What is Micro Fiber? | Properties of Microfibers

What is Micro Fiber? 

Microfiber or microfiber is synthetic fiber finer than one or 1.3 denier or decitex/thread. This is 1/100th the diameter of a human hair and 1/20th the diameter of a strand of silk. The most common types of microfibers are made from polyesters, polyamides (e.g., nylon, Kevlar, Nomex, trogamide), or a conjugation of polyester, polyamide, and polypropylene (Prolen).

Microfiber combines two basic fibers, Polyester and Polyamide (a Nylon by-product). These fibers are usually “split” and formed into a woven fabric of 80% Polyester (the scrubbing and cleaning fiber), and 20% Polyamide (the absorbing and quick drying fiber).

These threads are very small in diameter making them super soft. Rated in denier, the unit for measuring fineness of fabric, a strand of cotton has a rating of 200. A human hair has a denier of 20 and a strand of silk has a denier of 8. Microfiber has a denier of 0.01 to 0.02! At minimum, 100 times finer than a human hair. Softer than silk, yet bull-dog tough, split Microfiber cloth attracts dust, grime, oily films and salt residues like a magnet.

The unique surface structure of split Microfiber cloth contains hundreds of thousands of micro fiber “hooks” per square inch! These micro-hooks grab, lift, and hold dust and grime without the need for cleaning solutions. Microfiber cloth can be used damp or dry. Used dry, Microfiber cloth works like a chamois. The super absorbent weaves holds up to seven times its weight in fluid and will not scratch paint, glass, acrylics or plastic window tint films.

Properties of Microfibres 
Microfibers are made solely from man-made fibers. They are the finest of all the fibers. Sportswear from microfibers functions particularly well. It is breathable and at the same time provides reliable protection against wind and rain. Fashionable apparels in microfibers have graceful flow, silk-like feel and are extremely comfortable. Microfiber clothing is not sensitive, retaining its positive qualities after washing or cleaning.

Comparison of microfiber with other textile fiber

General Properties of Microfibers 

1. Ultra-fine linear density (less than 0.1 dtex/f), finer than the most delicate silk.
2. Extremely drapeable & Durability.
3. Very soft, luxurious hand with a silken or suede touch.
4. Washable and dry-cleanable.
5. Shrink resistance.
6. High strength, although the filaments are super fine.
7. Insulates well against wind, rain and cold.
8. Anti-microbial agents help to protect both family members and work staff from the dangers of the bacteria that cause odor and mildew.
9. Microfibre is hypoallergenic, and so does not create problems for those suffering from allergies.
10. Microfibre is non-electrostatic.
11. Microfibres are super-absorbent, absorbing over 7 times their weight in water.
12. Microfiber dries in one-third of the time of ordinary fibres.
13. Microfibres are environmentally friendly
14. Improved breathability
15. Vivid prints with more clarity and sharper contrast
16. Appearance retention
17. Can be made windproof and water resistant
18. The greater fiber surface area also results in higher rates of dyeing at lower temperatures, and decreased fastness to light, crocking (fastness to rubbing), water & ozone.

Preparation of weaving machines

To obtain satisfactory weaving performance, it is essential to have not only a correct yarn preparation, but also an efficient organization which permits to have warps available at the right moment, thus avoiding any dead time with style or beam change. All these prerequisites aim at ensuring to the weaving mills a sufficient flexibility and at permitting them to cope promptly with a variable market demand.

Currently several weaving mills have installed weaving machines which enable to perform the quick style change (QSC), leading to a considerable reduction of the waiting time of the machine.

The following chart presents the possible alternatives for the preparation of the weaving machine:

Changing style means producing a new fabric style, weaver’s beam changing means going on weaving the same fabric style just replacing the empty beam with a full beam of same type. Drawing-in consists of threading the warp yarns through the drop wires, the healds and the reed (fig.1). Depending on the styles of the produced fabrics and on the company’s size, this operation can be carried out manually, by drawing-in female workers operating in pairs (a time consuming activity which requires also skill and care), or by using automatic drawing-in machines.

