CN106544770A - A kind of three rove pair drawing-off fancy yarn process units and production method - Google Patents

Abstract

The invention provides a three-roving double-draft fancy yarn production device and production method, including a rear roller drafting pair composed of rear rollers and rear rubber rollers, a middle rear roller drafting pair composed of middle rear rollers and middle rear rubber rollers The drafting pair of middle front rollers composed of pair, middle front rollers and middle front rubber rollers, the front roller drafting pair composed of front rollers and front rubber rollers, the rear rollers, middle rear rollers and middle front rollers are driven by servo motors separately, The roller shaft of the front roller is driven by the main motor, and the rear top roller and the middle and rear top rollers use stepped rubber rollers to realize that the first and second rovings of different colors are fed by the drafting pair of the rear roller and the drafting pair of the middle and front rollers. The first rear drafting action of the middle front roller drafting pair and the front drafting action of the front roller drafting pair, the third roving is subjected to the second rear drafting of the middle rear roller drafting pair and the middle front roller drafting pair function and pre-drawing function, and then realize the production of two-color or three-color fancy yarn, enrich the variety of yarn, and increase the added value of yarn.

Description

A three-roving double-drawing fancy yarn production device and production method

technical field

The invention relates to the technical field of spinning, in particular to a three-roving double-draft fancy yarn production device and production method.

Background technique

With the continuous advancement of the times, people's requirements for clothing materials continue to increase. At present, the textile and clothing industry is in an era of pursuing fashion, diversification and high quality. Therefore, new requirements have been put forward for the development of textile raw materials, among which fancy yarns have gradually entered people's field of vision and occupy an irreplaceable position. Fancy yarn refers to the yarn with special structure and appearance effect obtained by processing fiber or yarn with special raw materials, special equipment or special technology in the process of spinning and thread making. It is a decorative yarn in yarn products. A kind of yarn that works. Fancy yarn has unique structure, flexible shape, rich color expression, diversified use of raw materials, and creativity. These make fancy yarn products easy to introduce new ones and produce more differentiated textile products. In today's pursuit of personalized consumption In this era, the market has endowed fancy yarn with a broad space. Among them, segment colored yarn is a kind of fancy yarn that is widely researched and applied at present. It has a new style of multi-color combination. It not only has thickness changes in the axial direction of the yarn, but also has fancy colors that appear alternately in discontinuous distribution. Presents irregular and unique flower and color effects. At present, the production of segment colored yarn is mainly carried out on the traditional spinning frame with three rollers. The white roving is continuously fed by the middle roller, and one colored auxiliary yarn is intermittently fed by the rear roller. Segment color effect. This method has lower modification cost and higher efficiency, but the yarn dryness uniformity is poor. In view of this, in the Chinese patent "Segment Color Spinning Transmission Device (Patent No.: ZL200420081737.2)", a segment color yarn production device with four loops is provided, but this device still uses double roving feeding, and at the same time , the first roller and the second roller are still controlled by the same motor, so the main draft cannot be adjusted freely.

In view of the above problems, the present invention provides a three-roving double-draft fancy yarn production device and production method, which adopts four-row rollers driven separately, and the rear top roller and the middle and rear top rollers adopt stepped rubber rollers to realize feeding. The three rovings are divided into two groups to complete independent drafting, and then realize the production of two-color or three-color fancy yarns, enrich the variety of yarns, and increase the added value of yarns.

Contents of the invention

The purpose of the present invention is to provide a three-roving double-draft fancy yarn production device and production method to realize the production of two-color or three-color fancy yarns, enrich the variety of yarns, and increase the added value of yarns.

