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Plant Safety || Textile Plant Safety

Plant Safety || Textile Plant Safety

#Textile #Plant #Safety #PlantSafety Safety Safety is defined as being free from the occurrence of accidents. Accident The Accident is defined as an unplanned and uncontrolled event in which an action or reaction of an object, person, substance, radiation results in a person’s injury. Classification of Accidents Significance of safety in Industry Accident-free zone and safe atmosphere will result in improvement in the work culture. It will increase productivity. It will decrease the less labor turnover. It will increase the profits of the company. It results in the harmony of the company. Cost aspects of Accidents There are 2 types of costs. Direct Cost Indirect cost Direct cost It’s related to accident history like downtime cost, medical expenses, etc. It also includes the exgratia of the worker's family. Indirect cost It includes below. Cost of production Cost of machine replacement Cost of training a worker. Advantages of safety program in an industry Increased productivity Lower labor turnover Improves production Improved labor-management relation Substantial reduction in direct and indirect costs Causes of accidents: Unsafe acts of person: Taking unsafe posture or position Unsafe loading/placing Using unsafe equipment Making safety devices inoperative. Operating at an unsafe speed Failure to use protective devices The unsafe mechanical condition of the machine Poor ventilation Bad light or glare Improper height Defective, rough, sharp, slippery area of machine Unsafe cloths Unsafely arranged or poor housekeeping Not wearing mask/goggles or earbuds. Unsafe process(chemical/electrical/Nuclear) Safety Measures Improved physical and mechanical conditions Precautions are taken for the new machine Providing protective equipment Good housekeeping & odor Periodic inspection of machine and methods. Committed management Workers cooperation Strong and stable Trade unions Safety postures Safety contest Safety day/week Safety training We can measure the accidents from the below formulae. Interpretation: Safe-t-score is a dimensionless number and it is a statistical tool for measuring the rate of accidents. +ve Number= Worsened situation -ve Number= Improved situation If the score is between +2 & -2 change is not significant. If the score is >+2 record is significantly worst. If the score is <-2 record is better. Examples: Given the following data with respect to the industry at 2 different locations for 2 different places. Carry out safe-t-score test and interpretation. Location X: Location Y: Interpretation: Compare to 2 locations, location X is better. In location X even though the accidents increased by 50%, the change is not significant. It is in the range of -2 to +2 The situation in Y is worsen as t is >+2. A 10% Increase in accidents is highly significant. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Picking || Types of picking mechanism

Picking || Types of picking mechanism

Picking: It is defined as the process of inserting weft yarn through the shed. It is the second Primary motion in weaving. The objective of picking: The objective of picking is to propel the weft carrying element or the weft yarn along the correct trajectory maintaining requisite velocity through the shed in order to provide lateral sets of yarn in the fabric. Type of picking mechanism: Negative/conventional Picking mechanism. Semi-Positive Picking mechanism. Positive / Unconventional picking mechanism. Negative/conventional Picking Mechanism: In this mechanism, the shuttle is used as a carrier and the weft yarn placed in it is called pirn. Functions of Negative picking: To deliver the shuttle along the correct flight path. To project the shuttle at a Predetermined velocity. Types of Negative picking: Over picking Under picking Semi-Positive Picking Mechanism: In this mechanism, the weft carrier travels into the shed through a weft carrier guide. Projectile loom is an example of a semi-positive picking mechanism. Positive Picking: In this type of picking the weft carrier is controlled mechanically i.e., air, water, needle, or rapier. Over Pick: In this type of picking mechanism, the picking arm position is situated above the shuttle box then it is known as over pick. Under Pick: In this type of picking mechanism, the picking arm position is situated Under the shuttle box then it is known as Under pick. Difference between Over pick and Under Pick Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Fabric Inspection 10-Point System

