The Karl Mayer Guide to Technical Textiles

KM

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Contents Page

Introduction 4

Basic constructions 9

Three-dimensional structures 13

Directionally oriented structures 18

Composite fabrics 26

Stitch-bonded nonwovens 31

Please note: Warp knitting machines are divided in two categories: tricot machinesand Raschel machines. In most cases Raschel machines are used forthe production of technical textiles.

Stitch-bonding machines are regarded as a special form of warpknitting machines, especially suited for the manufacture of technicaltextiles, nonwovens and composites.

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Introduction

The production of technical textiles is a rapidly developing trade in textile industry.New end-uses are developed daily and in most cases technical textile structuresare used to replace expensive, heavier or technically inferior constructionstraditionally produced from other materials. To achieve the objective of afavourable performance/cost ratio, the structures and production methods must be carefully designed.

Warp knitting is by far the most versatile fabric production system in textiles.Warp knitted fabrics can be produced elastic or stable, with an open or closedstructure; they can be produced flat, tubular or three-dimensional. Fabric widthcan be over 6 m without seams or even up to a multiple of this width if it is anet construction.

The new concept of fabric engineering was conceived during the evolution oftechnical textiles as a natural development of the trial and error methods. Thecommercially available fabrics failed in many cases to satisfy the specificationsset by the producer and the designers and textile engineers were called upon tocreate entirely new structures. The properties in this case have to be ,,built-in“ or applied to specific areas of the fabric at the correct orientation so as to withstand expected forces while maintaining economical production cost.

The flexibility of warp knitting techniques makes them attractive both to thedesigner and to the manufacturer of technical textiles. This guide is designed tomake the reader conversant with warp knitting technology, to demonstrate thebasic structural configurations available, and to show only a few of the multi-tude of end-uses actually associated with it.

The major yarn to fabric conversion systems are illustrated on the next page.Woven and weft knitted structures are well known due to their seniority in thehistory of mankind and their common use in apparel industry. Warp knittingtechniques, dating back only a couple of centuries, are virtually unknown to thetextile consumer and the products are frequently mistaken for woven or weftknitted ones. The loop structure of warp knitted fabrics is similar in appearanceto that of weft knitted structures. The mechanical properties are in many casessimilar to those of a woven cloth and even better for certain applications.

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Conventional textile structures

Woven fabric structure

Warp knitted fabric Bi-axial orientated structure

Knitted fabric (flat or circular knitted)

Some technical terms of warpknitted structures

1 - A warp-knitted loop2 - A stitch course - a horizontal row

of loops produced during oneknitting cycle.

3 - A wale - a vertical row of loopsproduced by a single needle.

4 - An underlap - a straight length ofyarn connecting the loops producedduring consecutive knitting cycles.

5 - Left side (technical back) - thefabric side illustrated. The underlapis on the surface.

6 - Right side (technical face) - thefabric side with the loops showingon the surface.

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The basic construction of a warpknitting machine is similar to that of a weaving machine, especially in theyarn supply system from warp beams(1) and the fabric batching via thetake-up (3). The fabric is produced,however, by intermeshing loops in theknitting elements (2) rather thaninterlacing warps and wefts as in a weaving machine.

Features of a typical warp knittingmachine in standard configuration (RS series):

- sturdy construction

- up to 6 guide bars (6 warp-beamunwinding points) for flexibility ofstructures, end product, and fabricdesign

- up to 40 needles per inch for open orvery dense structures

- up to 6.60 m working width

- up to 2,000 courses per minute

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The mechanism of loop formation

1 - The needles are at knock-over posi-tion - lowest position - after com-pletion of the previous stitch course. The holding-down sinkersare positioned in between theneedles.

2 - The needles ascend to clearingposition - highest position. The clo-sing elements rise to a less extentso that the hooks open. The fabricis secured by the holding-downsinkers.

3 - The yarn guides (guide bars) swingin between the needles to the hookside.

4 - The yarn guides are shogged side-ways by one needle and then swingback in between the needles. An overlap is produced. The holding-down sinkers start towithdraw.

5 - The needles descend. The closingelements descend slowlier so thatthe hooks are closed trapping thenewly wrapped yarns. The yarnguides are shogged sideways andstart to re-position (underlap).

