EP2651626A2

EP2651626A2 - Arrangement and method for deforming the lamination of semi-finished fibre products

Info

Publication number: EP2651626A2
Application number: EP11805411.3A
Authority: EP
Inventors: Viktor Klitni
Original assignee: MT Aerospace AG
Current assignee: MT Aerospace AG
Priority date: 2010-12-16
Filing date: 2011-12-13
Publication date: 2013-10-23
Also published as: DE102011010635B3; WO2012079744A2; WO2012079744A3

Abstract

The present invention relates to an arrangement for deforming the lamination of semi-finished fibre products, comprising a mould core that can be arranged on a support for receiving in succession semi-finished fibre layers and a pressure element arranged vertically with respect to the mould core for preceding positioning of the semi-finished fibre layers. The support and/or pressure element are designed to be movable towards each other, the mould core is dimensionally stable and the outer contour thereof replicates the inner contour of a non-hardened laminate of a profile to be produced and the pressure element is elastically deformable. The invention also relates to a method for deforming lamination of semi-finished fibre products in a laminating process and the use of the above-mentioned arrangement.

Description

Arrangement and method for forming laminating

of semifinished fiber products

The invention relates to an arrangement and a method for the forming lamination of semifinished fiber products.

In the context of the present invention, semifinished fiber products may be understood as fiber layers whose fibers are interwoven or intertwined to stabilize the layers. Before forming such semi-finished fiber products should be wetted or impregnated with a suitable resin system.

For the production of three-dimensional structures, such as pipes or struts, however, mainly so-called prepregs, ie fiber prepregs impregnated with resin, are used and laminated by hand. For this purpose, it is necessary to deposit the semifinished fiber layers or prepregs successively either in mold halves or over a positive mold core. Such a method is described for example in DE 10 2007 015 909 AI.

A laminate, for example for struts, can consist of 100 individual layers or blanks or more of the selected semifinished fiber product. It must be compacted several times, which is done by applying a vacuum. Further, in hand lamination, concavities in the form of blisters and wrinkles occur on the concave-shaped surfaces of the mold halves.

Better results are obtained by depositing the semi-finished fiber products on convex-shaped surfaces.

However, the fundamental disadvantage of hand lamination lies in the fact that the shaping or bonding of each blank can be done only pointwise, while a großflä ^¬ chige, continuous forming would be desirable. This disadvantage has the consequence that the working speed and the Product quality and reproducibility are highly dependent on the skills of skilled workers. Another weakness of hand lamination is a poor and inhomogeneous compression of the laminate. As a countermeasure, the aforementioned time-consuming vacuuming is applied after each or a certain number of layers.

As a result, hand lamination is unsuitable for economical mass production in any case.

The object of the present invention is therefore to provide an arrangement and a method with which the disadvantages which occur during manual lamination can be avoided. Productivity and reproducibility as well as quality of the end product should be improved.

The present invention is on the one hand an arrangement for laminating semifinished fiber products, comprising a mold core arranged on a support for successively receiving semi-finished fiber layers and a vertically underneath pressure element, wherein the carrier and / or the pressure element are mutually movable, the pressure element elastically deformable is formed and the mandrel is dimensionally stable relative to the pressure element and its outer contour of the inner contour of a non-cured laminate of a profile to be produced is modeled.

Under a mold core, which is dimensionally stable relative to the pressure element, a mold core is to be understood, which consists of a material which is stronger compared to the material of the pressure element. In other words, the mold core material itself can have a certain elasticity, but always bes lower. As the elasticity of the material of the pressure element.

The elastically deformable pressure element first serves as a receiving surface for the semifinished fiber layer, ie a finished chose to cut a preferably pre-impregnated with resin fiber layer. The semi-finished fiber layer or the prepreg preferably comprises carbon fibers or other fibers suitable for the respective case in a respectively suitable matrix material.

The mandrel disposed on a carrier is pressed onto the deposited semifinished fiber layer and into the elastically deformable pressure element. Since the elasticity at each point of the elastically deformable pressure element is the same, the pressure force at any point of the laminating front is always the same. Behind the lamination front, a surface pressure which is always increasing with the continuous pushing in of the mold core into the pressure element is ensured.

