200 mm, preferably in the range from 5 to 100 mm, in particular in the range from 10 to 30 mm.

The process steps required to produce a fiber-reinforced thermoplastic molded article from the hybrid yarn according to the invention are also objects of the present invention.

The first of these steps is a method for producing a textile fabric (semi-finished product I) by weaving, knitting, knitting, laying or tangling the hybrid yarn according to the invention together with other yarns, where appropriate, the hybrid yarn used according to the invention having the features described above and the proportion of the hybrid yarn is chosen so that it significantly affects the shrinkage of the fabric. Sufficient of the hybrid yarn according to the invention is preferably used here so that the proportion of the hybrid yarn in the total amount of the woven, knitted, knitted, laid or tangled yarn is 30 to 100% by weight, preferably 50 to 100% by weight, in particular 70 to 100% by weight .-%.

The fabric is preferably produced by weaving with a thread density of 4 to 20 threads / cm or by unidirectional or multidirectional laying of the hybrid yarns and stabilization of the scrim by cross-laid binding threads or by local or full-surface bonding.

The second of these processing steps of the hybrid yarn according to the invention into the end product consists in a process for the production of a permanently deformable sheet (semi-finished product II), whereby after the fabrication of a sheet by weaving, knitting, knitting, laying or tangling a hybrid yarn, the result may be obtained together with other yarns Sheets are subjected to a heat treatment at a temperature below the melting temperature of the lowest melting fiber material or an infrared treatment until they are shrunk in at least one direction by 3 to 120% of their initial size.
The heat treatment is preferably carried out at a temperature of from 85 to 250 ° C., preferably from 95 to 220 ° C.

It is particularly preferred and expedient to adjust the extent of the shrinkage, by appropriate choice of the temperature and duration of the heat treatment, so that the shrinkage corresponds approximately to the elongation which occurs during processing into the fiber-reinforced thermoplastic molded body.

Alternatively, the permanently deformable fabrics according to the invention, in which the reinforcing filaments (A) contained therein are present in a crimped state, can of course also be obtained by using the above-described methods by weaving, knitting, knitting, laying or tangling a hybrid yarn, if necessary produced together with other yarns using a shrinked hybrid yarn according to the invention, in which the filaments (A) are already in crimped form and the filaments (B) are in shrinked form, the proportion of the hybrid yarn being chosen so that it makes it stretchable Fabric significantly influenced.
It should only be noted here that the tensile load during the manufacture of the fabric does not exceed the tensile stress of the shrunk hybrid yarns according to the invention.

The last step in the processing of the hybrid yarn according to the invention consists in a method for producing a fiber-reinforced molded part consisting of 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight of a preferably sheet-like reinforcement material made from low-shrinking filaments, which is embedded in 10 to 80, preferably 15 to 45, in particular 25 to 55% by weight of a thermoplastic matrix, and 0 to 70, preferably 0 to 50, in particular 0 to 30% by weight of further fiber components and additionally up to 40% by weight , preferably up to 20% by weight, in particular up to 12% by weight, of the weight of the fiber and matrix constituents, auxiliaries and additives, which is characterized in that a permanently deformable textile fabric (semifinished product II) described above according to the invention is used a temperature which is above the melting point of the thermoplastic filaments and below the melting point of the low-shrinking filaments becomes.

The following exemplary embodiments illustrate the production of the hybrid yarn according to the invention, the semifinished products I and II according to the invention and a fiber-reinforced thermoplastic molded body according to the invention.

example 1

A multifilament glass yarn of 2 x 680 dtex and a multifilament yarn made of polyethylene terephthalate POY yarn with a titer of 5 x dtex 300f64 (= 1500 dtex) are fed together to a swirling nozzle in which they are swirled by a stream of compressed air. The polyester POY yarn has a dry heat shrinkage maximum of 65%, with a peak temperature of 100 ° C and a dry heat shrinkage tension maximum of 0.3 cN / tex at a peak temperature of 95 ° C; its melting point is 250 ° C.
The swirled hybrid yarn obtained has a total titer of 2260 dtex; the opening length, measured with the ITEMAT device, is 19.4 mm. The yarn has a tenacity of 25.8 cN / tex and an elongation at break of 3.5%.
Samples of the hybrid yarn were shrunk at 95, 150 or 220 ° C for 1 minute. The shrinkage obtained was 56-57%. The KD diagram of the shrunk yarn shows that the PET filaments are first stretched. After a stretch of 130 - 150%, the glass filaments start to wear, shortly afterwards the yarn tears off.

