WO2019161969A1

WO2019161969A1 - Thread structure

Info

Publication number: WO2019161969A1
Application number: PCT/EP2019/000056
Authority: WO
Inventors: Christoph Baumgart; Florian Neumann; Dirk Lange
Original assignee: Delcotex Delius Techtex Gmbh & Co Kg
Priority date: 2018-02-23
Filing date: 2019-02-25
Publication date: 2019-08-29
Also published as: EP3755833B1; CN112041491A; PT3755833T; EP4001480A1; EP3755833A1; CN112041491B; PL3755833T3; DE102018001440A1

Abstract

The present invention relates to a thread structure with thread bundles which are laid in parallel with respect to one another, composed of individual threads which are mutually crossing each other and form spacings between the thread bundles, each of which being provided with a thermoplast matrix in a volume-filling manner in the manner of a composite material.

Description

threadlike structure

The present invention relates to a filament structure according to claim 1. Prepregs are well known.

DE 69003875T 2 discloses a prepreg consisting of warp thread and

Weft threads is made, wherein the weft threads extend obliquely to the direction of the warp thread. This structure is created for a particular wearer and is not changed anymore.

U.S. Patent No. 5,553,654 discloses a belt of reinforced construction. The individual reinforcing elements have different directions of laying.

US 2005 / 0085147A 1 discloses a prepreg woven from bundles of fibers with gaps between the bundles filled by auxiliary yarns so that no openings are formed in the final product.

The object of the present invention is to produce such prepregs with an increased utility value in a simple manner, while ensuring that the composite structure uniformly stabilizes the final product over the entire areal configuration of the final product.

This object is achieved by the invention by the features of the main claim.

From the invention, there is the advantage that such a thread structure can be produced in the simplest way, practically as a raw fabric, in open form, which already has a dimensionally stable structure a priori, because the thermoplastic matrix in the individual filament bundles not only stabilizes the filament bundles, but also the entire thread structure.

It depends essentially on the fact that the thermoplastic matrix is present in a volume which can flow into the intermediate spaces provided between the individual bundles of fibers in a subsequent pressing operation under the known parameters of pressure, temperature and time and in this way in this downstream pressing process for a uniform Laying the Einzelfädert in the final product ensures.

It is therefore essential idea of the invention, between the individual laid thread bundles, each of which runs parallel to the direction and form spacings between them in the transverse direction, to determine the distances so large with regard to the thermoplastic matrix present in the respective bundle of fibers that this thermoplastic matrix together with the under Pressure from each thread bundle outwardly flowing monofilament forms a thoroughly uniformly interspersed with individual threads in each direction composite body, which is also interspersed by the manufacturer provided excess of thermoplastic matrix over the entire longitudinal and transverse dimensions with the thermoplastic matrix.

This is a significant advantage of the invention, because the invention has recognized that the flow process of the individual threads in the originally available free areas between the filament bundles in each direction causes virtually homogeneous material properties, so that corresponding material properties such as tensile strength, etc. can be ensured.

It is particularly advantageous that the dimensioning of the filament bundles, so their cross-sectional dimensions and the associated released points between the Filament bundles can be gesti mt easily on the respective end product.

Of course, the open lattice structure applies in all directions which lie transversely to the respective laying directions of the directionally parallel bundles of fibers.

The thread structure of the present invention can be made as a semi-finished, sandwich or lightweight board.

It is essential in any case, the enforcement of the thermoplastic matrix through the entire bundle of filaments. This means that practically no air inclusions in the thermoplastic matrix are to be allowed, at least in the technically feasible range, so that the flow of the matrix in the downstream process can also lead to a full-volume matrix fraction in the end product.

In the downstream process, a complementary thermoplastic material can also be processed without further ado, so that thanks to the invention a two-sided anchoring of this supplementary thermoplastic material as a result of penetration through the plastic matrix present in the original prepreg leads to improvement of the material characteristics.