In order to achieve the above purpose, a three-roving double-draft fancy yarn production device includes four drafting roller pairs: the rear roller drafting pair composed of the rear roller and the rear rubber roller, the middle rear roller and the middle rear rubber roller. The drafting pair of middle and rear rollers, the drafting pair of middle and front rollers composed of the middle front roller and the middle front rubber roller, the drafting pair of front rollers and the front roller, the roller shaft of the rear roller is driven by the first servo motor Driven to rotate, the roller shaft of the middle and rear rollers is driven to rotate by the second servo motor, the roller shaft of the middle front roller is driven to rotate by the third servo motor, and the roller shaft of the front roller is driven to rotate by the main motor. The main motor is a variable frequency motor, the first servo motor, the second servo motor, the third servo motor, and the main motor are connected through a programmable logic controller, and the rear rubber roller includes a rear rubber roller shaft. The first left rubber roller, the first middle rubber roller and the first right rubber roller are connected in sequence on the shaft. The lengths of the first left rubber roller, the first middle rubber roller and the first right rubber roller are the same, and the first The left rubber roller, the first middle rubber roller and the first right rubber roller can rotate freely around the rear rubber roller shaft respectively, and the diameters of the first left rubber roller and the first right rubber roller are the same and larger than that of the first middle rubber roller. diameter, the middle and rear cots include a middle and rear cot shaft, on which a second left cot, a second middle cot and a second right cot are sequentially connected, and the second left cot The rubber rollers, the second middle rubber roller and the second right rubber roller have the same length, and the second left rubber roller, the second middle rubber roller and the second right rubber roller can rotate freely around the axis of the middle and rear rubber rollers respectively, so The diameter of the second left rubber roller and the second right rubber roller is the same and smaller than the diameter of the second middle rubber roller, and the diameter of the second left rubber roller and the second right rubber roller is equal to the diameter of the first middle rubber roller, so The diameter of the first left rubber roller and the first right rubber roller is equal to the diameter of the second middle rubber roller, and the middle front rubber roller and the front rubber roller are rubber rollers whose diameter remains constant. A collective bell mouth is installed between the pair and the middle front roller drafting pair. Press the pressing assembly during spinning, so that the first left rubber roller and the first right rubber roller are closely pressed against the rear roller, and the first middle rubber roller is suspended in the air. , the second middle rubber roller is tightly pressed with the middle rear roller, the second left rubber roller and the second right rubber roller are suspended in the air, the middle front rubber roller is tightly pressed with the middle front roller, the front rubber roller is closely pressed with the front roller, the first roving and The second roving is respectively pressed and fed between the back roller and the first left cot and the first right cot, and then passed through by the middle and rear roller and the suspension between the second left cot and the second right cot respectively. , After passing through the collective bell mouth, it is pressed and passed between the middle front roller and the middle front rubber roller, and is drafted by the first rear drafting zone composed of the rear roller draft pair and the middle front roller draft pair, and finally the front roller Press and output between the roller and the front rubber roller, and be drafted by the front draft zone composed of the middle front roller draft pair and the front roller draft pair to obtain the first strand; the third roving is drawn by the rear roller and the first middle roller The rubber rollers are suspended in the air and slide through, then pressed and fed between the middle rear roller and the second middle rubber roller, and then pressed through between the middle front roller and the middle front rubber roller after passing through the collective bell mouth, and received by the middle The drafting effect of the second rear drafting zone composed of the rear roller drafting pair and the middle front roller drafting pair, and the final pressing output between the front roller and the front rubber roller, Being subjected to the drafting effect of the front drafting zone formed by the front roller drafting pair and the front roller drafting pair, the second sliver is obtained, and the first roving, the second roving, and the third roving are all colored rovings, and the The first roving and the second roving are rovings with the same raw material and weight, and the colors of the first roving, the second roving and the third roving are all different.