6 - The needles descend to knock-overposition and the previous loop slipsfrom the needle stem over theneedle hook. The loops in theneedle hooks are interlaced withthe previous loop, thus producing a new course of loops.

The fabric producing elementsof a warp knitting machine

1 - Compound needle - The needles areassembled in a rigid needle bar andmove simultaneously.

2 - Slide (closing element) - The elements to close the needlehooks are placed in a rigid bar andoperate simultaneously.

3 - Knock-over bar

4 - Holding-down sinker - The sinkersare assembled in a rigid sinker barand act simultaneously.

5 - Yarn end - The yarn ends areusually fed off a warp beam.

6 - Yarn guides - The yarn guides -also called guide needles - are alsosimultaneously operated. One orseveral yarn guides are assigned toeach needle.

7 - Warp-knitted fabric

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Stitch-bonding as a special caseof warp knitting technique

Stitch-bonding is considered to be aspecial case of warp knitting techniquewhile the loop formation cycle is simi-lar to that of warp knitting. Importantdifferences are as follows:

- constructive design of stitch-bondingarea (e.g. horizontal needle arrange-ment, fixed retaining, backing rail)

- needle types applied („Stitching-needle“)

- reference size for machine gauge(number of needles per 25 mm)

- conversion of unbonded fibrous websto purely mechanically stitch-bondednonwovens to 100% from fibres

Characteristic features for stitch-bonding machines are:

- sturdy construction of machine- a maximum of two stitch-forming

guide bars- machine gauge up to 22 needles per

25 mm- high production output

up to 2,500 courses per minuteup to 6,100 mm working width

weitere Unterschiede:

1 - Warp-beam let-off position infront of machine and knitting yarnfeed from the front

2 - Fabric take-down verticallydownwards

3 - Fabric batching behind themachine

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Stitch-bonding elements:1 Stitching needle2 Closing wire3 Guide needle 1st guide bar4 Guide needle 2nd guide bar5 Knocking-over sinker6 Backing rail7 Retaining pin8 Warp guide needle

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Example: Stitch-bonding machine with chopper (glasschopping device)

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The structure illustrated herein is themost basic one. It is called tricot stitchor 1 and 1 (1 needle underlap and 1needle overlap).

It is dimensionally stretchable in thewidth . . .

. . . as well as in the length.

Basic constructions

Elastic structures

For a structure to be stretchable itshould be designed with:1 - open fabric construction2 - short underlaps.

Such a structure made of polyester or glass yarns is coated and mouldedinto a light-weight three-dimensionaland extremely tough „honeycomb“construction.

Example for end-use:False floor for private and institutionaluse to accommodate power and communication cables.

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Stable structures

To increase the lengthwise strength, a specific stitch construction is used(pillar stitch).

To increase the widthwise stability, the underlaps are lenghtened (e.g. satin stitch).

A dimensionally stable structure isachieved by combining these two types of stitch construction (e.g. pillar - satin).

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Open structures

One way to produce an open structureis to knit unconnected pillarscontinuously while a connectingunderlap by horizontal yarns isproduced only every few courses.

This open polyethylene net is used towrap pallet packing units, stacks ofcrates for safer shipment or asillustrated to stabilise round bales ofhay or straw in the field.

The structure shown in the illustration is used as shading net and can be produced in various shade grades.

Another way to produce an openstructure is to form loops continuouslyon the same needle and to interlacethem laterally at certain intervals.

The net shown in the photograph is for extremely heavy duty purposes. High-strength polypropylene orpolyester yarns are used therein. The net is used to protect persons andbuildings. Fishnets are other possibleend-uses.

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Closed structures

Closed structures of warp knittedfabrics can be produced by:

decreasing the loop size

using heavier yarn materials

making longer underlaps

using more guide bars

Example for end-use of closed structures:High-quality flags produced on anautomatic three-needle bar warpknitting machine

combining any of the above methods

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Three-dimensional structures

Three-dimensional structures can beproduced both on single-needle barwarp knitting machines (pile fabric)and on two-needle bar Raschelmachines (spacer or tubular fabrics).

