non woven products and production
TRANSCRIPT
-
7/30/2019 Non Woven Products and Production
1/69
Nonwoven FabricsA brief description of nonwoven fabrics usedas Technical TextilesDr Muhammad Mushtaq Mangat
www.mushtaqmangat.orgDec 24, 2012
-
7/30/2019 Non Woven Products and Production
2/69
Nonwoven fabricsA nonwoven is a textile structure producedby the bonding or interlocking of fibres, orboth, accomplished by mechanical,
chemical, thermal or solvent means andcombinations thereof (ASTM D 1117-80).[1]
-
7/30/2019 Non Woven Products and Production
3/69
Nonwoven fabrics are broadly defined assheet or web structures bonded together byentangling fibre or filaments (and by
perforating films) mechanically, thermally or chemically. They are flat, porous sheetsmade directly from separate fibres or frommolten plastic or plastic film. They are notmade by weaving or knitting and do notrequire converting the fibres to yarn.
[4]
-
7/30/2019 Non Woven Products and Production
4/69
ContiA nonwoven is a sheet of fibres, continuousfilaments, or chopped yarns of any nature or origin, that have been formed into a web by
any means, and bonded together by anymeans, with the exception of weaving or knitting. [4]
-
7/30/2019 Non Woven Products and Production
5/69
[2]
-
7/30/2019 Non Woven Products and Production
6/69
[3]
-
7/30/2019 Non Woven Products and Production
7/69
Hygiene
[http://en.wikipedia.org/wiki/Nonwoven_Fabric]
baby diapers or nappiesfeminine hygiene
adult incontinence productswet wipes
bandages and wound dressings
disposable bath and face towels
disposable slippers and footwear
-
7/30/2019 Non Woven Products and Production
8/69
Medical
isolation gowns
surgical gowns
surgical drapes and covers
surgical scrub suits
caps
medical packaging: porosity allows gassterilization
-
7/30/2019 Non Woven Products and Production
9/69
Filters
gasoline, oil and air - including HEPA filtration
water, coffee, tea bags
pharmaceutical industry
mineral processing
liquid cartridge and bag filters
vacuum bagsallergen membranes or laminates with nonwoven layers
-
7/30/2019 Non Woven Products and Production
10/69
Geotextilessoil stabilizers and roadway underlayment
foundation stabilizers, erosion control, canalsconstruction
drainage systems, geomembrane protection
frost protection, agriculture mulch, pond andcanal water barriers, sand infiltration barrier for drainage tile, landfill liners
-
7/30/2019 Non Woven Products and Production
11/69
Other
carpet backing, primary and secondary, compositeschopped strand material, backing/stabilizer for machine embroidery
packaging where porosity is needed, insulation
(fiberglass batting), pillows, cushions, and upholsterypadding, batting in quilts or comforters
consumer and medical face masks, mailingenvelopes
tarps, tenting and transportation (lumber, steel)wrapping, disposable clothing (foot coverings,coveralls), weather resistant house wrap
-
7/30/2019 Non Woven Products and Production
12/69
Advantages of Nonwoven
A continuous process, straight from fiber tofinish product
Low labor cost
Mass-production approach
Suitable for insulation containing only 23%fibers by volume
For stiff reinforcing, fiber content may beover 80% by volume
-
7/30/2019 Non Woven Products and Production
13/69
Nonwoven Production
MethodsLaying of fibers and BondingDirect membrane (electro spinning)
Difference of batt and webBatt is first layers and web is the wholematerial [1]
-
7/30/2019 Non Woven Products and Production
14/69
Nonwoven ProductionIn three stages
Web FormationWeb BondingFinishing Treatments
-
7/30/2019 Non Woven Products and Production
15/69
Methods of batt production using
carding machines
Two main stepsWeb manufacturingBonding of fibers; thermal, mechanical,
chemical bonding etc.