Fig. 1− Drawing-in:

Fig. 2 shows one of the most established heald drawing-in machines. The drawing-in begins by placing the weaver’s beam, the harness and the row of healds on the proper anchor brackets, then the drawing-in program is typed in on the computer and the machine is started. A sort of long needle picks up in sequence the threads and inserts them with only one movement into the drop wires, the healds and the reed dents, which are selected each time and lined up to that purpose. The computer controls the different functions and supervises them electronically, ensuring the exact execution of the operation and interrupting it in case of defects. The machine can be used with the usual types of healds, drop wires and reeds and can process a wide range of yarn types and counts, from silk yarns to coarse glass fibre yarns. The drawing-in speed can in optimum conditions exceed 6,000 threads/hour.

Fig 2.: Heddle drawing-in machine:

Fig. 30 presents another automatic drawing-in machine which carries out same functions as previous machine, however without needing the weaver’s beam. In fact it is fed by a common cotton twine which it inserts among the various elements of the warp stop motion, of the harness and of the reed according to the program set up on the computer and under its control and supervision. At the end of the drawing-in, the drawn-in devices are moved on the frame of a knotting station in which an automatic warp tying-in machine joins the drawing-in threads together with the threads of the beam. This operation can be made also on board the loom.

Fig 3:– Automatic drawing-in machine (Staubli KK / Korea Branch):

This machine offers the advantage of working always under optimum operating conditions (use of same yarn), independently of the quality of the warp to be prepared and in advance in respect to warping, therefore with higher flexibility. The drawing-in rate can reach 3600 threads/hour. Fig.4  shows a harness and a reed with already drawn-in threads, ready to be brought to the knotting station.

Fig. 4:–  A harness and a reed with drawn-in threads ready to be moved to the knotting station:

The piecing-up of the warp yarns (Fig. 5) permits to the weaving mills which are in a position to use it (not many mills at the moment) to simplify and speed up considerably the loom starting operations in case of warps which were drawn-in or tied-up outside the weaving machine. The warp threads are laid into a uniform layer by the brush roller of the piecing-up machine and successively pieced-up between two plastic sheets respectively about 5 cm and 140 cm wide, both covering the whole warp width.

The plastic sheet can be inserted into the weaving machine simply and quickly, avoiding to group the threads together into bundles; the threads are then pieced-up on the tying cloth of the take-up roller.

Fig. 5 − Piecing-up:

If a new drawing-in operation is not necessary (this expensive operation is avoided whenever possible) because no style change is needed, the warp is taken from the beam store and brought directly to the weaving room, where it is knotted on board the loom to the warp prepared with the knotting machine.

As an alternative to the usual knotting on board the loom, the knotting outside the loom or stationary knotting of a new warp with an already drawn-in warp can be carried out in the preparation department. The devices bearing the threads of the old warps are taken from the weaving machine and the knotting can be started in the preparation room under better conditions, leaving the weaving machine free for rapid cleaning and maintenance operations.

The stationary knotting, in particular, takes place in following stages:

• Taking out of the loom the prepared beam with the harness
• Transport of the beam into the weaving preparation department
• Fastening of the heald frames and of the reed on the proper frame
• Knotting
• Passing of the knots by proper drawing
• Warp piecing-up
• Temporary maintenance of the new warp with the harness
• Transport of the new warp inclusive of harness with proper carriage
• Loading of the weaving machine and start of the weaving process using plastic sheet (fig.7)
• Weaving

Fig. 6 − A knotting machine in operation on a warp with colour sequence, tensioned on the proper frame:

Fig. 7 − Harness loading in the weaving machine:

The automatic knotting machines can process a wide range of yarn types and counts at highly reliable and rapid operating conditions (up to 600 knots/minute), with mechanical or electronic control on double knots and on the sequence of warp patterns in case of multi-coloured warps. Fig. 6 shows a knotting machine in operation on a warp with colour  equence, tensioned on the proper frame.

Principle of Winding Machine

There are two widely used types of winding machine:

1.) drum winders (used to wind staple-spun yarns into random-wound packages)

2.)precision winders (for winding filament yarns into precision-wound packages).