Pile fabricsThe three-dimensional characteristicmanifests itself by pile loops on one or on both fabric faces. The loops areformed by means of pile sinkers orother auxiliary elements (e.g. via needles) or produced by enhanced yarn feed of individual systems.

The pile loops are fixed by:a) a stitch-forming yarn system provi-

ded in front of the pile systems, or

b) intermeshing of the front piles bythemselves

End-uses: Special cleaning cloths,incontinence wear, fibre-reinforcedplastics

Cleaning textiles (cleaning mop)

Spacer and tubular fabrics

The following diagrams are used todemonstrate the knitting principles ona double-needle bar Raschel machine.The following points should be noted:

1 The knitting action of each needlebar is similar to that of a standardRaschel machine.

2 The needle bars are operating alternately.

3 The guide bars swing between the needles of each needle bar in turn.

4 Each guide bar can be shogged tomake an overlap on either needle barand so form knitted loops on theselected needle bar. A warp-knitteddouble-face fabric is produced.

5 Typical features of warp-knitteddouble-face fabrics are:The fabric has got two right sides,that is, there are loop heads both onface and back.

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Guide bar 1 forms overlaps (loops) onlyon needle bar I. Guide bar 2 formsoverlaps (loops) only on needle bar II.Two separate fabrics are formed.

Guide bar 1 forms overlaps on needlebar II while guide bar 2 overlaps onlyneedle bar I. Two fabrics are produced.They are joined however by the under-laps into a single fabric sheet. The ideal way to produce a plateddouble-face fabric made of two materials.

Guide bar 1 is fully threaded and over-laps needle bar I. Guide bar 4 is alsofully threaded and overlaps needle barII. Guide bars 2 and 3 are threadedonly through one yarn guide each atthe extremities of fabric and overlapboth needle bars. A seamless tubularwarp-knitted fabric is formed. Withthe right threading arrangement many tubes can be formed across themachine and the diameter of tubes can easily be altered by changing thethreading arrangement.

Guide bar 1 is fully threaded andoverlaps needle bar I. Guide bar 4 isalso fully threaded and overlaps needlebar II. Guide bars 2 and 3 which arethreaded to form together a full set ofyarns overlap both needle bars. A spacer fabric is formed.

Warp-knitting cycles on a double-needle bar Raschel machine

Guide bars 1 and 2 are shogged tooverlap both needle bars (N I; N II) andso form loops on the respective needlebar. A knitted double-face fabric isproduced.

N I N II

N II

N I

N II

N II

N II

N II

N II

N IIN I

N II

N II

N I

N I

N I

N I

N I

N I

N I

1 2

1 2

1 2 3 4

1 2 3 4

1 2

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Horizontal tube production for sacks

Horizontal tubes can be producedusing the principles explained earlier.During phase 1, the guide bars aredriven to form two separate fabricfaces. During phase 2, the two fabricfaces are jointed to each otherhorizontally in certain intervals bychange in lapping. The colour-markedjoining guide bar produces the bottomseam of packing sack and joins the twofabric faces in vertical direction (3).

Here are a few examples for end-usesof sack structures (horizontal sacks ascontinuous packing sack runs) forvarious packing purposes, used infully-automatic packing lines.

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Vertical tube production

With a combination of fully threadedguide bars (A) to produce two separatefabrics and another combination ofpartly threaded guide bars to make the connection between the two guidebars and/or fabrics, tubes of differentsizes can be formed. With the appro-priate number of guide bars (B) evenbranched tubular structures can beproduced.

Use of coarse tubular structures aspacking materials.

Branched artificial blood arteries areproduced on a fine gauge Raschelmachine with 16 guide bars.

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Spacer fabric production

To form a spacer structure, fullythreaded guide bars are used to formeach of the side fabrics while anadditional fully threaded guide barjoins the two fabric sides by joiningthreads. The spacer fabric may be up to 60 mm in thickness.

The spacer fabric incorporatedherein offers an excellentseating comfort thanks to itsperfect climatic behaviour.

Here, an elastic spacer fabric is used asunderwear for diver’s suits.