Fabric Inspection 10-Point System

#Textile #Gate #Tf_Gate #Testing #FabricTesting #FabricGrading #Fabric #FabricInspection 10-point Fabric inspection system: It is one of the Fabric inspection systems where a maximum of 10 penalty points can be awarded to one defect. This system was introduced in 1955 which was adopted by Textile Distributors and the National Federation of Textiles. This is the earliest inspection system and is designed to identify defects and assign each defect a value based on the severity of the defect. Criteria for giving Penalty points: In this system warp and weft, direction faults are separately inspected and assigned defects points accordingly. In lengthwise/ warp way: In Width wise / Weft way: According to this system if the total defect points per 100 yards of fabric are 100 or more then the fabric will be rejected. Note: No one yard should be penalized more than 10 points. A combination of warp and weft defect running in one yard should not be penalized more than 10 points. Any warp or weft defect occurring repeatedly throughout the entire piece makes its “second”. Cloth is inspected on face side only unless specified. Grading: First Quality: A piece is graded as “First” if the total quality points do not exceed the total yardage of the piece. E.g. 100-yard piece got the penalized of 70. Second Quality: A piece is graded as “second” if the total penalty points exceeded the total yardage of the piece. Advantages of the 10-Point system: Oldest and most used in the woven finished fabric. In its length of fabric is used and along the length of warp and weft defects are indicated. Disadvantages of the 10-Point System: It was difficult in practical use. It has Width limitations. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Sizing in Textile | Part-I

Sizing in Textile | Part-I

#Textiles #Sizing #WarpYarns Sizing: It is defined as the process of coating the yarn/warp sheets with the adhesive binder. Generally sizing is done to warp yarns to minimize the yarn breakages during the weaving process. Objectives of Sizing: To improve weavability of the warp or to overcome inherent deficiencies of the yarn to withstand the stresses and strains of weaving. This can be attained by improving primarily the abrasion resistance of the yarn. This in turn is achieved with the formation of a film around the yarn along with some penetration of sizing ingredients. What sizing should do: To improve the abrasion resistance of the yarn. To reduce the hairiness of the yarn. To reduce generation of static charge for polyester blend yarns. To improve the breaking strength of cellulosic yarns. What sizing should not do: Should not reduce the elongation-at-break of yarns below the norm. Should not excessively increase missing ends and cross-ends. Quality of sized beam: A perfect sized beam should have: Ends wound straight and parallel to each other, with no rolled, crossed, stuck, or loose ends. Uniform tension from end to end. Uniform warp density throughout the sized beam. Selvage ends not high or low but flat with the warp. Uniform applications of size. Performance Assessment: The real test of sizing lies in weaving. However, to check the performance of a sizing process, the following tests should be carried out: Percent size add-on. The moisture content of sized yarns. Single yarn breaking strength and elongation-at-break. Stretch on yarns during sizing. Lappers and migration of ends. Droppings at looms. Invisible loss of sizing ingredients. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Fabric Inspection | 4 point system

Fabric Inspection | 4 point system

#Textile #Tf_Gate #Quality #FabricQuality #4PointSystem #FabricGradingSystem Fabric Inspection: It is defined as the process of maintaining the quality of raw materials used during the production of the finished product is known as inspection. Four Point System: In this system, one should inspect at least 10% of the total rolls in the shipment. Make sure that at least one roll from each color needs to be inspected. Criteria for giving penalty points: Note: a maximum of 4 points should be charged to one linear yard. Also, note that only “major” defects are charged. The acceptable score varies. Many countries use 40 points per 100 yards as an acceptable defect rate. However, many find this is not acceptable. Calculation of total points per yard: In 4 point system, fabric quality is evaluated by unit points/100 sq. yds. Points / 100 sq. yd. = (Total points in roll * 36 * 100)/ (Fabric length in yards * Fabric width in inches)
Normally fabric rolls containing 40 points per 100 square yards are acceptable. Example: A fabric roll of 135 yards long and 58 inches wide containing the following defects Therefore, Points / 100 sq. yd. = (30 x 36 x 100) / (135 x 58) = 13.79 points So, defect is accepted. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Textile Gate Solved Papers | Tf_Gate 1991

