report on waving

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Letter of Transmittal

Mr. Mohammad Abu Sayeem

Director

Institute of Textile Engineering & Clothing Technology

Subject: Submission of report on Mitali Textile Mill at Madhabdi inNarshingdi.

Dear Sir,Here is the report on the Mitali Textile Mill That we are asked to submitunder your supervision.

We sincerely hope that the report and the recommendations would help youmaking effective decisions. We truly appreciate this assignment and enjoyed itvery much. We will be highly obliged if further assistance in interpreting ouranalysis.

Sincerely yours

Md. Nazmul Hasan Shifat, ID: 101779

Md.mohabbat Alam, ID: 101814

Asish Kumar Dhar, ID: 101831

Semester: 5 th

Institute of Textile Engineering and Clothing Technology.


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ACKNOWLEDGEMENT

At the outset, I wish to express my gratitude to everybody who has assisted informulation of this report. There are many to whom expression of gratitude isinevitable, but there some special people who has to be given prominence, withoutwhom I would not have reached the conclusion of this report.

I wish to thank

Mr. MOHAMMAD AYUB, Chairman, ITECT.

Mr. M. A. SAYEEM, Director, ITECT.

Mr. Jaidul Haque, Principal, ITECT.

For providing this wonderful opportunity, channeling and motivation.

No amount of Gratitude is adequate for

Mr. Hanif Mohammad , Proprietor, Mitali Textile Mill.

Md. Sobganullah Tulu, Weaving Technician.

For their consent in allowing us to conduct our study.

We are equally thankful to all other people (who were experienced with so manyinterviews as interviewee) who have been consulted for their valuable opinion.


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1. ABOUT MITALI TEXTILE MILL (MTM)Mitali Textile Mill established in the year 1984. It is situated at Choto Godharchar,Madabdi in Norshingdi. The mill has modern machinery on its back process.

Basically it is a fabric weaving mill but it is also prepare sized warp beam for other cottage and small weaving mill.

According to its machines and production process MTM has production capacity

of 5500 yds of gray or raw fabric and 90000 yds of warp yarn sheet per day butdepending on market demand and other circumstances it is producing 4200 yds of gray or raw fabric and 80000 yds of sized warp yarn sheet.

At present around 120 workers are working in two circular shifts in MTM.

1. ORGANIZATIONAL HIERERCHY

Hanif Mohammad, Co-Proprietor. Samsur Rahman, Co-proprietor.

Amolendo Gun Chowdhury, Manager.

Firoj Ahmed, Asst. Manager.

Aslam Mia, Supervisor (sizing).

Gulam Mustafa, Prodution Manager.


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Layout of MTM


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PRODUCTION

2. Production Flow chart


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3. PREPARATORY PROCESS FOR WEAVINGThe yarns as manufactured and packaged after spinning are not in the optimumcondition to enter looms directly so as to produce fabrics. Package size, build andother factors make it necessary for the yarn to be further processed to prepare it to

be handled efficiently during fabric manufacturing. The yarn package as it comesfrom spinning must be repackaged to meet the particular needs and demands of fabric manufacturing.

3.1. WINDING

Winding is the process of transferring yarn from one type of package to another package.

Pic: Winding M/c

3.1.1. OBJECTIVE: To transfer yarn from spinner bobbin to another suitable package

for warping machine.

To make a continuous supply of yarn in the subsequent process.

To remove yarn faults like hairiness, neps, slubs and foreign matters.

3.2. CREELING


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Creeling is the process of setup warp yarn package on the creel for withdraws warpyarn to prepare warp beam.

4.2.2. OBJECTIVE: To assemble warp ends. To withdraw warp yarns.

4.2.3. Creels: Independently of the warpingsystem, the threads are fed from bobbins placedon creels. The creels are simply metallic frameson which the feeding bobbins are fitted; they areequipped with yarn tensioning devices, which in modern machines are provided

withautomaticcontrol andcentralizedtensionvariation.Moreover the creels

are equipped with yarn breakage monitoring systems. The creel capacity is the parameter on which the number of warping sections or beams depends.Pic: Stop Motion

Pic: Tensioning Device Pic: Creel

3.3. WARPING


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Warping is a process by which a long length of warp yarn is wound on a warper beam. The winding of warp yarn from packages in to a warp beam is calledwarping.

Pic: Warping M/c

3.3.1. OBJECTIVES: To create a limited number of warp threads (creel load), of a warp composed

of any number of threads with the desired length. To arrange threads according to the desired sequence. To manufacturing warp beam with said characteristics.

