Industrial Sewing Process
Industrial sewing is far more complex process when compared with general sewing done at home. It requires many preparations and mathematical calculations for producing garments with perfect seam quality. For conducting industrial sewing, one must possess the required technical knowledge as the flat sheets of fabrics having holes and slits are given curves and folded in three-dimensional shapes in very complex ways that require a high level of skill and experience in order to get smooth, wrinkle-free designs. Apparels thus designed are then cut using templates and sewn by manual laborers or automatic sewing machine. The seam quality is very sensitive to cloth tension that differs from time to time in the whole sewing process. As such, the cloth has to be handled with great care while it is guided towards the sewing machine needle.
Even before the actual work of sewing starts, there are many pre sewing tasks that have to be accomplished. These can be enlisted as recognizing the fabric's shape as appropriate tensional force depends on the properties of fabric; deciding fabric edges to be sewn – whether sewing for joining two parts of cloth or for decorative purposes; planning of sewing process to establish the sequence of seams to be stitched; and identification of seam lines as the seam lines are situated inside the fabric's outer line and therefore distance between the two (seam allowance) has to be determined.
The Sewing of Clothes
The actual sewing process consists of guiding the fabric along the sewing line with a certain speed that is in harmony with the speed of sewing machine. The errors of fabric orientation are either controlled manually or through automatic machines. When one edge of seam line is sewed, the fabric is rotated around the needle till the next edge of the seam line coincides with the sewing line. The process is repeated until all the edges of seam line are sewed.
While sewing, many factors have to be considered such as thread tension and consumption because the correct balancing of the stitch and the tension given to the threads is very important for quality stitch formation. Care has also to be taken for presser- foot displacement and compressing force. Presser- foot is the part of sewing machine that holds the fabric in place as it is being sewn. If this system is not efficient then it results into irregular seams and many other defects, especially when running on high speed. Needle penetration force measurement is also very important for the analysis of quality problems or 'sewability testing' and for quality monitoring.