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Spinning & Weaving
  Developments in blowroom, card & draw frame

The trend in Indian spinning mills is now to replace manual bale opener with automatic bale opener, and carding and draw frames have also gone through an evolution in the last one decade. So, what are the changes that have happened in these pre-spinning departments? Reeti Pal Singh and V K Kothari highlight the developments.

The conventional short staple spinning system involves different machines to convert raw cotton to quality yarn. The quality of a yarn is judged by many parameters, like evenness, count CV%, strength, imperfections, yarn appearance, etc. Now-a-days, various parameters relating to comfort like yarn water absorbency, yarn surface friction, etc, are also given importance. Thus, in short staple spinning system, to produce yarn of acceptable quality, the raw material has to be processed through a sequence of machine. Developments in these machines are carried out to enhance yarn quality. The machine manufacturers are coming out with different models of the machines featuring different modification/innovations, which enhance quality.

Different categories of developments

These developments or innovations can be divided in different categories:

1. Minor modifications.

2. Modification related to quality/production monitoring or enhancement in production/speed.

3. Major modifications.

Minor modifications are the simple alteration of the previous version/model of the machine that has nothing to do much with the quality or production/speed of the machine. So these modifications are aimed at just giving the customers a new look to the machine. Second type of modification relates with enhancement in production/speed or with the online quality/production monitoring. Major modifications are really significant modifications, which are helpful in improving the product quality.

There are the changes that have been brought in the machine to improve the product quality not only on the same machine but also at subsequent machines. As so far machine manufacturers are concerned, they are providing machines with all the above stated categories, but publicised the machines under the category of major developments though these developments may be coming under first two categories. These developments will be analysed in the subsequent section.

To discuss modern developments in detail, subsequent sections are divided in the categories according to the machines used to spin the yarn. I.

Developments in blowroom

Main objective of the blowroom is opening and cleaning of the material without over-stressing or damaging the fibres. The opening means to increase the specific volume (cc/g) of the feed material and is adjudged from the tuft size whereas cleaning means to remove impurities. The tuft size of 2 - 3 mg is considered to be optimum, but as low as 0.1 mg is achievable[1]. The visual appearance of the waste extracted at different stages of opening and cleaning is shown in Figure 1 [2]. Increase in the opening/cleaning intensity increases waste removal, but also leads to fibre damage, fibre loss and increase in neps level (Figure 2). Hence it is very important to find out optimum opening/cleaning. The modern developments in blowroom will be discussed in the subsequent sections.

1. Difference between types of plucking roller of automatic bale opener

The trend in Indian spinning mills is now to replace manual bale opener to automatic bale opener. The automatic bale opener gives smaller tuft size (Figure 3), thus results in better opening and cleaning efficiency of the subsequent machines [3]. The manual bale opening process relies more on the sincerity and efficacy of the worker, and has more variation in the tuft size fed to the bale opener.

1.1. Rieter Automatic Bale Opener (UNIfloc A 11)

Rieter UNIfloc A 11 uses single plucking roller, called as take-off roller (Figure 4). The take-off roller (Figure 5) along with narrow grid results in small tufts size [3]. The same roller can be used for processing cotton as well as man-made fibres. The roller teeth can also be replaced individually. The automatic bale opener regularly measures the profile of the lay down material for gradual level out the bales as shown in Figure 6 [4].

1.2. Trützschler Automatic Bale Opener (BLENDOMAT BO-A)

Trützschler's BLENDOMAT BO-A is fitted with two plucking rollers rotating in opposite direction (Figure 7). But at any given time, only one plucking roller is working while other is raised according to the travel direction of the machine (Figures 8 a, b). Thus, direction reversal of the plucking roller and, hence wear-intensive braking and acceleration after every passage of the bales is avoided. The plucking roller strips off the tufts by penetrating into the bale surface while the three supporting rollers give a firm grip over the bales [5]. This is what they call 'Penetration inversion mechanism', which ensures gentle fibre removal and gives good opening. It can process three different cotton/blend lots simultaneously that can be fed into three separate cleaning lines as shown in Figure 9 [6].

1.3. Marzoli Automatic Bale Opener (SuperBlender B12SB)

Marzoli automatic bale opening Super Blender B12SB (Figure 10) has two plucking rollers with 254 blades on each roller, which ensures small flock size [7]. Automatic bale opener can process four different mixings. The detacher of the bale opener follows the contour of the lay-down and plucks the raw material down to the ground (Figure 11). The production, with a working width of 2,250 mm, is stated to be 1,600 kg/hr.

