DE102014111268A1 - Production of a textile reinforcing material for a fiber composite material - Google Patents

Abstract

A method of producing a textile reinforcing material (1) for a fiber composite, comprising at least the following steps: a) weaving a fabric (2) with a plurality of warp threads (3) and a plurality of weft threads (4) with a weaving machine; b) weaving a first thread system (6) obliquely to the warp threads (3) and weft threads (4) during step a); c) weaving a second thread system (7) obliquely to the warp threads (3) and weft threads (4) during step a); and d) generating at least a first overlapping area (8) with a first overlapping direction (9) between the first thread system (6) and the second thread system (7) during steps a) to c), wherein the first thread system (6) and the second thread system (7) in the at least one first overlapping region (8) run parallel through at least one loop (10).

Description

The present invention relates to a process for producing a textile reinforcing material for a fiber composite. Such fiber composites regularly consist of a textile embedded in a matrix material and are characterized by a high specific strength. Such materials are therefore used in particular in automotive or aerospace engineering.

As textiles, because of their advantages, fabrics are frequently used as reinforcing material in fiber composites. These advantages include good drapability, high security against delamination, cost-effective production and / or a flexible production process. The main disadvantage of fabrics is the limitation with regard to the orientation of the warp threads and weft threads which are orthogonal to one another. Therefore, several layers of the fabric are often necessary, which leads to increased process and labor costs and especially at +/- 45 ° reinforcements to high waste.

One approach to solving this problem is multi-axial weaving techniques that produce fabrics with more than two thread orientations. However, most of these methods are not industrially available or extremely expensive to manufacture. In addition, productivity is often severely limited and only fabrics with narrow widths (eg less than 30 cm) can be produced. This makes such semi-finished products, especially for mass production so far unattractive.

From the WO 2011/095262 A1 A multiaxial weaving technique emerges which is also known to the person skilled in the art as "open reed weaving technology" (ORW technology). In this multiaxial weaving process, two additional thread systems are woven into the fabric at almost freely adjustable angles. This is done by two laterally displaceable needle systems, which laterally guide the multiaxial threads and can lower them for binding. The immersion of the threads is made possible by an open top Riet. The lateral laying of the multi-axial threads is done in a zig-zag pattern with a maximum offset of 30 cm. Although the resulting reversal points of the zigzag pattern strip-shaped pieces (between two reversal points) can be produced multiaxial tissue, but an oblique thread pattern over the entire Rietbreite or tissue width is not possible. As a result, according to the prior knowledge of experts, these fabrics can not be used as reinforcing material for larger components made of fiber composite material in order to achieve reinforcement in an oblique direction, since no force flow can take place at the reversal points of the yarns in ORW technology.

The object of the invention is therefore to solve the problems described with reference to the prior art at least partially and in particular to provide a method with which textile reinforcing materials for a fiber composite material can be produced, which are characterized by a high multiaxial load capacity. In addition, a reinforcing material for a fiber composite material is to be specified, which is characterized by a high multiaxial resilience.

These objects are achieved with a method and a reinforcing material according to the features of the independent claims. Further advantageous embodiments of the invention are specified in the dependent claims. It should be noted that the features listed individually in the dependent formulated claims can be combined with each other in any technologically meaningful manner and define further embodiments of the invention. In addition, the features specified in the claims are specified and explained in more detail in the description, wherein further preferred embodiments of the invention are shown.

The method proposed here for producing a textile reinforcing material for a fiber composite material has at least the following steps:

a) weaving a fabric having a plurality of warp yarns and a plurality of weft yarns with a loom;

b) weaving a first thread system obliquely to the warp threads and weft threads during step a);

c) weaving a second thread system obliquely to the warp threads and weft threads during step a); and

d) generating at least one first overlapping region with a first overlapping direction between the first thread system and the second thread system during steps a) to c), wherein the first thread system and the second thread system run parallel in the at least one first overlapping region and together form at least one loop ,

The proposed method for producing a textile reinforcing material for a fiber composite material is carried out in particular according to the open reed weaving method. The open-reed weaving method is known to those skilled in principle and is particularly on page 2, line 32 to page 4, line 4 of WO 2011/095262 A1 described (the local description is here fully made the subject of the description). Thus, the method is particularly feasible with a weaving machine that masters the open reed weaving technology. The textile reinforcing material produced by the proposed method is used to produce a fiber composite material. For this purpose, the textile reinforcing material is embedded in a matrix material after its production. Duroplast, an elastomer or a thermoplastic can be used in particular as matrix materials.

