Air-Jet Loom:
Air-jet weaving is a type of weaving in which the filling yarn is inserted into the warp shed with compressed air. We can define air-jet loom in different ways. A loom in which the weft yarn is propelled through the shed by means of a jet of air. OR, A shuttleless loom capable of very high speeds that uses an air jet to propel the filling yarn through the shed. OR, A loom using a jet of air to carry the yarn through the shed. Air-jet loom is one of the two types of fluid jet looms where another one is water jet loom.
Air-jet loom have become very popular in recent years. The air-jet weaving machine was selected as one of the top innovations of the last decade by the Textile World magazine. The number of air-jet weaving machine manufacturers has increased considerably over the past several years. Intensive research and development on air-jet weaving machines have continued. As a result, air-jet looms are getting wider, faster and more economical than before.
Background of the Invention of Air-Jet Loom:
U.S. Pat. No. 4,606,152 illustrates a method and apparatus for grinding or buffing a metal reed of an air jet loom by manually moving a buffer along the tunnel while the reed is positioned on the loom.
U.S. Pat. No. 4,640,316 illustrates another apparatus for treating an air jet loom reed while on the loom wherein air measuring apparatus is manually moved in sliding motion along the top of the loom reed.
Heretofore there was no method or apparatus available which would uniformly and consistently permit measurements of air flow and at the same time provide a means to make indicated adjustments to the loom reed to meet requirements as to air flow performance. Accordingly, objects of this invention include analysis and regulation of air flow for different types of filling with reduction in air consumption of the loom.
Another object of the invention is to permit the correction of problems associated with filling insertion and to assist in speeding up the loom while providing higher quality of cloth with fewer loom stops.
Summary of the Invention:
It has been found that a method and apparatus may be provided for optimizing air flow characteristics of an air jet loom by removing the reed from the loom and positioning same in a frame where a carriage is provided for rolling contact according to a predetermined path for measuring the air flow characteristics and for altering the physical nature of the air tunnel to accommodate improved air flow.
Brief Description of the Drawings of Air Jet Weaving Machine:
The construction designed to carry out the invention will be hereinafter described, together with other features thereon.
The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:
Description of a Preferred Embodiment:
The drawings illustrate a method and apparatus for enhancing air flow characteristics in an air jet loom reed broadly designated at 10. The reed 10 has a tunnel 11 and a bottom channel 12. The air jet loom reed is first removed from an air jet loom (not shown). The air jet loom reed is then positioned in a mounting frame A in a fixed preferably inverted at least partially upright position. In inverted position the bottom channel 12 is at the top, with a top channel 13 on a lower guide rail 14 of the frame A. The rail 14 of the frame A is opposite an upper frame rail formed by a channel 15.
A carriage B driven by a pulley C is illustrated for driving a buffing device D and an air measuring device E at a predetermined speed along the reed. The carriage is illustrated as being suitably supported as by a wheel F which rolls on the bottom channel 12 of the loom reed. Thus, the path of the buffing device relative to the tunnel of the air jet loom reed is located with respect to an upper portion of the loom reed when fixed in the inverted position.
The frame A is carried by a tubular base support 16 and the lower guide rail 14 is supported by a bracket 17 while the channel 15 is carried by posts 18. A bar magnet 19 is provided to hold the reed 10 in position upon the frame A. Rolling contact of the carriage is maintained by the rollers G (Fig. 2) with the respective reed channels 12 and 13. A roller 15a is provided for positioning the carriage in respect to the channel 15.
Thus, Figs. 1 and 2 illustrate a universal mounting frame A which can be used for all known air jet reeds of a tunnel variety of varying lengths, heights and locations of air jet tunnel relative to top or bottom channel of the reed. The reed is held in place in the frame by the lower guide or alignment rail 14 and the magnetic bar holder 19 together with the gravity effect of the weight of the reed.
The drive pulley C together with a nylon coated cable 20 provide uniform or other predetermined motion to the carriage along the reed. The pulley is driven by a motor 21. It is important to note in the drawings that the top channel 13 of the reed 10 (as mounted in the loom) is located along the bottom of the frame and the bottom channel 12 of the reed 10 (as mounted in the loom) is located exposed at the top of the frame (e.g. This is the reverse of the arrangement in the air jet loom).