1.4. Lakshmi Bale Plucking Machine LA 17/LA 28

Lakshmi Automatic Bale Plucker LA 17/LA 28 is fitted with twin plucking rollers (Figure 12). The depth of the cut can be programmed as per the requirement. The varying production rate can be achieved by varying the traverse speed, depth of cut and the type of grill[8]. The grills of the plucking rollers are selectable according to the required tuft size. The plucking roller has replaceable strips with teeth. Thus, in case of any damage, only that strip can be replaced without removing the grills or contact rollers, thus reducing downtime. Bale plucker can process four different assortments at a time and can feed into separate cleaning lines.

2. Compact Blowroom Line (Shorter Blowroom Line)

Automatic bale opener efficiently makes the tuft size smaller leading to better opening/cleaning of the subsequent machines. The modern cleaners give intensive but gentle cleaning. The use of 3 to 4 beaters in series (CVT-4 Cleaner of Trützschler) in the same machine rather than 2 or 4 machines in tandem in line gives same cleaning. Thus, the modern blowroom line becomes shorter without any compromise on the quality of the material.

2.1 Compact Blowroom Line of Trützschler

Trützschler compact blowroom line consists of automatic bale opener, Multi Function Separator along with waste re-feeding, Pre-Cleaner (CL-P), Integrated Mixer (MX-I with 10 trunks) along with CLEANOMAT Cleaner (CL-C 4), and Foreign Part Separator (Figure 13). The compact blowroom requires less space and lower energy consumption in transporting the fibre tufts to the next machine[9]. The installation size comparison of normal blowroom line (1,000 kg/h of blowroom production) against Trützschler compact blowroom (2,000 kg/h production) has been shown in Figure 14.

2.2 Blowroom Line of Rieter

The Rieter blowroom line consists of automatic bale opener UNIfloc A 11, intensive pre-cleaner UNIclean B 11, homogeneous mixer/blender UNImix B 70 and gentle fine cleaner UNIflex B 60 as shown in Figure 15 [2].

3. Mote knife with suction in place of grid bars

The trend of using mote knife with an open slot along suction was initially incorporated on carding in the pre-carding and post-carding zones. Recently, the same principle was adopted by Trützschler on cleaning machines in blowroom. Such a cleaning system consists of deflector blade, mote knife and suction hood (Figure 16). Trash particles released due to centrifugal forces are separated at the knives and are continuously taken away by suction keeping the hood clean permanently. The deflector blade setting depends upon the type of cotton processing.

When processing clean cottons or for low degree of cleaning, deflector blades can be kept almost closed, but fully opened for high trashy cotton and/or high degree of cleaning. The blade adjustment can be made manually or via, motor. It also gives trouble free processing of sticky cottons as such cotton otherwise sticks to the grid bars [10]. The removal of dust by suction results into good running behaviour in OE and ring spinning and gives better yarn quality (Figure 17).

4. Multiple beaters instead of single beater in a single machine

The trend of using multiple beaters/cleaners in tandem on the same machine has been introduced by Trützschler. The machine has the combination of clamped and unclamped feeding of the material to the beaters. The initial feeding of the material to the first beater is clamped through the feed rollers, thus giving intensive beating. Subsequently, material is transferred to other beaters in web form in unclamped manner, thus giving gentle cleaning action.

Gradual increase in the speed of the beater, clothing fineness and angle of clothing teeth from first to last beater give progressive cleaning of the material. It is claimed by manufacturer that multiple beater can replace 3 to 4 conventional blowroom cleaners [10]. A study was conducted in a spinning mill, where a conventional blowroom line was replaced with Cleanomat CVT 3. The results shown in Figure 18 indicate overall improvement in cleaning efficiency and reduction in yarn imperfections, power consumption along with saving of good fibres [5].

5. Better mixing/blending of raw material

The cotton fibre parameters, being a natural fibre, differ from bale to bale. Thus bales coming from different stations and/or varieties should be mixed thoroughly to spin yarn of consistent quality. Similarly, blending of dissimilar fibres should also be done properly at blowroom stage. Mix homogeneity depends on the methods of mixing and type of mixing/blending machine used. When mixing the different bales in tuft form, smaller the tuft size better would be the homogeneity [11]. More number of reverse chutes in mixing equipment gives better homogeneity. Two blenders working in series or tandem produces better homogeneity than one with similar, total capacity.