In the case of a cylindrical shaping or laminating core, a core enclosure of more than 270 ° can be achieved in conjunction with a pressure element made of a suitable material. It is therefore possible to ensure in a simple manner a full-surface exact pressing or compaction analogous to an intermediate vacuum.

Preferred embodiments of the arrangement will become apparent from the dependent claims.

Accordingly, the pressure element is held in a frame so that it can be moved vertically up and down and rotated about its longitudinal axis by at least 180 ° and additionally below the pressure element a conveyor belt for feeding semi-finished fiber layers to the lower side of the pressure element is provided.

Such an arrangement further enhances productivity and reproducibility while maintaining improved product quality. The mold core and the support receiving the mold core are preferably designed and connectable to one another such that the mold core can be evacuated.

The carrier suitably has connecting elements for connection to a guide mechanism. This ensures optimum power transmission.

The mandrel is also provided over its outer surface with a non-stick finish, which is preferably a flexible release film. This flexible release film preferably adheres by the negative pressure generated on the mandrel. This ensures that the release film can be kept wrinkle-free and slip-proof on the mandrel and the detachment of the layer stack formed at the end is facilitated. The latter could also be achieved by forming the mandrel itself from a material having anti-adhesive properties.

The elastically deformable pressure element is advantageously a cushion from a foam having a selected and matched to the application or tunable Elasti ^¬ capacity. Again, a flexible release liner may be disposable on the foam pad, or the surface thereof may have non-stick properties. This property of the pad ensures a safe transfer of the semi-finished fiber layer to the mandrel.

The surface contour of the foam pad can also be adapted to the contour of the mold core and thus of the ustellenden profile. The surface contour of the foam cushion can thus also be the positive or negative mold of the mold core, but is preferably flat.

The invention also relates to a method for shaping Fa ^¬ serhalbzeugen or semifinished fiber layers in a lamination process using the arrangement described above, where to- next a blank or a layer of semi-finished fiber on the elastically deformable pressure element is aligned and stored, the mold core is lowered by means of the carrier on the semi-finished fiber tray and printed in the elastically deformable pressure element, wherein the semi-finished fiber layer is uniformly pressed against the mandrel, so that they return when returning the carrier adheres to this and the process is repeated until the desired thickness of the laminate to be produced.

The same applies to an arrangement according to claim 3 with the modifications explained in more detail below.

Preferably, the mandrel is connected to the transverse arm of a hydraulic press, so that the step of indenting into the foam pad is automated. Also possible is a robot arm or a pneumatic or hydraulic cylinder.

From the description of the attached drawings, further details and advantages of the present invention will become apparent. In the drawings shows

1 shows an inventive arrangement for carrying out the method according to the invention.

Fig. 2a to 2c sectional views of the arrangement according to

Fig. 1 to illustrate the process sequence;

Fig. 3 shows a v / eitere embodiment of an inventive

Arrangement for carrying out the method according to the invention

Fig. 4 shows a variant of the arrangement according to the invention

Fig. 1, in particular for the production of curved, profiled components; 5 shows a further variant of the arrangement according to the invention according to FIG. 1, wherein a plurality of pressure elements are arranged in or on a turntable;

6 shows a further variant of the arrangement according to the invention according to FIG. 1, wherein the pressure element is moved on a conveyor belt under the mold core;

1 shows schematically an arrangement 1 for laminating semifinished fiber products according to a first embodiment of the present invention.

The profile to be produced with the arrangement according to FIG. 1 corresponds to a strut, in particular a floor strut. The arrangement according to FIG. 4 is adapted to the production of a curved profiled component, such as for example fuselage for aircraft fuselages, etc.

In Fig. 1, the reference numeral 2 denotes a carrier. The carrier 2 substantially corresponds to a U-profile with closed end faces 7. In the carrier 2, a mold core 3 is arranged or integrated, the outer contour 6 corresponds to the shape of a (floor) strut. This means that the external dimensioning of the mold core 3 at each point corresponds to the internal dimension of a strut profile to be produced. Under struts are here substantially elongated cylindrical, oval or flattened hollow body, which gradually taper in their end portions and at the ends lastaufnehmende elements, optionally integrally formed include understood. The mold core 3 reflects this structure or outer contour again.