If the creeling capacity is equal or higher than the number of warp threads, thewarping would simply entail the direct winding on the warp beam of the threadscoming from the creel. Generally this condition does not take place and, even withcreels of high capacity, the number of creeling positions never corresponds to thenumber of threads, which is always by far higher than the number of bobbinswhich the creel can contain.

Depending on the kind of intermediate carrier used, the industrial warping processcan be carried out according to two different technologies:

I. Sectional warpingII. Beam warping or direct warping

Direct Warping: It consists of preparing number of full width warping beam withrequired length, called as one set. The total no of ends warped in number's of beam


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depending on the capacity of creel. These all beams of one set put together onsizing creel for the sizing process, which result in formation of weaver's beam.

Use of Direct Warping

Direct warping is used for prepare a set of one color, either grey or dyedyarn.

To prepare large set length of yarn in each warping beams of the set & prepared number of small length sized beam from this set which reduce thewarping and sizing machine downtime.

Multi-color warps with complicated patterns can be formed successfully onthis type. It gives one set so less inventory and handling of beams is there.

Beam warping or direct warping is used mostly when several beams of same warplength have to be prepared; this kind of warping is carried out in two separatestages:

At first the proper warping takes place: the available threads (CreelCapacity) are wound on a large cylinder called Beam And so many beams

are prepared as indicated by the result of following expression:

Number of beams =


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In the second stage the threads wound on the beams are simultaneouslyunwound to form the weavers beam.

The way in which threads are assembled during this second phase shows that thenumber of the beams should be preferably an integer number.


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Pic: Expanding Comb Pic: Pressure Roller

3.4. SIZING

Sizing is the process by which an adhesive coating is material coating is appliedaround the surface of warp yarn.

In the weaving process, the warp yarns are subjected to rubbing and chafingagainst various metallic parts of the looms as they are threaded through backrest,drop wires, harness and reed. They constantly are rubbed together during shedding.The warp yarns are subjected to tension constantly as well as intermittently duringlet-off, take-up, shedding and beat up. These two reasons lead to increase the end

breakage level during weaving, which should be minimized.

Pic: Sizing M/c

3.4.1. Objectives

To strengthen the yarn by causing the fiber adheres together.

To make the outer surface of the yarn smoother so that hairs protruding fromone yarn in the warp should not became entangled with the hairs protrudingfrom a neighboring yarn.


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To lubricate the warp yarn so that there is less friction when they rubtogether in the weaving process.

To make the warp yarn stronger and more resistant to abrasion.

To adhere the projecting fibers with the warp yarn and remove hairiness.

3.4.2. Slasher Sizing Machine

Slasher sizing machine is most widely used. About all types of yarns can be sized by this machine.

The slasher sizing machine is consists of thefollowing primary units:

Creel- Unwinding zone.

Size boxes- sizing zone.

Drying cylinders- Drying zone.

Lease rods- Splitting zone.

Head stock- Weavers beam preparationzone.

Creels- Unwinding zone : The beam creel ismerely a device or frame on which beams are

placed in a manner convenient for unwinding. Thecreel can hold as few as one beam one beam and

usually as many as fourteen. At the slasher, many warp beams are combined toform a single weavers beam.

Pic: Unwinding Zone

Size box- Sizing zone: The yarn next enters the size box. The size box contains thesize solution, known as size liquor. The yarn is feed into size the box by means of a


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guide roll. It then passes under a dip or immersion roll. This roll is capable of being moved up or down allowing the yarn to be held in the size liquor for a desire period of time. The yarp sheet then passes through two rolls known as squeezerolls. The purpose of the squeeze rolls is Pic: Sizing zone

followed:

To squeeze out excess size.

To physically drive the size into theyarn for proper penetration.

The size box also contains pipes whichsupply solvent, size ingredients and steam to

heat the size liquor. In this way , thetemperature and concentration and hence the viscosity of the size is kept asconstant as possible to assure both correct anduniform size pick up by the warp yarns.

Drying cylinder- Drying zone: After theyarns have been exposed to the size liquor andhave picked up the required amount of size,the size solvent must be driven off. Thisdrying may be done by exposing the yarns tohot air, by passing them over heated cylindersor can. The yarn is dried by coming in contactwith these hot cans.

Pic: Drying zone.

Lease rods- Splitting zone: The function of the lease rods in the splitting zone isto separate the individual yarns which are stuck together because of the drying of the size film in the drying section. To achieve this, a series of lease or bust rodswith one large diameter busting rod are used.