5.1 Rieter UNImix B71/B75 blending machine

Rieter UNImix blending machine claims to have random distribution of the tufts to the 8 mixing chambers and then the fibre blending takes place at three different points within the UNImix. This technology has been termed as a '3-point mixing process' [12]. The first stage is a controlled time offset of the tuft layers in the mixing chambers by 90° deflection of the tufts in the tuft storage. The second mixing point comprises a spiked feed lattice, which picks small tufts at random out of the layers of the 8 mixing chambers and transports them to the next mixing point. The third blending level is achieved by mixing of the fine tufts in the active mixing chamber above the spiked feed lattice (Figure 19). This results in constant homogeneity of the fibre blend and constant yarn quality subsequently. Different raw materials can be processed and required setting can be made via, the control panel during machine operation [13].

5.2 Rieter UNIblend A 81 Blending Machine

Rieter 'UNIblend A 81' can be used for multi-component blending. It can precisely measure deviation in fibre percentage less than 1%, and, thus avoid colour non-uniformity in the end product. It can even mix/blend 98% white with 2% black fibres [14]. This blending machine can mix from two to eight individual components in any desired ratio. It is also possible to split the line, after the dosing blender, into four different carding lines, each of which can contain a different blend ratio of the same components (Figure 20).

5.3 Difference between continuous dosage and weighing System

In continuous dosage system, different components are filled into each chute accordingly (Figure 20). Each chute has an individually, continuously working dosage system. A conveyer belt transports the evenly sandwich layered material to the compressing/opening take-off unit. Thus, the each tuft contains all components in right proportion (Figure 21 a). The blend ratio, in case of continuous dosage system is maintained, which otherwise varies with weighing pan method (Figure 21 b)

5.4 Trützschler Multimix MPM

Trützschler mixer can have 6 or 10 trunks depending upon the application. The rotating flaps forward the material in sequence to the individual trunks but these trunks are emptied at the same time resulting in homogeneity of the mix (Figure 22 a). Once all the trunks are filled, the transport air is routed past the trunks to prevent material compaction. As soon as the trunks are empty, refilling starts immediately so that a loose layer of tufts is formed on the conveyor belt from the individual trunks. At the end of the conveyor belt, material from all the trunks lies in layers in a sandwich form that ensures ideal feeding for the CLEANOMAT Cleaner. For better mixing and homogeneity, two mixers can also be set in tandem (Figure 22 b).

6. Removal of colour contaminants and other impurities

The cotton that reaches the mills has natural as well as other added contaminants. Contaminants and other foreign parts can either be sorted out manually or with machine. But the advantage of machine sorting over manual sorting is that this system does not depend upon the efficacy and sincerity of the worker. Thus, modern blowroom line incorporates system, which eliminates such impurities. The system is also equipped with fire-protection devices.

6.1 Barco Cotton Sorter for detection and removal of contaminants in raw cotton

Cotton Sorter of BarcoVision uses ultra-fast CCD cameras to detect contaminants from raw cotton in the blowroom line and then removed by means of high speed air guns. The system can be installed in an existing blowroom line without adding any fan capacity to elevate the cotton and drop it through the inspection zone. This system has a transparent tunnel where cotton is diffusely illuminated in the inspection zone. The individual tufts are observed by means of 4 high resolution CCD line scan cameras that acquire images from both the sides simultaneously, thus enhancing the detection capability (Figure 23).

Contaminants are described as a deviation in colour and size from raw cotton in terms of contaminant width (number of pixels) and length (number of scan lines). Tolerances in colour are defined by means of threshold levels (limits). The objects with a colour value below this limit is being identified as a contaminant. On the horizontal X-axis, the number of camera pixels is indicated, whereas the Y-axis displays the colour level. A value of zero corresponds with black, whereas 255 means white. The normal cotton is recognised as close to the white level [15,16].

6.2Trützschler Multi Function Separator

Trützschler Multi Function Separator SP-MF (Figure 24) is positioned immediately after the automatic bale opener, and includes fire protection, heavy part and metal separation along with dedusting and waste re-feeding. This machine has an integrated micro-computer control system to control all the functions.

