Spinning Process of Yarn
Spinning Process of textile industry the comber machine is used to convert combed sliver from lap to produce finer and higher quality yarns. The comber machine improves the uniformity and strength of fibers. The function of combing machine is straightening and parallelizing of fibers and the removal of short fibers and impurities.
Functions of Combing Machine :
A combing machine is a one type spinning machine for spinning process of yarn which has comb to straighten the fibers and extract neps, foreign matter and short fibers. Combing machine is used to produce higher count yarn(stronger , more even, more compact, finer, smother). The yarn which is produced by using combing machine is called combed yarn.This machine produces finer yarn by removing short fibers below a pre-preselected length. It reduces length variation in the cotton mixing for yarn market. It removes neps and foreign matter form the cotton. This machine improves fiber parallelization and straightens of the fibers from spinning wool.
Main Parts of this Textile Machinery:
- Lap roller
- Tension roller
- Feed roller
- Top nipper
- Bottom nipper
- Top combe
- spinning wheel
- Bottom comb
- Detaching roller
- Drafting roller
- Cloth cleaner
- Calendar roller
- Coiler calendar roller
- Coiler head
Feature of Spinning Can for Combed Yarn:
- Made to exact dimensions to meet industry requirement’s.
- Top quality anti static polyethylene sheet for cans, and strong, uniform “jupee” fiber sheet for fiber cans, ensures uniform quality and thickness of the can wall.
- Meets the tough requirement’s of advanced spinning technology.
- Spinning can made from special high carbon steel.
- Specially heat-tempered for combed yarn can
- Coils engineered in varying diameters to nest within themselves, thus providing additional capacity when can is full.
- Dimensionally and geometrically accurate; consistent in every respect.
- Calibrated for precise silver weight control.
- Custom made to each customer individual Spring can system. Pressure and right requirement’s.
- All Spring can system design to significantly reduce waste.
- High impact on nylon wheel for combed yarn can
- Non rotating dusts shields reduce up between
- Combed yarn wheels and truck assembly.
Feature of Comber:
- In lap preparation, total draft, fibre parallelisation, no of doublings, lap weight etc should be done properly (based on trial).
- Higher the lap weights (gm/m) lower the quality. It depends on type of comber & fibre micronaire.
- If finer micronaire is used, lap weight is reduced to improve combing efficiency.
- If coarse micronaire is used, lap weight is also increased.
- If fibre parallelisation is too much, lap sheets sticking to each other is more (It happens if micronaire is very low also). If lap sheets are sticking to each other, total draft between carding & comber are reduced.
- If draft is less, fibre parallelisation is also less, hence loss of long fibres in noil will be more.
- Top comb penetration should be highest for better yarn quality. But care should be taken to avoid top comb damage.
- Damaged top comb will affect the yarn quality very badly.
- Setting between unicomb & top nipper should be same & it should be around 0.40-0.5mm.
- Feed weight is about 50-58gm for combers like E7/4 & is 65-75 gm for combers like E62 or E7/6.
- The lower the feed length, the better the yarn quality. Trials to be conducted with different feed lengths & it are decided based on quality & production requirement.
- Required waste should be removed with the lowest detaching distance setting.
- For cottons with micronaire up to 3.5, top comb should have 30 needles/cm & for cottons with more than 3.8 micronaire, top comb should have 26 needles/cm.
- Trials to be conducted to standardise waste percentage.
- Piecing wave should be as low as possible & index should be decided based on cotton length & feed length.
- Spectrograms should be attended. Comber sliver Uster should be less than 3.5.
- Head to head waste% should be as low as possible.
- Variation in waste percentage between combers should be as low as possible(less than 1.5%).
- If cotton with low maturity coefficient is used, it is better to remove more noil to avoid shade variation problem.
