EP1112400B1 - Method for producing a multiaxial structure out of multifilament threads - Google Patents

Abstract

The invention relates to a method for producing a multiaxial structure out of multifilament threads which are superimposed with different orientations. The threads of the 0° position run in a direction of production and are inserted between the remaining multifilament layers superimposed with different orientations. In addition, the threads of the 0° position are guided in the area located in front of the stitch bonding machine by auxiliary means which ensure the correct superimposition or distribution thereof.

Description

The invention relates to a method of manufacture a multiaxial scrim made of multifilament threads according to the Preamble of the main claim.

A device for producing a multiaxial scrim Multifilament threads are, for example, in the literature reference "Rationalization of the production of long fiber reinforced composite materials through the use of multiaxial fabrics "from Karlheinz Hörsting, Verlag Shaker, Aachen 1954, in particular Pages 30 and 32.

The functioning of such a machine is said to be better Understanding of the invention are briefly explained below:

The multifilament threads are drawn off from the bobbin and fed wagons that moved on adjustable rails and the multifilament threads in the required Orientation ± 25 ° to 90 ° in a so-called needle transport chain lay down. You can use a reed on every shot car Density of the registered threads can be adjusted, thus determine the basis weight of the individual layers. For the the precise oscillation in the needle transport chains swings Shot car in the edge area beyond the transport chain. When braking at the reversal point, the excess delivered Material compensated by a thread storage. By a corresponding movement, the multifilament threads are behind the needles of the transport chain pressed. For parallel filing to ensure the multifilament threads is then a Offset of the shot wagon reed in the production direction accordingly the range of threads. After this The shot carriage swings out of alignment again and moves to opposite side of the scrim.

By cascading several weft insertion systems then the clutch is in different orientations layered.

The feeding of the 0 ° filaments - that is, in the production direction stretch - takes place directly from a warp beam or an additional coil gate immediately before a knitting or Sewing machine.

The loose thread scrim is fixed with the help of a conventional knitting or sewing machine realized. Subsequently the marginal areas of the scrim, which are in the Transport chain lie, separated, because here due to strong Filament curvature fiber damage present. The finished Multiaxial scrims are then wound onto a fabric tree.

The weft multifilaments are in the production direction seen at an angle of ± 22.5 ° to ± 60 ° and more and also stored in a 90 ° direction, while the so-called Warp threads are fed in the 0 ° direction, d. H. so run parallel to the production direction.

The so-called multifilaments in the 0 ° position lie with the Completed multi-axial scrims are currently always the top Layer.

Such multi-axial scrims often consist of very flexible and multifilaments and fragile fibers the winding of the finished scrim leads to the goods tree then when the 0 ° multifilaments are placed in the top layer are overstressing the fibers of these Multifilament threads. With a multitude of individual layers, for example having six or seven layers Multiaxial scrims have therefore been used so far that one produced fabrics with, for example, three layers in which the 0 ° multifilaments are also arranged in the uppermost layer then one of these scrubs turned over so that two Layers were placed on top of each other in which the 0 ° multifilaments were arranged in the middle, i.e. theoretically in the so-called neutral zone, in which case it already is once stitched scrims were sewn a third time, namely the two fabrics had to be sewn together. This led to the fact that due to the large number of sewing processes Damage to the fibers of the multifilaments occurred.

DE 39 10 245 A1 describes a method and a device for the production of a thread grid. Around to achieve extensive isotropy of the thread grid proposed here that above, below or between the individual coulters of those already deposited and in the transverse direction as well as threads running in the diagonal direction to insert in the longitudinal direction. Feeding in the longitudinal direction, d. H. So the 0 ° thread is immediately before the sewing point then not possible if the 0 ° threads between the individual Cross threads are to be laid. This on any one However, the 0 ° threads fed in place retain their desired Location and desired even distribution not at, but shift so that different thicknesses and thus different strengths in the cross direction of the scrim seen inevitable.

The invention has for its object a multiaxial scrim to create where it is possible to use the 0 ° multifilament threads to feed at any point on the scrim, their predetermined Secure position and still make a clutch, that is made up of seven layers, for example, but only one only has to be sewn once.

This object of the invention is achieved by Teaching of the main claim solved.

So it becomes a multi-axial scrim with, for example, seven layers proposed, with the 0 ° positions between the others ± 22.5 ° to 90 ° layers can be worked in and safely kept in their desired orientation, location and distribution become.