6.3 Rieter Vision Shield, Metal Shield, Fire Shield and the Combo Shield

Rieter blowroom line is fitted with Vision Shield, Metal Shield, Fire Shield and the Combo Shield of JOSSI Systems AG, Switzerland to detect foreign material. The vision shield detects and eliminates foreign fibres whereas metal shield is for detection and diversion of any metallic particle (size 2 mm, at velocities of 33 m/s) through sensor and digital signal processing. Metal Shield can extract metallic as well as non-magnetic metallic particles hidden inside tufts. The Fire Shield detects and diverts any incandescent particles like sparks or embers and immediately shuts down the machine. It evacuates all materials from the ember infected duct, and activates various alarm functions. The Combo Shield combines the function of both Metal Shield and Fire Shield.

6.4 Trützschler Foreign Part Separator SECUROPROP SP-FP

Trützschler's patent-pending process, Foreign Part Separator SECUROPROP SP-FP, detects coloured as well as white and transparent particles such as PP or PE foil. Foreign fibres can only be separated, if these are optically detected. To avoid tiny foreign particles hiding in or behind the tufts, a fibre web is formed by an opening roll within the SECUROMAT [17]. A colour camera scans the web on the surface of the opening roll and on detection of a foreign particle compressed air impulse of a nozzle blows it into a waste suction device (Figure 25).

The distance between the place of detection and the separating unit is very short, thus ensuring a high reliability of the separation. SECUROPROP SP-FP uses the physical properties of plastics, which make them appear coloured in polarized light (Figure 25). This light is generated in the background of a rectangular fibre channel and the tufts are scanned by two cameras. These detect the false colours or contrasts generated by the polarisation in light polypropylene and transparent or semi-transparent PE foils and can detect contaminants of as small size as 2 x 2 mm [9].

6.5 Loptex Optosonic Sorter

The Loptex Optosonic Sorter is equipped with an Optical Sensor to detect coloured contamination and Acoustic Sensor for colourless material. The raw material is first passed in front of the Acoustic Sensor and then the Optical Sensor (Figure 26). The Acoustic Sensor emits ultrasonic waves and detects any contamination with a compact surface structure like plastic and reflects these waves into the receiver. The receiver then triggers the ejection device. The Optical Sensor consists of standard fluorescent light tubes and photo sensor arrays [18]. The coloured contaminations reflect less light to the photo sensor arrays, which then trigger the ejection device thorough pneumatic valves, blowing them into the waste container.

7. On-line parameter settings

One of the most significant modernisations, which has been brought in the blowroom line, is the online setting of opening/cleaning machine parameters like beater speed, distance between grid bars, distance between grid bars and beater, distance between beater and feed roller, etc. The cleaning intensity and amount of waste extracted can be programmed and adjusted while the machine is in production.

7.1 Rieter VarioSet

The opening and cleaning intensity depends, apart from other parameters, on distance between beater and feed roller, speed of beater and grid bars setting. The Rieter VarioSet System adjusts these parameters while the machine is in running state. The cleaning intensity (0.0 to 1.0) and relative quantity of waste (1 to 10) are entered to the VarioSet through the operator's panel or remotely via, the ABC-Control system. On Rieter UNIclean B12 cleaner, these two parameters, adjust the beater speed and grid bars setting to get the required level of waste extracted (Figure 27). In case of Rieter UNIflex B 60 cleaner, the parameters entered are fibre length, relative amount of waste (1 to 10) and cleaning intensity (0.0 to 1.0). The staple length of the fibres is converted for the basic setting of the feed trough nip. The relative amount of waste primarily adjusts the grid bars setting and the cleaning intensity adjusts the rotational speed of the beater and the feed trough nip (Figure 28).

7.2 Trützschler WASTECONTROL and CLEANCOMMANDER

The Trützschler's waste sensor WASTECONTROL BR-WCT is attached to a Cleaner CLEANOMAT and optically measures good fibres in the waste and amount of suction for fibres. This system detects the waste quality and automatically sets the deflector blades of the cleaner by servo-motors (Figure 29). Thus the degree of cleaning for each cotton quality can be optimised. The Figure 30 shows the relationship between the waste extracted and the total amount of waste. Ideally for example, with cotton having a trash content of 2%, the total waste removed would be 2%. The degree of cleaning would then be 100% (green line). But the aim is to achieve optimum cleaning (yellow line). This point represents a compromise between a high level of cleaning and low fibre loss. It is claimed that with the CLEANOMAT cleaners, the actual achievable line lies very close to the theoretical ideal, ie, the good cleaning with minimum good fibre loss.

