Pultrudates Having Elevations and Grooves and Method for Production Thereof

Abstract

A pultrudate (1) with fibres running in the longitudinal direction (L) and a resin matrix which surrounds the fibres, and a top and a bottom side (2, 4), wherein the top side (2) has continuous elevations (5) and/or grooves (3) and the bottom side (4) has continuous grooves (3) or elevations (5), which are arranged such that elevations (5) and grooves (3) of one pultrudate (1) interact with grooves (3) and elevations (5) of the adjacent pultrudate (1′).

Claims

1. Pultrudate (1) with fibres running in the longitudinal direction (L) and a resin matrix which surrounds the fibres, and a top and a bottom side (2, 4), characterized in that the top side (2) has continuous elevations (5) and/or grooves (3) and the bottom side (4) has continuous grooves (3) or elevations (5), which are arranged such that elevations (5) and grooves (3) of one pultrudate (1) interact with grooves (3) and elevations (5) of the adjacent pultrudate (1′).

2. Pultrudate according to claim 1, characterized in that the elevations (5) are interrupted at predetermined intervals (d) in the longitudinal direction (L).

3. Pultrudate according to claim 1 or 2, characterized in that the grooves (3) have a first width and the elevations (5) have a second width, and the first width is about 5 mm to 20 mm greater than the second width.

4. Pultrudate according to claim 1, 2 or 3, characterized in that the grooves (3) have a width of 8 to 30 mm and the elevations (5) have a width of 2 mm to 10 mm.

5. Component of a rotor blade having at least two pultrudates (1, 1′) arranged above one another, wherein a top side (2) of a pultrudate (1) is arranged adjacent to a bottom side (4) of an adjacent pultrudate (1′), characterized in that a bottom side (4) of the pultrudate (1) has elevations (5) and/or grooves (3) running in the longitudinal direction (L), a top side (2) of the adjacent pultrudate (1′) has corresponding grooves (3) and/or elevations (5), and corresponding grooves (3)/elevations (5) are inserted into one another and keep the adjacent pultrudates (1, 1′) at a predetermined distance (d) from one another.

6. Component according to claim 5, characterized in that grooves (3) are formed alongside one another on the bottom side (4) of the pultrudates (1) and continuous elevations (5) are formed on the top side (2).

7. Component according to claim 5 or 6, characterized in that the pultrudates (1, 1′) are spaced apart from one another by 0.05 mm to 0.5 mm.

8. Method of producing a pultrudate (1, 1′), resin-impregnated fibres being guided through a pre-mould which has elevations and/or grooves on a top side (2) and a bottom side (4) which form grooves and/or elevations into the top side (2) and the bottom side (4) of the pultrudate (1, 1′).

9. Method of production for a component of a rotor blade, pultrudates (1, 1′) according to claim 1 being arranged above one another and a resin infusion process is carried out.

Description

[0030] The invention is described with reference to an embodiment in three drawings. In the drawings:

[0031] FIG. 1 shows a pultrudate according to the invention in a view from above,

[0032] FIG. 2 shows the pultrudate in FIG. 1 in a view from below,

[0033] FIG. 3 shows a stack of two pultrudates according to the invention according to FIG. 1 for producing a girder.

[0034] A pultrudate 1 according to the invention is illustrated in FIG. 1. Pultrudates 1 are extruded fibre-reinforced plastic components. Pultrudates 1 are usually produced by unrolling rovings, which are bundles of fibres stored on spindles or rolls.

[0035] The rovings/fibres are impregnated with resin after the unwinding in a suitable form. The resin-impregnated fibres are then drawn through a pre-mould station. They are then arranged alongside and above one another in a flat rectangular cross-section and are adhered to one another and brought into the pultrudate shape illustrated in FIG. 1. In the pre-mould protrusions are provided on a top side and grooves are provided on a bottom side, so that correspondingly in the preformed pultrudate 1 grooves 3 are formed on its top side 2 and elevations 5 are formed on its bottom side 4 when the pultrudate 1 is drawn through the pre-mould. Then the pultrudate 1 is cured.

