The fabric is formed by winding the yarn with a knitting needle and then stringing the coils together. The knitted material is soft and has good wrinkle resistance and breathability, as well as greater extensibility and elasticity. It is suitable for underwear, tights and sportswear. Knitted fabrics can also be used as outerwear after changing structure and improving dimensional stability.

The dyeing of knitted fabrics made of cellulose fibers and their blends with elastic fibers, such as double-rib knitted fabrics, single-sided plain knitted fabrics, yarn-added plush fabrics and rib knitted fabrics, currently usually adopts reactive dye intermittent dip dyeing and semi-continuous cold pad-batch process (CPB). At present, a new continuous dyeing method for knitwear is being put into the market, which has obvious economic and ecological significance.

Pure cotton woven fabrics can be dyed by discontinuous or continuous methods. In contrast, the dyeing of knitted fabrics made from cellulose fibers and their blends with elastic fibers, in most cases, adopts discontinuous dip dyeing or semi-continuous cold pad-batch (CPB) process.

Dyeing knitted fabrics with jet dyeing machine has both advantages and disadvantages. The well-known advantages are: the whole dyeing process is completed in one machine; Flexible product form (different batch sizes are available); Ease of fabric treatment process; The color light is easy to adjust. The disadvantages of jet dyeing are: the dyeing time is relatively long; Huge water consumption; The amount of salt is very high; Not suitable for large batches (batch to batch); Due to the yarn quality, the fabric is fluffy or fluffy; Knitted terry itself is easy to deform (longitudinal distortion); It is very difficult to determine the dyeing formula in the laboratory.

There are also advantages and disadvantages in the semi-continuous CPB dyeing process of knitwear. Advantages: this method has low energy consumption and small equipment space; The fabric dyed by this method has no pilling; The batch size is flexible. Shortcomings: this method still cannot be used for continuous production, and it takes a long time to fix the color, and the fabric tension is uneven during the process of dip rolling; It is difficult to change from laboratory to actual production; There is batch color difference problem; It is unfavorable to use a large amount of silicone oil.

Use the experience of continuous dyeing of woven fabrics for reference and apply it to knitted fabrics. The objective requirements for continuous dyeing of cotton and its elastic fiber blended knitted fabrics with reactive dyes include: low fabric tension; Good appearance performance (no pilling); Good feel; Low water consumption; Low consumption of chemical materials (such as salt); The processing time is short; Low energy consumption; Rapid color matching in laboratory; Good reproducibility; Low cost. The following three points should be considered: dyed knitted fabrics need to be properly treated to be suitable for continuous treatment; Continuous dyeing equipment needs to be particularly suitable for processing technology and textile materials; The fully proven dyeing process (Econtrol) should be selected.

For knitted fabrics containing elastic fibers, pre-shaping is required before dyeing to ensure fabric quality. It is particularly important to note that the selvage gluing. For this purpose, a new selvage gluing device is designed to accurately realize the dyeing process. This device is equipped with a new selvage drying unit GlueFlue, which is a device combining infrared ray and convection drying. As a drying and fixation equipment, a new type of HorfloreThermwx6500 has been developed. This new concept equipment is equipped with a stepless variable speed fan, a new upper roller drive (combined with tension control and speed sliding adjustment), indirect gas heating (with steam or circulating oil bath heating) and large fabric capacity, fully realizing the fault-free dyeing requirements of high elastic knitted fabrics (and two-way elastic woven fabrics).

The article originates from the knitting denim factoryhttp://www.in-it.com.cn/