5. OPERATION￿

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￿-￿. Underlay programs

Four types of underlay patterns are available. These four types can also be combined. Refer to the examples of use to

determine which type of underlay to use.

Parameter No.￿

45

 

46

 

47

58

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Underlays sewn together￿

 

Saw-shape underlays￿

 

Rectangle underlays￿

Zigzag underlay stitch￿

3931Q

 

3932Q

3933Q

3934Q

Underlays sewn together￿

This type of underlay pattern is used for resewing if the knife has operated before the seam has been formed, such as when sewing is complete without the upper thread breaking even though the lower thread has run out. It is particularly useful for sewing up the hole made by the knife beforehand at times when zigzag stitches do not hold properly.

The pile of fluffy fabrics is pressed down before sewing, so that the buttonhole finish looks more attractive.

Saw-shape underlays

This type of underlay is useful for stretch materials to prevent them from stretching.

It is useful for preventing dimples from forming during bar tacking. Radial-type buttonholes are useful for preventing dimples.

It is also useful for strengthening the buttonholes to stop the seam from unravelling, which can often happen with materials with coarse weaves.

Rectangle underlays

This type of underlay is useful for stretch materials to prevent them from stretching.

This is effective in preventing seams from unravelling in materials which appear not to have a very coarse weave. It also serves to reinforce the buttonhole.

If the seam is hidden and the seam width seems small, you can sew 2 - 3 rectangle underlays to make the material look more voluminous.

Underlays such as (1) to (9) in the illustration can be sewn in slightly different positions by changing the setting value for parameter No. 50 (underlay offset) so that the seam does not become too stiff and to further increase the feeling of volume.

Zigzag underlay stitch

If parameter No. 58 (Zigzag underlay stitch width) is set after saw-shaped underlay stitches or rectangle underlay stitches have been set, zigzag underlay stitches will only be sewn for the first cycle of saw-shaped underlay stitching or rectangle underlay stitching.

This is particularly effective in preventing seams from unravelling in materials which appear not to have a very coarse weave. It also serves to reinforce the buttonhole.

If parameter No. 58 (Zigzag underlay stitch width) [Dimension A in the illustration] is set to about 0.4 mm, the zigzag underlay stitches will be even stronger than other underlay stitches.

Note:

When sewing underlays, the number of bar tacking stitches will increase, so that thread breakages or broken needles may occur. To avoid such problems, reduce the number of underlays or drop the sewing speed.

￿When underlays above are sewn together, the order of sewing is underlays sewn together ￿ saw-shape underlays ￿ rectangle underlays.

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HE-800A