the existing sewing technology and equipment of my country's knitting industry are mainly based on medium and high-speed lockstitch sewing machines (commonly known as "flat cars"), medium and high-speed overlock sewing machines (commonly known as "copy carts"), interlock sewing machines and other sewing machine models. .
since the knitted fabric is composed of a string of loops, the edges of the garment pieces after cutting are prone to fall off. therefore, the edges of the garment pieces should be overlocked (commonly known as "handover") before sewing and processing with a lockstitch machine. lockstitch sewing machines and overlock sewing machines are the main types of sewing knitted garments. in the sewing process, generally pay attention to the following points.
1. since the stitches of knitted fabrics have the characteristics of longitudinal and transverse extension and the shortcomings that the edge loops are easy to fall off, the stitches for sewing knitted garments should meet: (1) the stitches should have a stretch that is compatible with the knitted fabric and strong. (2) the stitches should be able to prevent the fabric loops from falling apart. (3) properly control the density of stitches. for example, the stitch density of the lockstitch sewing machine for thick fabrics is controlled at 9-10 stitches/2cm, the stitch density of the overlock stitching machine is 6-7 stitches/2cm, and the stitch density of the lockstitch sewing machine for thin fabrics is controlled at 10-11 stitches/ 2cm, the stitch density of the overlock machine is 7-8 stitches/2cm.
2. sutures generally, pure cotton knitted fabrics use 9.8tex×4 or 7.4tex×3 pure cotton and polyester-cotton blended yarns, and chemical fiber knitted fabrics use 7.8tex×2 elastic nylon yarns and 5tex×6 nylon yarns. the suture must meet the following quality requirements:
(1) pure cotton thread (suture) for sewing machine should be combed cotton thread, which has high strength and uniformity.
(2) the suture should have a certain degree of elasticity, which can prevent the thread from breaking due to the twisting or squeezing of the thread during the sewing process.
(3) the suture must be soft.
(4) the sutures must be even and smooth, to reduce the obstruction or friction of the sutures in the grooves and pinholes, and to avoid defects such as thread breakage and uneven stitch tension.
3. sewing needles sewing machine needles are also called sewing needles and machine needles. in order to achieve the ideal fit of the sewing needle, the sewing material and the sewing thread, a suitable sewing needle must be selected.