Example 2

A multifilament high modulus aramid yarn from dtex 220f200 dtex and a multifilament yarn made from polyethylene terephthalate POY yarn with a titer of 2 x dtex 111f128 are fed together to a swirling nozzle, in which they are swirled by a stream of compressed air.
The polyester POY yarn has a dry heat shrinkage maximum of 65%, with a peak temperature of 100 ° C and a dry heat shrinkage tension maximum of 0.3 cN / tex at a peak temperature of 95 ° C; its melting point is 250 ° C.
The swirled hybrid yarn obtained has a total titer of 440 dtex, the opening length, measured with the ITEMAT device, is 21 mm, the maximum Shrinkage results at 98 ° C and is 68%.

PET

= Polyethylenterephthalat; PBT = Polybutylenterephthalat

PEI

= Polyetherimid (®ULTEM der Fa. GE Plastics)

POY

= Teilorientiertes Garn, gesponnen mit einer Spinnabzugsgeschwindigkeit von 3500 m/min, unverstreckt.

The hybrid yarns of the table according to the invention can be produced in an analogous manner to that described in Examples 1 and 2. The abbreviations used in the table have the following meanings:

PET

= Polyethylene terephthalate; PBT = polybutylene terephthalate

PEI

= Polyetherimide (®ULTEM from GE Plastics)

POY

= Partially oriented yarn, spun at a spinning take-off speed of 3500 m / min, undrawn.

Example 13

A fabric with a plain weave is made from the hybrid yarn produced according to Example 1.
The thread density in the warp is 12.6, in the weft 10.6 threads per cm. This fabric (semi-finished product I) is shrunk free in the oven at 200 ° C. for 1 minute. This results in a shrinkage of 50% in the warp and in the weft direction. The fabric thus obtained (semifinished product II) has very good permanent deformability. The maximum possible area enlargement during deep drawing is over 250%.

Example 14

A fabric with a plain weave is made from the hybrid yarn produced according to Example 1.
The thread density in the warp is 10.4, in the weft 10.6 threads per cm. This fabric (semi-finished product I) is shrunk in the oven for 1 minute at 200 ° C on the stenter. A shrinkage of 4% in the warp and in the weft direction is permitted.
The fabric thus obtained (semi-finished product II) has sufficient permanent deformability. The possible increase in area when deforming is about 8%.

Example 15

A fabric with a plain weave is made from the hybrid yarn produced according to Example 1.
The thread density in the warp is 7.4, in the weft 8.2 threads per cm. This fabric (semi-finished product I) is shrunk in the oven for 1 minute at 200 ° C on the stenter. A shrinkage of 12% in the warp direction and 15% in the weft direction is permitted.
The fabric thus obtained (semifinished product II) has good permanent deformability. The possible increase in area when deforming is about 30%.

Example 16

A fabric with a plain weave is made from the hybrid yarn produced according to Example 1.
The thread density in the warp is 12.6, in the weft 5.2 threads per cm. This fabric (semi-finished product I) is shrunk free in the oven at 200 ° C. for 1 minute. This results in a shrinkage of 50% in the warp direction, in the weft direction there is no shrinkage.
The fabric thus obtained (semifinished product II) has good permanent deformability. The maximum possible area enlargement during deep drawing is approx. 50%.

Example 17

A semifinished product II produced according to Example 15 is drawn into a fender mold and heated to 280 ° C. for 3 minutes. After cooling to about 80 ° C., the raw molded fender body can be removed from the deep-drawing mold.
The fiber-reinforced thermoplastic molded body obtained has excellent strength. The reinforcement filaments are very evenly distributed and largely stretched.

The molded body is finished by trimming, smoothing and painting.

Claims (40)