A method for producing fancy yarn with three rovings and double drafting, comprising the production of single-color yarn segments, double-color yarn segments, and three-color yarn segments, wherein the main motor drives the front roller to rotate at a speed v1, and the rotation of the front roller is determined by the spindle speed Determined with the design twist, during the production of the single-color yarn section, the first servo motor stops working, the second servo motor drives the middle and rear rollers to rotate at v2 speed, and the third servo motor drives the middle and front rollers to rotate at v3 speed, at this time the first The feeding of the first roving and the second roving is stopped, and the third roving slips through the space between the back roller and the first middle rubber roller, and is subjected to the second back draft composed of the middle rear roller draft pair and the middle front roller draft pair. The draft effect of v3/v2 times of the stretch zone, and the draft effect of v1/v3 times of the front draft zone composed of the front roller draft pair and the front roller draft pair, the front roller speed v1, the middle rear Roller speed v2, third roving linear density T1, spun yarn density T2 satisfy v1/v2=T1/T2, the front roller speed v1, middle rear roller speed v2, middle front roller speed v3, the first (v3×v3)/(v1×v2)=k1 is satisfied between the ratio k1 of the drafting multiple in the rear drafting zone and the drafting multiple in the front drafting zone, and k1 is designed according to actual spinning requirements; the production of the two-color yarn section , the first servo motor drives the rear roller to rotate at v4 speed, the second servo motor stops working, the third servo motor drives the middle front roller to rotate at v5 speed, at this time the third roving stops feeding, the first roving and the second roving Press and feed between the rear roller and the first left rubber roller and the first right rubber roller respectively, and receive the v5/v4 times draft of the first rear draft zone composed of the rear roller draft pair and the middle front roller draft pair stretching effect, and the drafting effect of the v1/v5 times of the front drafting area formed by the front roller draft pair and the front roller draft pair, the front roller speed v1, the back roller speed v4, the first roving and The second roving density T3 and the spun yarn density T2 satisfy v1/v4=2×T3/T2, the front roller speed v1, the rear roller speed v4, the middle front roller speed v5, the draft in the front drafting area (v5×v5)/(v1×v4)=k2 is satisfied between the multiple and the ratio k2 of the draft multiple in the second rear drafting zone, and k2 is designed according to actual spinning requirements; in the production of the three-color yarn segment, the first The servo motor drives the rear roller to rotate at v6 speed, the second servo motor drives the middle and rear roller to rotate at v7 speed, and the third servo motor drives the middle and front roller to rotate at v8 speed. Press and feed between the first left rubber roller and the first right rubber roller, and receive the draft effect of v8/v6 times of the first rear draft zone composed of the rear roller draft pair and the middle front roller draft pair, and the middle The draft effect of v1/v8 times of the front draft area composed of the front roller draft pair and the front roller draft pair, the third roving passes through the suspended slip between the rear roller and the first middle rubber roller, and is subjected to the middle and rear draft action of v8/v7 times of the second rear drafting zone composed of the drafting pair of rollers and the drafting pair of middle front rollers, and v1 of the front drafting zone consisting of the drafting pair of middle front rollers and the drafting pair of front rollers /v8 times the drafting action, the front roller speed v1, rear roller speed v6, middle rear roller speed v7, first roving and second roving density T3, third roving density T1, and spun fine yarn density T2 satisfy 2×T3×v6+T1 ×v7=T2×v1, satisfy between the ratio k3 of the front roller speed v1, the middle and rear roller speed v7, the middle front roller speed v8, the drafting ratio of the second rear drafting zone and the drafting multiple of the front drafting zone ( v8×v8)/(v1×v7)=k3, the ratio of the front roller speed v1, the rear roller speed v6, the middle front roller speed v8, the draft ratio in the front draft zone and the draft ratio in the second rear draft zone Between k4 satisfies (v8×v8)/(v1×v6)=k4, and k3 and k4 are designed according to actual spinning requirements.

During spinning, the main motor drives the spindle to rotate through the spindle belt, and then drives the twist generated by the rotation of the bobbin to be transmitted from bottom to top, so that the yarn obtained after drafting rotates around its own axis, and then a fancy yarn with a certain twist is obtained. , the obtained fancy yarn is wound on the yarn bobbin after passing through the yarn guide hook and the traveler, and the rotation of the bobbin drives the traveler to rotate around the steel collar. Since the speed of the traveler is smaller than the speed of the bobbin, the fancy yarn is continuously wound on the on the bobbin.

The present invention adopts four-column rollers driven separately, and the rear top roller and the middle and rear top rollers adopt stepped rubber rollers, so that the three fed rovings are divided into two groups to complete independent drafting, and then realize two-color or three-color fancy yarn production, enrich the variety of yarns, and increase the added value of yarns.