Textile Gate Solved Papers | Tf_Gate 1991

#Gate #Tf_Gate #Tf_Gate_1991 #Textile #TextileCoach 1. Range of Maturity Ratio (M) of cotton is: 0 to 1 0 to 100 0.2 to 1.2 0.5 to 1.5 Ans: 3 2. If d is the diameter, the ratio of air flow through a fibre plug during fibre fineness measurement will be proportional to d d2 d4 1/d2 Ans: 2 3. If 6 slivers each having CV(%) of 6 are doubled, the CV(%) of the resultant sliver will be √6 6 12 25 Ans: 1 4. A 36s cotton yarn with a twist multiplier of 3.5 will have 18 TPI 21 TPI 30 TPI 36 TPI Ans: 2 We know that TPI = TM x √Count Therefore TPI = 3.5 x √36 = 21 5. When twist is increased in a Spun yarn, its strength Increases Decreases Does not change First increases and then decreases Ans: 4 6. In a tensile test, if the strain rate is increased, the apparent tensile strength of a ring spun yarn will Increases Decreases Not change Show no trend Ans: 2 7. Standard CSP value for a combed cotton yarn is 1,850 2,000 2,250 2,800 Ans: 2 For carded = 1800 {1700-1900} 8. With an increase in the friction between the yarns, the tear strength of a fabric will be Increases Decreases Not change Show no trend Ans: 2 9. Air Permeability of fabrics is generally measured with a pressure drop across fabrics equivalent to the water head of 1mm 10mm 10cm 1m Ans: 2 10. If T is the thermal insulation of each layer of fabric, the thermal insulation of two layers of fabric together will be Greater than 2T Equal to 2T Less than 2T Ans: 1 11. Indigosal O is suitable for wool since. It has good affinity for this fiber It can be applied from an alkaline bath It can be developed by means of acidified sodium nitrite. Ans: 1 12. Solamine Black is A mineral color An Oxide A Pigment Ans: 2 13. Astrazon Blue GL is recommended For dyeing acrylic fabrics with a light fastness of 7-8 For dyeing polyester For mass coloration of polypropylene Ans: 1 14. O-Nitrodiphenyl amine disperse dyes have better light fastness due to. The presence of intermolecular hydrogen bonding Resonance Stability Strong dye fiber intraction Ans: 2 Fill in the blanks: The density of polypropylene in 0.91 g/cc and that of viscose is 1.52-1.49 g/cc Friacetatic fibers are soluble in Glacial Acetic Acid and Methylene Chloride at room temperature. Sisal is an example of a leaf fibre wile cotton is a seed fiber. The protein in wo ol is known as Keratin while that in silk as fibroin. The initial modulus of PET is generally Lower than Viscose while the elongation at break is higher than viscose. At standard conditions the moisture regain values of acetate and acrylic fibers are 1.32 and 1.16 respectively. The term degumming is associated with Silk fibre while retting with Jute fibers. MEG and TPA are the monomers for PET The end group is PET are COOH, OH while in ny lon are COOH, NH2 The glass transition temperature of nylon G is 50oc in dry static and 29o in water Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Textile Gate solved Papers Part-III | Tf_Gate 1992

Textile Gate solved Papers Part-III | Tf_Gate 1992

#Gate #Tf_Gate #SolvedPapers #Textile Fill in the Blanks Example of seed fibers is cotton and Kapok A cross-section of NaOH swollen cotton fibers shows a ring in the secondary wall which is better known as Lumen. The hollow Space in cotton fiber is known as Lumen while that in wool is called Medulla. The sulfur-containing amino acids in wool are cysteine and methionine. Stem fibers are also known as Bast Fibers Linen is made up of individual cells named Ultimate The monomers used in the production of PET are MEG and TDA Acrylics that contain less than 85% of acrylonitrile by weight are termed. Ziegler–Natta is the catalyst used during the polymerization of polypropylene. Asbestos is a naturally occurring mineral fiber. The dilute solution viscosity of a branched polymer is Higher than that of the corresponding linear polymer in the same solvent. Anionic polymerization produces a Low molecular weight distribution in the polymer. A monomer capable of forming a six-membered ring undergoes a Side reaction. A cross-linked polymer has a high molecular weight. A redox indicator is most suitable for Suspension or Aqueous dispersion Polymerization. Benzylamine can act as a Stabilizer in polyethylene terephthalate manufacture. The degree of crystallinity can be best determined by the X-ray Diffraction technique. Besides melt spinning nylon 6 fiber may also be produced by the wet spinning method. Differential thermal analysis can be used for obtaining Tg, Tc, Tm of a polymer. Azoic colors can be prepared on the substrate. Reactive dyes form a Covalent bond with the fiber. Indigo is a Vat dye. Pigments are applied along with an Emulsion. Acrylic fibers are dyed with Cationic dyes. Rapidogen colors are a mixture of a diazoamino base and a Sodium Naphthol. A low-temperature catalyst for curing pigment colors is MgCl2 Steaming of printed polyester fabrics is carried out in a loop ager at 100-200oC. Carbonization treatment is given to printed polyester/viscose rayon fabric to dissolve Cellulosic material. True or False. Cellulose acetate can be melt spun False Wool dissolves in sulphuric acid False Cotton behaves as a cross-linked polymer True A copolymer has a lower melting temperature than that of the respective homopolymers. False Variation in relative humidity of air has no effect on the tensile characteristics of the fiber. False The displacement of an absorption band towards a longer wavelength is called redshift. True The colors that are on the textile fabrics are due to subtractive color mixing. False Optical density is the same as absorbance. False The visible region is from 300nm to 700nm. False The lightfastness is assessed with the help of a greyscale. False A diazonium compound couples with phenol at m-position. False Hydroxyl and amino groups do not influence the color and dyeing properties of azo dyes. False Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Disadvantages of Ring Spinning

