The stitch length of the industrial sewing machine is generally between 6-13mm. The influence of different stitch length on the seam direction strength has the following aspects:
When the stitch length is greater than 10mm, because the stitch length is too large, some flat yarns will come out of the gap of the stitch length and the thread will not be broken during stretching, making it difficult for the seam strength to meet the standard requirements;
When the needle distance is 6-8mm, the number of needles is moderate, there is no de-threading phenomenon in the test, and the thread and thread are broken at the same time when the sample is stretched and broken, and the seam strength can meet the standard requirements;
When the stitch length is less than 6mm, the stitching strength is easy to ensure, but the amount of thread used increases significantly, which increases the cost. If the stitch length is too small, the damage to the flat yarn of the woven bag will inevitably increase, and the stitching strength will decrease with the decrease of the outer distance.