According to step a), a fabric of the textile reinforcing material is woven with a plurality of warp threads and a plurality of weft threads with a weaving machine. Such a loom, which in particular dominates the open reed weaving technology, is also in particular from page 9, line 1 to page 14, line 32 of WO 2011/095262 A1 known (the local description is here fully made the subject of the description). With this, the warp threads and weft threads are crossed at right angles. In this case, the warp threads form the carrier, in which successively the weft threads are drawn from a first selvedge to a second selvedge. The warp threads run parallel to a longitudinal side of the fabric and the weft threads parallel to a transverse side of the fabric.

According to step b), a first thread system is woven in at an angle to the warp threads and weft threads during step a). Furthermore, according to step c), a second thread system is woven obliquely to the warp threads and weft threads during step a) (and optionally at the same time as step b)). The first thread system and the second thread system are therefore additional thread systems in addition to the warp threads and weft threads. The first thread system is, in particular, a first thread that is woven obliquely into the fabric or a plurality of first threads that are woven obliquely into the fabric and extend in particular parallel to one another. Correspondingly, the second thread system is, in particular, a second thread or a plurality of second threads that are obliquely woven into the fabric and that run in particular parallel to one another. The majority of the first threads of the first thread system and / or the plurality of second threads of the second thread system run in particular in an identical (but staggered) pattern to one another and / or in particular with an offset in a weft direction of the weft threads and / or with an offset parallel to the warp threads. The warp threads, the weft threads, the first thread system and / or the second thread system preferably consist essentially of glass fibers, carbon fibers, ceramic fibers, aramid fibers, boron fibers, basalt fibers, steel fibers, natural fibers and / or nylon fibers. By "oblique" is meant in particular that the first thread system and the second thread system or the first threads of the first thread system and the second threads of the second thread system, in particular over their entire length, not parallel to the warp threads and weft threads, but at an acute or obtuse angle relative to the warp threads and weft threads , In particular, the first thread system and / or the second thread system can extend at an angle of 45 ° to the warp threads and / or weft threads.

According to step d), during steps a) to c), at least one first overlapping region is produced with a first overlapping direction between the first thread system and the second thread system, wherein the first thread system and the second thread system run parallel in the at least one first overlapping region and together form a loop. The execution of steps a) to d) takes place in particular at least partially simultaneously. The at least one first overlapping area is an area in which the first thread system and the second thread system are in particular completely parallel. This means, in particular, that the first thread system and the second thread system touch in the at least one overlapping region substantially over their entire length. A loop is to be understood in particular as meaning a region of the first thread system and of the second thread system which extends between two bonding points. As Abbindepunkt applies here an area of the fabric in which the first thread of the first thread system and the second thread of the second thread system are secured by a warp thread and / or a weft thread to the fabric. Furthermore, the warp threads and the weft threads intersect at the setting points. In addition, the first thread of the first thread system and the second thread of the second thread system can run in the binding points between the warp threads and weft threads, so that the first thread of the first thread system and the second thread of the second thread system clamped in the setting points in particular between the warp threads and wefts are. After embedding the fabric in the matrix material, the matrix material serves as an adhesive which bonds the first thread system and the second thread system in the at least one overlapping region. By means of such a binding design, it is possible to produce a fabric which, in addition to a warp direction (0 °) and the weft direction (90 °), has a further reinforcement direction. Furthermore, the first thread system and the second thread system form over the at least one first overlapping region a, in particular straight, connection between two longitudinal sides, two transverse sides and / or one longitudinal side and one transverse side of the fabric. It should be clarified at this point that the fabric may have further thread systems running obliquely to the warp threads and weft threads, which form further overlapping areas, so that the fabric has further reinforcing directions. In addition, it is also possible to transfer the proposed method to other types of textile, such as knitted fabrics.

In addition, it is advantageous if the first thread system and the second thread system are laid in a zigzag pattern during steps b) and c). The zig-zag pattern is a pattern of short stretches lined up at equal angles (repeated) so that their ends describe two parallel lines or arcs.

In addition, it is advantageous if the zig-zag pattern in a weft direction has a maximum offset of 30 cm (centimeters). The offset is preferably 5 cm to 30 cm. The weft direction extends in particular parallel to the weft threads. In addition, an "offset" is understood in particular to be the shortest connection between two (neighboring) corner points of the zig-zag pattern parallel to the weft threads.

Moreover, it is advantageous if the first thread system and the second thread system run parallel in the at least one first overlapping region until the first thread system or the second thread system changes direction.

Furthermore, it is advantageous if the first thread system and the second thread system connect at least over the at least one first overlapping region two longitudinal sides, two transverse sides and / or one longitudinal side and one transverse side of the fabric. This means in particular that the first thread system and / or the second thread system extend to one edge or both edges of the fabric. The connection takes place (essentially) in a straight line.

