Patent DE-19913647-A1 (DE)
Title: Material of multi-layer multi-axial yarn layers, is produced continuously with an initial knitting bed to bond the yarns of a layer followed by further beds to bond in additional layers of 0 degrees and other orientations
Inventor: WIENANDS CHRISTIAN
IPC: D04B21/14
Filed: 1999-03-25
Abstract: To produce knitted/needled multi-axial bands of yarns, in a number of layers with defined yarn orientations, one layer is fed at first continuously into the machine by an initial knitting bed. A second knitting bed, after the first in the working direction of the machine, knits/needles at least one further layer.  A number of layers are formed at the first knitting bed and, subsequently, by the insertion of at least one further layer the number of layers and additional layers are knitted/needled together. The yarns are on a 0 deg  orientation in at least one layer in a selected succession of layers, and a number of layers with a 0 deg  yarn orientation are between and/or outside other layers where the yarns have a different angular lie, fixed in place. The initial knitting bed secures the yarns over only a part of the working width, and the following knitting bed bonds the yarns in another width section which is the whole working width minus the section worked at the first bed. The two knitting beds are coupled together, or operate independently with separate drives and controls. The yarn layers are positioned with the yarns on the required orientation, to be bonded by the knitting bed immediately after they are laid in place.  An Independent claim is included for a modular assembly to produce the material with a longitudinal conveyor fitted with yarn holding pins or hooks. At least one weft insertion stage and a yarn guide or displacement grid is outside the conveyor. The assembly has at least two knitting beds in succession along the direction of material travel, where at least one yarn layer is bonded immediately after it is laid in place. Preferred Features: At the first knitting bed, a number of yarn layers are knitted/needled together. At the second knitting bed, at least one further yarn layer is positioned, for all the layers to be bonded together. The knitting beds have guide bars, needle bars, sliding bars and knocking-over bars. The weft insertion system has an initial module and the assembly to feed the standing yarns at 0 deg orientation with the knitting bed as a second module. The preferably structure is one initial and at least two second modules. The knitting beds extend each over part of the material width so that, together, they cover the whole working width. The center zone of the working width, where the first knitting bed is interrupted, has a support to prevent the yarns from sagging. The second knitting bed works the yarns which pass by the first knitting bed. The yarn support is a conveyor belt which is in contact with the material where the support is required, with a needle surface to grip the material for its forward movement. The guide bars have a removed section across the working width, otherwise lying through. The needle bars, sliding bars and knocking-over bars are interrupted where the yarns are supported against sagging. Where the yarns are supported, a part of the needle bars, sliding bars and knocking-over bars are formed as a second knitting bed, with a separate drive. The removed section of the guide bars has a separate drive and control.