1. Eine Fadenlage aus -/+ 45°-Multifilamentfäden,

2. eine Fadenlage aus +/- 45°-Multifilamentfäden,

3. eine Fadenlage aus 0°-Multifilamentfäden,

4. eine Fadenlage aus + 90°-Multifilamentfäden,

5. eine Fadenlage aus 0°-Multifilamentfäden,

6. eine Fadenlage aus +/- 45°-Multifilamentfäden und

7. eine Fadenlage aus -/+ 45°-Multifilamentfäden.

According to an essential proposal of the invention, it is provided that the 0 ° positions between their insertion point and the sewing are fixed by floating floating reeds arranged in front of the sewing point in their distribution specified at the insertion point or are brought back into their desired distribution position. For example, it is possible to manufacture a scrim that is built up in succession from the following layers of thread:

1. A thread layer of - / + 45 ° multifilament threads,

2. a thread layer made of +/- 45 ° multifilament threads,

3. a thread layer of 0 ° multifilament threads,

4. a thread layer of + 90 ° multifilament threads,

5. a thread layer of 0 ° multifilament threads,

6. a thread layer of +/- 45 ° multifilament threads and

7. a thread layer made of - / + 45 ° multifilament threads.

The free floating reeds ensure the correct position of the 0 ° multifilament threads in front of the sewing or knitting machine, itself if these multifilament threads become tangled when the following through the weft entry car in other orientations filed multifilament threads should have moved and are secured at a distance from each other the sewing point fed.

Another possible embodiment of the invention exists in that the 0 ° multifilaments over a with the usual needle chains Circulating funding supported and up to Sewing point. This funding can be used as a conveyor belt be trained and equipped with a variety of fine needles be the retention of the when inserted into the Needle chain predetermined distribution of all layers up to the sewing point guaranteed. It should be noted here that the 0 ° multifilaments not be included in the needle transport chain, but theoretically free floating on the already filed, in the weft threads bound to the needle transport chains are deposited position, but due to the fine needles of the conveyor belt are kept secured against distribution. As a grant can a conveyor belt or a slat can be used or a belt cloth.

But it is also conceivable that the individual thread layers are independent of their orientation in addition to that in the needle transport chains held weft threads deposited on a surface the multifilament threads due to one of the Surface of this area and the prevailing vacuum fix the scrim suction pressure up to the sewing point to lead.

Finally, it is possible that at least the threads of the 0 ° position material fit, d. H. form-fitting in their arrangement secured or distributed. in this connection the threads of the 0 ° position can be self-locking be connected or with at least one of the in different Orientations oriented multifilament thread layers. The material-tight position securing or distribution securing can by spraying an adhesive or wetting of the 0 ° threads, these threads then either with yourself or with the adjacent multifilament thread layer be glued. It is also possible to bring about heat setting, what is the use of a themoplastic Requires material, either in the form of powder is entered or with which the threads of the 0 ° position are coated or with the threads of the neighboring Multifilament thread layer are coated.

Through the proposal (s) according to the invention achieved that damage to the individual multifilament threads by multiple sewing regardless of whether it is Threads in the ± 22.5 ° to 90 ° position or whether it is Threads in the 0 ° position is avoided, since only one time Sewing the large number of individual thread layers are done got to. This not only prevents damage, but also considerable handling costs the fabric saved and the distribution of the 0 ° threads in the area the sewing point is completely secured.

According to the invention, the 0 ° warp filaments can be arranged at any height in the layer of the scrim, so that the scrim can be better adapted to the requirements regarding tensile strength.
The fixation of the 0 ° warp filament is secured from the entry point to the sewing point - in any case immediately before the sewing point. These advantages achieved are particularly important when the multifilament threads are formed entirely or partially from carbon fibers.

An embodiment of the invention is described below the drawing explained.

Fig. 1

schematisch eine Näh- oder Wirkmaschine zur Herstellung eines Multiaxialgeleges, in

Fig. 2

eine Ansicht auf einen Rietkamm, in

Fig. 3

eine Schnittleiste der Linie 3- 3 in Fig. 2 und in

Fig. 4

eine Ansicht auf eine abgeänderte Ausführungsform der Erfindung.