1.) drum winders:

They are also called as “Random Winders”. Drum-winding machines rotate the forming package through surface contact with a cylindrical drum, and the yarn is traversed either by an independent traverse, typically a wing cam, or by grooves in the drum. Figure  1   illustrates the two types of traverse systems

Fig 1: Winding traverse motion

• Wing Cam:

There are several different independent traverse systems, but the simplicity of the wing cam makes it a useful example to describe. As shown, the end, A, of a yarn guide bar moves the yarn while the other, B, is made to move around the periphery of the cam, traveling one circuit of the periphery per revolution of the camshaft. As B makes one circuit of the cam, A reciprocates, moving the yarn through a return traverse (i.e., double traverse) along the length of the bobbin. The reciprocating yarn guide limits the winding speed because of the inertia on reversals. A very high rate of traverse is impeded by the mechanics of the guide system, since forces of 16 to 64 times the weight of the yarn guide can be present during the reciprocating action. The reciprocating guide can be replaced by a spirally grooved traverse roller, which moves the yarn along the traverse length. In this case, only the yarn undergoes reversal as it is held in the traversing groove of the rotating roller, and speeds in excess of 1500 m/min can be achieved. A further advantage of the grooved traverse roller is that, as a result of tension, the yarn being wound enters the groove without the need for threading up as is required with the independent traverse system.

• Grooved Drum:

With the grooved drum system, the surface speed of the drum, and the traverse speed are kept constant. A continuous helical groove (i.e., interconnected clockwise and counter clockwise helical grooves) around the drum circumference guides the yarn along the traverse length as the yarn is wound onto the bobbin. A continuous helix has points of crossover of the clockwise and counter clockwise helices. To retain the yarn in the correct groove during its traverse, particularly at the intersections, one groove is made deeper than the other, and the shallower groove is slightly angled.

2.)precision winders:

They are also known as Spindle driven Winders. the Principle of precision winder is as shown in figure.

With precision winders, the package is mounted onto a drive spindle, and a reciprocating yarn guide, driven by a cylindrical cam coupled to the spindle drive, is used to move the yarn along the traverse length. The reciprocating yarn guide limits the winding speed because of the inertia on reversals.

The term precision refers to the control of positioning each layer of yarn as it is wound onto the bobbin. There is a precise ratio of spindle to traverse speed. Therefore, as the package diameter increases, the wind and TR are kept constant.

Fabric Construction and Weaving Operations

Fabric Construction:

Textiles are important for everyone. It is used for covering body, for warmth or coolness, personality enhancement and sometimes to display one’s status in the society. From the wholesale textile manufacturer and merchant to the retailer and the end- user, the customer, everyone consumes textile. Not only those who are in this direct trade are related to this product but there are certain industries which are indirectly associated with textile. Automobile industry is a good example of this type of industry which uses textile in various forms. Others who use textile in one or the other form may include designers, interior decorators, craftspersons, advertisers using hoardings and banners, painters etc.

Weaving- What is it?

Weaving is a major process of making fabric or cloth . In it, two distinct sets of yarns called the warp and the filling or weft are interlaced with each other to form a fabric. Yarn is a long continuous length of interlocked fibers. The lengthwise yarns which run from the back to the front of the loom are called the warp. The crosswise yarns are the filling or weft. A loom is a device for holding the warp threads in place while the filling threads are woven through them. Yarns made from natural fibers like cotton, silk, and wool and synthetic fibers such as nylon and Orlon are commonly used for weaving textile. But other fibers can also be used for weaving. Yarn intended for the warp goes through operations such as spooling, warping and slashing to prepare them to withstand the strain of the weaving process.

Weaving operations:

Four major operations are involved in weaving- Shedding, Picking, Beating up (Battening) and Taking up and letting off.

Shedding:

Each alternate warp yarn is raised to insert the filling yarn into the warp to form a shed.

Picking:

As the warp is raised, the filling yarn is inserted through the shed by a carrier device. Different types of looms are used for carrying the filling yarn through the shed- Shuttle loom, shuttle less looms, circular looms etc.

Beating up (Battening):

With each picking operation, the reed pushes or beats each filling yarn against the portion of the fabric that has already been formed. Reed is a comb like structure attached to the looms. It gives the fabric a firm, compact construction.