Disadvantages of Ring Spinning

#Textile #Spinning #RingSpinning #Gate #Tf_Gate Following are the disadvantages of choosing Ring Spinning Process Process stages are more numerous, Roving stage exists as an extra process compared to the other systems. Yarn breakages are more numerous as a result of ring traveler friction and yarn air friction. interruptions, broken ends, and piecing up problems exist because of the yarn breakages. The high speed of the traveler damages the fiber. The capacity of the cops is limited. Energy cost is high. Low production rate. New Spinning processes have difficulty in gaining widespread acceptance. Owing to their individual limitations, the new spinning processes are confined to restricted sectors of the market. The ring frame can only survive in the longer term if further success is achieved in the automation of the ring spinning process. Also, spinning costs must be markedly reduced since this machine is a significant cost factor in a spinning mill. The cost structure in the ring-spinning mill is shown in the graph. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Gate Solved Papers Part-II | Tf-Gate 1992

Gate Solved Papers Part-II | Tf-Gate 1992

#Gate #Textile #TextileCoach #Tf_Gate #SolvedPapers 21. The coarser fibers preferentially migrate To the surface of the yarn. To the core of the yarn. At random. Ans: 1 22. Longer and finer fibers require a card cylinder having Higher wire point density. Lower wire point density. Higher speed Ans: 1 23. On the scutcher the ratio of fan speed to beater speed required for synthetic fibers as compared to cotton fibers is Higher Lower Equal Ans: 1 24. On a good ring frame, the spinning tensions for cotton yarn would be around. 1.0 g/tex 0.1 g/tex 0.001 g/tex 0.11 g/tex Ans: 1 & 4 25. Balloon control rings are more effective At the end of the doff At the middle of the doff At the beginning of the doff Throughout the doff Ans: 4 26. If the difference between the number of thick and thin places is very high, the machine to be checked first would be Draw frame Speed frame Ring frame Card Ans: 4 27. The waste removed in the blow room while processing man-made fibers should be around 0.1% 1% 2% 3% Ans: 2 Avg is 0.5% to 1% 28. The amount of spin flash applied by fiber manufacturers to polyester staple is around. 0.16% 0.48% 1.0% 5% Ans: 1 29. The traveler weight employed for polyester blend, compared to that employed for cotton is Less More The same Ans: 1 30. The most Preferred beater for processing man-made fibers Shirley opener Kirschner beater Creighton Three bladed beater Ans: 1 31. During sizing pickup will increase if Sizing speed increases Squeezing pressure increase The position of the immersion roller is lowered Temperature of drying cylinder decreases Ans: 1 & 3 32. Fabric cover on a loom is improved by Raising the backrest Having early shedding Having late pickup None of the above Ans: 2 33. Activation of bottom change on an automatic loom is preferred by weft feeler compared to weft fork because It increases the loom efficiency It improves the quality of fabric It reduces the weft waste It reduces the workload of workers. Ans: 3 34. In shuttle less weaving, weft waste is minimum on Air-jet loom Water-jet loom Rapier loom Gripper (or projectile) loom Ans: 1 35. On Sulzer projective loom, the number of projectiles depends on Weight of projectile Width of loom Speed of loom Picking force Ans: 2 36. Circular looms are preferred over conventional looms When the weft pattern is complicated When the silk yarn is involved When hose type of fabric is required Because circular looms give higher efficiency Ans: 3 37. In triaxial weaving weft is inserted In single picks In double picks By two pick cycle None of the above Ans: 1 38. Gauge of winder with trap type(serrated) slub catcher for 25 tex yarn will be 0.1-0.2 m 0.6-0.7mm 1.0-1.3mm Ans: 2 For combed 1.5-2 times of yarn dia. For carded 2-2.5 times of yarn dia. 39. Percent waste in sizing department calculated on the yarn processed in the sizing is normally 0.5-0.8% 1.2-1.5% 2.0-2.5% Ans: 2 40. If the specific volume and twist factor of yarn are 1.0 cm3 /g and 60 tex1/2 turns/cm respectively, what will be its twist angle? 