Of course, the use of plastics that are compatible with the original plastic of the prepregs is recommended. In that regard, the invention offers the additional advantage that in the second processing step, a lower pressure is sufficient to bring the thermoplastic materials together in Kapillarverbünd. This is achieved in particular by the elements already present in the original bundles of filaments impregnated with a thermoplastic matrix and therefore the existing in the final product filament structure must be contacted only in the microscopic range of the supplementary applied thermoplastics under a pressure that produces only the capillary composite.

Attention is also paid to the injection technique for the injection of thermoplastic material into the originally existing bundles of fibers.

The thermoplastics used today have well-known kinematic state variables that can be adjusted so that it can come to a full volume impregnation of each thread bundle, so that later end products no longer have air pockets.

Thus, the invention shows that it can, hitherto unknown, also have constant grating values in the structure of the end product, so that reliable predictions with regard to the material characteristics can be made.

Since the invention basically has holes defined by longitudinal and transverse dimensions in all embodiments, which are located between the individual bundles of filaments, at least before the filament bundles are pressed under the parameters of temperature, pressure and time in a further processing step, such a filament structure can also be used be defined by their grid values.

Grid values are those characteristics which define the size of the recesses between the filament bundles, for example the X - or Y values in a Cartesian coordinate system. In the case of multidirectionally laid thread bundles, this applies accordingly.

Of particular advantage in addition to anchoring in the capillary also possibly a way to chemically anchor the subsequently used thermoplastics and the aforementioned possibility of changing the thread geometry in terms of the structure of the Endpro product.

From the dependent claims, advantageous developments of the invention.

It can be provided only two preferably perpendicular intersecting directions for the filament bundles.

Depending on the requirements of the end product, it may also be advantageous to provide more than two directions. For this embodiments are given.

However, it is essential in any case that at least as many layers of individual threads are provided in each bundle of filaments, and so much thermoplastic matrix, that the existing in the original thread structure side gaps between the bundles of filaments by filling the filaments into the adjacent originally released sides are filled up ,

The production of the thread structure as a roller conveyor offers manufacturing technology the lowest cost per unit length and in particular the ability to prepare the roller conveyor in the form of blanks for further processing.

In the following the invention will be explained in more detail by means of exemplary embodiments.

Show it:

Fig. 1 shows the basic principle of the invention;

2 shows a three-dimensional view of

Invention, here in the form of a fabric;

3 is an enlarged view of a

Thread bundle;

Fig. 4 one in more than two parallel

Directions misplaced arrangement of

Filament bundles;

Fig.5 schematic representation of the flow process;

Fig.6 presentation of the thread structure,

Cutting, end product.

Unless otherwise stated below, the following description applies to all figures.

The figures show a thread structure 1 with mutually directional parallel thread sets 2,3,4; 2 ', 3', 4 ';

It is essential that between the parallel filament bundles in a direction transverse thereto distances exist, in which there is no material, and this transverse to all laying directions in which the respective filament bundles are laid.

It is an open fabric, but it is quite possible a scrim or another form of the respective flat end product of the thread structure without limiting the invention thereto.

In that regard, the invention also applies to, for example, unidirectional thread bundles, in which only transversely to the direction of the laid thread bundles significant distances in the sense of the invention exist.

Unidirectional thread bundles could be fixed in this case by occasional transverse auxiliary threads to each other.

From this product of the filament structure, a downstream process, for example by injection molding or forming, can be used to produce highly varied components for all sorts of industrial applications.

It is essential to the extent that the thread structure is completely and uniformly impregnated with a thermoplastic matrix form fit and that the filament bundles can not move relative to each other after the filament structure has been preconsolidated accordingly. Preconsolidation in this sense means that a dimensional stability of the lattice structure with the openings therein must be achieved.

This is known per se by known manufacturing methods such as production of a fabric, a fabric or the like.

As particularly Fig.3 shows, the filament bundles are 2,3,4; 2 ', 3', 4 '; 2 '*, 3' ', 4' 'of the thermoplastic matrix 6 completely penetrated.