Taking up and letting off:

With each shedding,Picking, Battening operation, the new fabric must be wound on the cloth beam which is called ‘taking up’. At the same time, the warp yarns must be released from the warp beam which is called l ‘letting off’.

As the shuttle moves back and forth across the width of the shed, a self edge is woven which is called selvage or selvedge. The selvage prevents the fabric from muddling. It is usually more compact and strong than the rest of the fabric. There are different kinds of selvages depending upon the expected use of the fabric- Plain Selvages, Tape Selvages, Split Selvages, Fused Selvages, Leno Selvages and Tucked Selvages.

Knitting:

After weaving, the most prevalent method of fabric construction is knitting. Its popularity has grown tremendously over the recent years . Today, knitting is a very big industry which has two main divisions.

One division manufactures knitted goods for apparel production, sewing centers, consumers and others. The other division manufactures finished apparel such as hosiery, sweaters and underwear.

The knitted fabric has the advantage of stretchability which provides fit and comfort. It also gives warmth. At the same time, they are porous and provide breathing comfort. It is light in weight and wrinkle- resistant. However, certain specialized techniques like Pak- nit or Permasized have to be used so that it may not shrink too much. Also, care should be taken so that not a single loop breaks. If even one loop breaks, a hole is made and it starts running. This disadvantage can be eliminated by variation in the stitch that protects the fabric from raveling.

The kind and quality of the needle also affect the quality of the knitted fabric. Different kinds of needles are used in knitting latch needle, spring- beard needle, compound needle etc.

Weft and warp knitting:

There are two major varieties of knitting: weft knitting and warp knitting. In weft knitting, one continuous yarn forms courses across the fabric. In warp knitting, a series of yarns form wales in the lengthwise direction of the fabric.

The knitting machine also called knitting frame, knitting loom, or hand knitting machine, is used to manufacture knit fabrics. These fabrics are produced on a fixed bed of hooked needles. The Knitting machines can be hand driven or motor powered.

The machines come in domestic and industrial models, with either flat or circular beds that produce rectangular or tubular fabrics. The fabric produced by a knitting machine has a more fine texture than hand-knitted fabric.

December 27, 2013

Basic Weaving Operations With Warps & Wefts Weaving Preparing

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Weaving:

Weaving is the most basic process in which two different sets of yarns or threads are interlaced with each other to form a fabric or cloth. One of these sets is called warp which is the lengthwise yarn running from the back to the front of the loom. The other set of crosswise yarns are the filling which are called the weft or the woof.

Preparing Warps and Wefts for Weaving:
The warps form the basic structure of fabrics. As such, they are made to pass through many operations before actual weaving is done. These
operations include spooling, warping and slashing. In spooling, the yarn is wound on larger spools, or cones, that are placed on a rack known as creel. From the creel, the yarns are wound on a warp beam, which looks like a huge spool. These lengths of hundreds of warped yarns lie parallel to one another. These yarns are unwound for slashing, or sizing. The yarn is coated with sizing with the help of slasher machine. Slashing prevents chafing or breaking of yarns during weaving process. Sizing is either starch based or a synthetic like polyvinyl alcohol or a water soluble acrylic polymers. The sized yarns are then wound on a final warp beam and are ready for the loom.

The filling yarns experience less strain during the weaving process. Their preparation includes spinning them to the required size and giving them just the right amount of twist desired for the kind of fabric they will be used.

Basic Weaving Operations:
No matter what type of weaving is being done, four major operations are performed in sequence and are continuously repeated.

Shedding:
In shedding, alternate warp yarns are raised to insert the filling yarn into the warp to form a shed. Shedding is automatically performed by the harness on the modern weaving looms. Harness is a rectangular frame to which a series of wires, called heddles, are attached. As each warp yarn comes from the warp beam, it passes through an opening in the heddle. The operation of drawing each warp yarn through its appropriate heddle eye is known as drawing in.

Picking:
As the warp yarns are raised through shedding, the weft yarn is inserted through the shed by a carrier device. A single crossing of the filling from one side of the loom to the other is called a pick. Different methods are used for carrying the filling yarn through the shed in different kinds of looms. There are many types of looms including shuttle loom, shuttle less loom, and circular loom.