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Directionally oriented structures

Directionally oriented structures orD.O.S. are unique multi-ply fabricswhich are produced by warpknitting/stitch-bonding techniques.With these techniques straight ends ofabsolutely parallel and noncrimpedyarns are inserted into the structuresat almost any desirable angle. Fabriccharacteristics can be engineered toenhance the in-plane properties onlyin the required orientations so that thefabric produced has the ideal combina-tion of excellent mechanical propertiesand cost-effective production.

Warp direction: mono-axial

Multi-axial

Diagonal: bi-axial

Weft direction: mono-axial Diagonal and weft: tri-axial

Perpendicular: bi-axial Diagonal and horizontal: tri-axial

The range of D.O.S.:

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Heat-reflecting and shade-providingwarp-knitted sun-protection fabric.The special properties of this structureare: economical production, highstrength and high dimensional stability.No sagging of the fabric and goodrolling behaviour due to stretched weft yarn layers. The porous structureprevents heat accumulation andensures additional shading. The aluminium coating serves for sun reflection and heat insulation.

This close-up photograph shows thesimplicity of this structure, the unifor-mity of the yarn arrangement, and thefine loop binding element.

Mono-axial structures

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Bi-axial structures

Bi-axial technical structures are formed as a combination of magazineweft insertion and a mislapping guidebar to obtain the lengthwise andwidthwise reinforcement respectively.

High-quality laminating substrate foradvertising sheets, backlit awnings,sun protection, camping chairs, anddeck chairs

Bi-axial, dimensionally stable structuresfor coating and laminating

Mega-Poster for advertising applica-tions, open structure, coated, ink-jetprinted of up to 5 m in width

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Advantages of mono- and bi-axial D.O.S.

Unlike the arrangement in a wovenstructure, the yarns in D.O.S. areabsolutely straight and parallel.

- Yarn properties are fully utilised towithstand deformation forces.

- Optimally structured modulus.

- Fabric engineering is simple andfabric properties can be pre-calculated according to the intended end-use.

Any yarn type can be processed - from low-twist soft staple yarns tohigh-tenacity filament yarns.

The secured interlacing of yarns, evenin very open mesh structures, makestransportation and handling duringfurther operations such as coating andlaminating much simpler.

Excellent tear and tear propagationresistance. The yarn layers tend tobunch together under load. A greaterextent of force is so required todestroy the structure.

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Weft insertion systems

The principle of magazine weft insertionin warp knitting involves the insertionof long yarn ends, stretched in parallelacross the whole width of machine.Insertion of a yarn sheet into thehook-needle chains accounts for thehigh productivity of warp-knittingmachines. In dependence on the weftyarn materials processed, the MSUS(magazine return weft insertion) or the EMS (single-end magazine weftinsertion) principles are used. Furtherto parallel weft insertion a slightlycrossed weft insertion (typical ofMalimo) is possible.

The advantages of weft insertionsystems:

- Working width of up to 245“ (6.22 m)

- Production speed of up to 1,400 r.p.m.,that is, a weft insertion rate of up to7,560 m/min* (on the basis of 24yarn ends)* depending on the relevant productto be produced

- Weft take-up speeds of up to 320 m/min (on the basis of 24 yarn ends)

- Flexible weft insertion system (weftrepeat, number of weft yarn ends)

- All yarn types including high-tenacityand fragile technical yarns can beinserted

- High flexibility of yarn counts

- Very high efficiency and productivity

EMS principleMSUS principle

Weft insertion typical of Malimo

Knitting area of Raschel machine withmagazine weft insertion

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Multi-axial structures

Multi-axial multi-ply structures arefabrics bonded by a loop system, consisting of one or several yarn layersstretched in parallel. Said yarn layersmay have different orientation and different yarn densities of single ends.

Multi-axial multi-ply fabrics are usedto reinforce different matrices. Thecombination of multi-directional fibrelayers and matrices has proved capableof absorbing and distributing extra-ordinarily high strain forces.

Multi-axial structures for substrates

The typical feature of warp-knittedmulti-axial multi-ply structures forsubstrates is the interlacing of singleends in line with the stitch courses and the associated almost smoothprocessing of fed yarns. These productsare multi-ply structures with angles of 30° up to 60° and/or 90°/0°

A multi-axial multi-ply fabric demon-strating the two diagonal yarn sets inaddition to the bi-axial yarn setscreated by the mislapping guide bar(warp or ST-yarn) and the magazineweft insertion system (weft).