Each thread bundle consists of a multiplicity of shown individual threads 5 which are embedded in the full-volume thermoplastic matrix.

The thermoplastic matrix present in each bundle of fibers connects the pairs of intersecting filament bundles at the connection points of the fabric / fabric. stable in relation to each other so that semi-finished products made of the thread structure can be cut to any desired size to match the end product.

This offers the advantage that it is easily possible for the end user to position the semifinished product as a cutting precisely in the end product without the basic structure of the fabric / fabric changing during further processing.

To achieve a homogeneous installation pattern of the respective bundles of fibers in the end product, it is proposed that the bundles of fibers have the same width and the same thickness in each direction.

For one exemplary embodiment, it is proposed that the fabric or scrim constructions have a thread spacing of more than 2 mm and, depending on the requirement profile for the end product, be arranged at right angles and / or biaxially and / or multiaxially in different directions.

However, this is not a limitation of the invention. In this respect, all technically sensible grid structures with corresponding longitudinal and transverse dimensions of the distances between tween the filament bundles are covered by the claim.

As also shown in particular in Figure 3, each thread bundle has multilayered individual filaments 5, which are distributed more or less uniformly in the bundle of filaments and are enclosed by the thermoplastic matrix flush and full volume.

For this reason, the filament bundles have a width 9 and a height 10, so that in each bundle of filaments as many layers of filaments can be accommodated and so much thermoplastic matrix can surround these filaments that when pressing the filament structure under the known parameters pressure, temperature and time the original ones rametern pressure, temperature and time, the originally existing distances 7, 8 between the individual filament bundles are filled by flowing the monofilaments 5 in the adjacent originally released distances 7.8.

It is essential in this process that in the process of finishing for the production of the final product 14 so much pressure, temperature and time is exerted on the originally existing structure, that the existing thermoplastic matrix at least in the originally released distances 7,8 with entrainment may displace the embedded in it individual filaments 5, so that in the end a three-dimensionally shaped end product arises with evenly embedded individual filaments coming from the original bundles of filaments.

6 shows the presentation of the thread structure according to the invention as a roller conveyor 12, which can serve for example for the production of blanks 13, which can be processed after appropriate 3-D deformation as an end product, here for example as a can lid 14th

Furthermore, it should be expressly mentioned that the thread structure can also be produced in the form of a presentation in carbon look in order to be able to serve appropriate customer groups if necessary.

The invention has also made the surprising finding that not only thermoplastic materials alone can be used, but also thermosetting plastics.

This was especially the case with thermosetting plastics of only small thickness, since they remain elastic when cured, provided that they have a small thickness.

Furthermore, the invention also relates to a method for producing the thread structure according to the invention, which has been found to be advantageous.

In this method, which applies to all the embodiments already mentioned, initially an intermediate structure of a flat structure, such as a fabric or a scrim is produced, wherein the filament bundles of the subsequently desired thread structure to be laid accordingly.

This intermediate structure is then so abundantly charged with a liquefied plastic, which may be both thermoplastic and thermoplastic, that after the application of excess plastic must be removed.

In the process, however, this excess plastic is only removed to the extent that each bundle of fibers remains trapped in full volume by remaining plastic.

In this way, it is ensured that each individual bundle of fibers forms a composite material for itself with a plastic matrix which is virtually free of air inclusions and in this way gives the thread structure in each main direction of the laid bundles of fibers considerable strength properties. Even while the originally liquefied plastics are liquid, the undesired excess quantities are removed mechanically or aerodynamically from the intermediate structure by suitable measures. This can be done for example via roller pairs or cross-flow. Thereafter, at least once the mandatory holes between the individual filament bundles are free. If the originally liquefied plastic has not yet dried off, it is recommended to subject the lattice structure prepared in this way to subsequent drying; this can be done without contact, for example by infrared heating or the like in an oven or under an infrared radiator, so that subsequently the dried finished lattice structure Product, the thread structure according to the invention, can be rolled up, so as to become role presentation.

