Patent Application
20080023130
In the preferred embodiment shown in the Figures, the tool 9 object of this invention comprises a stacking table 11 with an upper surface 13 including an area with the shape of the piece to be manufactured and a head 15 supported on a gantry 17. The table 11 includes means allowing the upper surface 13 to move along said table and rotate about an axis located in its central part and the gantry 17 includes means so that the head 15 can move along the width of the table 11.
Head 15 incorporates:
The tool 9 is structured such that on one hand the head 15 can be located at different heights over the table 11 and on the other hand can activate all or part of the mentioned means. Therefore, for example the tool 9 can be configured so that the automatic means for placing tapes 19, the compacting means and the microwave emission means 25 are activated, which will usually occur during the stacking of the piece, or the tool can be configured so that only the microwave emission means 25 are activated, which will occur when individual operations for curing the piece are desired.
The tool 9 however is structured such that the arrangement of the mentioned means can be changed so that they can act in a different order.
In this sense one possible arrangement would be one in which the order of action is as follows: first the automatic means for placing tape, secondly the compacting means, and thirdly the microwave emission means 25. In this case the microwave emission means cure the layer that is in the course of being stacked.
In an alternative arrangement the order of action would be as follows: first the microwave emission means 25, secondly the automatic means for placing tape, and thirdly the compacting means. In this case the microwave emission means cure the layer located under the layer that is in the course of being stacked.
The features of the different components of the tool 9 and particularly the power required of the microwave emitter 25 will vary according to the features of the piece to be manufactured, and very particularly on its thickness. Therefore the microwave emitter 25 must be flexible enough so as to work at different powers so as to be able to vary the power emitted throughout the material curing process.
As a merely illustrative example, some features of a preferred embodiment of the tool 9 are indicated below:
A significant advantage of this invention is that the tool 9 can have a single control panel for the different means previously mentioned, simplifying their handling and control.
Described below is the process object of this invention which has the purpose of using different techniques together for manufacturing a piece of composite material “outside an autoclave”, and particularly the following techniques:
In a first embodiment, the process object of this invention is carried out as follows:
Manufacturing the piece begins with the placement of the first layer of material. In this operation, using for example the tool 9 previously described, the prepreg located on the reel 31 passes through a blade system 33 towards the compacting roller 35, which positions it above the upper surface 13 of the stacking table 11. The separating paper accompanying the prepreg is wound on reel 37. Then the compacting roller 39 and the ultrasonic unit 41 carry out compacting operations on the prepreg tape 19 placed on the stacking table 11. Then the material is cured to a certain degree using the microwave emitter 25. This operation is carried out by suitably moving the head 15 of the tool 9 until all the material corresponding to a layer of the piece is placed, compacted and partially cured.
This layer cannot be completely cured because it has to have a certain degree of stickiness so that the next layer can be suitably placed on it.
The next layer will be placed in a similar manner to the first one (ATL or FP, compacting roller, US), and the action of the microwave emitter 25 will cause the partial curing of the second layer and also of the first.
The placement of different layers will therefore bring about successive curing cycles of the previous layers until reaching the required degree of curing. Finally to obtain suitable curing of the last layer after it is placed, it is necessary to carry out a specific curing cycle by means of the action of the microwave emitter 25.
In an embodiment of the process 80 mm wide prepreg tape has been stacked with an ATL head at a speed of 2 m/min, the frequency of the compacting unit is 20 kHz and the power of the microwave emitter is 0.1 kW.
In a second embodiment of the process object of this invention the curing of the different layers would be carried out once the stacking is complete.
Therefore if the tool 9 is used the different layers forming the piece are stacked in the same manner as previously described and are compacted one by one with the heating roller 39 and the ultrasonic compacting unit 41.
Once all the layers of composite material with the suitable size and orientation are stacked, they are cured using the microwave emitter 25, carrying out the necessary passes with the head 15 until the desired polymerization of the polymer chains is obtained.
Any modifications comprised within the scope defined by the following claims can be introduced in the preferred embodiment described above.
| Number | Date | Country | Kind |
|---|---|---|---|
| ES2006/070124 | Jul 2006 | WO | international |