Four yarn layers placed in perfect ordereach on top of the other. Each layershows the uniformity of the non-crimped parallel yarns interlaced bystitches. The structure is dimensionallystable in all directions: +450/-450/0°/90°.

Applications are: inflatable bodies,such as airships, inflatable boats,inflatable life-rafts, rescue tents, gasmembranes, V-belts, flexible roofingmembranes etc.

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Multi-axial structures for fibre reinforced plastics

The typical feature of warp-knittedmulti-axial multi-ply structures forfibre reinforced plastics is the stitching-through principle, ensuring auniform distribution of yarn ends andpreventing gap formation. In addition,fibrous webs, films, foams and othermaterials can be incorporated. Anglepositions of-45° through 90° up to+45° and 0° are generally used, beinginfinitely variable.

- Due to the noncrimped and parallelyarn sheets, such as multi-axialmulti-ply structures are particularlysuitable to reinforce plastics to formfibre reinforced plastics (F.R.P.).

- The special characteristics of suchcomposites are:

- low specific weight

- adjustable stiffness between extre-mely stiff and extremely stretchable

- resistance to corrosion andchemicals

- highest mechanical load resistance

Applications:

Rotor blades for wind power stations.Moulded parts for automotive, aircraft,and ship building.Equipment for sports and leisure-timeactivities e.g. skis, snowboards, surfboards, sports boats . . .

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a b

Advantages of multi-axialmulti-ply structures

■ Dimensionally stable in anydirection

■ Isotropic distribution of stressforces, uniform strain behaviour

■ Optimal utilisation of tensile yarnstrength in any directions of strainunlike woven fabrics

■ Reinforced 3rd dimension, that is, in Z-direction, thus reduced delamination tendency by theinterlacing yarn system

Unlike woven fabrics, multi-axial multi-ply structures have a high shearing strength under diagonal forces

■ Directly oriented, parallel yarn layersstraightly placed each on top of theother -without yarn crimp, providingthe following advantages:

- enhanced interlaminar shearingstrength

- quick curing of resin- reduced resin quantities- increased impact resistance- excellent draping characteristics

■ Lowest weight per unit area atmaximum total strength possible

■ Cost effective production andeconomical ready made

■ Product-relevant and variable layerstructure in various angulardirections, allowing for additionalmaterials to be incorporated, to bemanufactured in only one operation.

Yarn materials to be used:Fibreglass, aramid, carbon, high-tenacity PES, PA, PE, PP. Used as matrix materials are:

Thermosetting or duroplastic materials,polyvinyl chloride PVC, ethylene vinylacetate EVA, synthetic rubber, recentlyalso pressure setting matrix materialssuch as concrete, cement and the like.

Example for good mould capability ofmulti-axial multi-ply structures

Multi-ply structure

Woven fabric

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Composite fabrics

Composite fabrics are also uniquestructures produced using warp knit-ting and stitch-bonding techniques.The idea behind composite fabrics is tocombine several materials of partlyopposite properties to create a singlemembrane that performs much morebetter than its components. With allother textile manufacturing techni-ques, the components are producedindividually and then combined withdifferent gluing, soldering or sewingtechniques. With the latest warpknitting, Raschel, and stitch-bondingmachines, the composite fabric isproduced in a single, simple and veryproductive operation.

The most popular composite fabric is abi-axial reinforced nonwoven.

Any fabric to be pierced can bereinforced with a mono-, bi- or multi-axial yarn element on Raschel and/orstitch-bonding machines. Webs,mechanically bonded webs, unbondedchopped strand mats (CSM) and,moreover, nonwovens bonded thermal-ly or by binder are reinforced.

The knitting elements of this Raschelmachine with web feed facility areengineered to place the two verticallyentering reinforcements (warp/weft)onto the nonwoven.

Schematic illustration of a bi-axialreinforced nonwoven with elements:warp, weft, interlacing yarns andnonwoven.

Web on the reverse side of composite fabric

1 - web2 - weft yarn3 - warp yarn4 - interlacing yarn

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1 2 3 4

2 3 4

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Bi-axial reinforced nonwovens

Bi-axial reinforced nonwovens are frequently used as substrate for laminating or in the field of geotextiles.