Pic: Splitting zone


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Headstock- Weavers beam preparation zone: the yarn is now ready to be puton the loom beam. It is threaded through an expansion or zigzag comb which isadjusted to allow the warp sheet to come to the width required to fill the loom

beam. The yarn is wound onto the loom beam at the headstock in a manner similar

to that in the beaming operation.

Pic: Beam preparation zone

3.4.3. Factors Influencing Sizing Parameters:

Type of yarn, spun or filament Spun yarn parameters such as twist, count,and fiber blend

Spinning system: Sing, rotor, air-jet, compact, etc. Type of weaving machine: Shuttle, projectile, rapier, air-jet, water-jet,

multiphase, etc. Type of fiber: Natural or manmade Fiber blend Construction and weave of fabric Environmental laws

3.4.4. The concentration of the size and add-on depend upon the followingfactors:

Yarn Count: Lower Count has higher surface areas and therefore requiresmore size.

Construction of fabrics: The higher number of warps per unit space, thehigher the size requirement.

Type of weave: Plain weave fabrics aremore difficult to weave due to a greater number of interlacements compared toweaves with long floats such as satin.


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The loom type: For example, shuttle or shuttle less, and weaving conditionsinfluence the type and amount of size to be applied. The use of a water-jetloom also influences the characteristics of the size selected. The size should

be water soluble during application but should be water insoluble when

dried, so that when the pick is inserted by the water jet the size is notremoved.

Type of sizing machine: Conventional, pre dryer type or single-end sizing;each has different application procedures and constraints.

3.4.5. Controlling Points of Sizing

Viscosity of size the solution.

Sizing machine speed.

Size add-on levels.

Concentration of the size mixture. Volume of the size box.

Threading arrangement.

Condition of squeeze rolls.

Squeezing pressure.

Hardness of squeeze rolls. Diameter of squeeze rolls.

Number of size box.

Yarn count and size box warp density per unit space.


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3.4.6. Process of sizing

The process consists of laying warp yarn parallel and sizing the yarn with a

mixture to strengthen it to withstand the rigors of weaving.

Warp yarn is withdrawn in sheet form from warp beams which are placed at the back of the sizing machine. The yarn is then passed through sow box. Size solutionis applied by immersion. After removing surplus solution that occurs at this state,the yarn is dried and arranged on a loom beam.

3.4.7. Process Control in Sizing

The process control program in sizing should, therefore, comprise of the followingaspects:1. Selecting the correct size recipe and size pick -up level2. Ensuring correct preparation of size paste3. Control of

Size pick up Stretch

Moisture content

Quality of beam Machine speed Machine efficiency A method to calculate the expected level of productivity

3.4.8. Sizing Ingredients

Adhesive: Modified starch, fabric glue, tapioca starch, carboxyl methyl cellulose(CMC), poly-vinyl alcohol (PVA), polyester resin (Binder) etc.

Function

Coat the warp yarn with a film.

Impart smoothness.


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Bind the protruding fibers to the yarn surface.

Increase elasticity.

Lubricant: Mineral waxes, oils, paraffin wax, animal fat etc.

Function

To give a softer feel to the sized yarn.

To reduce stickiness of yarn.

To smoothen the yarn.

3.4.9. Choice of Size Recipe

The suitability of size recipe for the type of yarn should take into account, fabricconstruction, and end use as follows:

1. Cotton Yarn- Starch Based2. Polyester etc. - Polyvinyl Alcohol (PVA) based3. Count-

Fine and Superfine count- thin boiling Starches. Coarse Count- Ordinary starch.

4. Fabrics- Heavy Fabrics- Modified starches. Light and Medium- Ordinary starches.

5. Machines Conventional sizing Machines- Low viscosity starch. High speed sizing machines- High viscosity starches.

6. Unbleached calendared sort of fabrics- More weighting agents, antisepticsofteners etc. are used.

7. Bleached sorts- ordinary starches

8. Constructions Finer Counts and Heavier Constructions- More size pickups Coarse counts- Less size pickups

7. Plied yarns- low size pick up or nil even


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4.4.10. Control of size pickup

For control on variation of size pick up, the two steps required are:1. determination of average size pick up on the beam2. Suitable adjustment in sizing conditions

1. Determination of size pick up

Example: The weight of sized yarn on a beam was found to be 82.5 lbs. The beamcontains 1050yards of warp, whose count before sizing was 50s cotton. If thenumber of ends in the warp is3000, calculate the following:a. The weight of size on the yarn

b. The % of size put on the yarnc. The count of sized yarn

a. Weight of size on warp = weight of sized warp- weight of same length of unsized warp

Now weight of unsized warp =

=

=75 lbs.

