In practice, when spinning medium high grade cotton colored yarn, two kinds of cotton blending methods are generally used; when spinning CVC T / C colored yarn, the proportion of raw cotton blended is particularly high, because there are more impurities short fibers in cotton compared with chemical fiber, it is suitable to separate make roll, mix according to proportion in the drawing process; when blending less colored fiber in color spinning, When the content of color fiber is small, we can use the method of mixing color strip cotton roll to make sliver.

The following is the blending method for several representative varieties of hemp grey yarn in the production process.

Group mixing

Due to the high requirement of uniformity consistency of each fiber, the raw materials are generally mixed in groups before being put into the box, that is, the total weight of each box of raw materials is divided into several groups with equal weight, the weight of each component in each group is determined according to the percentage of each component of raw materials. For example, the requirement of C / T 318 is that the dry weight percentage of each component is 65% of cotton, 35% of polyester (including 17% of white polyester 18% of black polyester). Before loading, the raw materials are divided into several groups, each group is 40kg, each component is fully mixed with 40kg as the cotton mixing unit, then scattered put into the box. First of all, the dry weight ratio of cotton / polyester is converted to the wet weight ratio of 65% × (1 + 8.5%) / 35% × (110 O.4%) = 70.5/35 under the standard condition

The theoretical values of each component in each group are:

Cotton 70.5 / (70). 5 + 35) × 40-26.73 (kg)

Polyester 40-26.73-13.27 (kg)

Among them, white polyester 17 / (17 + 18) × 13.27-6.45 (kg), black polyester 13.27-6.45-6.82 (kg)

In the actual process, the cotton drop rate (mainly for cleaning carding, generally about 5%) is considered, while the polyester drop rate is very small, which can be ignored.

The actual content of cotton in each group is 70.5 × (1 + 5%) / [70.5 × (1 + 5%) + 35] × 40-27.16 (kg) polyester 40

—27．16—12．84(kg)

White polyester 17 / (17 + 18) × 12.84-6.24 (kg)

Black polyester 12.84-6.24:6.60 (kg)

That is to say, 27.16 kg of cotton, 6.24 kg of white polyester 6.6 kg of black polyester are evenly mixed in the tank according to the wet weight in each 40 kg group.

For the varieties with large proportion of polyester small blackness, the color fiber cotton are first mixed in groups in the clear flowers, such as t / C 406 (t67 / C33), the dry weight ratio of each component is cotton 33%, white polyester 61% black polyester 6%. We first mix black polyester cotton to make strips, then separately make white polyester into strips then mix them with black cotton strips to meet the quality requirements of the varieties.

According to the proportion requirements, the standard blending ratio of cotton black polyester is 33 × (1 + 8.5%) / 6 × (1 + O.4%) to 35.8/6. Considering the cotton dropping in the carding process (about 5%), the actual blending ratio of cotton black polyester is adjusted to 35.8 × (1 + 5%) / 6-37.6/6

The weight of cotton is 37.6 / (37.6 + 6) x40-34.5 (kg) in each 40 kg mixing unit

Black polyester 40-34.5 = 5.5 (kg)

According to the ration of raw cotton black polyester strips the ratio of matching pieces, the ration of pre drawing of white polyester strips is determined. In the process of matching, the spacing between the two kinds of fiber strips should be the same as far as possible, the components should be evenly distributed.

For example, C / T102 (C65 / T35) has a dry weight ratio of 65% cotton, 33% white polyester 2% black polyester. Considering the situation of water impurity falling of cotton, the ratio of wet weight of cotton to that of white polyester can be increased by about 13%. The ratio of wet weight of cotton to that of white polyester is 65 × (11.13%) / 33-73.45/33. The bales are directly packed arranged in boxes, then a certain amount of white polyester is weighed according to the ratio to fill the boxes evenly in several places to make cotton white polyester rolls. According to the ration of cotton rolls, the ration of black polyester strips is determined, the ration is in accordance with the requirement The black polyester sliver the cotton white polyester roll are divided by the carding machine to make the sliver in proportion.

Back flower application

In the production process of hemp grey yarn, enough attention should be paid to the problem of matching using recycled yarn. In principle, special spinning is generally used to digest raw materials at one time. For the varieties that can be digested at one time have high quality requirements, in principle, there is no need to use use as little as possible, the produced flowers can be used in the varieties with low quality requirements.

One

Notes on flower recycling

(1) In order to prevent excessive neps in the yarn, the amount of back flower should be too large (generally no more than 2% - 5%).

(2) Pay attention to whether the blackness is the same, adjust the blackness to be the same then use it properly.

(3) Pay attention to whiteness. There are always some differences in the color of different varieties of polyester. For those differences, pay attention to the control of quantity.

(4) Pay attention to whether the raw cotton content meets the requirements. Some varieties have a high polyester content in the recycled flowers. When using, the amount must be controlled to avoid insufficient cotton content.

Two

How to use flowers

Taking T / C 413 (dry weight ratio of cotton 339 / 6, white polyester 54%, black polyester 13%) as an example, this paper briefly describes the method of flower recycling. In this kind of cotton blending, 40 kg (29.6 kg cotton, 10.4 kg black polyester) of cotton black polyester are used to mix cotton in groups, then the cotton black polyester are made into cotton black polyester strips by winding them in the upper box; the white polyester is made into cotton black polyester strips by separately winding them in the upper box pre drawing strips of a certain weight, the cotton white polyester strips are mixed in a certain proportion of the number of cotton white polyester strips through three passes. We usually adopt two methods for the matching of their back flowers.

(1) Direct match

The method is to take all the components of the flowers into account, get a new blending proportion by calculation, mix the upper box strictly according to this proportion. The advantage of this method is that it omits a mixed process of flowers. The disadvantage of this method is that once the amount of flowers is determined, it can be changed at all, otherwise it is easy to cause the blackness to be unqualified.

Directly in each group