Description of drawings

Fig. 1 is a structural schematic diagram of a three-roving double-draft fancy yarn production device of the present invention.

detailed description

As shown in Figure 1, a three-roving double-draft fancy yarn production device includes four rows of drafting roller pairs: the rear roller drafting pair composed of rear roller 4 and rear rubber roller 5, the middle and rear rollers 6 and the middle and rear rollers. The middle and rear roller drafting pair composed of rubber roller 7, the middle front roller drafting pair composed of middle front roller 8 and middle front rubber roller 9, the front roller drafting pair composed of front roller 10 and front rubber roller 11, the rear roller The roller shaft is driven to rotate by the first servo motor 12, the roller shaft of the middle and rear rollers is driven to rotate by the second servo motor 13, the roller shaft of the middle front roller is driven to rotate by the third servo motor 14, and the roller shaft of the front roller is driven by the main motor 15 drive to rotate, the main motor is a variable frequency motor, the first servo motor, the second servo motor, the third servo motor, and the main motor are connected through a programmable logic controller 16, and the rear rubber roller 5 includes a rear rubber roller shaft. The first left rubber roller, the first middle rubber roller and the first right rubber roller are connected in sequence on the roller shaft. The lengths of the first left rubber roller, the first middle rubber roller and the first right rubber roller are the same, and the first left rubber roller 1. The first middle rubber roller and the first right rubber roller can rotate freely around the axis of the rear rubber roller respectively. The diameters of the first left rubber roller and the first right rubber roller are the same and larger than the diameter of the first middle rubber roller. Roller 7 comprises middle and rear rubber roller shaft, is connected with the second left rubber roller, the second middle rubber roller and the second right rubber roller successively on the middle and rear rubber roller shaft, the second left rubber roller, the second middle rubber roller and the first The length of the two right rubber rollers is the same, the second left rubber roller, the second middle rubber roller and the second right rubber roller can rotate freely around the axis of the middle and rear rubber rollers respectively, the diameter of the second left rubber roller and the second right rubber roller The same and smaller than the diameter of the second middle rubber roller, the diameter of the second left rubber roller and the second right rubber roller is equal to the diameter of the first middle rubber roller, the diameter of the first left rubber roller and the first right rubber roller is equal to the second middle rubber roller The diameter of the rubber rollers, the middle front rubber roller 9 and the front rubber roller 11 are rubber rollers whose diameter remains constant, and a collection bell mouth 21 is additionally installed between the middle and rear roller draft pair and the middle front roller draft pair. Press the pressing assembly so that the first left rubber roller and the first right rubber roller are tightly pressed with the rear roller, the first middle rubber roller is suspended in the air, the second middle rubber roller is tightly pressed with the middle rear roller, the second left rubber roller and the The second right rubber roller is suspended in the air, the middle front rubber roller is tightly pressed with the middle front roller, and the front rubber roller is closely pressed with the front roller. The rubber rollers are pressed and fed, and then passed through the middle and rear rollers, the second left and the second right rubber rollers, and then pass through the collective bell mouth and then passed between the middle and front rollers and the middle and front rollers. Press and pass between the back rollers and the middle front roller drafting pair to form the drafting effect of the first rear drafting area, and finally press the output between the front roller and the front rubber roller, and be affected by the middle front roller drafting pair and the drafting effect of the front roller drafting on the formed front drafting zone to obtain the first strand; the third roving 3 is passed through by the slippery suspension suspended between the back roller and the first middle rubber roller, and then by the middle back roller and the first middle rubber roller Press and feed between the second middle rubber rollers, and then press and pass between the middle front roller and the middle front rubber roller after passing through the collective bell mouth, and receive the second middle and rear roller draft pair and the middle front roller draft pair. The drafting effect of the rear drafting area, the final pressing output between the front roller and the front rubber roller, is affected by the drafting pair of the middle front roller and the front roller The drafting effect of the roller drafting on the formed front drafting zone, obtains the second strand.