In the embodiment shown in FIG. 1, the carrier 2 has connecting elements 8 for guiding it. The connecting elements 8 serve to connect the carrier / mold core to an automatically operable guide mechanism (not shown), for example a press. Vertically below a pressure element 5 is arranged. The pressure element 5 is elastically deformable, preferably a soft, elastic foam. The pressure element 5 extends in the same direction with the mandrel 3 and the carrier 2. On the pressure element 5 semi-finished fiber layers 4 are preferably stored with the same fiber orientation. The semifinished fiber layers 4 are preferably prepregs of carbon fibers, which are pre-impregnated with a suitable resin.

The stored semi-finished fiber layers 4 are to be transformed by means of the arrangement 1 corresponding to the mandrel 3. The semifinished fiber layers 4 are not positioned directly on the pressure element 5, but on an interposed non-stick finish in the form of a flexible release film 10 (not shown). This prevents, for example sticky prepreg material adheres to the foam pad 5. As already mentioned, the release film can be saved if the surface of the foam cushion itself has non-stick properties.

Also, the mandrel 3 is coated on its outer contour with a flexible release film 9 (not shown) or even consists of a material with non-stick properties, such as silicone, on its surface. In the case of the release film 9, a fresh film is used for each component or laminate to be produced. It is also conceivable here a cap, for example made of plastic, which is mounted on the mandrel, for example by means of a clip connection to minimize the time required to set up the tool.

Furthermore this sucked in the case of the elastic sheet 9 with ^¬ means of a vacuum to the mold core. 3 The vacuum v / ird over an intake manifold 12, not shown here, which is preferably arranged on the support 2 on an end face 7, comparable as in Fig. 3, applied. Optionally, the mandrel 3 additionally not shown small holes have to ensure the suction of the film over its outer contour 6 uniformly. The support 2, or mold core 3 can be made heatable, if necessary, to increase the tackiness of the resin in the prepreg, if that is necessary for better adhesion to the mandrel 3.

In FIGS. 2a, 2b and 2c, the forming process is now shown, wherein the elements of the arrangement 1 are shown in a sectional view. In FIGS. 2a, 2b and 2c, the reference numerals 3, 4, 5 and 8 stand for the same elements as in FIG. 1.

Thereafter, a semi-finished fiber layer 4 is deposited on the foam pad 5 according to FIG. 2a. The mandrel 3, or support 2 is connected via the connecting elements 8, for example, with a hydraulic press or a robot arm or a pneumatic or electric cylinder and so lowered to the Schaumstoffkis ^¬ sen 5, respectively the semi-finished fiber layer 4 and penetrates with its apex starting in the semi-finished fiber layer. 4 one. The mandrel 3 is then pressed by means of the hydraulic press or the like further into the elastic foam pad 5 according to FIG. 2b, whereby the semi-finished fiber layer 4 gradually applies laterally upwards to the mandrel 3. If the mold core 3 is bevelled at the transition to the carrier 2 and the foam pad 5 has a suitable elasticity, the deformation may be such that the semifinished fiber layer 4 surrounds the mold core up to 270 ° and thus the end product of the forming has a nearly closed profile.

Due to the stickiness of the semifinished fiber 4 (prepreg), the semifinished fiber 4 remains on returning the hydraulic press or the like from the foam pad 5 to the mold core 3. This process can be assisted by the flexible, but not shown separating film 10 and further by heating the carrier 2 during the Forming process can be promoted, since it allows the sticky ^¬ speed of the semifinished fiber 4, if necessary, increase.

This process is repeated until all required layers have been used up on the mandrel 3, i. the desired thickness of the laminate has been achieved.

Thereafter, the formed but still soft laminate is used for hardening process in a mold, as described for example in DE 10 2007 015 909 and subjected to further processing steps.

With the arrangement according to the invention and the method according to the invention for shaping laminates, it is possible to set a reproducibly good quality of the end products with the exclusion of wrinkles and air inclusions, while at the same time minimizing the duration of the process. The arrangement can be operated manually insofar as the mold core 3 can be lowered on the carrier 2, for example by means of a lever, and driven back. By means of a hydraulic press or a robot arm or a pneumatic or Elektrozyiinder the assembly 1 can be automated so that only a few steps by the operator or a technician by hand must be performed, which again reduces the process time and increases the reproducibility and quality of the laminates produced. This result is made possible above all by the means of the foam cushion in all points even pressure of the semifinished fiber 4 to the mold core 3.