30o 34o 32o None of the above Ans: 2 Tan α = 0.0112 (1.0 cm3/g)1/2 x 60 = 0.672 α = tan‑1 (0.672) = 33.9o 41. The value of the retraction factor ranges between 0 to ∞ 1 to ∞ 0 to 1 Has no range Ans: 3 42. If the ratio of the strength of two-fold yarn to its component single yarn is four, what will be the ratio of their tenacities? 4 2 1 None of the above Ans: 2 43. Which of the following relationships is correct ef = ey cos2 Θ Ey = Ef cos2 α ef = ey / cos2 Θ Ey = Ef Cos2 α = Ef Where Ey =Yarn Modulus Ef =Fibre modulus α = Helix angle at yarn surface ey = yarn extension ef = fibre elongation Θ = Helfix angle of fibre Ans: a & C 44. The index of Blend irregularity (IBI) values proposed by Coplan and Klein may have the following interpretation IBI = 0, means complete randomness IBI =1, means perfect blending IBI > 1, means the presence of clustering IBI = 0, means perfect blending Ans: 3 45. Drawing Increases crystallinity Increases birefringence Decreases crystallinity Increase strength Ans: 1, 2, & 4 46. Nylon is drawing At glass transition temperature. At softening temperature At room temperature At 100% RH conditions Ans: 4 47. The denier of tow used for producing polyester staple fibers before the drawing is about 3000 30,000 300,000 None of the above Ans: 2 48. Heat setting in relaxed conditions Reduces strength Increases orientation Increases crystallinity Increases density Ans: 1, 3 & 4 49. False twist means Twisting in a false direction Not twisting Introducing equal and opposite twist Twisting with friction discs Ans: 3 50. Edge crimped yarns Have zig-zag configuration Have helical configuration Give stretch yarns Give modified stretch yarns Ans: 4 51. In the context of friction spindles for texturing the twister angle should be 30o 45o 60o 90o Ans: 4 52. Air-jet Texturing Reduces the strength considerably Does not decrease the strength Uses overfeeding to get the textured effect Uses air-jet to get the textural effect. Ans: 3 53. Stuffer box technique Is used to produce textural yarns for carpets Can process heavy denier yarns Is used to give crimp in staple fiber production Is suitable for monofilaments Ans: 1 54. A spin finish formulation contains Delustrant Whitener Lubricant Antioxidant Ans: 3 55. Gas singing machine is operated at a speed of 50-70 m/min 125-200 m/min 10-40 m/min 80-120 m/min Ans: 4 56. The desizing process mainly removes Wax and tallow Dirt and Colour Starch Natural impurities Ans: 3 57. Batch wise scouring is carried out in Winch Jigger Kier J-box Ans: 3 58. The most important ingredient of scouring composition is Wetting agent Alkali Emulsifying agent Sodium silicate Ans: 2 59. Wool and silk can be bleached with Sodium hydrosulphate Sodium Perborate Hydrogen Peroxide Sodium Hypochlorite Ans: 1 & 3 60. Polyester and acrylic fibers can be bleached with Sodium hydrosulphate Hydrogen Peroxide Sodium Chlorite Sulphur dioxide Ans: 3 61. Mercerization is carried out with NaOH of 10-15% conc. 15-25% conc. 5-10% conc. 25-35%conc. Ans: 2 62. An optical brightening is A synthetic bluing agent A colorless dye A fluorescent compound An optical whitener Ans: 1 & 4 63. Damage caused to cotton during bleaching can be assessed by measuring Cuprammonium Fluidity Methylene Blue Absorption Barium number White index Ans: 2 64. Efficiency of mercerization can be assessed by Dye sorption Deconvolution count Shrinkage Sinking time Ans: 2 Can you help us improve this page? 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Textile Gate Solved papers | Tf_Gate 1992