Specifications of Combing Machine:
|[label type=”label” title=”Specifications Name“]||[label type=”label” title=”Specifications Value“]|
|Machine Category||Combing Machine|
|Product Name||Automatic Comber Machine|
|Product Model||According to Manufacturer|
|Agent In Bangladesh||No/Yes|
|Max Speed||300 Neps|
|Type Of Circle||Single Cylinder Single Coil Forming|
|Delivery Can Size||24″ X 48″|
|Spool Size||300 mm|
|Draw Box Drafting||5/4|
|Cotton Fiber Length||25-51 mm|
|Theoretic Output||73 kg|
|Drafting Ratio||Draft 9.12-25.12|
|Nipper Rate Nips||500 r/min|
|Head Number*Head Gauge||8*470mm|
|Compressed Air Pressure||(6-8)*105 pa|
|Compressed Air Consumption||1.5 Nm³/h|
|Dimension (L*W*H)||7433*2120*1700 mm|
|Description||Adopt the combing components those are suitable for combe in the high speed running|
Feature of Combing Machine for Combed Yarn:
- Lapping Cotton feed automatically in textile industry by Comber machine,
- Yarn is combed by Combing Machine
- Wide range of raw material available in cotton yarn market and yarn market
- Spinning process of yarn combed in spinning mill
- Spinning wheel is used in this machine for spinning process.
- It works as dust removal equipment and ensure workers health.
Advantages of the Spinning Process:
- This machine improves uniformity and strength.
- This machine produces higher count of yarn.
- It reduces neps in the yarn combe.
- It improves smoothness and luster of yarn.
- It improves the spinning value of fiber.
- It combe yarn.
- It produces much clearer yarn and reduces the hairiness of yarn.
Disadvantage of the Spinning Wheel of the Machine:
- Better quality fibers are needed.
- Produces more wastage than other process.
- Combed yarn tendency is high to snarl.
Some Defects of Combed Yarn
Slubs, Thick and Thin Places-
Definition and Causes:This usually appears in yarns of lower quality where open-end spinning methods and inadequate and insufficient combing and /or carding processes are used. Apart from being clearly evident on the surface of the fabric, in some cases they also cause yarn breakage and create holes during the knitting or weaving process.
Preventive Suggestions: During the spinning process, and based on the origin and the quality of the base fibers, appropriate carding and/or combing processes should be used.
Corrective Measures: In plain structures such as Jersey or plain weave poplins and sheetings, etc. this defect will be clearly visible and there are no corrective measures available. In more detailed structures, certain secondary processes such as printing or sueding may cover or reduce the appearance of these areas.
Loop and Weave Distortion-
Definition and Causes: This manifests itself in the form of small multi-directional lines (crinkles) on the surface of the fabric. The main causes are the variation and inconsistency in the twist levels of yarns used. Yarns of different twist levels react in different forms after exposure to water and temperature. As a general rule, higher twist levels produce larger crinkle lines. This principle is often used, purposely, to produce fabrics with crinkle surfaces.
Preventive Suggestions: During the winding process and all throughout the spinning process yarn twist levels must constantly be monitored. Corrective Measures: For this problem, unfortunately, there are no corrective measures available.
Rnags and Picks on the Fabric Surface-
Definition and Causes:This is a common problem with light to medium weight knit fabrics constructed using textured continuous filament yarns with high number of filaments (96 and higher). In woven fabrics this is less evident. This is due to the fact that most knit structures have looser constructions compared to woven fabrics, where the construction is generally tighter. In knit fabrics yarns (and fibers) have more space and can get separated from the stitch when pulled. Generally, as the number of filaments increases, the susceptibility to snagging also increases. With flat continuous filament yarns this problem is less evident.
Preventive Suggestions: During the production process, to the extent possible, the contact with sharp elements must be avoided and eliminated.For dyeing these types of fabrics, dye machineries must be equipped with inner chamber Teflon linings to ensure a smooth circulation of fabric. Other machineries with which the fabric may come in to contact (slitters, tenter frames, etc.) must also be regularly checked for rough and sharp places. The use of silicone softeners must be avoided since these types of softeners tend to increase the slippage of fibers. In cases of very sensitive fabrics, an application of a coating of Sodium silicate in the finishing stage is recommended. Corrective Measures: For this problem, unfortunately, there are no corrective measures available.
The Appearance of Dead / Immature Cotton on the Fabric Surface-
Definition and Causes:During the cultivation and the growth process of cotton, and due to the deficiencies in soil preparation and nutrition, an incomplete growth, in certain portion of the crop, takes place. The incomplete growth causes the outer hard shell to remain with the affected fiber. These unshed outer shells appear on the surface of the fabric in the form of dark specs.
