With the Multi-axial UD Crossply machine in our Research and Technology Center we are able to make 1800 millimeters wide Crossply products.
In a Uni-Directional or UD the individual fibres are oriented parallel to each other and kept in this aligned position by a matrix material. This is realized by unwinding yarns from a creel, spreading them to a continuous layer of several fibres thickness, which is subsequently stretched by means of a considerable force for impregnation with the matrix material. In case of thermoplastics an extruder is used in combination with a calendar to guarantee thorough immersion of the fibres with matrix. The simplest way of making a crossply is cutting segments from the UD, stacking them in the desired orientation – normally 0/90o – and pressing them together. To transform this time consuming activity into a continuous process, Van Wees developed the multiaxial crossply machine in which splicing and lamination are combined. This means that rolls of crossply laminate can be generated in which the orientation between the continuous- and segmented layer can be varied from 45 to 90°. The thermoplastic behaviour of the matrix material not only enables the lamination in the crossply, but also makes it possible to weld the final material to the desired product instead of stitching. In comparison with coated fabrics, crossply laminates have distinguished advantages. Thanks to the spreading of the fibres into a thin layer, the impregnation with matrix material is much more effective, leading to intrinsically higher mechanical performance. Besides, the UD-layers can be orientated in directions that are optimal for accommodating the forces in the end application. In this way the reinforcement can be made more efficient, leading to a more lightweight and thinner technical textile.