Crossply material is a laminate consisting of minimum 2 layers of unidirectional fiber-layers, laminated together to form a multi directional laminate. Because the fibers in the laminate are positioned in a completely stretched manner, the construction yield of the material is nil. In contrast to woven or knitted fabrics, the forces exerted on the Crossply laminate are absorbed directly by the fibers.
Two different processes are possible with the Crossply machines.
- Single layer process.
- Multiple and Multi-axial process for tailored blanks.
The single layer process is used in those cases where the second layer is applied in the impregnation machine or in a second pass on this machine. This process is used for the ballistics industry in which case the UD tape is oriented at 90 degree and for the thermoset resin composite industry in which orientations of 90–45 degree are possible.
The multiple layer process is used for inclusion of the second layer on the Crossply machine. The second layer can be oriented in an angle of 90 up to 45 degree. This high speed process is especially interesting for the thermoplastic composites production. The material is spot welded after which it is wound. Multiple rolls can be consolidated in a lamination line. It is also possible to cut the material and do the consolidation in a mold or before molding by infra-red heating.
For making wider Crossply laminates and tailored blanks, it is possible to use multiple UD tapes next to each other as 0 degree layer. The second layer will bridge these wide UD layer and form a stable laminate which is rolled on large diameter drums.
Speed of operation is dependent on the working width up to 10 meters/minute.