Therefore weight of size on warp = 82.5 -75 = 7.5 lbs

a. Percentage of size on warp =

b. Count of sized yarn =

=

= 45.5s Cotton


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2. Control on sizing condition

1. Viscosity of size paste in size box: Any variation in the concentration or temperature alters the viscosity of the paste which in turn affects both the level of

size pick up and extent of penetration. Initially as the viscosity increases, the size pick-up also increases. But as the viscosity increases beyond a point, the size pick up is reduced.

2. Squeezing pressure and condition of squeezing nip: The squeezing pressuredetermines the extent of penetration of the size paste between the fibres of the yarnand also of the removal of excess size paste and hence the level of the size pick up.

3. Speed of the sizing machine: Other sizing conditions remaining unchanged, thesize pick up increases with increasing sizing speed and vice versa. This is becausethe time available to squeeze the surplus size from the yarn is less at high speeds.

4. Depth of immersion roller in size paste: the depth of immersion roller in the paste determines the duration for which the yarn remains immersed in the paste.This duration in turn influences both the level of size pick up and the extent of size

penetration.

5. Level of size paste in the size box: Variation in the level of size paste is animportant source of size pick-up variations both within and between beams.

6. Density of ends: When the density of ends is high, difficulties are encountered inobtaining adequate and uniform size penetration. Therefore size pick up may varyat these fabrics.

4.5. DRAWING-IN/TYING-IN

Drawing-In: After sizing, the sized warp beam is prepared further to be placed onthe loom. Drawing-in is the entering of yarns from a new warp into the weavingelements of a weaving machine namely drop wires, heddles and reed, starting up anew fabric style.


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All the warp threads have to be threaded through the heald eyelet and its gap in thereed prior to weaving. The heald is the part of the loom that is used to move thewarp threads up and down. The threads pass through eyelets on the heald. For asimple weave pattern alternate eyelets are moved up to raise the correspondingwarp threads, and the threads between are moved down. When the shuttle travels

back their positions are reversed. The reed is like a comb and its purpose is tocontrol the separation of the warp threads.

The open space between each wire of the hook is called dent. A warp end is passedthrough a dent with the help of the reed hook, after it passes through the heald.

This process is called denting.


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Tying-In: Tying-in is used when a fabric is being mass production. The tail end of the warpfrom the exhausted weavers beam is tied to the

beginning of the new warp.

Pic: Tying-in

4.6. WEAVING

Weaving is the process of interlacement between the warp and the weft yarn in afabric according to design. Mechanism implies construction and interaction of therelated parts of a machine. Weaving mechanism therefore denotes constructionarrangement and working principle or interaction of a weaving machine and itscomponents parts, in which a fabric can be manufactured.

Four fundamental operations of weaving in any loom are as follows:

Shedding: raising specific yarns by means of the harness or heddle frame.

Picking : inserting filling yarns through the shed

Beating up: pushing filling yarns firmly in place by means of the reed. Taking up and letting of: winding the finished fabric on the cloth beam and

releasing more of the warp from the warp beam.


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4.6.1. LOOM

The process of producing a fabric by interlacing warp and weft threads is known asweaving. The machine used for weaving is known as weaving machine or loom.Weaving is an art that has been practiced for thousands of years. The earliestapplication of weaving dates back to the Egyptian civilization. Over the years, boththe process as well as the machine has undergone phenomenal changes. Asof today, there is a wide range of looms being used, right from the simplesthandloom to the most sophisticated loom.

In order to interlace wrap and weft threads to produce a fabric, the followingmechanisms are necessary on any type of loom:

1. Primary mechanisms

2. Secondary mechanisms

3. Auxiliary mechanisms

1. Primary Mechanisms: These are fundamental or essential mechanisms.Without these mechanisms, it is practically impossible to produce a fabric. It is for this reason that these mechanisms are called primary mechanisms. The primarymechanisms are three in number.

a. Shedding mechanismb. Picking mechanismc. Beat-up mechanism

a. Shedding mechanism: The shedding mechanism separates the warp threadsinto two layers or divisions to form a tunnel known as shed.

b. Picking mechanism: The picking mechanism passes weft thread from oneselvedge of the fabric to the other through the shed by means of a shuttle, a

projectile, a rapier, a needle, an air-jet or a water-jet. The inserted weft thread isknown as pick.


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c. Beat-up mechanism: The beat-up mechanism beats or pushes the newlyinserted length of weft thread (pick) into the already woven fabric at a point

known as fell of the cloth. These three mechanisms namely shedding, pickingand then beat-up are done in sequence.