Hybrid yarn consisting of at least two types of filaments, at least one type (A) having a lower heat shrinkage and at least one type (B) having a higher heat shrinkage than the other filaments of the hybrid yarn, characterized in that - the first type (A) of filaments has a dry heat shrinkage maximum of less than 7.5% - the second type (B) of filaments has a dry heat shrinkage maximum of over 10% and its dry heat shrinkage tension maximum is so large that the total shrinkage force of the portion of the second type of filaments is sufficient to force the existing, less shrinking filaments to crimp, - The possibly present further filament types (C) have dry heat shrinkage maxima in the range from 2 to 200% - And wherein at least one of the filament types (B) and / or (C) of the hybrid yarn is a thermoplastic filament, the melting point of which is at least 10 ° C, preferably 20 to 100 ° C, in particular 30 to 70 ° C below the melting point of the lower-shrinking component of Hybrid yarn lies. Hybrid yarn according to claim 1, characterized in that the filaments are intermingled. Hybrid yarn according to at least one of claims 1 and 2, characterized in that it has a total denier from 100 to 24000 dtex, preferably from 150 to 18000 dtex, in particular from 200 to 10000 dtex. Hybrid yarn according to at least one of Claims 1 to 3, characterized in that the proportion of the less shrinking filaments (A) is 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight, the proportion of the higher shrinking filaments (B) 10 to 80, preferably 15 to 45, in particular 25 to 55% by weight and the proportion of further fiber components 0 to 70, preferably 0 to 50, in particular 0 to 30 wt .-% of the hybrid yarn. Hybrid yarn according to at least one of Claims 1 to 4, characterized in that the proportion of thermoplastic fiber whose melting point is at least 10 ° C lower than the melting point of the low-shrinking fiber is 10 to 80, preferably 15 to 45, in particular 20 to 40% by weight. -% of the hybrid yarn is. Hybrid yarn according to at least one of Claims 1 to 5, characterized in that the maximum dry heat shrinkage difference ΔS _MAX between the less shrinking (A) and the higher shrinking (B) type of filament is more than 2.5% points, preferably 5 to 75% -Points, especially 10-60% -points. Hybrid yarn according to at least one of claims 1 to 6, characterized in that the less shrinking filaments (A) have a dry heat shrinkage maximum of less than 3%. Hybrid yarn according to at least one of claims 1 to 7, characterized in that the less shrinking filaments (A) have an initial modulus of over 600 cN / tex, preferably from 800 to 25000 cN / tex, in particular from 2000 to 20,000 cN / tex Maximum tensile force of more than 60 cN / tex, preferably from 80 to 220 cN / tex, in particular from 100 to 200 cN / tex and a maximum tensile force elongation of 0.01 to 20%, preferably from 0.1 to 7.0%, in particular from 1 , Have 0 to 5.0%. Hybrid yarn according to at least one of Claims 1 to 8, characterized in that the less shrinking filaments (A) are inorganic or pre-shrunk and / or fixed organic filaments. Hybrid yarn according to at least one of claims 1 to 9, characterized in that the less shrinking filaments (A) are metal, glass, ceramic or carbon filaments. Hybrid yarn according to at least one of Claims 1 to 10, characterized in that the less shrinking filaments (A) are glass filaments. Hybrid yarn according to at least one of claims 1 to 11, characterized in that the less shrinking filaments (A) are pre-shrunk and / or fixed aramid filaments or high modulus polyester filaments. Hybrid yarn according to at least one of claims 1 to 12, characterized in that the higher shrinking filaments (B) have a dry heat shrinkage maximum of over 20%. Hybrid yarn according to at least one of claims 1 to 13, characterized in that the higher shrinking filaments (B) have a dry heat shrinkage tension maximum of 0.1 to 3.5 cN / tex, preferably 0.25 to 2.5 cN / tex, exhibit. Hybrid yarn according to at least one of claims 1 to 14, characterized in that the higher shrinking filaments (B) are synthetic organic filaments. Hybrid yarn according to at least one of claims 1 to 15, characterized in that the higher shrinking filaments (B) are stretched polyester, polyamide or polyetherimide filaments. Hybrid yarn according to at least one of claims 1 to 16, characterized in that the higher shrinking filaments (B) are polyester POY filaments. Hybrid yarn according to at least one of claims 1 to 17, characterized in that the higher shrinking filaments (B) are polyethylene terephthalate filaments. Hybrid yarn according to at least one of Claims 1 to 18, characterized in that at least one of the filament types of the hybrid yarn additionally contains auxiliaries and additives, in an amount of up to 40% by weight, preferably up to 20% by weight, in particular up to to 12% by weight of the weight of the fiber components. Textile fabric consisting of or containing a portion of the hybrid yarn of claim 1 that significantly influences its shrinkage capacity. Textile fabric according to claim 20, characterized in that the fabric is a woven, knitted or crocheted fabric, a stabilized scrim or an optionally bonded nonwoven. Textile fabric according to at least one of claims 20 and 21, characterized in that the fabric is a woven fabric. Textile fabric according to at least one of Claims 20 to 22, characterized in that it is a stabilized, unidirectional