Beating Up:
This weaving operation is also called battening. In it, all warp yarns pass through the heddle eyelets and through openings in another frame that looks like a comb and is known as reed. With each picking operation, the reed pushes or beats each weft yarn against the portion of the fabric that has already been formed. It results in a firm and compact fabric construction.

Taking Up and Letting Off:
As the shedding, picking and battening processes are being operated, the new fabric is wound on the cloth beam. This is known as ‘taking up’. At the same time, the warp yarns are released from the warp beam which is known as ‘letting off’.

The pattern of the weave depends on the manner in which groups of warped yarns are raised by the harnesses to allow the insertion of the weft yarn. These differences are responsible for producing different types of fabric weaves. Weave patterns can create various degrees of durability in fabrics apart from their utility and looks.

Shuttle Loom:

The shuttle loom is the oldest type of weaving loom which uses a shuttle which contains a bobbin of filling yarn that appears through a hole situated in the side. The shuttle is batted across the loom and during this process, it leaves a trail of the filling at the rate of about 110 to 225 picks per minute (ppm). Although very effective and versatile, the shuttle looms are slow and noisy. Also the shuttle sometimes leads to abrasion on the warp yarns and at other times causes thread breaks. As a result the machine has to be stopped for tying the broken yarns.

Shuttle less loom: 

Many kinds of shuttle less looms are used for weaving such as Projectile Looms; Rapier Looms; Water Jet Looms; and Air Jet Looms.

Projectile Loom:

 It is sometimes called missile loom as the picking action is done by a series of small bullet like projectiles which hold the weft yarn and carry it through the shed and then return empty. All the filling yarns are inserted from the same side of the loom. A special tucking device holds the ends of the wefts in place at the edge of the cloth to form the selvage. This loom needs smooth, uniform yarn which is properly sized in order to reduce friction. Projectile loom can produce up to 300 ppm and is less noisier then the shuttle loom.

Rapier Loom: 

Rapier loom comes in many types. Early models of it use one long rapier device that travels along the width of the loom to carry the weft from one side to the other. Another type of rapier loom has two rapiers, one on each side of the loom. They may be rigid, flexible or telescopic. One rapier feeds the weft halfway through the sheds of warp yarns to the arm on the other side, which reaches in and carries it across the rest of the way. Rapier looms are very efficient and their speed ranges from 200 to 260 ppm. These looms can manufacture a variety of fabrics ranging from muslin fabric to drapery fabrics and even upholstery fabrics.

Water Jet Loom: 

In it, a pre measured length of weft yarn is carried across the loom by a jet of water. These looms are very fast with speeds up to 600 ppm and very low noise. Also they don’t place much tension on the filling yarn. As the pick is tension less, very high quality of warp yarns are needed for efficient operation. Also, only yarns that are not readily absorbent can be used to make fabrics on water jet looms such as filament yarn of acetate, nylon, polyester, and glass. However, it can produce very high quality fabrics having great appearance and feel.

Air Jet Looms: 

In the air jet weaving looms, a jet of air is used to propel the weft yarn through the shed at speeds of up to 600 ppm. Uniform weft yarns are needed to make fabrics on this loom. Also heavier yarns are suitable for air jet looms as the lighter fabrics are very difficult to control through shed. However, too heavy yarns also can’t be carried across the loom by air jet. In spite of these limitations, air jet loom can produce a wide variety of fabrics.

Circular Looms: 

These looms are particularly used for making tubular fabrics rather than flat fabrics. A shuttle device in it circulates the weft in a shed formed around the machine. A circular loom is primarily used for bagging material.

Different Types of Yarn Spinning System

Spinning:

The present participle of the verb ‘to spin’ used verbally, adjectivally, or as a noun, meaning process or the processes used in the production of yarns or filaments.The term may apply to: (i) The drafting and, where appropriate, the insertion of twist in natural or staple man-made fibres to form a yarn;
(ii) The extrusion of filaments by spiders or silkworms; or
(iii) The production of filaments from glass, metals, fibre-forming polymers or ceramics.