Surprisingly, it has been shown that a thread structure interspersed with thermosetting plastic can be rolled up.

The small thickness of the thermosetting plastic on the thread structure allows a high flexibility, without risk of breakage, although it is a thermosetting plastic.

LIST OF REFERENCE NUMBERS

1 thread structure

2 bundles of fibers, horizontal

3 bundles of threads

4 bundles of threads ·

2 'thread bundles, vertical

3 'thread bundles, vertical

4 'thread bundles, vertical

2 '' thread bundles, diagonal

3 '' thread bundle, diagonal

4 '' thread bundle, diagonal

5 single thread

6 thermoplastic matrix

7 distance between 2,3,4

8 distance between 2 ', 3', 4 '

9 width

10 thickness

11 flow process

12 roller conveyor

13 cut

14 can ends

Claims

claims

1. Thread structure (1) laid with parallel directions

Filament bundles (2, 3, 4); (2 \ 3 ', 4'); (2 ", 3", 4 ") composed of monofilaments and intersecting with each other to form transverse spacings with respect to their respective laying direction to each adjacent bundle of filaments, only the bundles of filaments (2, 3, 4); (2 \ 3 ', 4'); (2 ", 3", 4 ") while leaving the interstices (7, 8) between them in the manner of a composite material provided with a thermoplastic matrix,

characterized in that

each thread bundle (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") has multilayered filaments and that

at each thread bundle (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") so many layers of individual threads (5) are provided and so much

Thermoplastic matrix (6) that when pressing the thread structure under the known parameters pressure, temperature and time, the original distances (7,8) between the individual filament bundles (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") are filled by flowing (11) of the monofilaments (5) into the adjacent originally left clearances (7, 8).

Second thread structure (1) according to claim 1, characterized in that the thread bundles (2, 3, 4); (2 \ 3 ', 4'); (2 ", 3", 4 ") from the

Thermoplastic matrix (6) are fully interspersed.

3. thread structure (1) according to claim 1 or 2, characterized in that the thermoplastic matrix (6) in the thread bundles (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") is injected.

4. thread structure (1) according to any one of claims 1-3, characterized

characterized in that the filament bundles (2, 3, 4) and (2 ', 3', 4 ') are provided in only two intersecting directions.

5. thread structure (1) according to any one of claims 1-3, characterized

characterized in that the filament bundles (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") are provided in more than two intersecting directions.

6. Thread structure (1) according to one of the claims 1-5, characterized

characterized in that the filament bundles (2, 3, 4); (2 ', 3', 4 '); (2 ", 3", 4 ") have the same width (9) and the same thickness (10) in each direction.

7. thread structure (1) according to any one of claims 1-6, characterized

characterized in that the thread structure (1) is opened as a roller conveyor (12).

8. thread structure (1) according to claim 7, characterized in that from the roller conveyor (12) blanks (13) for the final product (14) are made.

9. thread structure (1) according to any one of claims 1-8, characterized

characterized in that the thread structure (1) is carbon

Has

Method for producing a thread structure (1) according to any one of claims 1-9, characterized in that after the production of a planar structure as an intermediate structure, which then corresponds to the thread structure (1), the intermediate structure is so abundantly charged with a liquefied plastic that after the admission the excess plastic is only so far removed that each thread bundle (3, 4) remains full of volume of remaining plastic volume filling.

11.A method according to claim 10, characterized in that the

excess plastic is squeezed off by a parallel to the path of movement of the thread structure (1) on both sides arranged to this pair of rollers and that before the subsequent drying a cross-flow is directed to the intermediate product to free the holes located between each thread bundles.

12. The method according to claim 10-11, characterized in that after the squeezing the thermoplastic matrix by a

preferably non-contact drying is solidified

13. The method according to claim 10-12, characterized in that the drying takes place by means of an infrared source.

14. The method according to claim 10-13, characterized in that the thread structure is fed after drying a Aufrollstation, where it is wound up into a roll.