scrim. Permanently deformable textile fabric consisting of, or containing a portion of the hybrid yarn of claim 1 which significantly influences its shrinkability, the less shrinking filaments (A) of the hybrid yarn contained therein being crimped. Permanently deformable textile fabric according to claim 24, characterized in that the less shrinking filaments of the hybrid yarn contained therein are crimped by 5 to 60%, preferably 12 to 48%, in particular 18 to 36%. Fiber-reinforced molded part consisting of 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight of a sheet-like fiber material made from low-shrinking filaments, which is embedded in 10 to 80, preferably 15 to 45, in particular 25 to 55% by weight. % of a thermoplastic matrix, 0 to 70, preferably 0 to 50, in particular 0 to 30% by weight of further fiber components and additionally up to 40% by weight, preferably up to 20% by weight, in particular up to 12% by weight. % of the weight of the fiber and matrix components, auxiliaries and additives. Fiber-reinforced molded part according to claim 26, characterized in that it contains fillers, stabilizers and / or pigments as auxiliary substances and additives. Fiber-reinforced molding according to at least one of Claims 26 and 27, characterized in that it is produced by deforming a textile fabric of Claim 24 at a temperature which is above the melting point of the thermoplastic filaments and below the melting point of the less shrinking filaments. Fiber-reinforced molded part according to at least one of claims 26 to 28, characterized in that it is produced by stretching deformation. A process for producing a hybrid yarn of claim 1, characterized in that filaments (A) with lower heat shrinkage, filaments (B) with higher heat shrinkage and possibly other types of filament (C) are intermingled in a interlacing device, characterized in that - the first type (A) of filaments has a dry heat shrinkage maximum of less than 7.5% - the second type (B) of filaments has a dry heat shrinkage maximum of over 10% and a dry heat shrinkage stress maximum of the higher shrinking filaments is so large that the total shrinkage force of the portion of the second type of filaments is sufficient to force the crimped, lower shrinking filaments to be used, - The additional filament types (C) which may be used have dry heat shrinkage maxima in the range from 2 to 200% - And wherein at least one of the filament types (B) and / or (C) is a thermoplastic filament, the melting point of which is at least 10 ° C., preferably 20 to 100 ° C., in particular 30 to 70 ° C. below the melting point of the lower-shrinking filaments. A process for producing the textile fabric of claim 20 by weaving, knitting, knitting, laying or tangling a hybrid yarn together with other yarns, if necessary, characterized in that the hybrid yarn used has the features mentioned in claim 1 and that the proportion of the hybrid yarn is chosen so is that it significantly affects the shrinkability of the fabric. A method according to claim 31, characterized in that the proportion of the hybrid yarn in the total amount of woven, knitted, knitted, laid or tangled yarn 30 to 100 wt .-%, preferably 50 to 100 wt .-%, in particular 70 to 100 wt. -%. Method according to at least one of claims 31 and 32, characterized in that the fabric is produced by weaving with a thread density of 4 to 20 threads / cm. A method for producing a permanently deformable fabric of claim 24, characterized in that after the production of a The fabric by weaving, knitting, knitting, laying or tangling a hybrid yarn, possibly together with other yarns according to claim 20, the fabric is subjected to a heat treatment at a temperature below the melting temperature of the lowest melting fiber material or an infrared treatment until at least in one direction 3 to 120% of its initial size has shrunk. Process according to claim 34, characterized in that the heat treatment is carried out at a temperature of 85 to 250 ° C, preferably 95 to 220 ° C. Process according to at least one of claims 34 and 35, characterized in that the extent of the shrinkage is adjusted by appropriate selection of the temperature and duration of the heat treatment so that the shrinkage corresponds approximately to the elongation occurring during processing. A process for producing a fiber-reinforced molded part of claim 26, consisting of 20 to 90, preferably 35 to 85, in particular 45 to 75% by weight, of a sheet-like fiber material made from low-shrinking filaments, which is embedded in 10 to 80, preferably 15 to 45 , in particular 25 to 55% by weight of a thermoplastic matrix, and 0 to 70, preferably 0 to 50, in particular 0 to 30% by weight of further fiber constituents and additionally up to 40% by weight, preferably up to 20% by weight , in particular up to 12% by weight of the weight of the fiber and matrix constituents, auxiliaries and additives, characterized in that it is formed by deforming a textile fabric of claim 12 at a temperature which is above the melting point of the thermoplastic filaments and below the melting point of the low shrinking filament lies, is produced. Use of a hybrid yarn of claim 1 for the manufacture of a flat structure of claim 20. Use of the flat structure of claim 20 for producing a permanently deformable flat structure of claim 24. Use of the permanently deformable fabric of claim 24 for the production of a fiber-reinforced molded part of claim 26.