Textile Gate Solved papers | Tf_Gate 1992

#Gate #Tf_Gate #SolvedPapers #Textiles #GatePaperswithSolutions #TextileCoach 1. During length measurement of Fibrograph 2.5% span length was found to be 25mm. it means. 2.5% of fibers clamped are 25mm in length. 2.5% of fibers clamped are longer than 25mm. 2.5% of fibers clamped are 25mm or longer. 2.5% of fibers clamped are less than 25mm. Ans: 1 2. The count of yarn is 20 Tex. It is equivalent to a yarn of 29.5 Ne. (English Count) 180 Denier. 50 Nm (Metric count) None of the above. Ans: a, b, & c Tex to Ne. We Know that Tex = i.e., Ne. = Therefore, 20 Tex = = 29.525 Ne. Tex to Denier We know that 1 Tex = 9 Denier Therefore, 20 Tex = 20 x 9 Denier = 180 Denier Tex to Nm We know that Tex = i.e., Nm = 1000/Tex Therefore, 20 Tex = 1000/20 = 50Nm. 3. The resultant count of two cotton yarns is 16s Ne. If the doubling process causes a contraction of 10% in the component yarns, the count of the component single yarn will be? 35.2s Ne 28.8s Ne 32s Ne None of the above Ans: 1 Given that Resultant count= 16s Let’s assume that the two single yarns are of the same count. Then the count of a single yarn is 32 As mentioned, there is a 10% contraction during the doubling Therefore, count of single yarn = 32 + 10% contraction = 32+ 3.2 = 35.2s 4. The number of thin places were detected at -30% and -50% thin place setting on a uster imperfection indicator. The incidence will be higher at -30% 505 None of the above Ans: 1 The incidence will be more at thin places and less thin cross-section 5. Under CRL and CRE conditions of testing, what happens to the rate of loading when the length of the specimen is increased? The rate of loading does not change for CRL conditions. Rate of loading decreases for CRE conditions. Rate of loading increases for both conditions. None of the above. Ans: 1 & 2 6. with respect to tear strength which of the following statements are correct? Tear strength of twill weave > Tear strength of plain weave. Tear strength of high set fabric < Tear strength of the low set fabric. Tear strength does not depend upon weave and set. Tear strength depends upon thread strength. Ans: 1, 2 & 4 7. which of the following phenomenon may be described by passion Distribution The number of warp breakages on a loom. Breaking load of yarn. The number of neps in a given area of card web. The number of end breakages in ring spinning. Ans: 3 8. The correct relationship between specific surface (s) and diameter (d) of a fiber can be described by S = 1/d S = 4/d S = (perimeter of Cross-section) / (Area of Cross-section) None of the above Ans: 2 & 3 9. The standard error of estimate of difference of two means having a sample size of n1 and n2 and the pooled estimate of standard deviation s, is Ans: 1 & 3 10. Which of the following relationships is/are correct? Ans: 1 & 4 11. The U% of a single yarn is 17.3%. The expected CV% of a 3-ply yarn made from these single yarns would be? 12.5 10.0 17.3 None of the above Ans: 1 CV of single yarn is = 1.25 * U% = 1.25 * 17.3 = 21.625 % CV% of 3 ply yarn = CV of single yarn / √n where n = no. of doublings = 21.625 / √3 = 12.5% 12. The weight per meter of cotton sliver normally lies between 500 mg and 1000 mg 3g and 4g 10g and 15g 40g and 60g Ans: 2 13. The RKm of a yarn is equal to g/tex g/den breaking length in Km CSP Ans: 3 14. The number of fibers in the cross-section of a 20s cotton yarn would be approximately 85 170 340 680 Ans: 2 The average fibers in yarn cross-section are 100-200 15. Roller and clearer card is used for carding of Cotton Cotton waste Wool Man-Made fibers Ans: 2 & 3 16. Sectional warping is considered more practical than beam warping For executing big orders. For producing striped fabrics. When sizing is considered necessary. When the two-fold yarn has to be used in warp and weft Ans: 2 17. Sizing gives to the yarn Higher breaking strength Increased elongation at break Increased pliability None of the above Ans: 1 18. 1kg of 20 Ne will have a length of 16,800 yards 33,600 meters 20,000 meters 16,800 meters Ans: 2 We know that Ne = (Length in yards) / (840 x weight in pounds) 1 kg = 2.2046 lbs 20 = length / 840 x 2.2046 Therefore, length = 20 x 840 x 2.2 yards Length = 36,960 yards 1 yard = 0.9144 meters 36,960 yards = 33,796 meters 19. A sheeting fabric having 30 tex in warp and 20 tex in weft, and having 40 x 30 ends and picks per centimetre respectively 90 g/m2 170 g/m2 180 g/m2 250 g/m2 Ans: 3 Given that Ends per cm = 40 Picks per cm = 30 GSM = 0.1 [(N1 x n1)+ (N1 x n1)] = 0.1 [(30 x 40) + (20 x 30)] = 0.1 x 1800 = 180 g/m2 20. In an automatic loom Weft break is repaired automatically. The warp break is repaired automatically. Exhausted weft bobbin is replaced automatically. Exhausted warp bobbin is replaced automatically. Ans: 3 Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Textile Calculations (Spinning) Part-I