In Fig. 3 shows a particular embodiment of an inventive arrangement 1 for the forming lamination of semi-finished fiber products is shown. With the Fig. 1 matching parts are provided with the same reference numerals.

The arrangement 1 includes the mold core 3 held in a carrier 2. On the carrier 2, connecting elements 8 are provided, with which carrier 2 and mandrel 3, for example, with a press, not shown, as described in Fig. 1, is connectable. The mandrel 3 is thus kept movable in the vertical direction in each case. Furthermore, an intake manifold 12 for applying a vacuum is provided on the front side 7 of the mold core 3 and in the carrier 2. As has been described with reference to FIG. 1, a flexible separating film 9 may thus be sucked onto the mold core 3, if appropriate.

Vertically below the mold core 3, a pressure element 5 is again arranged, which consists of an elastic material. The materials of mandrel 3 and pressure element 5 may be matched with respect to their strength and elasticity. The same applies here as for the first embodiment according to FIG. 1

The pressure element 5 is held or mounted in a frame 13 in such a way that it can be moved up or down in the vertical direction on the one hand and rotated by at least 180 ° about its central longitudinal axis on the other hand.

Below the pressure element 5, a conveyor belt 14 is provided at a distance which is greater than the height of the pressure element 5. With the conveyor belt 14 blanks of the semifinished fiber 4, which are stored on positioning slats 15 or the like, transported and driven in particular under the pressure element 5. The positioning laths 15 each positioned as required semi-finished fiber layers 4 are deposited in a storage space 19 on the conveyor belt 14. When a positioning bar, 15 is located with deposited thereon semifinished fiber layers 4 under the pressing element 5 v / ill be lowered the pressing element 5 to the semifinished fiber sheet 4, at the same time, the carrier 2 is lowered with the mold core 3 from the top of the pressure element 5 and presses in this hineinge ^¬. On the mold core 3, a vacuum is now applied via the intake manifold 12. As a result, the transfer of a semi-finished fiber layer 4, which was already deposited on the upper side of the pressure element 5, supported on the mandrel 3. At the same time, a semi-finished fiber layer (s) is sucked by the positioning bar 15 against the lower side of the pressure element 5. Then, the mandrel 3 is driven vertically upwards, as well as the pressure element 5. The latter is then rotated by 180 °. Another Positionierlatte 15 with stored semi-finished fiber 4 is moved under the pressure element 5 and the process steps repeated until the laminate has reached the desired thickness.

Thereafter, the reshaped but still soft laminate is again used for the curing process in a mold, as described for example in DE 10 2007 015 909 and subjected to further processing steps.

With this type of arrangement for the reshaping lamination of semi-finished fiber products, the production process can be further optimized in terms of productivity and reproducibility.

FIG. 4 shows a variant of an arrangement according to FIG. 1, in which the pressure element or the foam pad 5 has a curved surface contour 11. The curvature 11 of the pressure element 5 corresponds to the curvature of the mandrel 3. This can be bent profiled components, such as frames for aircraft fuselages manufacture. On the curved surface 11 of the foam pad 5, a semi-finished fiber layer 4 is again stored, which is pressed into the foam ^¬ fabric pad 7 with the help of the form ^¬ core 3, which is for example as described above with a hydraulic press or the like. The procedure is then the same as described in FIGS. 2a, 2b and 2c.

In Fig. 5 a further variant of the invention An ^¬ order shown in FIG. 4 is shown. It is different from the in the variant shown only in that a plurality of pressure elements 5 are arranged on a turntable 16. On the respective pressure elements or foam pad 5 fiber semi-finished layers 4 are positioned in the intended sequence. By rotating the plate, the foam pad 5 are moved to the semi-finished fiber layers 4 gradually under the mold core 3, not shown here. The successive transfer of the semifinished fiber layers 4 on the mandrel 3 is carried out as the further processing of the still soft laminate as described previously.