This is important because it exposes the bottom of the reed channel for exact and uniform rolling motion of the carriage along any type of reed. All types of loom reeds have critical reed dimensions which are referenced from the bottom of the bottom channel and from the front of the bottom channel to the sides of the tunnel and to the bottom of the tunnel. Dimensions to and from the top channel of the reed are considerably less critical and in fact can vary from one reed to another within limits without effecting the function of the reed in the weaving process.
Universal adjustment of the air measuring device E, illustrated as a Pitot tube within the air jet tunnel 11, is provided by the mounting which also provides universal adjustment of the buffing or grinding wheel D in and around any and all sections of the air jet tunnel. Various types of buffing or grinding wheels designed for different buffing purposes may be utilized. Any such device or operation for altering the surface as configuration of the tunnel is referred to herein as a buffer or buffing. A universal mounting 23 (Fig. 3) for an air jet nozzle as illustrated at 24 is provided at any desired location relative to the tunnel and at a variable distance from the Pitot tube. The carriage B may be variable in width to permit extensive changes of the distance of the Pitot tube from the nozzle and also permit use of multiple nozzles if this is desirable. This feature is useful because at present the location of the nozzles on the loom relative to the tunnel are fixed. This is true in the case of each type of loom. This capability provides for a means to determine the optimum nozzle location for different types of filling materials depending on count, denier, twist, etc.
An air cylinder 25 and a potentiometer 26 are illustrated in Fig. 4 connected in relationship to the buffing mechanism universal mounting 22. The buffing mechanism having the wheel D is located by moving it in or out of the desired position. A desired pressure of the buffing wheel may be applied to any selected part of the tunnel. Further, by means of the potentionmeter the speed of the wheel D is regulated providing for a constant surface speed during its motion across the air jet reed and accommodating any wear in the buffing wheel. Since the Pitot tube E also has a universal mounting capability both up and down and in and around of the air jet reed tunnel air flow, i.e. pressure drop, measurements may be made in any locations in the profile of the air jet tunnel.
A nozzle 27 of vacuum system is located in the carriage. It is moved into position automatically when buffing is performed, and out of the way when measuring is performed. Its purpose is to clean the reed and constantly remove any particles created during the buffing process. Thus, apparatus has been provided for measuring air flow for all types of air jet reeds for all known air jet looms.
The measuring of air flow by pressure drop from a known pressure can be performed anywhere in the cross section of the tunnel and at any distance from the Pitot tube to the nozzle. A variety of nozzles can be used and the nozzle location is variable relative to the tunnel and the Pitot tube. The number of nozzles is also variable.
Air pressure to the nozzles can be set at variable pressures. Once air flow measurements are taken with potentially a variety of methods, the air flow can be recorded in any suitable way. Adjustments in air flow throughout the cross section of the air jet reed tunnel and over the full length of the air jet reed tunnel are possible. Variations in air flow can be produced in both cross sections and over the length of the air jet reed to accommodate optimum filling stop arrangements, different fillings, air consumption and resulting power conservation, loom speed as measured in picks per minute, and cloth quality. These adjustments are accomplished by removing or creating slight burrs on the metal profile dents, varying the surface finish of the metal profile dents, modifying the shape of the metal profile dent to increase or decrease air flow and to increase or decrease turbulence, varying nozzle location relative to air jet tunnel, and changing nozzle design.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
Air-jet weaving machines are under constant development. Current research is mainly focused on the air and yarn interaction as well as the guide system to increase the yarn velocity and reduce the compressed air consumption. Widening of the application range is another topic of the current developments.
Different Parts of Air-jet Loom:
I already published an article on Different Parts of Air Jet Loom and Their Functions.
Working Principle of Air-Jet Loom:
We already know that air-jet loom is a shuttleless loom that uses a jet stream to pull the weft yarn across the shed. The working principle is to use air as the weft insertion medium, and the compressed airflow is used to pull the frictional traction force of the weft yarn, and the weft yarn is taken through the shed, and the jet generated by the jet is used to achieve the purpose of weft insertion. This weft insertion method enables the weaving machine to achieve high speed and high yield.
The major components of the insertion system are the tandem and main nozzles, ABS brake system and relay nozzles which are relatively simple in design. The insertion medium mass to be accelerated is very small, relative to the shuttle, rapier or projectile machines, which allows high running speeds. Unlike rapier or projectile insertion systems, there are not many mechanically moving parts to control and insert the filling yarn.
