How To Do Well Cotton Grade Examination?

The cotton standard stipulates: according to the maturity, color characteristics and quality of the mill, the quality standard of the cotton is checked according to the physical standard, combined with the literal conditions. Cotton grade 。 How do I grasp and apply the three conditions of cotton in the cotton sensory inspection?

Inspection of cotton in early or early stage

　　 Cotton grade Due to the influence of many factors, the quality of cotton fiber is usually too early in the growth and development of cotton fiber, and the climate is not good enough. There is not enough thickening period in the growth period of cotton fiber, that is, the thickening period of cell wall is insufficient, and the coefficient of daily rotation is too low. Under these conditions, because of the early cotton growth at the roots of cotton plants and lack of light, the growth of cotton is generally poor in maturity, weak in hand pull, broken in head, and poor in cotton fiber color. For example, the special location of Xinjiang, Gobi beach, the newly reclaimed saline alkali soil, poor soil, low nutrient content, lack of water, dry early or early cotton, or early diseases and pests of cotton, short length, stiff pieces, poor maturity, color white. In the process of sensory inspection, we should consider the grade to a lower level, a better grade can be set to three, and a worse grade is four.

Inspection of cotton in the middle and later stages

In the late cotton picking stage, the temperature of the late maturing varieties suddenly dropped, and the frost was frosted, causing frost cotton. Frost cotton can be divided into light frost cotton and heavy frost cotton. Light frost cotton is white, dark or heavily stained, but most of the fibers are ripe and well colored, with little emphasis on yellow. Heavy frost cotton is lighter, and the background is generally yellowish and dark red. Some of the frost cotton maturity, strength, fineness, appearance can reach three, but the color is four or five yellow than the standard grade cotton, for frost cotton in the standard, there should be four or four. For light frost cotton or slightly heavier frost cotton, the inner quality can be up to three grade, but the color to the top or near the five grade can be classified as four grade cotton. The heavy and especially heavy frost cotton can be set to five grade. The late maturity varieties of frost cotton, maturity and poor strength, have bad cashmere, the frost is heavier, especially heavy can be set to six.

Inspection of several special cotton varieties

1. test of rain and rust cotton. During the cotton picking process, due to weather reasons, rain and rain are too long and time is too long, resulting in rain and rust cotton. Because of rain dyeing, the color of cotton shell is stained on the surface of cotton fiber. It is yellow brown, light and light rain and rust cotton. After the seeds are cleaned, the rain and rust are dispersed after skin cleaning machine is rolled, and it is not easy to find in the lint test process. Light rain and rust cotton can be classified as three grades. Proper attention should be paid to inner quality and light color. However, heavier rain and rust cotton should be considered to be lower than grade one, and grade four is better.

2. for cotton with larger or larger moisture. After rain, cloudy day and morning dew picked cotton, the cotton produced and processed in winter, snow and ten or twenty degrees below zero, because of the high moisture absorption of cotton, when testing, due to large moisture, elastic feel is small, silk, neps obvious, surface appearance is also ugly. I tend to set a lower level, such as the four level. But after balancing, placing and expanding, the moisture content is small, the resilience is restored, and the sash and neps are loose. It is possible to upgrade a grade to three levels, resulting in differences.

3. have not been cleaned by seed cleaning machine or leather cleaner. Cotton inspection 。 Leather cotton It is the lint cleaned after the sawtooth cotton gin has been processed and the lint cleaner has been cleaned. Compared with lint cotton without lint cleaner, the impurities, silk and key contamination are obviously reduced, and the fibers are smooth and the color is good. But PI Qing cotton's fine impurities, defects, neps, fiber part of the hook was broken, short fiber content increased, some fibers were bruised. The leather cleaning machine cotton is better than the lint cotton lint which has not been washed by the lint. It has not improved the internal quality of the cotton fiber, and is not as good as the latter. Therefore, in my opinion, when testing cotton with no skin cleaning machine, we should consider the value of textile application and emphasize the internal quality. We should not emphasize the appearance and color and processing quality too much. We should make comprehensive grading. For example, after three grade seed cotton processing, the internal quality is three grade, the processing quality is slightly worse, the poor cotton can be set to grade three, and the poor, especially poor grade four is suitable.