FIG. 6 schematically shows another production line for the forming lamination of semi-finished fiber products. The common principle with all other arrangements according to the present invention is a vertically movable mandrel 3 and a vertically underneath can be arranged foam pad 5. Here, the foam pad 5 is mounted on a conveyor belt 14. On the conveyor belt 14 a semi-finished fiber layer 4 is positioned. The foam pad 5 passes as a first station a sensor 17. The sensor 17 is used to determine the position of the semi-finished fiber layer 4. The information regarding the position of the semi-finished fiber layer 4 is input to a resin distributor 18. The resin distributor 18 sprays the semi-finished fiber layer 4 with a suitable resin in a suitable amount. The thus treated semi-finished fiber layer 4 may be subjected to a drying step. Thereafter, as before, the reshaping is performed, passing through the stations so many times until the laminate has reached the desired thickness and the soft laminate is processed as previously described. This variant can, of course, and as preferred, be operated directly with prepregs, that is to say with resin pre-impregnated fiber layers, then without sensor 17 and resin distributor 18.

With the illustrated in Figs. 1 to 6 embodiments of the present invention, an improved quality due to increased compactness of the produced laminate, a clear improved reproducibility of the work result and a significantly reduced process duration guaranteed.

LIST OF REFERENCES

arrangement

carrier

mold core

Fiber layer or semi-finished fiber

presser

Outer contour of the mold core

Face of the wearer

connecting element

flexible release film on the mold core

flexible release film on the pressure element surface contour of the foam cushion intake manifold

frame

conveyor belt

positioning bar

turntable

sensor

resin distribution

stagnation zone

Claims

claims

1. Arrangement (1) for the reshaping lamination of semi-finished fiber products, comprising a on a support (2) can be arranged mold core (3) for the successive absorption of semi-finished fiber layers

(4) and a vertically underneath can be arranged pressure element

(5) for the previous positioning of the semi-finished fiber layers (4), wherein the carrier (2) and / or the pressure element (5) are designed to be movable toward each other, the pressure element (4) is elastically deformable and the mandrel (3) relative to the pressure element (5 ) is dimensionally stable and its outer contour

(6) the inner contour of a non-cured laminate of a profile to be produced is modeled.

2. Arrangement according to claim 1, characterized in that the pressure element (5) in a frame (13) is held such that it moves in the vertical direction downwards and upwards and can be rotated about its longitudinal axis by at least 180 ° and in addition below the pressure element (5) a conveyor belt (14) for supplying semi-finished fiber layers (4) to the lower side of the pressure element (5) is provided.

3. Arrangement according to claim 1 or 2, characterized in that the mold core (3) and the carrier (2) are designed and connected to each other such that the mold core (3) is evacuated.

4. Arrangement according to at least one of claims 1 to 3, characterized in that the carrier (2) has connecting elements (8) for connection to a guide mechanism.

5. Arrangement according to at least one of claims 1 to 4, characterized in that the mold core (3) over its outer contour (6) is provided with a non-sticking equipment.

6. Arrangement according to claim 5, characterized in that the non-sticking equipment is a flexible release film (9).

7. Arrangement according to claim 6, characterized in that the flexible release film (9} by means of generated negative pressure to the mold core (3) adheres.

8. Arrangement according to at least one of claims 1 to 7, characterized in that the pressure element (5) is a foam pad.

9. Arrangement according to claim 8, characterized in that on the foam cushion, a flexible release film (10) is arranged anor- denbar.

10. Arrangement according to claim 8 or 9, characterized in that the surface contour. (11) of the foam pad is adapted to the contour (6) of the mold core (3) and thus of the profile to be produced.

11. The arrangement according to claim 10, characterized in that the surface contour (11) of the foam cushion is realized by introducing harder formkernprofiltreuer segments (12) pillow in the foam.

12. A method for forming semi-finished fiber products in a laminating nierprozess using the arrangement according to at least one of claims 1 to 11, wherein first a blank of the semi-finished fiber on the elastically deformable pressure element (5) is aligned and stored, the mandrel

(3) by means of the carrier (2) on the fiber semi-finished products

(4) lowered and pressed into the elastically deformable Andruckele ^¬ ment (5), wherein the semi-finished fiber layer (4) is uniformly pressed against the mandrel (3) so that it remains adhering to the returning of the carrier (2) and the Repeat process until the desired thickness of the laminate to be produced. A method according to claim 11, characterized in that the mandrel (3) by means of the connecting elements (8) with a hydraulic press, a robot arm, a pneumatic or electric cylinder is connected.