Conventional Covered Yarn

 

 

Supply Ability

Supply Ability     10000 Kilogram/Kilograms per Month

Packaging & Delivery

Packaging Details   65cm*45cm*36cm also can with pallets

Lead Time:

Quantity(Kilograms)	1 - 1000	>1000
Est. Time(days)	7	To be negotiated

Double covered yarn (DCY
Raw material:	Spandex/latex + Polyester/nylon
color:	raw white， black, colors as request
Packing:	PP bags/cartons carton size 65*45*36.5 0.5kg/cone,24kg/carton 23kg/bag 268carton/20ft 400bags/20ft 635carton/40hq 715bags/40hq
spandex double covered yarn	spandex+polyester	1407575,2107575,560150150,2807575,etc.
spandex+nylon	1407070,2107070,4207070,560140140, etc.
latex double covered yarn	latex+polyester	907575,1007575,1107575,63#150150,52#150150 etc.
latex+nylon	907070,1007070,1107070etc.
More details can be customized.
Samples can be sent to check whether conform to your requirements.

 

 

 

PUT INTO USE

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Our yarn can be used for leggings, silk socks, denim, bra, socks, underwear, ribbons, elastic tapes, gloves, shoe uppers, and so on.

 

 

 

 

 

Q: What is the Comparison of traditional and Siro spun nylon filament core-spun yarn?

A:

For high-strength and durable, non-ironing, stable size and anti-pilling, moisture absorption, beautiful and comfortable fabrics, such as sewing thread and military uniforms, core-spun yarn is superior to the general pure spun yarn and blended chemical fiber fabric yarn, and can meet the requirements. However, the traditional core-covered yarn has poor covering effect, and sometimes its structure is like a strand twisted together with the filament and the outer fiber strips, which does not have the peeling strength suitable for mechanical finishing, thus reducing the added value of the core-covered yarn and limiting the potential use of the core-covered yarn [1].

 

Siro spinning core-spun yarn is a single yarn with linear properties, its strength, elongation and uniformity are better than traditional core-spun yarn, and it has soft hand feel and good covering effect. In order to produce the core-spun yarn with good quality and meet the requirements of customers economically, the production equipment and yarn performance of traditional and Siro spun nylon filament core-spun yarn are compared, the differences between the two are analyzed, and the reasonable spinning process is pointed out.

1. Equipment transformation

 

1.1 Equipment modification of traditional spinning core-spun yarn

 

 

Conventional core-spun yarn can be produced on generally modified spinning frames. Firstly, a core-feeding mechanism and a pre-drawing mechanism are installed on the general spinning frame. The bobbin filament is unwound under the traction of the yarn guide roller, not through the drawing mechanism of the spinning frame, but through the pre-drawing mechanism and the V-shaped groove guide wheel, fed from the collection device behind the front roller, combined with the drafted whisker, and then through the front roller and the yarn guide hook, the ring spindle is turned into the filament core yarn.

 

Then modify the roving frame. Because the overall size of the nylon filament used is greater than 200mm×500mm, a roving frame is changed from six columns of single-layer spindle to four columns of single-layer spindle, and the spindle distance is changed from the original 210mm to 130mm. The core feed device is located above the roving frame, so the roving frame is lowered by 30mm to make room for additional filament station posts, brackets and spindles. In consideration of operability, only two rows of long wire brackets and spindles are installed on the station column, and one row of long wire brackets and spindles are installed using the space in front of the roving (Figure 2). In this way, the roving and filament can be reasonably distributed, and the filament is led out by the guide rod and fed into the front pliers of the draft area, and the roving is led out by the guide rod and the yarn dividing rod and fed into the post-draft area.

 

Hold the transverse rod in place to ensure that the roving whisker that is fed through the flare into the draft area does not move. The wire guide wheel is installed in the position of the shaking frame to effectively control the filament always in the center of the roving bar when the front roller is output, reduce the core defects such as exposed core yarn and improve the covering effect. The predraft of the filament is controlled by a change draft gear, which can change the draft multiple between the guide roller and the front roller.

 

1.2 Equipment modification of Siro spinning core-spun yarn

 

 

The Siro core-covered yarn can be spun on a spinning frame equipped with Siro spinning device and core-covered yarn device. The core yarn of the Siro core-covered yarn is fed into the front roller pliers through the wire guide wheel, and two parallel outsourced fiber rovers enter the three-roller long and short leather ring drafting device through the collector, laying in the drafting area. When the outsourced short fiber passes through the front roller, the core yarn is between the two rovers and always located in the middle, and the three are combined and twisted to the yarn bobbin.

 

A Siro spinning component is added to a spinning frame fitted with a core spinning device. The roving feed separator is installed, the single head yarn guide is changed into a double head yarn guide in the draft back area and the middle of the draft area, and the single head collector at the front roller is changed into a double head collector, the spacing between them is equal to the roving distance, and the center line of the front and back three horns is in a straight line. This ensures that the two fed rovers are always parallel apart in the draft area.