The drawing shows in

Fig. 1

schematically a sewing or knitting machine for producing a multi-axial scrim, in

Fig. 2

a view of a reed ridge, in

Fig. 3

a cutting strip of line 3- 3 in Fig. 2 and in

Fig. 4

a view of a modified embodiment of the invention.

1 to 3, a sewing or knitting machine 1 is used Production of a multi-axial scrim shown. With 2, 3, 4, 5 and 6 are the weft insertion systems for the +/- 24 ° to 90 ° threads shown and with 7 and 8 the thread feeds running in 0 ° position.

Riet 9 and 10 are in these thread feeds of the 0 ° threads switched on and the threads are over pulleys 11 and 12 inserted into the clutch.

Immediately in front of a sewing point 16 are floating in the clutch Riete 14 and 15 turned on in their position between the weft insertion systems 2, 3, 4, 5 and 6 inserted multifilament threads are kept. So can for example, these reeds 14 and 15 by threads, ropes or Wires are held stationary at the start of the machine are arranged.

Fig. 2 shows a view of a reed comb, for example of the free-floating reed 14, and Fig. 3 shows how the in 0 ° position introduced multifilament thread 8 guided in this reed becomes.

Even if the 0 ° multifilament thread 7 is on its way from the insertion point to the sewing point 16 between the in +/- 25 ° to 90 ° inserted threads should have shifted or is no longer correctly aligned in its position, the 0 ° multifilament thread 7 through the floating reed 15 again returned to its desired position and the 0 ° multifilament threads immediately before the sewing point 16 in the desired distribution aligned so that the stitching and so that the overall scrim is done so that all threads take the desired position.

4 is a rotating conveyor belt 20 recognizable, on the multifilament threads in the +/- 25 ° - 90 ° position are arranged, between these threads 0 ° multifilament threads 7 and 8 are indicated. While the in Production direction at an angle of +/- 22.5 ° - 90 ° Weft threads essentially through the needle transport chain they will be secured in their position as well by needles 21 arranged on the conveyor belt 20 in their Location and distribution secured. In Fig. 4 these are needles Exaggeratedly large and at an exaggerated distance from each other shown to illustrate the invention. In in practice, these are fine conifers or needle beams, the needles being very fine and in a very slight Are spaced from each other.

Fig. 4 is intended to clarify that the 0 ° multifilament threads 7 and 8 prevented by these needles 21 be to move across the conveyor belt 20 and thus are fed to the sewing point in a secure position and distribution, which is also indicated purely schematically at 22 in FIG. 4. In Fig. 4 are indicated by 23, the sewing or warp threads, which by the Needles 22 are drawn into the clutch and thereby the Sew the clutch to the one not shown in the drawing Goods tree is led.

Claims (8)

1. A method for producing a multiaxial structure from multifilament threads superimposed on each other in different orientations, the threads of the 0° layer being aligned in the direction of production and being inserted between the other multifilament layers laminated in different orientations, characterised in that the threads of the 0° layer are guided by auxiliary means for securely maintaining the position and distribution of said threads in the area preceding the stitch-bonding machine.
2. A method according to Claim 1, characterised in that the multifilaments of the threads of the 0° layer are fixed by freely-suspended combs in their distribution predetermined in the feed area before being fed into the stitch-bonding machine and therefore before stitching of the structure.
3. A method according to Claim 1, characterised in that the multiaxial structure is laid on a conveyor means running in the direction of production and equipped with a multiplicity of fine needles which securely maintain the distribution of all layers predetermined before insertion up to the stitching point, and securely maintain the distribution and position of the threads of the 0° layer before their introduction into the stitch-bonding machine and therefore before the stitching of the structure.
4. A method according to Claim 3, characterised in that a circulatory conveyor belt is used as the conveyor means.
5. A method according to Claim 3, characterised in that an endless feed lattice us used as the conveyor means.
6. A method according to Claim 3, characterised in that a webbing belt is used as the conveyor means.
7. A method according to Claim 3, characterised in that the multifilament threads of the axial structure including the threads of the 0° layer are laid on a surface maintained under partial vacuum, are sucked thereto and transported to the stitching point thereon.
8. A method according to Claim 1, characterised in that at least the threads of the 0° layer are maintained securely in their position and distribution by being arranged form-fittingly with each other or with at least one of the multifilament layers aligned in different orientations.

Images