It is also advantageous if, via the first thread system, the second thread system and its at least one first overlapping region, a force can be transmitted between two longitudinal sides, two transverse sides or one longitudinal side and one transverse side of the fabric. This means in particular that the force between two longitudinal sides, two transverse sides or one longitudinal side and one transverse side of the fabric, in particular after the embedding of the fabric in the matrix material, predominantly or even alone on the first thread system, the second thread system and their at least one first overlap region is transferable.

Moreover, it is also advantageous if, during step d), the at least one first overlap region with a length of 1 to 500 mm (millimeters) is produced. In the case that the first thread system and / or the second thread system consists of glass fibers, the length of the at least one first overlap region is preferably 1 mm to 35 mm. In particular, when using polypropylene as the matrix material, a tensile strength is achieved in the at least one overlap region between the first fiber system and the second fiber system, which corresponds to 95% of the tensile strength of a comparable continuous fiber.

It is also advantageous if during step a) a third thread system is woven obliquely to the warp threads and weft threads, wherein the first thread system, the second thread system and the third thread system each offset by one third of a laying width to each other, so that at least a second overlap region is generated with a second overlapping direction between the first thread system, second thread system or third thread system. In particular, the laying width is to be understood as meaning the width of the offset of the zigzag movement of the individual needles.

Furthermore, it is advantageous if the tissue is embedded in a matrix material after step d).

As a further aspect of the invention, a reinforcing material for a fiber composite material is proposed which comprises a fabric to which a first thread system and a second thread system is attached, wherein the first thread system and the second thread system obliquely to warp threads and weft threads of the fabric and wherein first thread system and the second thread system form at least a first overlap region with a first overlap direction. For further details of the reinforcing material, reference is made to the description of the method according to the invention.

In addition, a weaving machine with shedding elements is proposed, through which a weaving shed limited by warp can be formed, further comprising means for entry of a weft thread in the shed in a weft direction and a displacement drive, which drives a displacement device in weft direction, through which a first thread system or a second thread system in the weft direction can be moved, wherein the displacement drive can be controlled by a control device is and wherein the control device is set up and provided for carrying out the method according to the invention.

The invention and the technical environment will be explained in more detail with reference to FIGS. It should be noted that the figures show particularly preferred embodiments of the invention, but this is not limited thereto. The same components are provided in the figures with the same reference numerals. They show schematically:

1 a first embodiment of a textile reinforcing material produced by the proposed method;

2 : an enlarged view of one in the 1 overlap area shown; and

3 A second embodiment of a textile reinforcing material produced by the proposed method.

The 1 shows a first embodiment of a textile reinforcing material 1 with a tissue 2 , The tissue 2 has a long side 14 and a transverse side 15 on and includes a variety in the 2 shown warp threads 3 and weft threads 4 , When weaving the fabric 2 was according to steps a) to c) of the proposed method, a first thread system 6 and a second thread system 7 at an angle to the warp threads 3 and the weft threads 4 into the tissue 2 woven. The first thread system 6 is in the figures as solid lines and the second thread system 7 shown as dashed lines. In the embodiment shown, the first thread system 6 from a plurality of first threads 17 and the second thread system 7 from a plurality of second threads 18 , each parallel and in a weft direction 12 offset from one another. The first threads 17 of the first thread system 6 and the second threads 18 of the second thread system 7 are each in a zigzag pattern 11 into the tissue 2 woven in and point in the weft direction 12 between in the longitudinal direction 19 neighboring vertices 5 an offset 13 on. During weaving of the fabric 2 and weaving in the first thread system 6 and the second thread system 7 into the tissue 2 according to steps b) and c) of the method according to step d) of the method between the first thread system 6 and the second thread system 7 a plurality of first overlapping areas 8th with a first overlap direction 9 generated, wherein the first thread system 6 and the second thread system 7 in the first overlapping areas 8th run parallel and together at least one in the 2 shown loop 10 form. Furthermore, the first overlap areas 8th in the first overlapping direction 9 each have a length 16. The first thread system 6 and the second thread system 7 form over the first overlapping areas 8th a plurality of straight connections across the entire tissue 2 ,

The 2 shows in an enlarged view that in the 1 marked with II area. To recognize the (approximately) at right angles chained together warp threads 3 and weft threads 4 of the tissue 2 , Furthermore, in the 2 the parallel course of a first thread 17 of the first thread system 6 and a second thread 18 of the second thread system 7 shown between bonding points 20 together a plurality of loops 10 form.

