Several quality problems that are easy to occur in spinning production

1.1 The harm of neps

The number of neps in the yarn not only affects the appearance quality of the yarn and gray fabric, but also directly affects the dyeing effect of the fabric, causing dyeing Defects, as people have higher and higher requirements for the appearance quality of textiles, neps have been listed as important defects to control.

1.2 Formation and distribution of neps

(1)When harvesting cotton, there are many harvesting methods that will produce neps and impurities in the raw cotton. Currently, harvesting methods are roughly divided into manual harvesting and mechanical harvesting methods. Foreign manual harvesting methods are mainly used to pick long-staple cotton and fine-staple cotton, except for other methods. , all are mainly mechanized harvesting. Mechanical harvesting brings a large amount of impurities to the lint, and even a small amount of neps, which makes it difficult for the ginning factory to remove the impurities. It also causes a certain number of neps in the ginning raw cotton. .

(2)In the production of blowroom cotton, there is a contradiction between removing impurities in raw cotton and increasing neps and short lint. The faster the speed of each department of blowroom cotton, the better the impurities are removed, and the longer the process of the blowroom cotton production line is. The more neps increase, so we should strive to shorten the process of the blowroom cotton production line, optimize the process technology of impurity removal and neps, and strive to improve the quality of the blowroom cotton production line.Try to increase as little neps and short lint as possible.

(3)The greater the proportion of immature fibers in raw cotton, the greater the chance of producing neps and short lint. Efforts should be made to control the distribution of immature fibers before the raw cotton enters the blowroom cotton production line to reduce the mixing of immature fibers. Proportions and differences in cotton.

(4)The carding machine is the main process for reducing neps. Many neps can be carded or eliminated on the carding machine. Therefore, the carding machine must be fast and accurate, and strengthen carding, especially the cover plate and tin The carding function between lints needs to be strengthened. The new carding machine is equipped with a fixed cover, which improves the impurity removal function and carding effect of the cotton feeding part. These are very important for reducing neps.

(5 )Online and offline monitoring and control of neps in raw cotton can control the increase in the number of neps in production. The AFis raw cotton property detector can be used to check the percentage of immature fibers and the total amount of neps in raw cotton package by package. Those exceeding the specified index will be discarded, so as to control the neps in the opening. Regarding the quantity of each process of blowing and carding, new carding machines such as DK803, DK903, DC03, etc. can also detect the dynamic changes of neps online, alarm according to the increase of neps exceeding the limit, and automatically adjust the distance between the cover plate and the cylinder. Automatically grind the cover plate to stabilize product quality.

(6)After long-term practice and testing of digital accumulation, the general nep control standards are as follows:

Raw cotton 200 grains/g
Opening and cleaning cotton 400 grains/g
Card 80 grains/g
Combed 20 grains/g

① According to the initial processing and the quality of the raw cotton itself, the general nep ration is 200 grains/g, and the minimum is 100 grains/g. High 400 grains/g. ② The neps in the blowroom process increase to 400 neps/g, which is a low of 200 neps/g and a high of 700 neps/g. ③ The card sliver contains 80 neps/g, high 200 grains/g, low 50 grains/g. ④ After combing and waste removal, the neps in the combed sliver are generally controlled below 20 grains/g. ⑤The neps’ quantitative changes in other processes such as drawing and roving did not change much, but they all increased slightly.

Immature fibers have a greater impact on increasing neps and short lint. The distribution and content percentage of immature fibers when blending raw cotton with cotton should be controlled.

The concept of foreign fibers refers to other fibers with different dyeing properties from cotton fibers, such as wool, linen, silk, and chemical fibers. <SPAN style="BOX-SIZING: border-box !important; PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; MAX-WIDTH: 100%; WORD-WRAP: break-word !important; FONT-SIZE: 16px; PADDING-TOP:

(1)At present, our country has entered the WTO. Domestic companies are using different processing methods to harvest and package raw cotton from all over the world. Domestic raw cotton is also mixed with foreign fibers, commonly known as “three silks”, which seriously threatens our country’s cotton. The spinning quality of textile enterprises and the product quality of downstream processes. For this reason, many domestic enterprises have organized manpower to set up a workshop to pick the “three yarns”. This requires a lot of labor and the effect is unstable and incomplete. It is a difficult problem to improve the appearance quality of spinning and fabrics. .

(2)Currently in many blowrooms The production line is equipped with technical equipment to remove foreign fibers, which uses photoelectric principles.Combined with the meticulous opening technology in blowroom cotton, foreign fiber detection and removal are carried out, such as the SCFO foreign fiber detection and separation system of Germany’s Trützschler Company, which is installed in the feeding part of the carding machine. It can effectively eliminate a considerable part of foreign fibers. The basic condition for applying this technical system is to separate and loosen the fibers in the blowroom and blowroom process, and make the fibers free and single-fiber as much as possible. In the blowroom-carding system Installing this device for removing foreign fibers in the feeding part of the carding machine will produce better results. The effect is reflected in the number of times the electronic yarn clearer on the automatic winding machine removes and cuts off foreign fibers, which can reduce the number of cuts by 50% and improve the efficiency of the automatic winding machine’s electric cleaning. If the opening and cleaning system is not equipped with a device for removing foreign fibers, The efficiency of the electronic yarn clearer of the winding machine is about 40 cuts per 100,000 meters.

(3)Only the automatic winding machine has an electronic yarn clearer that removes foreign fibers, but there is no foreign fiber remover, so the electronic yarn clearer cuts off more times and the automatic winding machine Machine production efficiency is low.

Only the opening and cleaning system is equipped with equipment to remove foreign fibers, but there is no electronic yarn clearing function for foreign fibers in the automatic winding machine. Yes, the removal of foreign fibers is obviously incomplete.

Only if a foreign fiber yarn clearing system is installed in the blowroom cotton production, and a foreign fiber yarn clearing system is installed on the automatic winding machine Electronic yarn clearer can remove foreign fibers more thoroughly and achieve better results.

(4)There are many domestic devices for removing foreign fibers and electronic yarn clearers for winding machines that remove foreign fibers, and they can be selected according to specific circumstances.