Features/Advantages:

■ Good surface covering power ofnonwoven

■ Excellent processability due to anti-slip grey fabric structure

■ During the coating process (prefe-rence is given to calender coating)

- tear and tear propagationresistance

- cohesion of substrate and matrixare increased by the webfilaments (bunching effect).

■ Thanks to one-sided coating on theyarn side, the nonwoven side allowsfor:

- protection of coat/foil whenbeing incorporated e.g. in refusedumps

- moisture drainage system e.g. inparty tents to prevent water dripformation

- enhanced wear comfort ofprotection suits

■ Constructive increase of themechanical properties of nonwovenby bi-axial yarn layers in accordancewith the product-specific require-ments. Although nonwovens them-selves do not have good mechanicalproperties, the exceptional tearresistance of the composite fabric is achieved by the directionallyoriented reinforcement.

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■ Improved flame-retardant propertiesby using fibreglass nonwovens, rein-forced by glass yarns and used asbituminous roll roofing for the insulation of flat roofs.

Example:Laminating substrate

Lengthwise (warp) Widthwise (weft) Weight (D.O.S.) Weight (web) Weight (grey fabric) Weight (coated)Tear propagation resistance* -Warp -Weft

Both coated fabrics are produced withidentical 550 dtex PE yarns. The rawmaterial cost of the knitted compositenonwoven is around 50 % of that of

D.O.S. Composite structure Woven

2.5 ends/cm 14 ends/cm2.5 ends/cm 14 ends/cm33 g/cm2 -50 g/cm2 -88 g/cm2 165 g/cm2

518 g/cm2 550 g/cm2

175 N 120 N142 N 120 N

the woven fabric.* Tear propagation resistance testaccording to the trapezoid methodDIN 53363

■ Improved foot-fall sound attenuationand heat insulation with textileappearance -used as secondarycarpet backing.

■ Reduced material cost (less yarn material needed)

Comparison of composite andwoven fabrics

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Bi-axial reinforced compositefabrics for geotextiles

A composite fabric specially designedfor use in soil geotechnical structuresis the symbiosis of the properties of anonwoven and those of a reinforce-ment structure. The strength propertiesof substrate system are permanentlymaintained, differences in the carryingcapability are compensated for, andthe carrying capability is altogetherenhanced.

Fabric properties:- High tensile strength- Less elongation- Good water permeability- Very low creep- Very good fabric/soil interaction

Fabric function: Function performed by:

Functional description

Separation Nonwoven Prevents admixtures and harmful grainrearrangements

Filtration Nonwoven Ensures non-pressurised water flowbetween different soil layers

Drainage Nonwoven Drains gravitational water according totransverse gradient

Protection Nonwoven Protects the yarn layers from damages

Reinforcement Bi-axial multi-ply structure

Prevents deformations by instant tensilestrength absorptionIncrease and stabilisation of soil carryingcapacityEnsures high resistance to mechanicalloads during placement and operation

Application:Railroad foundation

- Reduced dumping heights - Reduction of granular materials - Separation of different soils - Better drainage

- High friction coefficient betweengeotextile and soil

- Faster consolidation (settlement)of subsoil

- Uniform load distribution reducesthe danger of soil breaking

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Bi-axial and multi-axialreinforced composite fabricsfor fibre reinforced plastics

Another attractive example forcomposite fabrics are substratematerials for laminated structures to produce fibre reinforced plastics.Such yarn materials as fibreglass,carbon, aramid in conjunction withfibrous webs, chopped strand mats(CSM) and substrate cloths arepreferably used.

A stitch-bonding machine wasdeveloped to make bi-axial fabrics onwhich purely mechanically bondedcomposite articles combined of un-bonded CSM, parallel weft (90°), andwarp yarns (0°) can be produced in one operation only.

The multi-axial machine offers theunique possibility to produce multi-axial composites e.g. in the combina-tion of CSM, multi-axial yarn layers,and unbonded CSM on the top face of fabric in one operation.

