Knitted garments are mostly made of cotton and chemical fiber cotton yarn, which are characterized by softness, elasticity, breathability, sweat absorption, and comfortable wearing, such as sportswear and underwear. As clothing, knitted clothing has its own characteristics in addition to its commonality with woven clothing.
Process flow:
Spinning→weaving→cloth inspection→cutting→sewing→ironing→inspection
(1) Spinning
The purpose of spinning is to wind the incoming cotton yarn into a package with a certain structure and specification, which is suitable for knitting production. In the spinning process, it is necessary to eliminate some defects on the yarn, and at the same time make the yarn have a certain uniform tension, and carry out necessary auxiliary treatments on the yarn, such as waxing and oiling, to improve the weaving performance of the yarn. Increase production efficiency and improve product quality.
(2) Weaving
Weaving is a process in which yarns are organized into coils interlaced with each other by a loom to form a fabric. This is also the fundamental difference between knitted garments and woven garments.
Weaving methods can be divided into two categories: weft knitting and warp knitting. Most of the fabrics used as knitted clothes are weft knitting fabrics. Weft knitting is to feed one or more yarns into the working needles of the knitting machine in the weft direction, so that the yarns are sequentially bent into loops, and strung together to form a weft knitted fabric. The machines used to weave such knitted fabrics are called weft knitting machines. Weft knitting has greater adaptability to the types and linear densities of processed yarns, and the types of knitted fabrics produced are also very wide. There are many kinds of weft-knitted fabrics, which can be woven into gray fabrics for inner and outer garments of various organizations, and can also be woven into single-piece formed and partially formed products. At the same time, the process and machine structure of weft-knitted fabrics are relatively simple and easy to operate. The production efficiency is relatively high, therefore, weft knitting has a large proportion in the knitting industry. There are many types of weft knitting machines, which are generally distinguished by the number of needle beds, the form of needle beds and the type of needles used. Warp knitting is composed of one or several groups of parallel yarns arranged on the knitting needles and woven along the longitudinal direction at the same time. The machines used to weave such knitted fabrics are called warp knitting machines. Generally, warp-knitted fabrics have lower decoupling and extensibility than weft-knitted fabrics, and their structure and shape are more stable, and their uses are also wider. In addition to producing clothing fabrics, they can also produce mosquito nets, curtains, and laces. For decorative fabrics, medical fabrics, etc., warp knitting machines can also be distinguished by needle beds and knitting needle types.
(3) Cloth inspection
Since the quality of the gray cloth is directly related to the quality and output of the finished product, before cutting, it is necessary to check whether the number of pieces, size, density, batch number, and linear density meet the requirements according to the ingredient list of the cutting cloth, and check the gray cloth one by one according to the standard when inspecting the cloth. Carry out inspection, and mark and record the quality of all kinds of defects that affect the quality of finished products, such as color spots, missing stitches, holes, oil stains, etc.
(4) Cutting
The main technological process of knitted garment cutting:
Material cutting→borrowing defects→scribing samples→cutting→binding.
Borrowing defects is an important part of improving product quality and saving materials. During the material cutting process, the defects on the gray fabric should be borrowed to the cutting parts or seams as much as possible.
Knitted fabrics are cut according to the warp mesh accessories, and the cutting generally adopts the nesting method, and the commonly used ones include flat sleeves, mutual sleeves, inlaid sleeves, spliced sleeves, and split sleeves.
The following items should be paid attention to when cutting knitted fabrics:
(1) Do not use fold marks and printed edges on obvious parts of clothing.
(2) Do not use tapered hole marks in tailoring, so as not to affect the appearance of the garment.
(3) Sewing
The existing sewing technology and equipment in my country’s knitting industry are mainly medium and high-speed lockstitch sewing machines (commonly known as “flat cars”), medium and high-speed overlock sewing machines (commonly known as “cocker cars”), interlock sewing machines and other sewing machine models. .
Since the knitted fabric is composed of coils, the edges of the cut pieces are prone to fall off, so the edges of the pieces should be overlocked (commonly known as “overlapping”) before sewing with a lockstitch sewing machine. Lockstitch sewing machines and overlock sewing machines are the main types of sewing knitted fashion. In the sewing process, generally pay attention to the following points.
1. Stitches Since the fabric of knitted fabrics has the characteristics of longitudinal and transverse extensibility (ie elasticity) and the disadvantage that the edge loops are easy to detach, the stitches for sewing knitted fashion should meet the following requirements:
(1) The stitches should have the stretchability and strength suitable for knitted fabrics.
(2) The stitches should be able to prevent the loosening of the fabric loops.
(3) Appropriately control the density of seams. For example, the stitch density of the lockstitch machine for thick fabrics is controlled at 9 to 10 stitches/2cm, the stitch density of the overlock sewing machine is 6 to 7 stitches/2cm, and the stitch density of the thin fabric is controlled at 10 to 11 stitches/2cm 2cm, the seam 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 threads, and chemical fiber knitted fabrics use 7.8tex×2 elastic nylon threads and 5tex×6 nylon threads. Sutures shall meet the following quality requirements:
(1) Pure cotton thread (sewing thread) for sewing machines should be combed cotton thread, which has high strength and uniformity.
(2) The suture should have a certain degree of elasticity to prevent thread breakage due to twisting or squeezing of the thread during the sewing process.
(3) Sutures must be soft.
(4) The sutures must be even and smooth, so as to reduce the obstruction or friction of the sutures in the grooves and pinholes, and avoid defects such as broken threads and uneven stitch tension.
3. Sewing needles Sewing machine needles are also called sewing needles and machine needles. In order to achieve the ideal cooperation between the sewing needle, the sewing material and the suture, it is necessary to select a suitable sewing needle.
(6) Ironing
Knitted garments are ironed to make them look flat and accurate in size. When ironing, put the liner inside the garment to keep the product in a certain shape and size. The size of the liner is slightly larger than that required by the garment to prevent the size from being too small after shrinkage. The temperature of ironing is generally controlled between 180°C and 200°C, which is safer and less prone to yellowing and scorching.
(7) Finished product inspection
Finished product inspection is a comprehensive inspection before the product leaves the factory, including two major items: appearance quality and internal quality. The contents of appearance inspection include dimensional tolerance, appearance defects, seam fastness, etc. Internal testing items include fabric weight per unit area, color fastness, shrinkage rate, etc.
Post time: Dec-15-2022