Embroidery machines for placing reinforcement fibres. Different textile technologies like spinning, weaving and knitting are well known and used to create fibre-reinforced composites a fairly long time. A radically new technology to build up reinforcement fabrics (preforms) is the free orientation, placing and fixing of reinforcement materials through an embroidery machine.
The machines can be used in applications where the production of components or textile structures requires the stitching of variable-geometry ply stacks, where fabrics need to be reinforced locally, or where fabrics must be assembled. Single layered rovings are fixed to the base material by stitching. During the process, the base material is moved by the embroidery machine’s pantograph using numerical control, enabling to lay rovings in any direction and quantity.
The most significant advantage of producing fibre-reinforced composites using an embroidery machine is to lay the rovings according to the distribution of forces within a structural component. High reproducibility of the component’s characteristics is another main aspect of this process. The roving layer’s reproducibility is approximately 0.3 mm.
It is accomplished by the following factors:
- automatic preform production
- high dimensional accuracy
- low mass tolerance and
- ever identical laying of rovings.
The cost efficient process is driven by high stitching speed on one hand and multiple working units on each machine to produces identical preforms. In comparison to other textile technologies the expensive loss of materials is very little. Accordingly the problem of waste disposal is minimal. CAD embroidery software ensures that the machine control programme is designed to take required orientations for specific reinforcement fibres into account. A large number of different patterns are used to stitch the fibre. Optional cutting and bending lines are also available, to be used in combination with a standard embroidering head for applying reference points.
ZSK hereby expanded its customer structure. Totally new branches started to adapt these latest embroidery techniques to their technical and constructing challenges. The automotive industry starts to stitch copper wires, aircraft design engineers experiment with laying their carbon fibre skeins with ZSK special machines and the building industry is testing new methods of reinforcing concrete constructions.