These techniques so offer best condi-tions for cost-effective production of long-staple reinforced compositeswith optimal bi- and multi-axial loadabsorption as being used for mouldedparts in automotive, boat, container,and sports equipment building as wellas for profiles etc. (see also „Bi- andMulti-axial structures“ chapter).

Pipe renovation

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Stitch-bonded nonwovens

Stitch-bonded fabrics made accordingto fibre-processing stitch-bondingmethods are purely mechanicallybonded nonwovens.Bonding takes place by:- one- or two-sided formation of

stitches from the fibres of length-wise-, cross-laid or random webs fed (web/pile web nonwovens), or

- stitching-over of said webs with amaximum of two stitch-formingknitting yarn systems (web/yarnnonwovens)

MALIVLIES

- Stitch-bonded Malivlies nonwovensconsist to 100 % of fibres.

- Fibres are grasped by the needlehook from a generally cross-laidfibrous web and pulled through thehalf stitches hanging on the needlestem, thus producing a stitch patternwhich resembles to that of a warp-knitted fabric on the reverse side ofweb.

- The intensity of stitch formation isdependent on the number of fibresin the needle hook and can be con-trolled by the position of insertionsinkers.

Advantages of MALIVLIES fabrics:

- Cost-effective production at workingwidths of up to 6.10 m and exclusiveuse of non-spun fibrous material

- All cardable kinds and blends offibres can be processed

- Well-proportioned strength-strainbehaviour in lengthwise andwidthwise directions, infinitelyvariable (through fibrous material,weight per unit area, machine gauge,intermeshing intensity, stitch length)

- Excellent draping characteristics andshaping facility

- Excellent recycling facility, processing of reclaimed fibres possible

Applications:Car headlinerLaminating substrate for seat uphol-stery fabrics (as foam substitutes),

flame-resistant interlinings in firemen’ssuits, cleaning cloths

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MALIWATT

- Stitch-bonded MALIWATT fabrics aremade from unbonded or pre-bondedfibrous webs stitched-over acrossthe total surface or partly with oneor two stitch-forming yarn systems.

- The possibility for embedding ofpierce-through plane and/or scattering materials is provided(nonwovens, composites).

Advantages of MALIWATT fabrics:

- Cost-effective production at workingwidths of up to 6.10 m

- All cardable kinds and blends offibres as well as all pierce-throughmaterials can be processed asbacking fabrics within a large weightper unit area range (15 ... 3,000 g/m2) with a fabricthickness of up to 20 mm

- Large count range of stitching yarnsprocessed (44 ... 4,400 dtex),featuring the possibility to workthrough pile sinker of up to 23 mm(one-side knitted pile)

- Strength-strain behaviour in length-wise and widthwise directions adjustable via backing fabric/knittingyarn material, weight per unit area,machine gauge, interlacing andtension of stitching yarn, stitchlength

- 0° direction can be additionally reinforced by noncrimped warp yarns

- High variety of variants due to thecombination of various materials tomake composites

- Special Maliwatt G configuration toprocess fibreglass webs and/or chopped glass strands even incombination with substrate fabricse.g. fibreglass fabrics

- Processing of reclaimed materialpossible.

Applications:Laminating substratesCleaning clothsInsulation materials(fibreglass)Substrates for fibre reinforced plastics

Adhesive tape e.g. to wrap around cable loops

Maliwatt -composite made from chopped glass strands (CSM)

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KUNIT

- Three-dimensional fabric made of100 % fibres, comprised of onestitch side and one pile loop sidewith almost vertical fibre arrangement

- A normally lengthwise-orientedfibrous web is folded and compactedinto a pile fibre web at feed speedfabric take-down speed and supportedby a brush bar. Further, fibres arepressed into the needles hook by thebrush bar and converted into astitch.

Advantages of KUNIT fabrics:

- Cost-effective production at workingwidths of up to 2.80 m and exclusiveuse of non-spun fibrous material

- All cardable kinds and blends offibres can be processed

- Very good air permeability, excellentcompression elasticity (due to vertical fibre arrangement) at lowweight per unit volume, fabricthickness of up to 10 mm

- Purposeful manipulation of pro-perties (via fibrous material, weightper unit area/volume, machine gauge,finish)

- Excellent shaping facility/drapingcharacteristics

- Very good recycling facility,processing of reclaimed fibres possible.