The 3 shows a second embodiment of a textile reinforcing material 1 with a tissue 2 , This second embodiment differs from that in the 1 shown first embodiment of the textile reinforcing material 1 through a third thread system 21 , which is also inclined to the in the 2 shown warp threads 3 and weft threads 4 into the tissue 2 was woven. The first thread system 6 (shown with solid lines), the second thread system 7 (shown with rough dashed lines) and the third thread system 21 (shown with fine dashed lines) each extend by one third of a laying width 22 offset from each other, so that a plurality of second overlap areas 23 with a second overlap direction 24 are formed. The textile reinforcing material 1 thus has a plurality of first overlapping areas 8th with a first overlap direction 9 and a plurality of second overlapping areas 23 with a second overlap direction 24 on.

The method according to the invention and the reinforcing material according to the invention advantageously permit a multiaxial force transmission over the entire fabric width of the fabric.

LIST OF REFERENCE NUMBERS

1

 textile reinforcing material

2

 tissue

3

 warp

4

 wefts

5

 vertices

6

 first thread system

7

 second thread system

8th

 first overlap area

9

 first overlap direction

10

 loop

11

 Zig-zag pattern

12

 Weft direction

13

 offset

14

 long side

15

 transverse side

16

 length

17

 first thread

18

 second thread

19

 longitudinal direction

20

 Abbindepunkt

21

 third thread system

22

 laying width

23

 second overlap area

24

 second overlap direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2011/095262 A1 [0004, 0013]
• WO 2011/095262 [0012]

Claims (10)

Process for producing a textile reinforcing material ( 1 ) for a fiber composite, comprising at least the following steps: a) weaving a fabric ( 2 ) with a plurality of warp threads ( 3 ) and a plurality of weft threads ( 4 ) with a weaving machine; b) weaving a first thread system ( 6 ) obliquely to the warp threads ( 3 ) and weft threads ( 4 during step a); c) weaving a second thread system ( 7 ) obliquely to the warp threads ( 3 ) and weft threads ( 4 during step a); and d) generating at least a first overlapping area ( 8th ) with a first overlapping direction ( 9 ) between the first thread system ( 6 ) and the second thread system ( 7 ) during steps a) to c), wherein the first thread system ( 6 ) and the second thread system ( 7 ) in the at least one first overlapping region ( 8th ) run parallel and together at least one loop ( 10 ) form. Method according to claim 1, wherein the first thread system ( 6 ) and the second thread system ( 7 ) during steps b) and c) in a zigzag pattern ( 11 ). Method according to claim 2, wherein the zigzag pattern ( 11 ) in a weft direction ( 12 ) an offset ( 13 ) of maximum 30 cm. Method according to one of the preceding claims, wherein the first thread system ( 6 ) and the second thread system ( 7 ) in the at least one first overlapping area ( 8th ) run parallel until the first thread system ( 6 ) or the second thread system ( 7 ) the direction changes. Method according to one of the preceding claims, wherein the first thread system ( 6 ) and the second thread system ( 7 ) at least over the one first overlapping area ( 8th ) two long sides ( 14 ), two transverse sides ( 15 ) or a longitudinal side ( 14 ) and a transverse side ( 15 ) of the tissue ( 2 ) connect. Method according to one of the preceding claims, wherein via the first thread system ( 6 ), the second thread system ( 7 ) and at least one first overlapping area ( 8th ) a force between two longitudinal sides ( 14 ), two transverse sides ( 15 ) or a longitudinal side ( 14 ) and a transverse side ( 15 ) of the tissue ( 2 ) is transferable. Method according to one of the preceding claims, wherein during step d) the at least one first overlapping region ( 8th ) with a length ( 16 ) is produced from 1 to 500 mm. Method according to one of the preceding claims, wherein during step a) a third thread system ( 21 ) obliquely to the warp threads ( 3 ) and weft threads ( 4 ), wherein the first thread system ( 6 ), the second thread system ( 7 ) and the third thread system ( 21 ) each by one third of a laying width ( 22 ) offset from each other, so that at least a second overlap region ( 23 ) with a second overlapping direction ( 24 ) between the first thread system ( 6 ), second thread system ( 7 ) or third thread system ( 24 ) is produced. Method according to one of the preceding claims, wherein the tissue ( 2 ) is embedded in a matrix material after step d). Reinforcing material ( 1 ) for a fiber composite material comprising a fabric ( 2 ) on which a first thread system ( 6 ) and a second thread system ( 7 ), wherein the first thread system ( 6 ) and the second thread system ( 7 ) obliquely to warp threads ( 3 ) and weft threads ( 4 ) of the tissue ( 2 ) and wherein the first thread system ( 6 ) and the second thread system ( 7 ) at least a first overlapping area ( 8th ) with a first overlapping direction ( 9 ) form.

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