Preventive Suggestions: During the spinning process, an intensified double carding and combing, depending on the severity of the fiber condition, will be required. Most of these impurities will be removed in the spinning process. However, some, after fabric construction (greige goods), will appear on the surface and they need to be cleaned up and removed. In cases where the problem on the fabric is not severe, a process of caustisization or mercerization will be sufficient to dissolve, remove and clean up the surface. In more severs cases, specifically with heavy weight woven fabrics such as Denims, Bull Denims, Canvas, etc. where open-end yarns are used, a pre-scouring treatment using Potassium Hydroxide is recommended. The use of dyestuffs with high dead cotton coverage is also recommended. Corrective Measures: Re- bleaching and Re-dyeing the fabric may be the only solution.
Non-Dyeable Cotton Fibers Due to Soil Contamination-
Definition and Causes:In certain cotton growing regions, such as Southern Brazil and certain regions in Pakistan, the soil is known to be contaminated with metal complex elements. These metals include Iron, Copper, Magnesium, etc. During the growth process some of these elements, Iron in particular, gets absorbed and becomes a part of the chemical composition of the cotton fibers. The presence of these metal particles in the fiber inhibits the fiber’s dye affinity and prevents a complete absorption and exhaustion of certain dyes and optical brighteners.
Preventive Suggestions: Prevention of soil contamination is not yet effectively possible.
Corrective Measures: The fabrics made from these yarns (fibers) are only suitable for dark colors and black. Bleaching the fabric into a bright white color is not always possible since the red or the brown cast of the contaminants is often present. Using these types of fabrics for white, pastel and bright colors should be avoided.
Definition and Causes:The horizontal lines, across the knitting courses and with distinctive repeat patterns are referred to as Barre lines. These are as the result of the tension differential in the intake of yarn in to the knitted loops. They could also be the result of the difference in the quality of the yarn cones (or cheese) used. In fabric constructions where spandex yarns, in particular bare or uncovered types, are used the excessive, inconsistent and unregulated stretch could be the cause.
Preventive Suggestions: Regular monitoring of yarn tensions plus ensuring that the yarn cones are from the same production merge will help to minimize or eliminate this problem.
Corrective Measures: Provided that these Barre lines are slight and are not too distinctive, using certain dyestuffs with high level of Barre coverage may be effective in helping to achieve a uniform dyed surface. In severe cases, however, no corrective measures are available.
Color Change Due to the Presence of Optical Brighteners-
Definition and Causes:Certain synthetic yarns, such as Polyester and Nylon, during the Melt-spinning processes, are tinted with optical brighteners. The presence of these brighteners will affect the dye affinity of the yarns and may cause illuminant Metamerism where the intensity and cast of a color appear to vary under different light sources.
Preventive Suggestions: When assigning yarns for production, using an Ultra Violet light source, the presence of these types of tints can be established. Prior to the dye process and in the preparation stage attempts should be made to strip and remove these tints using a strong alkali solution such as Sodium Hydroxide or Soda ash. In certain cases the use of Phosphoric acid is recommended.
Corrective Measures:For a fabric which has been constructed using tinted yarns no corrective measures are available.
Definition and Causes:Excessive twist levels in the yarn will cause the fabric to have an unstable appearance in the form of curled edges and off-grain and irregular course lines.
Preventive Suggestions:Monitoring and determining yarn’s twist level prior to production is of great importance. It is to be noted that twist level is determined based on the length of the fiber, types of spinning, and the direction of twist(S or Z).
Corrective Measures:With fabrics that are knitted with excessive yarn twist, a hot scour treatment will reduce the instabilities. However, as previously mentioned (in section 1 – C), in severe cases this fiber relaxation may cause crinkles on the fabric.
In the spinning mills the combing machine is very popular which used to produce smoother, finer, stronger and more uniform yarns. For higher count of yarn this machine must be needed. Md. Ferdus Alam, B.Sc. in Textile Engineering, Southeast University, Cell # 1723300700, Email- [email protected]  Obaidur Rahman, BSc in Textile Engineering, Bangabandhu Textile Engineering College, Tangail.