II. Modern developments in card

The card is the heart of the spinning mill because if we see the card sliver, it is just the magnified replica of the yarn. Quality of yarn is directly related to the quality of card sliver. Thus the modern developments, in the carding machine, are carried out to produce better sliver. The following sections discuss some of the modern developments in the carding machine.

1. Unidirectional feed Unidirectional feed

results in gentle fibre treatment because fibre feed and licker-in rotation is in the same direction. The latest version of Rieter card C60 (Figure 31) and Trützschler TC 07 (Figure 32) feature with unidirectional feed system.

2. Multiple Licker-in

The concept of using three licker-in place of one is basically for better cleaning of the feed material. Here the concept of clamped and unclamped feeding is used. The latest version of Rieter card (Figure 32) and Trützschler card (Figure 32) feature with multiple licker-in system. The modular design of Rieter C 60 card makes it possible to convert from 3 licker-in units to 1 unit.

3. Increase in the carding zone/width of card

The modern machines achieve production rates of 60 - 220 kg/h, compared with output of 5 - 15 kg/h in 1970 [19]. One of the many factors behind increase in the production, without deteriorating quality, is increase in the carding zone area, particularly width of the card and/or long carding section.

3.1 Rieter C 60 wide width card

Compare with the previous version of the card (C 51), Rieter C 60 Card has 50% more working width (from 1 m to 1.5 m) as shown in Figure 33. The diameter of the cylinder has been reduced (but RPM is increased) whereas the take-off roller diameter is increased [20]. Thus, the cylinder can take higher fibre mass, resulting in higher production without deterioration in carding intensity. An increase in production is equivalent to increased fibre mass on the cylinder that will result in poor sliver and yarn quality. But because of more carding width, the available carding surface is more, hence this enables output to be increased by 50% without deterioration in sliver or yarn quality[21].

3.2 Trützschler TC 07 Card with longest carding section

Trützschler TC 07 has 2.82 m carding section as shown in Figure 34. The pre-carding area ensures optimal fibre web preparation for better carding. Better the pre-opening, more intensive the carding and higher the production [22].

4. Use of Pre and Post-carding segments

The opening/individualisation of fibres achieved by the carding action between the cylinder and the flats is expressed by the number of wire points per fibre. Higher production rate decreases wire points per fibre and thus deteriorate carding action. So pre and post-carding elements are used to achieve better carding action.

4.1 Rieter Pre and Post-carding area on C 60 Card

Pre-carding zone of Rieter C 60 Card has 6 carding units along with guiding elements and mote knife. The guiding element and the associated mote knife extract impurities while suctions hoods take these extracted impurities to centralised waste chamber. Similarly, post-carding zone has 2 carding elements, one guiding element and a mote knife are used.

4.2 Trützschler Pre and Post-carding area on TC 07 Card

Pre-carding zone of Trützschler TC 07 card has 3 carding elements (2 clothing strips each) and 3 cleaning elements whereas post-carding area has 6 carding segments (12 clothing strips) with 3 cleaning elements. The pre- and post-carding area has total ten elements each.

Cleaning element, carding element and control element are standard parts whereas the remaining eight elements can be flexibly selected according to the required task. Cleaning element has a mote knife with a suction hood and is designed to separate tiny dirt particles, seed coat fragments, dust particles, and fibre fragments (Figure 35). Carding element consists of two clothing strips equipped with different clothing types and finenesses depending on raw material. The control element is similar to a cleaning element, but it manipulates air-stream on the cylinder surface thus optimise the function of the cleaning elements. When none of the elements described above is used in the pre- and post-carding area, a cover element is mounted.

4.3 Marzoli Pre and Post-carding area on C601 N Card

The pre-carding zone of Marzoli C601 N Card has nine carding segments and a knife to eliminate the waste[23]. The total length of the pre-carding zone is stated to be 720 mm whereas that of post-carding zone is 550 mm[24]. The post-carding zone has six carding segments with two suction and knives to eliminate remaining trash.

5. Integrated grinding system

Card wire grinding is not only a troublesome job but also time consuming. The machine manufacturers are now coming out with a unique idea of wire grinding on the machine itself while the machine is in production.