Textile Calculations (Spinning) Part-I

#Textile #Gate #Tf_Gate #Calculations #Spinning Q: What is the relation between CV% and U%? Also, write the difference between both. Ans: C.V. % = 1.25 X U% The irregularity U% is proportional to the intensity of the mass variations around the mean value. The U% is independent of the evaluating time or tested material length with a homogeneously distributed mass variation. The larger deviations from the mean value are much more intensively taken into consideration in the calculation of the coefficient of variation C.V. %. C.V. % has received more recognition in modern statistics than the irregularity value U%. The coefficient of variation C.V.% can be determined extremely accurately by electronic means, whereas the calculation of the irregularity U% is based on an approximation method. Q: While testing ring yarn in the Uster evenness tester the peak observed was around 9 cm in regularity trace. What will be the probable cause of the peak, explain. Ans: The probability of faults is due to damaged front roller cots or rollers in the R/F drafting zone. Explanation: The front roller diameter is 27 mm so the circumference of the front roller is (3.14 * 2.7 = 8.6 cm i.e. approximately 9 cm). so the cause of the fault is due to the front roller or cots in the R/F drafting zone. Q: Calculate the limit irregularity for a 20 Tex cotton yarn spun from 150 mTex fibres. If the actual measured CV% is 23.2%, what is the Index of Irregularity? Ans: The average no. of fiber in yarn cross section = (20 * 1000) / 150 = 134 For cotton limit irregularity CVlim = 106 / √134 = 9.15% Index of irregularity = CVact / CVlim = 23.2 / 9.5 = 2.54% Q: Two roving each with a CV of 8% are fed into a spinning zone. If the spinning unit adds a CV of 18%, what will be CV of the output yarn? Ans: CV% yarn w/o addition of CV in R/F is = CV% / √n = 8 / √2 = 5.7% CV % of output yarn = √(5.7+18) = 18.88% Q: On a draw frame Polyester and Cotton slivers are blended on a 6-ends-up system with a draft of 6 to get a 20 ktex sliver with approximately 67:33 P/C blend by weight. Input cotton sliver of 1.2 denier cotton fibre has a CV of 4% and the polyester sliver of 1.5 denier have a CV of 3%. Drafting introduces an additional CV of 2%. Calculate the Index of Irregularity, neglecting the variability of fibres. Ans: Sliver Linear density = 20 kTex = 20,000 Tex Polyester = 20000 x 0.67 = 13400 tex Cotton = 20000 x 0.33 = 6600 tex No. of cotton fibres in the sliver cross section = (6600 * 9)/1.2 = 49500 = N1 No. of polyester fibres in the sliver cross section = (13400 * 9)/1.5 = 80400 = N2 Total no. of fibres = 49500 + 80400 = 129900 = NT CVlim = 100 / √ NT = 100 / √129900 = 0.28 CVdoub = √(NcVc2 + NpVp2 ) / (Nc + Np) Nc & Np are no. of cotton and polyester sliver ends CVdoub = √(2 * 42 + 4 * 32 ) / (2+4) = 1.37% Actual CV% of input sliver CVactual = √(CVd2 + CVdraft2 ) = √(1.372 + 22 ) = 2.427 Index of Irregularity = CVact / CVlim = 2.427 / 0.28 = 8.66 Q: The U% of a single yarn is 17.3%. The expected CV% of a 3 ply yarn made from these single yarn will be, Ans: CV of single yarn is = 1.25 * U% = 1.25 * 17.3 = 21.625 % CV% of 3 ply yarn = CV of single yarn / √n where n = no. of doublings = 21.625 / √3 = 12.5% Q: Calculate the CV% of the combed sliver which is fed in the finisher draw frame. CV% of the Draw frame sliver is 1.85% and No. of doubling is 6. Ans: The formula is CV% of doubling = CV% of