Murata Vortex Spinning System
The Murata Vortex Spinning (MVS) process, based on Murata’s air-jet spinning technology, was introduced for the first time at the OTEMAS ’97 International Textile Machinery Exhibition in Osaka by Murata Machinery Ltd. The Vortex Spinning system is a revolutionary method for producing twisted yarns, mainly used in the production of both pure and blended synthetic and cotton yarns. Since the emergence of twisted yarns, it was evident that there were limitations in this field that hindered its widespread adoption. Murata’s Vortex Spinning is 3 to 5 times faster than rotor spinning and 10 to 20 times faster than ring spinning. Vortex yarns are commonly used in the production of bed sheets and light knitted blouses.
Murata Vortex Spinning is a modified version of air-jet spinning, and it has gained significant attention due to its advantages over ring, open-end, and air-jet spinning. This system offers high efficiency, yarn structure similar to ring yarns, less fiber fly, and, most importantly, the ability to use a broader range of fiber lengths for 100% cotton. Today, an increasing number of industries are adopting Murata’s Vortex Spinning, especially for producing artificial silk yarns that require moderate softness and anti-pilling properties. Recently, extensive research has been conducted on this system, particularly as it can produce polyester yarns requiring high gloss.
Features and Operation Method
Murata Vortex Spinning systems offer yarns with different structures and properties. Each system has its limitations and advantages regarding technical feasibility and cost-effectiveness. The MVS process is based on air-jet technology, covering a broader range of fiber lengths. Vortex yarn has a dual structure (core and sheath). In Murata’s Vortex system, fibers are drawn by an air vortex into the spindle nozzle. As they enter and pass through the nozzle, they are twisted by rotating air. This system can produce yarn at speeds of up to 400 meters per minute.
Murata Vortex Spinning, which uses high-speed air flow to twist the yarn, is one of the most promising technological innovations in the textile industry. In this spinning process, the dynamic behavior of fibers inside the nozzle, including their interaction with the air flow and contact with the nozzle walls, plays a crucial role in the twisting process.
Twisting Process in Murata Vortex Spinning
In the process of twisting staple yarns, the fiber sliver is held at one end, and the length of this fiber is adjusted to spin around its axis. The rotation of the fiber results in the formation of spiral shapes, increasing the number of twists. By applying this twist at this stage of Murata’s Vortex Spinning, fibers are positioned together to form a continuous yarn with special structure and properties. In traditional ring spinning, a mechanical rotating component is used to create the twist, and it remains the most commonly used spinning method. While ring spinning offers the widest range of twist counts, its disadvantages, such as low production speed, long processing time, and high energy consumption, limit its development.
Advantages of Murata Vortex Spinning
In comparison, the Vortex technique uses high-speed air flow to twist the fibers. This method greatly increases the twist speed of fibers, which can reach up to 200,000 rpm. Not only does this increase the production speed and shorten the spinning process, but it also reduces yarn production costs and energy consumption. On a global scale, energy shortages and increasing labor costs have made Murata’s Vortex Spinning one of the most promising technological innovations in the textile industry.
The spinning section of Murata Vortex Spinning consists of an air jet nozzle and a hollow spindle. Fibers that come from the front rollers are brought together and twisted by the high-speed air flow inside the nozzle. The fibers that spin around the tip of the hollow spindle attach to the core fibers, forming a twisted yarn. This yarn passes through the hollow spindle’
s aperture and is assisted by delivery rollers to enter the bobbin winding section. The most notable feature of Murata’s Vortex Spinning (the vortex system) is its ability to twist 100% cotton fibers at very high speeds (450 meters per minute). The yarn produced in this process has a structure very similar to ring-spun yarn.
Principles of Murata Vortex Spinning
Murata Vortex Spinning takes cotton sliver and processes it through a four-roller apron system to the desired yarn count (fine). The fibers are then sucked into a nozzle, where a high-speed air vortex twists them around the outside of a fixed hollow spindle. An air vortex at the free end of the fibers twists them around the intermediate fibers, creating a ring-like structure. This twisting process is also possible for carded slivers. The twist is applied while the fibers rotate around the tip of the spindle, just before they are drawn down through the center of the spindle.
The productivity of the MVS (Vortex) system is due to its high production speed. Furthermore, the yarn is made directly from the initial sliver and does not require a flyer. The yarn is cleaned and wound onto bobbins directly, making it ready for sale. The finished yarn is then bobbin wound after defects are removed. During the yarn formation process, since twist spread is prevented by the guide piece, fewer fibers receive false twist.
Increased Fiber Liberation
In addition, fiber detachment from the fiber bundle can occur at any point around the outer perimeter of the fiber bundle. This results in an increase in the number of liberated fibers in the yarn. As a result, Murata Vortex yarns have more liberated fibers compared to air-jet yarns. Their structure resembles ring-spun yarns, which is the ideal structure for Vortex yarns.
Fibers used in Murata Vortex Spinning include primary fibers such as polyester, viscose, cotton, and their blends, along with elastane sheaths and 100% staple fibers in the core.
The characteristics of MVS yarns and fabrics are comparable to ring yarns. For instance, fabrics produced from Murata Vortex yarns are just as soft and smooth as ring-spun fabrics. However, MVS requires fibers with good properties to achieve these results. The fibers must be clean, strong, have a minimum staple length of 28 mm, and be uniform. The production speed is almost independent of the yarn count, ranging from 300 to 400 meters per minute. This is equivalent to rotor and ring spinning for yarn counts ranging from 12 to 40 Ne. Therefore, Murata Vortex offers a serious alternative to rotor spinning for medium and long cotton fibers.
Production Cost
The production cost of Vortex yarn (Ne 40) is approximately 50% and 60% of ring and rotor yarns, respectively. Its fully automated process eliminates all rotating mechanical parts. The flexibility of Murata’s Vortex technology is significantly higher than that of false twist spinning methods and is likely to replace them. Blended yarns can also be produced without any issues. The MVS process is a revolutionary new technology for producing twisted yarns, and it appears to have wide applications in cotton yarn spinning.
Advantages and Disadvantages of Murata Vortex Spinning
Vortex technology was introduced in 1997 by Murata Machinery Ltd. as an air-jet method for twisting yarns. The key feature of Murata Vortex Spinning (MVS) is its ability to produce yarns at speeds of 400 meters per minute, approximately 20 times faster than ring spinning. Other advantages include low maintenance costs, automatic knotting, and the elimination of the flyer. The developers of Murata Vortex Spinning claim that the properties of MVS yarns and fabrics are similar to those of ring-spun yarns.
One of the issues with the Vortex system is the significant fiber loss during yarn formation. This problem is related to yarn quality variation, which is not detectable by standard uniformity testers. Therefore, defects may only become apparent in the finished fabric. The path the fibers follow in the air jet flow plays a crucial role in yarn quality. Most structural defects in Murata Vortex Spinning result from fiber deviation from their ideal path in the air jet.
Source: https://textilelearner.net