 

Between the front roller and the yarn guide hook is equipped with a breaking stop device, when one of the strands is broken, it can automatically break the other yarn, prevent single yarn, and require the interrupter to be sensitive and not cut by mistake.

 

To modify the roving frame, lengthening the cross bar support and installing the roving bracket on the original roving frame make the roving frame raise and widen, and the center distance of the lifting ingot is modified from 155mm, 350mm and 510mm to 100mm, 315mm and 480mm respectively. The center distance of the yarn guide rod is modified from 240mm and 140mm to 230mm and 130mm respectively, the height of the distance from the car surface is modified from 1130mm, 775mm and 450mm to 1030mm, 675mm and 390mm respectively, and the roving frame is increased from 50mm to 150mm. Thus doubling the roving capacity, allowing the original roving rack to accommodate only 420 roving pieces to be increased to 840 pieces, and reducing the accidental drafting of roving strips.

2. Yarn performance

 

With 60% combed cotton and 40% Modal blended chemical fiber fabric roving as the outer fiber and 80 denier nylon filament as the core yarn, 23.5tex traditional core-covered yarn and Siro core-covered yarn were produced on the above modified FA506S spinning frame. The spinning process adopted by the two spinning machines is: The draft multiple of the rear area is 1.394, the roller spacing of the front and rear area is 18mm and 40mm, the pressure of the front, middle and rear roller is 18, 10 and 14kg/ double ingot, the twist coefficient is 350, the front roller speed is 163rpm, the spindle speed is 10067rpm, and the core wire predraft multiple is 1.06. However, the feeding roving quantity of traditional core-covered yarn is 5.6g/10m, and the feeding roving quantity of Siro core-covered yarn is 3.1g/10m, and the spacing between the two roving is 4mm. The following is a comparison of the performance of JC/M (60/40) 23.5tex/N80D nylon filament core-covered yarn.

 

Table 1 Comparison of the performance of traditional core-covered yarn and Siro core-covered yarn

 

 

 

 

Obviously, the traditional core-spun yarn has poor covering effect and unstable quality, while the performance indexes of Siro spinning core-spun yarn are better.

 

2.1 Strength

 

The main factors affecting the strength of core-spun yarn are fiber raw material, twist coefficient, roving weight, back draft and distance between two rovers. Traditional spinning obtains strength through twisting and fiber transfer, while Siro spinning mainly obtains strength through the intertwining of single yarn. Siro spinning feeds a finer roving yarn, and the fibers are narrow, so that the surface fibers are effectively bound to the yarn body. The intertwining of the two single yarns makes the internal and external transfer of the fiber only half of the traditional spinning, the inclination Angle between the fiber and the spinning spool is small, and the fiber strength utilization is higher when the spinning thread is stretched [2].

 

2.2 Coating effect

 

A computer image analysis system is used to scan the surface of the core-covered yarn or the surface of the knitted fabric, and the scanned area is input to the computer to calculate the size of the core-covered yarn. If only the outer fiber is colored, the core fiber and the outer fiber can be clearly distinguished.

 

 

The peel strength of cored yarn can be measured indirectly by two different methods. The first method is to weave a small piece of knitted fabric sample on the loom, and then test its covering effect with computer image analysis system. The second method is to install a knitting needle on the spinning thread friction tester, give the core-covered yarn a certain degree of friction or imitate the knitting fabric finishing to make the core-covered yarn wear positively, and then wind the worn core-covered yarn parallel to the yarn plate, and use the computer image analysis system to test and calculate its covering effect. The coating effect of core-covered yarn tested by these two methods is obviously lower than that before finishing, and the percentage reduction shows the degree of damage caused by stripping of core-covered yarn during mechanical finishing [3].

 

The main factors affecting the covering effect of core-covered yarn are the content of outer fiber and core fiber, the predraft ratio of core fiber, the structural properties of core fiber and outer fiber, the design and installation of wire guide wheel, the spinning process of outer fiber, the twist coefficient of yarn formation, the speed of spindle, and the distance between two rovers. The internal and external transfer of fibers is the result of the coexistence of spinning tension and fiber geometry. With the increase of the width of the filament, the number of fibers along the edge of the twist triangle area increases, and the number of fibers involved and transferred in the same time increases, so that the probability of the outsourced fibers transferring to the core fibers increases. In order to make the two parallel feeding rovers transfer and hold each other well in the pre-draft area, the Siro spinning feed horn makes the two rovers parallel feeding at close distance, and the covering effect of the cored yarn is greatly improved.

 

 

 

The main factors affecting the hair of cored yarn are roving spacing, twist and spindle speed. The single yarn of the race winding yarn contains a small amount of twist, due to two twisting, the fiber output from the former roller is not subjected to sudden strong twisting force, the two ends of the fiber are not prominent, when the two yarn strips are arranged in a spiral around the core wire, many fiber ends are brought into the yarn strip by the adjacent single yarn strip, the surface fiber is a certain degree of loop knot, The core-spun yarn of Siro has less hair than that of traditional core-spun yarn.

 

2.4 Dry evenly

 

The combination effect of double roving feeding and the distance between the two roving is much less than 12-14mm, the fiber in the beard strip will not have a large slip, so the Siro spinning core yarn is better.