A method for producing fancy yarns with three rovings and double drafting, including the production of single-color yarn sections, two-color yarn sections, and three-color yarn sections, wherein the main motor 15 drives the front roller 10 to rotate at a speed v1, and the rotation of the front roller is determined by the spindle speed Determined with the design twist, during the production of monochrome yarn section, the first servo motor 12 stops working, the second servo motor 13 drives the middle and rear rollers 6 to rotate at v2 speed, and the third servo motor 14 drives the middle and front rollers 8 to rotate at v3 speed, At this time, the feeding of the first roving 1 and the second roving 2 is stopped, and the third roving 3 passes through the space between the rear roller 4 and the first middle rubber roller, and is drawn by the middle and rear roller draft pair and the middle front roller. Drafting action to v3/v2 times the composition of the second rear drafting zone, and v1/v3 times the drafting action of the middle front roller drafting pair and front roller drafting to the composition of the front drafting zone, front roller Speed v1, middle and rear roller speed v2, third roving linear density T1, and spun yarn density T2 satisfy v1/v2=T1/T2, front roller speed v1, middle and rear roller speed v2, middle and front roller speed v3. The ratio k1 of the draft multiple in the second rear draft zone to the draft multiple in the front draft zone satisfies (v3×v3)/(v1×v2)=k1, and k1 is designed according to actual spinning requirements.

In the production of two-color yarn section, the first servo motor 12 drives the rear roller 4 to rotate at the speed of v4, the second servo motor 13 stops working, the third servo motor 14 drives the middle front roller 8 to rotate at the speed of v5, and the third roving 3 stops at this time Feeding, the first roving 1 and the second roving 2 are respectively pressed and fed between the rear roller 4 and the first left rubber roller and the first right rubber roller, and are drawn by the rear roller draft pair and the middle front roller draft pair. The drafting effect of v5/v4 times of the first rear drafting zone, and the drafting effect of v1/v5 times of the front drafting zone composed of the middle front roller drafting pair and the front roller drafting pair, the front roller speed v1, Rear roller speed v4, first roving yarn and second roving density T3, spun yarn density T2 satisfy v1/v4=2×T3/T2, front roller speed v1, back roller speed v4, middle front roller The speed v5, the ratio k2 of the draft multiple in the front draft zone and the draft multiple in the second rear draft zone satisfies (v5×v5)/(v1×v4)=k2, and k2 is designed according to actual spinning requirements.

In the production of three-color yarn section, the first servo motor 12 drives the rear roller 4 to rotate at the speed of v6, the second servo motor 13 drives the middle and rear roller 6 to rotate at the speed of v7, and the third servo motor 14 drives the middle and front roller 8 to rotate at the speed of v8 At this time, the first roving 1 and the second roving 2 are respectively pressed and fed between the rear roller 4 and the first left rubber roller and the first right rubber roller, and are drawn by the rear roller draft pair and the middle front roller draft pair. The draft effect of v8/v6 times of the first rear draft zone, and the draft effect of v1/v8 times of the front draft zone composed of the middle front roller draft pair and the front roller draft pair, the third roving 3 is composed of The slippery passage suspended between the back roller 4 and the first middle rubber roller is subjected to the drafting effect of v8/v7 times of the second back draft zone formed by the middle back roller draft pair and the middle front roller draft pair, and The drafting effect of the v1/v8 times of the front draft zone composed of the middle front roller draft pair and the front roller draft pair, the front roller speed v1, the back roller speed v6, the middle back roller speed v7, the first roving yarn and The second roving density T3, the third roving linear density T1, and the spun yarn linear density T2 satisfy 2×T3×v6+T1×v7=T2×v1, the speed of the front roller v1, the speed of the middle and rear rollers v7, the middle The ratio k3 between the front roller speed v8, the draft ratio of the second rear draft zone and the front draft zone draft ratio k3 satisfies (v8×v8)/(v1×v7)=k3, the front roller speed v1, the rear roller speed V6, the speed of the middle front roller v8, the ratio k4 between the draft ratio of the front draft zone and the draft multiple of the second rear draft zone satisfies (v8×v8)/(v1×v6)=k4, and k3 and k4 are based on actual conditions Design for spinning needs.

During spinning, the main motor 15 drives the spindle to rotate through the spindle belt, and then drives the twist generated by the rotation of the bobbin 20 to pass from bottom to top, so that the obtained strands after drafting rotate around their own axis, and then obtain a flower with a certain twist. Type yarn, the obtained fancy yarn is wound on the bobbin after the yarn guide hook 17 and the traveler 18, and the bobbin rotates to drive the traveler to rotate around the steel collar 19. Because the rotating speed of the traveler is smaller than the rotating speed of the bobbin, the flower The formula yarn is continuously wound on the bobbin.

