Special attention when weaving from creel
Often tire cord fabric, geosynthetics, fiberglass- and carbon fibre fabric are woven from creels
When weaving from a creel special attention should be given to the warp delivery unit between creel and weaving machine. The warp delivery unit enables the right amount of warp to be fed to the weaving machine.
The right design of the warp feed system is very important and therefore deserves highest priority.
Warp delivery unit between weaving creel and weaving machine
The warp is pulled off from the creel by a feed roller of the delivery unit and feed according to the needs of the weaving process to the weaving machine.
The feed roller has to be with a suitable roll cover with the corresponding hardness and surface roughness. In some cases, a nip roller has to be added to the feed roller to ensure a warp feeding without slipping. The nip roller can be rubber coated and with a crowned lateral surface.
Uniform warp tension for the weaving process
In applications where traditional size warp beams are quickly woven out, bobbin creels could be an alternative option. Bobbin creels are used for many different technological applications, e.g. warping, weaving, warp-knitting and pultrusion procedures.
The bobbin creel must be able to accommodate an adequate number of bobbins and ensure that the yarn tension is equal across the entire warp sheet. The size of the bobbin creel and the number of package positions will depend on the number of yarns required.
Weaving from additional or larger beams on separate let-off frames is an ideal solution if the space requirement for the bobbin creel is too big.
Keeping tension constant
The warp feed device works as a warp tension controller between the bobbin creel and the weaving machine and feeds the yarn at the adjusted tension to the weaving position. The thread draw-off from the bobbin creel normally takes place on a lower tension than used for weaving.
There is no doubt about the fact that it is important to work with a sophisticated bobbin creel that keeps the tension constant over the warp sheet. If the run-off from the creel is not perfect, even the best warp feeding device cannot compensate tension variations across the warp width. The feed unit is used to draw-off the threads from the creel and feed the warp to the weaving machine at the correct tension.
Warp thread feed systems for Narrow Weaving Machines
In ribbon weaving mills the warp yarns are often stored on several sectional warp beams.
For conventional negative electronic let-off devices, the warp thread tension is created by braking the bobbins with belts or cables.
These devices are cost-effective and very simple, but a consistent thread tension from a full to empty bobbin is not ensured.
They do not provide an optimal solution for high-quality and elastic fabrics. There are various warp thread feed systems available for improving these negative characteristics.
The following types of feed systems can be distinguished:
– Feed from sectional warp beams
– Feed with feeding unit from creel