Ring spinning

In the spinning of man-made filaments, fibre-forming substances in the plastic or molten state, or in solution, are forced through the holes of a spinneret or die at a controlled rate. There are five general methods of spinning man-made filaments i.e. dispersion spinning, dry spinning, melt spinning, reaction spinning, and wet spinning, but combinations of these methods may be used.

In the bast and leaf-fiber industries, the terms ‘wet spinning’ and ‘dry spinning’ refer to the spinning of fibres into yarns in the wet state and in the dry state respectively.

Open-end Spinning;

Break Spinning:
A spinning system in which sliver feed stock is highly drafted, ideally to individual fibre state, and thus creates an open end or break in the fibre flow. The fibres are subsequently assembled on the end of a rotating yarn and twisted in. Various techniques are available for collecting and twisting the fibres into a yarn, the most noteworthy being rotor spinning and friction spinning.Rotor Spinning:
A method of open-end spinning which uses a rotor (a high-speed centrifuge) to collect individual fibres into a yarn is known as Rotor spinning. The fibers on entering a rapidly rotating rotor are distributed around its circumference and temporarily held there by centrifugal force. The yarn is withdrawn from the rotor wall and, because of the rotation, twist is generated.

Friction Spinning:
A method of open-end spinning which uses the external surface of two rotating rollers to collect and twist individual fibres into a yarn is known as Friction spinning. At least one of the rollers is perforated so that air can be drawn through its surface to facilitate fibre collection. The twisting occurs near the nip of the rollers and, because of the relatively large difference between the yam and roller diameters, high yarn rotational speeds are achieved by the friction between the roller surface and the yarns.

Air-jet Spinning:
A system of staple-fibre spinning which utilizes air to apply the twisting couple to the yarn during its formation is known as Air-jet spinning. The air is blown through small holes arranged tangentially to the yarn surface and this causes the yarn to rotate. The majority of systems using this technique produce fasciated yarns, but by using two air jets operating in opposing twist directions it is possible to produce yarns with more controlled properties but of more complex structure.

Centrifugal Spinning:
A method of man-made fiber production in which the molten or dissolved polymer is thrown centrifugally in fibre form from the edge of a surface rotating at high speed. The term is also used to describe a method of yarn formation involving a rotating cylindrical container, in which, the yarn passes down a central guide tube and is then carried by centrifugal force to the inside of a rotating cylindrical container.

Dispersion Spinning:
A process in which the polymers that tend to an infusible, insoluble, and generally intractable character (e.g., polytetrafluoroethylene) are dispersed as fine particles in a carrier such as sodium alginate or sodium xanthate solutions is known as Dispersion spinning. These permit extrusion into fibers, after which the dispersed polymer is caused to coalesce by a heating process, the carrier being removed either by heating or by a dissolving process.

Draw-Spinning:
A process for spinning partially or highly oriented filaments in which the orientation is introduced prior to the first forwarding or collecting device.

Dry Spinning (man-made fiber production):
The spinning process involving conversion of a dissolved polymer into filaments by extrusion and evaporation of the solvent from the extrudate is known as Dry spinning.

Flash Spinning:
A modification of the accepted dry-spinning method in which a solution of a polymer is extruded at a temperature well above the boiling point of the solvent such that on emerging from the spinneret evaporation occurs so rapidly that the individual filaments are disrupted into a highly fibrillar form.

Flyer Spinning:
A spinning system in which yarn passes through a revolving flyer leg guide on to the package is known as Flyer spinning. The yarn is wound-on by making the flyer and spinning package rotate at slightly different speeds.

Melt Spinning (man-made fiber production):
The spinning process involving conversion of a molten polymer into filaments by extrusion and subsequent cooling of the extrude is known as Melt spinning.

Reaction Spinning (man-made-fiber production):
A process in which polymerization is achieved during the extrusion of reactants through a spinneret system.

Ring Spinning:
A spinning system in which twist is inserted in a yarn by using a revolving traveller is known as Ring spinning. The yarn is wound on since the rotational speed of the package is greater than that of the traveller.