5.1 Rieter Integrated Grinding System (IGS-Top and IGS-classic)

Rieter IGS-System comes in two versions; IGS-Classic for cylinder wire grinding and IGS-Top for flat wire grinding. IGS-Classic has a grindstone, which moves across the cylinder under automatic control during production (Figure 36). This process is performed 400 times during the planned lifecycle of the clothing as compared with every 80 to 100 tonnes in case of manual grinding [25]. This results in better quality in terms of reduction in neps and trash of card sliver [15]. IGS-Top is installed permanently over the returning flats after the flats cleaning unit and it performs automatically more than 100 grinding cycles per clothing lifecycle. The flats rods are raised one after the other by spring force and pressed against the rotating grinding brush (Figure 36). Short, hard bristles grind the flat points while longer, softer bristles keep the later edges sharp. IGS-System gives prolonged cylinder clothing life to the tune of 10 to 20% [25].

6. Use of Autoleveller

To control card sliver count variations, count CV% and unevenness, modern cards are equipped with autoleveller.

6.1 Rieter medium and long term autoleveller on C 60 card

Medium-term leveller of Rieter C 60 card measures the feed mat thickness at the feed trough and, as required, the feed roller speed is adjusted through the control system (Figure 37). Similarly, long-term leveller measures the sliver thickness by the step roller pair and adjusts the chute system accordingly.

6.2 Trützschler short-wave and long-wave autolevelling system

For the short-term autolevelling, the Integral Feed Tray SENSOFEED of Trützschler TC 07 card constantly scans the thickness of the tuft web and the required adjustment in the speed of the feed roll is made through the card control system (Figure 38). Similarly, long-term autoleveller measures the sliver mass through the sensor in the card's sliver trumpet and controls the speed of the feed roller accordingly. A single sensor can be used for the entire card sliver counts.

6.3 Marzoli Short Term and Medium Term Levelling System

The short term leveller senses the web thickness (weight) through the load cell. When the web weight exceeds by ±10% of its basic, the sliver draft is adjusted via, microcomputer (Figure 39 a). This system functions over a sliver length as low as 4 cm[26]. The MT leveller senses the mat thickness (weight) and varies card draft as required (Figure 39 b). This system functions over a sliver length as low as 1 m (40").

7. Online flats setting and Licker-in waste setting

All the major machine manufacturers are improving the card with manual or motorized reproducible setting of licker-in mote knife and fats. The setting can be optimised while the machine is in running conditions.

7.1 Rieter flat and licker-in setting system

The C 60 Card of Rieter has a central flat setting system to adjust and reproduce the flats setting precisely. The licker-in under casing is also fitted with adjustable knife (manually or electronically) to alter the setting. Thus the optimal trash removal at the licker-in during the card production can be determined[13].

7.2 Trützschler precision setting and measuring system (PMS, PFS and TC-FCT)

Precision Knife Setting (PMS) System of Trützschler Card adjusts the distance of the knife to the needle points and clamping point between feed roll and needle roll to alter the degree of cleaning. The knife setting can be adjusted manually or through motor while the carding is running and can be seen through the transparent suction ducts (Figure 40 a). Similarly Precision Flat Setting (PFS) System adjusts the flat-cylinder gauge manually or through motor (Figure 40 b). A scale fitted on the frame shows the actual setting. The Flat Measuring System (FLATCONTROL TC-FCT) is used to measure the distance between cylinder and flat. For measurements, three regular flats are removed with measuring flat as shown in Figure 40 c.

7.3 Marzoli C601 N Card with deflector blade to adjust droppings

The licker-in undercasing of Marzoli C601 N Card has mote knives, carding segments, deflector blade and suction hoods [23]. The deflector blade can be adjusted to adjust the licker-in droppings as shown in Figure 41 [26].

8. Online neps monitoring

Trützschler NEP CONTROL TC-NCT monitors the card web during production and provides information regarding neps in card sliver. An optical electronic camera films the web under the take-off roll approximately 20 times per second (Figure 42). The camera moves about the whole working width of the card in a special, fully closed profile. The computer attached to the profile, evaluates the pictures with special analysis software, and indicates neps, trash particles and seed coat fragments in the card web.

9. Integrated draw frames

Now-a-days, the cards are available with integrated 3-over-3 drafting. Such cards are able to reduce one draw frame passage, particularly for low demand yarn or for OE spinning.

9.1 Rieter RSB Coiler for C 60 card

Rieter C 60 card can either be fitted with RSB series of coiler or SB series of coiler. The RSB coiler is essentially a complete autoleveller draw frame for sliver weight > 6.6 ktex at 120 kg/h whereas non-levelling SB series coiler is for a lighter sliver (3.5 - 6 ktex) at high production rates. The auto-leveller version is used for the OE direct process application.