Below figure 5 shows a schematic of air-jet weaving utilizing a multiple nozzle system and profiled reed which is the most common configuration in the market.
Air-jet loom use a jet of air to propel the weft yarn through the shed at rates of up to 600 ppm. Date from manufacturers indicate that air-jet looms operate at speed up to 2200 meters of pick inserted per minute. They can weave multicolored yarns to make plaids and are available with both dobby and jacquard patterning mechanism.
Data Processing in the Air-Jet Loom:
The principle of operation reflects recent findings in ergonomics research. A browser ready terminal with a color touch screen is the man-machine interface. Via simple menu prompting, the expertise stored in the machine provides the basic settings for the weaving process. Malfunctions are rectified by menu-assisted problem analysis. Service via the Internet offers additional online support. The weaving mill control and monitoring system can be integrated in the network. Machine and style data can be compiled on a PC outside the weaving room and transferred to the machine either online via a network or off-line via a memory card.
a) Intelligent Pattern Data Programming:
“SmartWeave” offers fabric designers intelligent support in the preparation of weave designs and pick repeats. The prepared pattern data are combined with the setting parameters of the style and transferred to the G6500 via data carrier or intranet. Once the data has been transferred, the machine can be set up quickly. Weaves, pick sequences, and setting parameters can of course also be programmed and/or modified directly at the terminal.
b) Network-Ready Touch-Screen Terminal:
The control interface is a user-friendly, Internet-ready touch-screen terminal. The logical structuring, with self-explanatory pictograms, guides the operator to the desired function simply and with a minimum of keying. To the Internet capability, remote interrogation of the machine parameters is possible. This allows potential improvements to be rapidly identified and put into effect.
Advantages of Air Jet Loom:
Air-jet loom is ideal for cost-effective production of bulk fabrics with a wide range of styles. Air-jet loom can handle both spun (natural, synthetic or blended) yarns and continuous filament yarns. Textured yarns are especially suitable for air-jet weaving due to high propelling force. However, monofilament yarns are not suitable for air-jet weaving because of low friction between air and yarn which is due to smooth surface of the monofilament yarn. A wide range of fabrics from gauze fabrics to dense, heavy cotton fabrics, from patterned dress fabrics to ribbon fabrics can be woven on air-jet weaving machines. Air-jet weaving is also ideal for fine glass fabric production. Specially designed air-jet weaving machines are used for tire cord manufacturing with tuck-in selvage in plain weave.
Different advantages of air-jet loom have pointed out in the following:
- High productivity.
- Low initial outlay.
- High filling insertion rates.
- Weft insertion performance is too much here (normally 600pm).
- Simple operation and reduced hazard because of few moving parts.
- Reduced space requirements.
- Normally, standard width of air jet loom is 190cm.
- Low noise and vibration levels.
- In case of air jet loom, noise level is lower than rapier loom and missile.
- low spare parts requirement.
- It consumes very low power.
- Reliability and minimum maintenance.
Disadvantages of Air-Jet Loom:
The disadvantages of air-jet loom are-
- Broken pick or miss pick has occurred due to excess air pressure of main nozzle.
- In case of air jet loom, pile up and buckle tip of yarn formed due to air resistance.
- Double pick may occur in air jet loom.
- Loom of weft yarn along weft direction formed due to variation of air pressure.
References:
- Handbook of Weaving by Sabit Adanur
- Automation in Textile Machinery: Instrumentation and Control System Design Principles By L. Ashok Kumar, M Senthil kumar
- Reference Books of Weaving (ACIMIT) by Giovanni Castelli, Salvatore Maietta, Giuseppe Sigrisi, Ivo Matteo Slaviero
- https://patents.google.com/patent/EP0228342B1/en
- https://textiletutorials.com
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- Different Parts of Air Jet Loom and Their Functions
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- Automation in Weaving Machines: Process, Benefits and Requirements
- Production Calculation of Loom with Formula and Examples
- Essential Parts which are Used in Weft Insertion Motion of Loom
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- Different Types of Modern Loom | Advantages of Modern Loom Over Conventional Loom
- Automation in Weaving Machines: Process, Benefits and Requirements
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