Claims (2)

1. a kind of double drawing-off fancy yarn process units of three rove, including four row drawing rollers pair：What rear roller and back cot were constituted Rear roller drawing-off to the middle rear roller drawing-off of, middle rear roller and middle back cot composition to, middle front roller and in before rubber roll composition Front roller drawing-off pair of the middle front roller drawing-off to, front roller and front rubber roll composition, the roller shaft of the rear roller is by the first servo Motor drives and rotates, and the roller shaft of the middle rear roller is driven by the second servomotor and rotated, the roller shaft of the middle front roller Driven by the 3rd servomotor and rotated, the roller shaft of the front roller is driven by mair motor and rotated, the mair motor is variable-frequency electric Machine, first servomotor, the second servomotor, the 3rd servomotor, mair motor are connected by programmable logic controller (PLC), It is characterized in that：The back cot includes back cot axle, is connected with the first left rubber roll in the rear in turn, glue in first on rubber roller Roller and the first right rubber roll, the length of the first left rubber roll, the first mid-rubber roll and the first right rubber roll are identical, the first left glue Roller, the first mid-rubber roll and the first right rubber roll can be freely rotated respectively around back cot axle, the first left rubber roll and the first right glue The diameter of roller is identical and more than the diameter of the first mid-rubber roll, and the middle back cot includes middle back cot axle, in the middle back cot It is connected with the second left rubber roll, the second mid-rubber roll and the second right rubber roll, the second left rubber roll, the second mid-rubber roll and on axle in turn The length of two right rubber rolls is identical, and the second left rubber roll, the second mid-rubber roll and the second right rubber roll can be respectively around middle back cot axles Freely rotate, the diameter of the second left rubber roll and the second right rubber roll is identical and less than the diameter of the second mid-rubber roll, described second The diameter of left rubber roll and the second right rubber roll is equal to the diameter of the diameter of the first mid-rubber roll, the first left rubber roll and the first right rubber roll Equal to the diameter of the second mid-rubber roll, it is described in before rubber roll and front rubber roll be that diameter keeps constant rubber roll, in the middle rear roller Pressure-applying unit is pressed during spinning by drawing-off to adding set horn mouth and middle front roller drawing-off pair between so that the first left glue Roller and the first right rubber roll are closely pressed with rear roller, and the first mid-rubber roll is hanging, and the second mid-rubber roll is closely pressed with middle rear roller, the Two left rubber rolls and the second right rubber roll are hanging, in before rubber roll closely press with middle front roller, front rubber roll is closely pressed with front roller, the One rove and the second rove respectively by pressing feeding between rear roller and the first left rubber roll and the first right rubber roll, then respectively by Between rear roller and the second left rubber roll and the second right rubber roll it is hanging it is smooth pass through, and after Jing after set horn mouth by middle front roller And in before between rubber roll pressed through by rear roller drawing-off to the leading to the first first break draft area for constituting with middle front roller drawing-off The effect of stretching, between last front roller and front rubber roll pressing output, by middle front roller drawing-off to and front roller drawing-off to composition The drawing-off effect of front draft zone, obtains the first yarn；3rd rove smooth is worn by hanging between rear roller and the first mid-rubber roll Cross, then by between middle rear roller and the second mid-rubber roll pressing feeding, and after Jing set horn mouth after by middle front roller and in before Pressed through by drawing-off work of the middle rear roller drawing-off to the second first break draft area with middle front roller drawing-off to constituting between rubber roll With, between last front roller and front rubber roll pressing output, by middle front roller drawing-off to and front roller drawing-off to composition before lead The drawing-off effect in area is stretched, the second yarn is obtained, first rove, the second rove, the 3rd rove are coloured rove, described the One rove and the second rove are raw material and quantitative identical rove, first rove, the second rove, the 3rd rove color it is equal Differ.