2. Secondary Mechanisms: These mechanisms are next in importance to the primary mechanisms. If weaving is to be continuous, these mechanisms areessential. So they are called the secondary mechanisms. They are:

a . Take-up motion

b. Let-off motion.

a. Take-up motion: The take-up motion withdraws the cloth from the weavingarea at a constant rate so as to give the required pick-spacing (in picks/inchor picks/cm) and then winds it on to a cloth roller.

b. Let-off motion: The let-off motion delivers the warp to the weaving area atthe required rate and at constant tension by unwinding it from the weavers

beam. The secondary motions are carried out simultaneously.

3. Auxiliary Mechanisms: To get high productivity and good quality of fabric,additional mechanisms, called auxiliary mechanisms, are added to a plain power loom. The auxiliary mechanisms are useful but not absolutely essential. This iswhy they are called the auxiliary mechanisms. These are listed below.


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a. Warp protector mechanism

b . Weft stop motion

c. Temples

d. Brake

e. Warp stop motion (Predominantly found in automatic looms)

a. Warp protector mechanism: The warp protector mechanism will stop theloom if the shuttle gets trapped between the top and bottom layers of the shed.It thus prevents excessive damage to the warp threads, reed wires and shuttle.

b. Weft stop motion: The object of the weft stop motion is to stop the loomwhen a weft thread breaks or gets exhausted. This motion helps to avoid cracksin a fabric.

c. Temples: The function of the temples is to grip the cloth and hold it at the samewidth has the warp in the reed, before it is taken up.

d. Brake: The brake stops the loom immediately whenever required. Theweaver uses it to stop the loom to repair broken ends and picks.

e. Warp stop motion: The object of the warp stop motion is to stop the loomimmediately when a warp thread breaks during the weaving process.


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Rapier Loom: In this type of weaving, aflexible or rigid solid element, called rapier isused to insert the filling yarn across the shed.The rapier head picks up the filling yarn and

carries it through the shed. After reaching thedestination, the rapier head returns empty to

pick up the next filling yarn, which completes acycle. A rapier performs a reciprocating motion.

Insertion of weft by rapier is a mechanicallymodern and refined version of the primitivemethod of fabric production. Rapier weavingmachines are known for their reliability and

performance. Rapier looms operate at speedsranging from about 200 to 260 ppm.

The advantage of rapier weaving machineare:

Minimum filling breaks.

Fewer machine stops.

Better fabric quality.

Higher productivity of machineand staff

Weaker filling yarn can be used.

Correct setting of filling wastelength and consequence lesswaste.


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Pic: Rapier loom

With double rapier system, normallytwo rapier inserted in shed fromopposite side and the weft istransferred from one to the other when they meet and there after theyare withdrawn. Weft supplied fromsingle package may be inserted as aloop is straightened out duringrapier withdrawal from shed or theend of the weft is transferred fromone rapier to another rapier.


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Air-Jet Loom: Ari-jet weaving is a type of weaving in which the filling yarn isinserted into the warp shed with compressed air. It is an advanced weaving method

with high efficiency and productivity.

The advantage of air jet weaving machine are:

High productivity.

Low initial outlay.

High filling insertion rates.

Simple operation and reduce hazard because of few moving parts.

Reduced space requirements.

Low noise and vibration levels.

Low spare parts requirements.

Reliability and minimum maintenance.


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Air-jet looms are suitable for use with medium weight yarns than very light andvery heavy yarns with operating speeds up to 600 ppm.

The air jet loom consists of 5 sets of

nozzles. Each set further comprises of fiverelay nozzles. The main function of relaynozzle is to guide yarn to the receivingend. There is a profile reed to guide theyarn for smooth flow andthe according to width of fabric Yarnfeeders are used which accumulates theincoming weft yarn.Pic: Air-jet Loom


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4.7. INSPECTION & FOLDINGGrey Fabric Inspection occurs in fabric inspectionfor the weaving/ spinning defects. The removabledefects are removed and noted down, andirremovable defects location is noted down and thefrequency is noted. There is a roller attachedcounter which counts the number of metersinspected and helps in location the position of thedefect. Then the fabric is folded in a desire length.

Pic: Fabric Inspection.

5. CONCLUTION

The purpose of this report is to explain what we did and learnt during our study period with Mitali Textile Mill (MTM). We have tried to sum upall the production processes in this report and also tried to give sometechnical assistant in this field.It is hoped that this report would serve as a cardinal vehicle to the improvementof the study program.

report on waving

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