As far as the automatic weft straightener goes, distorted weft correction takes place before the pre-setting of the final setting process just after the relaxing process.

The automatic weft straightener is installed just in front of the tenter then the weft is straightened and set on pins before the weft returns to its original position.

In short, the closer to the tenter the automatic weft straightener is installed, the more effectively the straightening process can be carried out.(chart 1)

In the case of weft of knitted fabric it tends to return to its original state more conspicuously than woven fabric.

When the automatic weft straightener is to be used for such knitted fabric, the detector of weft distortion is installed just behind the pinning device of the tenter and a skew correction device is installed under the operation platform.

This type of automatic weft straightener is used mainly to correct skewed parts and a stenter is used for correction of bowing.

Knitted fabric weft is easily distorted.

When tension is too strong at the entrance of the tenter, bowing occurs, when the rotating speed of the pulling roller at the exit of the tenter is faster than the pin running speed, bowing occurs.

Therefore it is necessary to straighten weft in consideration of such phenomena with knitted fabrics.

Furthermore, weft straightening before the coating process is important.
Because after coating, the fabric structure gets difficult to move thus weft straightening becomes difficult.

In this case, weft straightening should take place at pre-setting before the coating process.

It is more effective to correct weft by installing the automatic weft straightener just in front of the coating machine.

Fig-1 Installation of automatic weft straightener, in front of tenter.

In the case of textile printing, it is necessary to have weft correction just before printing, as when the pattern is printed on distorted fabric, the pattern gets deformed.

As mentioned before, weft correction is done at pre-setting and furthermore weft correction should be done by an automatic weft straightener installed over the in-feed device of the printing machine to enable a higer level of precision in the printed pattern.

Care should be taken in the use of an automatic weft straightener for printing in the following points.

An automatic weft straightener usually takes the center line of the fabric as its reference for straightening whereas a printing machine takes the edge of the fabric as its reference for printing.

Therefore, it is necessary to transfer the position of the weft straightener to fit the fabric edge.

The automatic weft straightener is provided with a transfer mechanism.

When omitting transfer of the weft straightener, skew correction performance will decrease and in the worst case, distortion will occur.

It is necessary to match the center of the fabric to be printed and center of the automatic weft straightener.

Fig-2 Installation of automatic weft straightener, in front of printing machine.