Laminating substrate e.g. for car seatupholstery fabrics (as foam substitute)

1 Stitching needle2 Closing wire3 Knocking-over sinker4 Backing rail5 Oscillating brushing device6 Fibrous web7 Fibre stitches8 Pile creases

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MULTIKNIT

- Three-dimensional fabric of 100%fibres, both top sides of nonwovenare formed into a closed surface bystitches and joined with each otherby almost vertically oriented fibres.

- One-side knitted pile fibre nonwovens made according to theKUNIT technique are used as basicproducts.

- The possibility for embedding ofpierce-through plane and/or scattering materials is additionallyprovided.

Advantages of MULTIKNIT fabrics:

- Production of three-dimensionalknitted structures of high thickness(up to 16 mm) exclusively fromfibres maintaining the vertical fibrearrangement between the outerplane stitch layers

- All cardable kinds and blends offibres can be processed

- Very good air permeability, excellentcompression elasticity (due to vertical fibre arrangement) at lowweight per unit volume

- Excellent shaping facility

- Very good recycling facility, processingof reclaimed fibres possible

- High variety of variants due to thecombination of various materials aswell as the possibility of only partlystitch formation to make composites.

Applications:Kynol activated ACMK carbonMultiknit for gas filtration (e.g. for usein super-clean rooms, inner car filters,protective suits, and masks)

Oil absorbing mat

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References:Dr. S. Raz ,“The Karl Mayer Guide to Technical Textiles“

edited by Karl Mayer Textilmaschinenfabrik GmbH , Obertshausen

Copyright 2000Reprint, even partially, only allowed with editor’s consent.

Edited by Karl Mayer Textilmaschinenfabrik GmbH, 63179 Obertshausen, Germany

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Germany KARL MAYER Textilmaschinenfabrik GmbHBrühlstraße 25, D-63179 ObertshausenTel.: +49-(0)6104-4020, Fax: +49-(0)6104-43574 Internet: http://www.karlmayer.deE-Mail: info@karlmayer.de

KARL MAYER Malimo Textilmaschinenfabrik GmbHMauersbergerstraße 2, D-09117 ChemnitzPF 713, D-09007 ChemnitzTel.: +49-(0)371-81430Fax: +49-(0)371-8143110E-Mail: info@karlmayer.de

U.K. Karl Mayer Textile Machinery Ltd.Kings Road, Shepshed, Leic. LE 12 9HTTel.: 0044/1509/502056Fax: 0044/1509/508065E-Mail: ghlehner@karlmayer.co.uk

USA Mayer Textile Machine Corp.310 Brighton RoadClifton, New Jersey 07012Tel.: 001/973/7733350Fax: 001/973/4733463E-Mail: edmtmc@aol.com

Mayer Textile Machine Corp.310 North Chimney Rock RoadGreensboro, North Carolina 27409Tel.: 001/336/2941572Fax: 001/336/8540251Mbmtmc@aol.com

Brazil Karl Mayer Máquinas Textêis Ltda.Avenida Presidente Costelo Branco, 7.777 CEP 05034-000 Sao Paulo/BrasilP. O. Box 61098-CEP 05071-970Tel.: 0055/11/8611933Fax: 0055/11/8612085 E-Mail: email@karlmayer.com.br

Japan Nippon Mayer Co. Ltd. No. 27-33 1-chome, Kamikitano Fukui-City, 918-85-22 Tel.: 0081/776/545500 Fax: 0081/776/273400 E-Mail: nmsecret@silver.ocn.ne.jp

P.R. China KARL MAYER TEXTILE MACHINERY LTD.159, East Renmin RoadHutang Town, Wujin CityJiangsu Province, P.R. ChinaTel.: +86-(0)519-6551541/42Fax: +86-(0)519-6553412 E-Mail: karlmr@public.cz.js.cn

Hong Kong KARL MAYER (H.K.) Ltd.Units 1601A-3, 16/F., Stelux HouseNo. 698, Prince Edward Road East,San Po Kong, Kowloon Hong KongTel.: 00852/27239262Fax: 00852/27398730E-Mail: mayerhk@pacific.net.hk

KM