Wet Spinning (man-made-fiber production):
The spinning process involving conversion of a dissolved polymer into filaments by extrusion into a coagulating liquid is known as Wet spinning. The extrusion may be directly into the coagulating liquid or through a small air-gap. In the latter case it may be known as dry-jet wet spinning or air-gap wet spinning.

August 31, 2013

Airlaid Web Formation Technique

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PRINCIPLE OF WEB FORMATION IN A SIMPLE AIR LAYING PROCESS:

RAW MATERIAL: 

• Natural or man-made textile fibre (cut length >25 mm)
• Short cut fibres (generally <25 mm)
• Wood pulp (1.5–6 mm)

Air laid fabric compared with carding technology has these features: 

• The fibers are oriented randomly on the fabric surface – isotropic structure.
• Voluminious webs can be produced
• The range of the area weight is wider (15 – 250 g/m2) but the mass uniformity of light air laid (up to 30 g/m2) is bad.
• Wide variety of processable fibers

AIR LAID – PRODUCTION PROBLEMS: 

• Low level of opening fiber material by lickerin roller Thus is suitable to use pre-opened fibers or combine air laid with card machine – Random card machine.

• Variable structures of web in width of layer due to irregular air flow close to walls of duct . This problem requires high quality design of duct.

• Possible entangling of fibers in air stream. This problem can be reduced by increasing the ratio air/fibers which nevertheless means decrease in performance and increase of energy consumption due to high volume of flowing air.

The relation between air flow and performance of device shows the importance of fiber length and fiber diameter. QA is air flow, K is device constant, P is performance of device (kg/hour), L is lenght of fiber staple (m) and D is fiber fineness (dtex).

QA = K.P.L2/D

Thus is suitable to use short fibers for this technology.

Random cards – combination of air laid and carding technology:

A major objective of this combination is isotropic textile fabric (random orientation of fibers) with good mass uniformity of light fabrics and with high production speed.

• The first part – card machine opens perfectly fibrous material so single fibers are as a output.
• The second part – air laid system uses the centrifugal force to strip the fibers off a roller and. put them down on an air controlled scrim belt.

Main variations of random cards I. Airlaid function of random card:

1) Random roller between main cylinder and doffer, which rotate in the opposite direction of the main cylinder.

MAIN VARIATIONS OF RANDOM CARDS:

Main variations of random cards II:

2) Centrifugal force of mean cylinder strips the fibers off.

AIR LAID AND RANDOM CARDS: USED FIBERS: 
Synthetic fibres, viscose, cotton and blends thereof; natural fibres such as flax, hemp, sisal etc.; Reclaimed textile waste and shoddy, cellulose pulp 1.7 – 2000dtex. Max. 120 mm staple length

FEEDING SYSTEM OF RANDO WEBBER:

RANDO-WEBBER SYSTEMS WITH PERFORATED SCREEN:

RANDO-WEBBER SYSTEMS WITH CYLINDRICAL CONDENSERS:

Rando–webber:

• Relatively narrow widths up to about two metres
• Webs of 10– 3000 g/m 2
• Virgin or recycled fibres
• Filtration, home furnishings, automotive fabrics, insulation and some medical specialities

RANDOM CARD K12 OF DR. E. FEHRER:

HIGH-PRODUCTION RANDOM CARD K21 OF DR. E. FEHRER:

• K12 is more particularly suited to coarse fibres (10–110 dtex), Basic weight range 20– 2000 g/m 2
• K21 is more particularly suited to synthetic and viscose rayon fibers of (1.7–3.3 dtex), Basic weight range 10–100 g/m 2

SCHEMATIC VIEW OF THE DOA AIRLAYING SYSTEM:

SCHEMATIC VIEW OF THE AIR LAYING SYSTEM:

CHICOPEE AIRLAYING SYSTEM:

• Air velocity ( 140 m/s)
• Surface speed of the cylinder ( 20–60 m/s)
• Staple fibres ranging from 13–75 mm

SPINNBAU AIRLAYING SYSTEM:

THIBEAU HYBRID CARD AIRLAYING MACHINE:

Thibeau hybrid system: 

• Typical MD/CD ratio of 1.2–1.5:1
• Production rate of 200–260 kg/h/m
• Web weights of 35–200 g/m 2
• Fibre types cotton, viscose rayon, PET, PP, PA
• Fibre length of 10–40 mm.