9.2 Trützschler Integrated Draw Frame IDF with Card TC 07

Similarly, Trützschler can also supply Integrated Draw Frame IDF with Card TC 07 and claims to eliminate one draw frame passage, particularly for rotor spinning. This levelling draw frame has 3 over 3 two-zone drafting system with a draft of 3-fold and delivery speeds 500 m/min (maximum).

10. Trützschler Magnotop system

Trützschler MAGNOTOP System uses high energy 'Superstrong neodymium magnets' to hold the clothing strips on the flat bars. One neodymium magnet, smaller than a cigarette pack, can hold or lift a weight of 100 kg. . The strong magnetic force exceeds the carding force by a multiple, thus keeps the strips exactly in place (Figure 43). When mounting conventional flat tops to the flat bars, the clothing strips are inevitably subject to deformation and thus grinding is necessary to get evenness that can be eliminated with MAGNOTOP. Strips can simply be peeled off from the side and removed with little effort in the card itself for replacement purpose. This significantly reduces the card mounting time from 14 hours to less than 2 hours.

11. Trützschler carding setting measurement system T-Con

Higher card productions result in higher heat, so increase in card temperature. The increase in temperature leads to different expansions of the machine parts, thus disturbing the card settings. T-Con calculates the distance of the carding elements objectively, based on various measuring values under production conditions (Figure 44 a). The various settings displayed on the card monitor include the flat-cylinder gauge, fixed carding segments, cylinder gauge, etc, and hence these settings can be optimised (Figure 44 b). T-Con also registers even slightest contacts of the clothing and shuts down the card long before damage can occur and protects against clothing damages.

III. Developments in draw frame

As far as draw frame is concerned, not much significant developments have been carried out, except one or two that will be discussed in the following section. All the machine manufacturers are supplying the draw frame with almost same kind of specifications (Table 1).

Table .1 Specifications of different makes of Draw frame

Particular

Lakshmi Machine Works Lts [27]

Rieter Machine works Ltd [28]

Vouk spa [29]

TOYOTA Textile Machinery [30]

Trützschler GmbH & Co. [31]

Model

LR SB 851

RSB

Unimax

DX8

TD 03

Delivery speed (max)

800 m/min

1100 m/min

1050 m/min

1000 m/min

1000 m/min

Drafting system

3-over-3 With pressure bar

4-over-3 With pressure bar

3-over-4 With pressure bar

3-over-3 With pressure bar

4-over-3 With pressure bar

Draft range

3.05 to 11.6

4.5 to 11.6

4 to 11.6

4 to 14

4 to 11

Roller loading

Pneumatic

Pneumatic

Spring or hydraulic 

Spring

Pneumatic

Autoleveller

Yes

Yes

Yes

Yes

Yes

No of deliveries

Single or twin (LD0/6)

Single or twin (SB)

Single or twin (Duomax)

Single or twin

Sigle

Can system (delivery)

Auto doffing
(round cans)

Auto doffing
(round or rectangulatr cans)

Auto doffing
(round cans)

Auto doffing
(round cans)

Auto doffing
(round or rectangulatr cans)

Particular Lakshmi Machine works Ltd. [27] Rieter Machine works Ltd. [28] Vouk spa[29] TOYOTA Textile Machinery [30]  Model LR SB 851 RSB Unimax DX8 TD 03 Delivery Speed (max.) 800 m/min. 1100 m/min. 1050 m/min. 1000 m/min. 1000 m/min. Drafting System 3-over- 3 With pressure bar 4-over- 3 With pressure bar 3-over-4 With pressure bar 3-over-3 With pressure bar 4-over-3 with pressure bar Draft Range 3.5 to 11.6 4.5 to 11.6 4 to 11.6 4 to 14 4 to 11 Roller loading Pneumatic Pneumatic Spring or hydraulic Spring Pneumatic Autoleveller Yes Yes Yes Yes Yes No. of Deliveries Single or twin (LD0/6) Single or twin (SB) Single or twin (duomax) Single or twin Single Can system (Delivery) Auto doffing (Round cans) Auto doffing (Round or Rectangular cans) Auto doffing (Round cans) Auto doffing (Round cans) Auto doffing (Round or Rectangular cans)

1. Auto break-draft setting

Incorrect break draft increases yarn U%, imperfections and neps whereas the total draft does not affect yarn quality much. Break draft plays a very significant role in yarn quality, thus must be set correctly.