[0036] A cross-section of the pultrudate 1 is illustrated in FIG. 1, wherein the pultrudate 1 is penetrated in cross-section to a large extent by fibres which also extend along the elevations 5 and in each case over the entire extent of the pultrudate 1 and also inside the elevations 5 in the longitudinal direction L of the pultrudate 1. Pultrudates 1 usually have widths of B=100 mm to 300 mm and heights of H=5 mm to 20 mm. These are endless components which can be wound on a roll after curing and thus can be transported to the place of use. Depending upon the degree of curing the pultrudates 1 are differently flexible. Completely cured pultrudates can actually be bent only with great difficulty, in particular in cross-section the pultrudates can hardly be bent, and in longitudinal section the pultrudates 1 can merely be wound up with a large radius.

[0037] FIG. 2 shows the pultrudate in FIG. 1 in a view from below. In the view from below it is crucial that the elevations 5 which are formed from the bottom side 4 of the pultrudate 1 in the longitudinal direction L are interrupted at intervals by interruptions 6. The elevations 5 are abraded along the interruptions 6 and are ground down to the height of the bottom side 4 of the pultrudate 1. The interruptions 6 make it possible that during a resin infusion process for producing a girder the resin flows through along the entire width B of the pultrudate 1 between two superimposed pultrudates 1.

[0038] A cross-section of a part of a girder structure using pultrudates 1 is illustrated by way of example in FIG. 3. In cross-section, girders are usually formed of three to five pultrudates 1 arranged alongside one another and up to ten pultrudates 1, 1′ arranged one above the other. The pultrudates 1, 1′ can be arranged above one another in stacks, but they can also be arranged in a group.

[0039] FIG. 3 shows that the elevations 5 on the bottom side 4 of the pultrudate 1 correspond to the grooves 3 on the top side 2 of an adjacent pultrudate 1′, that is to say that in the case of pultrudates 1 laid on top of one another the elevations 5 of one pultrudate 1 engage completely in the grooves 3 of the adjacent other pultrudate 1′. The elevations 5 are guided along their entire longitudinal extent in the grooves 3 of the adjacent pultrudate 1′.

[0040] The grooves 3 usually have a width of 8 to 30 mm, whilst the elevations 5 have a width of 2 to 10 mm, so that the elevations 5 do not completely fill the cross-section of the grooves 3 but are displaceable to and fro inside the grooves 3 along the width B. This different dimensioning of the elevations 5 and the grooves 3 is necessary because during the formation of the girder and during the infusion process the pultrudates 1 are pressed against the contact surface of a production mould and are bent in cross section. In order that a pultrudate 1 is not pressed out of the groove 3 of the adjacent other pultrudate 1′, the grooves 3 must have a greater width than the elevations 5, so that a relative movement of the grooves 3 with respect to the elevations 5 is possible which compensates for a different curvature.

[0041] Since the elevations 5 and the grooves 3 extend over the entire longitudinal extent of the pultrudate 1, interruptions 6 of the grooves illustrated in FIG. 2 are helpful and even necessary, so that during an infusion process the still liquid resin system can also flow through along the width B in FIG. 3 from right to left or left to right between the two pultrudates 1, 1′ which lie above one another. In this case the height of the elevations 5 of the pultrudate 1 is chosen to be greater than the depth of the grooves 3 of the adjacent pultrudate 1′, so that the pultrudates 1, 1′ do not lie completely directly on top of one another, but are spaced apart from one another at a distance d. The distance d is between d=0.05 mm and d=0.2 mm, that is to say in the tenths of a millimetre range. It is large enough that the resin system can be distributed completely between the pultrudates 1, 1′ and so an optimal adhered connection between the two pultrudates 1, 1′ can be produced.

[0042] The top and bottom sides 2, 4 of the pultrudate 1 according to FIG. 1 and FIG. 2 are usually provided with a peel ply which is laid at the top and at the bottom onto the not yet cured resin system on the top side 2 or the bottom side 4 and is peeled off after the curing and leaves behind a rough surface on the top and bottom sides 2, 4, so that the resin infused between the pultrudates 1, 1′ has a surface which is particularly large, because it is rough, available for adhesion and thus a very firm adhesive connection can be produced between the individual pultrudates 1, 1′.

LIST OF REFERENCE NUMERALS

[0043] 1 pultrudate

[0044] 1′ adjacent pultrudate

[0045] 2 top side

[0046] 3 grooves

[0047] 4 bottom side

[0048] 5 elevations

[0049] 6 interruptions

[0050] B width

[0051] d spacing

[0052] L longitudinal direction