“TURBO-UNIT”

TURBO-CARD RC 2-6 TR:

Turbo-Unit and Turbo-Card: 

• The turbo-unit TU is either fed by pre-carded webs via a feed plate intake or may be combined with a random card.
• The turbo-roll is equipped with carding segments.
• Aerodynamical web-forming by centrifugal force, doffer fan and suction conveyor
• Lower to medium fibre fineness range
• Staple length: approx. 10 – 80 mm
• Web weight: approx. 25 – 450 g/m 2
• Throughput depending on fibre fineness and fibre type: up to approx. 400 kg/h/m of working width
• Working widths: up to 4.000 mm
• Web speed: approx. 20 – 120 m/min

WEB FORMING MACHINE 008-0445 OF LAROCHE S.A.:

Laroche System: 

• Web weight ranges from 300 to 3000 g/m 2
• Production speed of up to 10–15 m/min
• Fibre length should be in the range 20–75 mm
• Cotton, man-made, glass fibres
• Hemp, flax, sisal, coconut
• Bed covers, mats, upholstery and insulation material, carrier material for carpets, industrial and geotextiles as well as furniture textiles

GENERAL PROPERTIES OF AIRLAID FABRICS: 

• HIGH ISOTROPICITY
• HIGH LOFT (IF REQUIRED)
• HIGH POROSITY (95–>99%)
• HIGH ABSORBENCY AND WICKING RATE
• SOFT HANDLE
• ADEQUATE TENSILE STRENGTH
• GOOD RESILIENCY (COMPRESSION RECOVERY)
• HIGH THERMAL RESISTANCE.

Air laid and random cards: end products:

• Chemical bonding: napkins, table cloths and wipes
• Thermal bonding: nappies (different components, i.e., acquisition layer, distribution layer and absorption core), feminine hygiene/incontinence products and insulation
• Spunlacing: wet and dry wipes for domestic and industrial applications medical textiles (including disposable gowns, curtains, wound-care dressings, bed sheets), filtration media
• Needle punching: interlinings and shoe linings, wadding, medical and hygiene products, geotextiles and roofing felts, insulation felts, automotive components, filters, wipes

Combination of unidirectional and cross directional web:

CROSSLAPPER WITH HORIZONTAL LAYING DEVICE:

Tasks of the web-laying machine:

• Increasing the web mass
• Increasing the web width
• Determining the web strength in the length and cross directions
• Improving the end product quality

LAP DRAFTER VSTG:

WORKING WIDTH UP TO 7.000 MM. INDIVIDUAL SERVO-DRIVES FOR 4 DRAFTING ZONES WITH INFINITELY VARIABLE DRAFTS. ONLY LITTLE CHANGES OF BATT WEIGHT REGULARITY BY FIBRE RE-ORIENTATION INCREASE STRENGTH IN MD.

MERITS AND LIMITATIONS OF CARD – CROSS LAPPING AND AIR LAYING:

August 31, 2013

3D Weaving Manufacturing Process of 3D

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3D-Weaving:

3D-Weaving is a complete new concept in case of weaving. The first method of 3D woven fabric denotes 3 Dimensional fabrics, that is length, width and breadth. In 3 Dimensional fabrics, the thickness is an important criterion. Ordinary fabrics also have length, width and breadth, but in the 3 Dimensional fabrics, the thickness is much more than ordinary fabric. The thickness is achieved by forming multiplayer using multi series of warp and multi series of weft, which are intersecting at regular 90o angle as in usual cloth weaving principle.

It cannot be performed with existing traditional methods and machines. It interlaces a multiple layer warp with multiple horizontal wefts and multiple vertical wefts producing directly shell, solid and tubular types of fully interlaced 3D fabrics with countless cross-sectional profiles.First demonstrated in 1997, Dual-Directional (D-D) Shedding System is indispensable for performing 3D-weaving. This path breaking development has advanced the technology of weaving to a new dimension for the first time in its more than 27000 years of history.