2. a kind of production of the double drawing-off Flamme fance yarn manufacturing methods of three rove, including plain yarn section, the production of double-colored yarn section, three dyed yarn Duan Sheng Produce, it is characterized in that：Mair motor drives front roller to rotate with speed v1, and the front roller is rotated is determined by spindle rotating speed and the design twist Fixed, in the plain yarn section production, the first servomotor quits work, and the second servomotor band disorder of internal organs rear roller is turned with v2 speed Dynamic, the 3rd servomotor band disorder of internal organs front roller is rotated with v3 speed, and now the first rove and the second rove stop feeding, and the 3rd is thick Yarn by between rear roller and the first mid-rubber roll it is hanging it is smooth pass through, by middle rear roller drawing-off to middle front roller drawing-off to group Into v3/v2 times of the second first break draft area of drawing-off effect, and middle front roller drawing-off to and front roller drawing-off to leading before composition Stretch v1/v3 times of area of drawing-off effect, the front roller rotating speed v1, middle rear roller rotating speed v2, the 3rd textured yarn density T 1, spun V1/v2=T1/T2, the front roller rotating speed v1, middle rear roller rotating speed v2, middle front roller rotating speed are met between fine yarn density T 2 (v3 × v3)/(v1 × v2)=k1 is met between the ratio k1 of v3, the second first break draft area drafting multiple and front draft zone drafting multiple, K1 is according to actual spinning Demand Design；In the double-colored yarn section production, the first servomotor drives rear roller to rotate with v4 speed, Second servomotor quits work, and the 3rd servomotor band disorder of internal organs front roller is rotated with v5 speed, and now the 3rd rove stops feeding Enter, the first rove and the second rove are fed by pressing between rear roller and the first left rubber roll and the first right rubber roll respectively, after being subject to Roller draft is acted on to the drawing-off with middle front roller drawing-off to constitute v5/v4 times of the first first break draft area, and middle front roller leads Stretch to and drawing-off effect of the front roller drawing-off to constitute v1/v5 times of front draft zone, the front roller rotating speed v1, rear roller turn V1/v4=2 × T3/T2 is met between fast v4, the first textured yarn and the second rove density T 3, spun fine yarn density T 2, it is described Front roller rotating speed v1, rear roller rotating speed v4, middle front roller rotating speed v5, front draft zone drafting multiple and the second first break draft area drawing-off times (v5 × v5)/(v1 × v4)=k2 is met between the ratio k2 of number, k2 is according to actual spinning Demand Design；The three dyed yarns section production In, the first servomotor drives rear roller to rotate with v6 speed, and the second servomotor band disorder of internal organs rear roller is rotated with v7 speed, the Three servomotors band disorder of internal organs front roller is rotated with v8 speed, and now the first rove and the second rove are left by rear roller and first respectively Pressing feeding between rubber roll and the first right rubber roll, by rear roller drawing-off to the first first break draft with middle front roller drawing-off to constituting The drawing-off effect of v8/v6 times of area, and middle front roller drawing-off to and front roller drawing-off to constitute v1/v8 times of front draft zone Drawing-off is acted on, the 3rd rove by between rear roller and the first mid-rubber roll it is hanging it is smooth pass through, by middle rear roller drawing-off to Drawing-off of the middle front roller drawing-off to constitute v8/v7 times of the second first break draft area is acted on, and middle front roller drawing-off to and front roller Drawing-off effect of the drawing-off to constitute v1/v8 times of front draft zone, the front roller rotating speed v1, rear roller rotating speed v6, in sieve afterwards Draw rotating speed v7, the first textured yarn and the second rove density T 3, meet between the 3rd textured yarn density T 1, spun fine yarn density T 2 2 × T3 × v6+T1 × v7=T2 × v1, the front roller rotating speed v1, middle rear roller rotating speed v7, middle front roller rotating speed v8, second Between the ratio k3 of first break draft area drafting multiple and front draft zone drafting multiple meet (v8 × v8)/(v1 × v7)=k3, it is described before Lora rotating speed v1, rear roller rotating speed v6, middle front roller rotating speed v8, front draft zone drafting multiple and the second first break draft area drafting multiple Ratio k4 between meet (v8 × v8)/(v1 × v6)=k4, k3, k4 are according to actual spinning Demand Design.