ADVANCES IN COMPOSITE MATERIALS - ECODESIGN AND ANALYSIS
LIBA technology
The Liba technology is by far the best adapted to produce multiaxial fabrics. The MAX 3 CNC machines use a Copcentra machine that is preceded by a number of 3 zones where the layers are formed with the help of carriers feeding the yarns under the desired angle along the table: 00 for the weft yarns and 260 to 600 for the rest. The warp yarns (900) are introduced in the knitting zone, using special guides. The layers are brought to the knitting zone and connected using pillar or tricot stitches. A non-woven mat (chopped glass fibres) can also be inserted, if the application requires it.
Fig. 12 illustrates the Liba system (source: www. liba. de). Liba also developed such a system also for carbon fibres (Copcentra MAX 5 CNC), where the carrier course is modified in order to reduce fibre waste.
The system allows obtaining fabrics with different degrees of compactness, made of different raw materials, as exemplified in Fig. 12 (source www. liba. de). The risk of fibre
destruction caused by the needles penetrating the layers is eliminated through the walking needle technique, where the needle bed is moved together with the layers.