 

2.5 Wear Resistance

 

The Siro cored yarn is dry and uniform, the section is round, the hair is less, the surface is smooth, and the friction of various yarn guides and healds is small, even if the surface fiber is locally friction, the internal fiber still maintains a positive connection, and will not immediately destroy the yarn structure, so the wear resistance is good.

 

 

3. Spinning process

 

The process parameters which have great influence on the quality of core-covered yarn are core wire predraft multiple, wire ring weight, yarn twist, roving feeding interval, spindle speed, roller pressure, draft multiple, etc.

 

3.1 The roving draft multiple, core wire predraft multiple, roller spacing and roller pressure of the two are similar.

 

3.2 Roving spacing

 

In the spinning process of Siro, the twist direction of the two single yarns above the convergence point is the same as that of the lower strand yarn, and the twist direction of the two yarns at the convergence point is less than that of the lower strand yarn. The twist trap effect formed by the two yarns at the convergence point is to block the twist back transfer, so that the twist twist of the single yarns on the upper side of the convergence point is smaller than that of the lower strand yarn, the twist triangle height decreases, and the twist of the yarn on the lower side of the convergence point increases. The twist of the single strand also increases. After two twisted single yarn is twisted into a strand, the number of times that the surface fiber of the single yarn is looped into the strand is equal to the number of twists on the single yarn.

 

The roving distance affects the size of the twist triangle, the distance between two rovers increases, the length of the single yarn on the upper side of the convergence point increases, the twist on the single yarn also increases, the yarn hair is less, and the wear resistance is good. However, due to the instantaneous wrapping of each other, a wrapped whisker must output longer, so the spinning tension of a single yarn strip is relatively large, resulting in instantaneous tension drafting, resulting in an increase in the number of sliding fibers in the single yarn strip and a large slip of the fibers in the whisker strip. When the slip amount is small, the yarn strip details will appear, and when the slip amount is large, the whisker strip will break. Therefore, the distance between the two rovers should not be too large, otherwise, the breakage will increase [3]. However, the distance between the two rovers is small, the twisting triangle area is weak and the twist is long, and the twist is low, which is easy to produce accidental drafting, affecting the spinning line dry and the spinning break. It can be seen that by changing the distance between the two rovers, the twisting triangle can be adjusted, so that the two strands fed at the same time can join in the pre-draft area, so as to realize the mutual transfer and clamping between the fibers, optimize the yarn dry, and reduce the defects of spinning yarn hairiness, thick details, and crossheading [2].

 

The distance between the two rovers should be determined according to the length of the outer fiber and the coating effect. In order to improve the coating effect of the yarn, the spacing between the two roving should be 3-5mm, which can accommodate a core wire. The core yarn is fed from the middle of the Angle between the two yarn strips, and the core yarn is always in the center of the yarn when twisting, so that the Siro core-covered yarn has a good covering effect.

 

3.3 Yarn twist factor

 

The twisting action causes the centripetal pressure between the fibers in the spinning thread and increases the friction between the fibers. In a certain twist range, the twist coefficient increases, the centripetal pressure of the outsourced fiber is large, the internal and external transfer of the fiber is more, the friction force between the fibers is increased, the outsourcing fiber is more tightly wrapped to the core fiber, and the anti-stripping performance of the core yarn is stronger, the hair of the spun yarn increases. The strength and covering effect of Siro spinning core-spun yarn is better than that of traditional core-spun yarn, so the twist coefficient of Siro spinning core-spun yarn is lower than that of similar traditional core-spun yarn for the same purpose.

 

3.4 Spindle Speed

 

As the spindle speed increases, the centrifugal force of the spinning line increases, the fiber will be thrown out of the surface of the spinning line, the wire ring is accelerated, the scraping effect is enhanced, at this time, the spinning tension increases, the spinning line hair increases. The quality of Siro spinning core-spun yarn is better, and its spindle speed is higher than that of traditional core-spun yarn.

 

peroration

 

The traditional core-covered yarn is spun on a spinning frame equipped with a core-covered yarn device, while the Siro spinning core-covered yarn is spun on a spinning frame equipped with a core-covered yarn device and a Siro spinning device. The outer fiber density of traditional core-covered yarn is more uniform and the appearance is hairy. The outer fiber of Siro spinning core-spun yarn has two dense areas, and the core yarn is always located in the center of the yarn, the appearance of the yarn is clean, the single yarn and the helix of the fiber are obvious, the fiber holding force is high, the yarn breaking strength is increased, the stretch length is increased, and the dry uniformity of the yarn is better than that of the traditional core-spun yarn, the spinning yarn has soft hand feel, less hair, and good wear resistance.

 

Siro spinning core-covered yarn not only has the advantages of winding yarn and core-covered yarn, but also greatly improves the covering effect of core-covered yarn and reduces the exposed core and empty sheath. However, in the spinning process, if the core yarn or one of the two rovers breaks, sometimes the broken stop device can not cut off other rovers or filaments in time, effectively preventing yarn defects such as hollow core, poor coating and details.