1.1 Trützschler TD 03 draw frame with AUTO DRAFT Technology

AUTO DRAFT of Trützschler TD 03 draw frame optimises break draft of draw frame under the prevailing conditions. It estimates the corresponding values of the break draft merely in one minute and takes important parameters, like fibre-fibre friction, fibre to metal friction, etc, into consideration while calculating the break draft (Figure 45).

2. CLEANcoil by Rieter

The deposition of spin finish on the underside of the coiler plate of draw frame when processing MMF leads to displacement of the sliver layer in can. To avoid this, the coiler has to be cleaned frequently resulting in production loss. Rieter has patented a coiler plate that has honeycomb like surface and claimed to reduce cleaning frequency from 2 to 3 hours to 1 - 7 days depending upon the type and quantity of finishing agents as shown in Figure 46[32].

References

1. K R Salhotra: Significance of Modern Developments in Blowroom, NCUTE Pilot Program on Spinning-Blowroom and Carding, IIT Delhi, Oct 9-11,1998
2. Blowroom System: Variations on Success, Rieter Textile System Information Brochure.
3.UNIfloc A 11: Efficient Cleaning Starts with Small Tufts, Rieter Textile System Information Brochure.
4. Hans Roosli: Rieter Blowroom and Carding - The Choice for Success in The New Millennium, Rieter Textile System Information Brochure.
5. Rajendra Ghatage: Modern Concept in Blowroom and Carding, NCUTE -- Program on Latest Textile Machinery Used Globally, D K T E, Ichalkaranji.
6. Fibre+Sliver Technology, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
7. Blowroom Machines, Marzoli Spa, Information Brochure.
8. Spinning Value: Lakshmi Automatic Bale Plucker LA 17/LA 28, Lakshmi Machine Works Ltd Information Brochure.
9. Blow-Room Machines, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
10. Installations for Fibre Preparation, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
11. R Chattopadhyay: Quality Consideration in Blowroom, NCUTE Pilot Program on Spinning-Blowroom and Carding, IIT Delhi, Oct 9-11, 1998.
12.UNImix B 70 Blending Machine: Unique Blending Technology, Rieter Textile System, Information Brochure.
13.Rieter -- the Frontrunner in Summer 2008 and Beyond, Press Release April 28, 2008, Rieter Machine Works Ltd, Winterthur.
14. Rieter 2000: Blowroom and Carding, Rieter Textile System Information Brochure.
15. Barco CottonSorter, BARCO-Loepfe Srl, Italy Information Brochure.
16. Cotton Sorter, BarcoVision, Belgium Information Brochure.
17. Specialists Form Bale to Sliver, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
18. Loptex Optosonic Sorter Digit +, Loptex SrL, Italy Information brochure.
19. Report on Experience with the Rieter C 60 Card, Link -- The Customer Magazine of Rieter Spun Yarn Systems, Vol 19/No: 51, December 2007.
20. C 60 Card -- a New Dimension in Carding, Link -- The Customer Magazine of Rieter Spun Yarn Systems, Vol 14/No: 30, Dec 2002.
21. The C 60- Card Technology and Flexibility for the Future, Link --The Customer Magazine of Rieter Spun Yarn Systems, Vol 16/No: 43, Sept 2004.
22.Trützschler TC 07, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
23.The New Concept of Spinning Mill has Taken Shape, Marzoli spa, Italy Information Brochure.
24. www.marzoli.it (English translation of Italian version).
25. IGS-System: For Consistent Carding Quality, Rieter Textile System, Information Brochure.
26. C 501 -- High Production Card, Marzoli Spa, Italy Information Brochure.
27. Spinning Value: Autoleveller Draw Frame LRSB 851, Lakshmi Machine Works Ltd, Information Brochure.
28. Draw Frames: Drawing in Perfection, Rieter Textile System, Information Brochure.
29. Unimax: Single Delivery Draw frame, Vouk Spa, Information Brochure.
30. Draw Frame DX8, Toyota Textile Machinery Division, Information Brochure.
31. Draw Frame TD 03, Trützschler GmbH & Co KG Textilmaschinenfabrik, Information Brochure.
32. The New RSB-D 40 Autoleveller Draw Frame -- A Firework Display of Innovations, Link -- The Customer Magazine of Rieter Spun Yarn Systems, Vol 17/No: 46, Sept 2005.

 Reeti Pal Singh Department of Textile Engineering, GZS College of Engg and Technology, Bathinda 151001. V K Kothari Department of Textile Technology, Indian Institute of Technology, New Delhi 110016.

published April , 2009
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