The current sewing processes and equipment utilized in our country's knitting industry are primarily centered around medium-to-high-speed lockstitch machines (commonly known as "flatbed machines"), medium-to-high-speed overlock machines (commonly known as "sergers"), and coverstitch machines.
Since knitted fabrics are composed of interlocking loops, the cut edges of garment panels are prone to unraveling; therefore, the edges of the panels should first be overlocked (commonly referred to as "serging the edge") before undergoing further sewing operations using machines such as lockstitch machines. Lockstitch machines and overlock machines are the primary types of equipment used for sewing knitted fashion garments. During the sewing process, the following key points should generally be observed:
The stitch formation should possess tensile elasticity and strength that are compatible with the knitted fabric.
The stitch formation must effectively prevent the loops of the fabric from unraveling.
The stitch density should be appropriately controlled. For instance, when working with thick fabrics, the stitch density for lockstitch machines should be set at 9–10 stitches per 2 cm, while for overlock machines, it should be 6–7 stitches per 2 cm; for thin fabrics, the lockstitch density should be 10–11 stitches per 2 cm, and the overlock density should be 7–8 stitches per 2 cm.
Sewing Thread: Generally, pure cotton knitted fabrics utilize pure cotton or polyester-cotton blend threads with specifications of 9.8 tex × 4 or 7.4 tex × 3. Chemical fiber knitted fabrics typically employ elastic nylon filaments of 7.8 tex × 2 or nylon threads of 5 tex × 6. The sewing thread must meet the following quality requirements:
Pure cotton thread intended for sewing machines should be made from combed cotton, which offers superior strength and uniformity.
The sewing thread must be uniform in thickness and smooth in texture to minimize obstruction or friction as it passes through the thread guides and needle eye; this prevents defects such as thread breakage and uneven stitch tension.
Sewing Needles: Sewing machine needles are also referred to simply as "sewing needles" or "machine needles." To ensure an ideal compatibility among the needle, the fabric being sewn, and the sewing thread, it is essential to select the appropriate type of needle.
