Requirements and process flow for stripping cotton linters Requirements for cotton linters production
(1) Stripping velvet in separate lanes
According to national regulations, cotton linters are divided into three categories, and each category is divided into 3 grades. The first type of down is usually the first down, the second type is usually the second down, and the third type is usually the third down. Linter of different lengths has different uses. Therefore, the velvet must be stripped in separate lanes, classified, and graded for packaging, so that the various types of linters produced have specified lengths and good quality.
In order to ensure that the length of each layer of short velvet meets the requirements of the user department, the principle of “light peeling in the first pass, more peeling in the second pass, and strive to complete the peeling in the third pass” must be implemented.
“Light stripping in the first pass” means that during the stripping process, the short velvet below 13mm will not be peeled off in the first pass at all, so as to ensure the length of the first-class velvet and improve its use value. The velvet yield of the first down should not exceed 3 times the lint yield of the cotton seed.
“Two layers of velvet peeling” means two layers of velvet peeling. Erdaorong is an important raw material for the production of nitrocellulose in the military industry and an important raw material for chemical production companies. The production process of nitrocellulose requires a certain degree of uniformity of short fibers. It is neither allowed that the proportion of long fibers (above 13mm) is too large, nor that the proportion of short fibers (below 3mm) is too large. Generally, the down yield of second-line down is 50% to 60% of the total down yield.
“Strive to peel off the cotton in three passes” means to scrape off the short lint on the cotton as much as possible. It is required that the residual lint rate of the cotton after three layers of lint should not exceed 4%.
(2) Removal of impurities
If linters contain too many impurities, the use value will be reduced, especially when linters are used as raw materials in the chemical industry, impurities will have a negative impact on production operations, product quality and production costs. It has a great impact. Some high-end products cannot use short velvet with too many impurities as raw materials.
Therefore, during the stripping process, it is necessary to strengthen the cleaning and lint cleaning, rationally distribute the vehicles, and completely remove the impurities in the cotton and linters to improve the quality of the cotton linters. The focus of the operation should be on removing impurities in the cotton before stripping, and attention should be paid to preventing the generation of new impurities during the stripping production process.
(3) Factor distribution
The yield and quality of cotton linters are closely related to the quality status of cotton seeds, and the grade, variety, growth conditions, particle size, maturity, finishing method, and finishing technology of cotton seeds And the difference in machine performance in the previous process will cause great differences in the lint content, impurity content and moisture content of cotton. This requires that during the stripping production process, the equipment should be appropriately adjusted according to the grade, maturity, velvet content, moisture content and other characteristics of the cotton seeds, and the vehicles should be reasonably allocated to improve the quality of cotton linters and thereby ensure Rational use of linters resources.
The key points for matching sawtooth velvet strippers are as follows:
1. The distance between the pick roller blade and the sawtooth tip
When the cotton grade is high, the distance between the pick roller blade and the sawtooth tip should be larger (comparable to The standard stipulates that the distance is 2~3mm higher). When the grade is low, the distance should be smaller (can be 2~3mm lower than the standard). When stripping the first down, the distance between the plectrum roller blade and the sawtooth tip should be larger. Peeling the second and third layers When velveting, the distance between cotton seeds should be smaller.
2. The opening degree of the density board
When peeling off the first velvet, peeling off low-grade cotton, if you want to reduce the lint yield, or if the cotton is processed for a long time, the opening degree of the density board should be larger; otherwise, it should be smaller; When the sub-roll is tight, the cracking degree of the density board should be larger; when the cotton roll is loose, the opening degree should be smaller.
3. The distance between the cotton seed comb and the rib row surface
When the cotton seed processing amount is large, the distance between the cotton seed comb and the rib row should be larger. When the cotton seed processing amount is small, the distance should be smaller.
4. Weight quality
When the density of the cotton roll is too loose, the weight of the weight should be larger; when the density of the cotton roll is too tight, the weight of the weight should be smaller.
5. The distance between the center of the weight and the center of the density board axis
When the density of the cotton roll is loose, the distance between the center of the weight and the center of the density board axis should be larger; when the density is tight, the distance should be smaller.
6. Cotton roll density
When peeling off high-grade cotton, the cotton roll density can be larger. When peeling low-grade cotton, the cotton roll density should be smaller; when it is required to increase the lint yield, the cotton roll density should be smaller. The density can be higher. When reducing the down yield, the cotton roll density should be smaller.
7. The sharpness of the saw teeth
When peeling high-grade cotton, the saw teeth should be sharper. When peeling low-grade cotton, the saw teeth should not be too sharp.
8. Saw shaft speed
When peeling off high-grade cotton, when peeling off the second or third down, the saw shaft speed can be faster; when peeling off low-grade cotton, when peeling off the first down, the saw shaft speed should be appropriate Slower.
(4) No damage to cotton seeds
Under the normal operation conditions of the machinery, it is necessary to maintain a certain output and quality, and to maintain the good condition of the cotton seeds, that is, no or less damage to the cotton seeds, which is important for seed preservation. Cotton seeds should be taken very seriously. Excessive damage to cotton seeds will not only damage the cotton seeds themselves, but also reduce the quality of linters due to increased impurities, thereby reducing the use value of cotton linters.
(5) Classification and grading into bales
During the stripping process, due to different grades of cotton seeds, different maturity levels, and different lint yields, the grades of lint stripped out will be different. Therefore, the lint must be peeled according to the different grades. Packaging, storage, and transportation by category and level.
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