single / √n where n = no. of doublings 1.8 = CV% of single / √6 CV% of singles = 4.41% i.e. CV% of comber sliver is 4.41%. Q: Two roving having 7.8 CV% are fed into the ring frame making yarns and ring frame adds CV% 4.8 then what will be the final yarn CV%. Three of the same yarn doubled in the doubling machine means what will be CV% of the doubled yarn? Ans CV of ring yarn (exclude of CV% added in R/F) = CV% of roving / √n = 7.8 / √2 = 5.52 CV% of ring yarn with added CV% in Ring frame = √ (5.522 + 4.82 ) = 7.32 CV% doubled yarn having 3 single of above yarn = 7.32 / √3 = 4.23 Q: A draw frame is fed with 8 cotton slivers of 0.25 Nm with a mean CV of sliver is 2.5%. What is the extent of the irregularity which is produced by the drafting elements of the draw frame? The CV of the output sliver is also 2.5%. Ans CV of doubling = 2.5 / √N = 2.5/√8 = 0.88 CVoutput = (CVdoub2 + CVadd2 ) 1/2 or CVadd = (CVo/p 2 - CVdou 2 ) 1/2 = (2.52 – 0.882 ) 1/2 = 2.34% Q: Mention the online yarn monitoring system used in rotor spinning and what kind of information we may obtain from ‘corolab-7’? Ans Schlafhorst has incorporated a yarn monitoring system on the rotor spinning machines using an optoelectronic sensor ‘Corolab7’ - It measures yarn diameter online and can provide details about the evenness, imperfections, detection of faults etc. Uster poly guard is an online yarn supervisory attachment for the automatic rotor spinning machines - Based on the capacitive measuring principle. - Gives detailed information for all the rotor heads. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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Winding Question & Answers Part-2

Winding Question & Answers Part-2

#Textile #Winding #Spinning #QandA #Gate #TF_Gate Q. Compare between ordinary & automatic shuttle. Ans: Q. State the Importance or Effects of tensioning Device. Ans: Too high tension: Can damage the yarn. The breakage rate may be greater. Elongation properties may change. Too low tension: Can lead to unstable or loose packages which will not unwind cleanly. Variation in yarn tension in different parts of a wound package can cause undesirable effects. For MMF: Too high tension:- Can cause molecular change which affects dyeability. Random variation in color shading. For Staple or Spun yarn: Too high tension:- May breakage at a thin place Q. Differentiate between cone winding & cheese winding. Ans: Q. What are the requirements of a tensioning device? Write down the factors that influence fore selection for tensioner? Ans: Requirements: The device must be reliable to control uniformly in tension. It must be easily threadable. It must neither introduce nor magnify tension variation. It must not introduce differences in a twist. It must not be affected by wear. It must not easily adjustable. It must not be affected by the presence of oil and dirt. It must not encourage the collection of dirt and dust. It must be capable of easy cleaning. The operating surface must be smooth. It must be inexpensive or cheap. It must be simple in design & operation. It must not cause damage to the yarn. Q. What is winding efficiency? Ans: It is the percentage expression of the ratio of actual production & calculated production. Can you help us improve this page? Send us your contribution at info@textilecoach.net, we will update this page and give you proper attribution!

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