-
7/30/2019 Non Woven Products and Production
16/69
Parallel laying methods
[1][1]
-
7/30/2019 Non Woven Products and Production
17/69
Batt and WebWeb planner weight is normally low (thin web)
Multiple webs increase planner weight anduniformity
Parallel laying is easiest and cheapest way
Mostly fibers are along the x-axis
Whatever method of bonding
Web strength depends upon the strength offibers not on the binding
-
7/30/2019 Non Woven Products and Production
18/69
Laying processesDry, most popular:
parallel-laidcross-laid
Wet
-
7/30/2019 Non Woven Products and Production
19/69
Parallel and Cross-
sectionalSpecial cards to make fibers more random,which have short length
It increases the strength
Gives buckling effect
Card modification can avoid layingunnecessary
Increase in thickness decreases the width offabric
-
7/30/2019 Non Woven Products and Production
20/69
Cross layingCards are placed at right angles to the mainconveyor
card web is traversed backwards andforwards across the main conveyor, whichitself is moving. The result is a zig-zag [1]
-
7/30/2019 Non Woven Products and Production
21/69
[1]
-
7/30/2019 Non Woven Products and Production
22/69
Characteristics of CrossWeb
Short width
Zig-zag marks
Edges are thicker than middle
Mismatch between card and input layer speed
Cross-laying angle is normally less than 10
Majority of fibres lie in or near the cross directionCross-laid fabrics are very strong in the crossdirection and weak in the machine direction [1]
-
7/30/2019 Non Woven Products and Production
23/69
-
7/30/2019 Non Woven Products and Production
24/69
Air laying
Direct final layer than making first layer
Production is high
Wider width web is possible 34 mUnopened lumps of fibers are vey common[1]
-
7/30/2019 Non Woven Products and Production
25/69
[1]
-
7/30/2019 Non Woven Products and Production
26/69
Air Laying Characteristics
Fabric made by air laying is more stronger
More random arrangement of fibers, it is alsocalled random-laid fabrics
-
7/30/2019 Non Woven Products and Production
27/69
Wet LayingDeveloped by paper industry
Textile fibers and wood pulp is mixed
More than 50% fiber makes it non-wovenFibers are used to control the cost
Mostly disposable items are made by using
this technique
-
7/30/2019 Non Woven Products and Production
28/69
non-woven wet tissues
-
7/30/2019 Non Woven Products and Production
29/69
[http://www.engr.utk.edu/mse/Textiles/Wet%20Laid%20Nonwovens.htm]
-
7/30/2019 Non Woven Products and Production
30/69
Spun laying
Direct laying from extrusion
Shortest way
More versatile
Small size machines have been developed
Much useful for microfibers, ultimately fine filters arepossible
Membrane are possible with nano fibers
Extra light weight fabrics are possible
Becoming popular due to short and versatile process
-
7/30/2019 Non Woven Products and Production
31/69
[1]
-
7/30/2019 Non Woven Products and Production
32/69
Spun Laying IssuesUneven batt
Coagulation and agglomerations of fibersgive un-even surface
Variation in pores is possible
Pore sizes and directions play a significantrole in strength and filtration process
-
7/30/2019 Non Woven Products and Production
33/69
Nano fibersmats
-
7/30/2019 Non Woven Products and Production
34/69
Flash SpinningA process to produce fine fibers without the application of finespinneret holes
It depends upon intramolecular bonds of polymers
Mainly polyethylene and polypropylene are used as substance
to produce fabricIntramolecular strength of PE and PP is weaker as compared toPET
Bending, twisting or abrasion is quite difficult for PE and PPfabrics
fibrillation.
In flash spinning the polymer is dissolved in
-
7/30/2019 Non Woven Products and Production
35/69
Flash SpinningPolymer is dissolved in a solvent
Extruded as a sheet
Blow is used to make polymer sheet
Mass bubbles have large surface area
Low wall thickness
Fibrillation is carried out, which makes a network of fibers of very fine sheet
Desired GSM is obtain
-
7/30/2019 Non Woven Products and Production
36/69
Flash Spinning ProductsFlash-spun material is only bonded in two ways:
melting the fibers under high pressure to makestrong adhesion of fibers, negligible air permeability, stiff sheets are produced
Partially pressure and heat, it make strong sheetsbut flexible called Tyvek. It is used for protectiveclothing in the
chemical, nuclear and oil industries, probably asprotection for the armed forces and garments
-
7/30/2019 Non Woven Products and Production
37/69
Melt blown
Polymer is melted and passed throughextruders of large area
Hot air is put on polymer streams, whichconverts it into fine fibers
Cold air is brought in contact, which solidifythe fibers
Fine fibers are collected on a perforatedconveyor
-
7/30/2019 Non Woven Products and Production
38/69
[1]
-
7/30/2019 Non Woven Products and Production
39/69
Flash Spinning ProductsUltrafine filters for air conditioning
Personal face masks
Oil-spill absorbentsPersonal hygiene products
-
7/30/2019 Non Woven Products and Production
40/69
Flash Sinning Products
-
7/30/2019 Non Woven Products and Production
41/69
Chemical Bonding
Batt and webs are bonded with adhesivespartially or fully
Normally synthetic lattices are used
Curing is done at higher temperature for proper binding
Chemical bonding process
-
7/30/2019 Non Woven Products and Production
42/69
Chemical bonding process
-
7/30/2019 Non Woven Products and Production
43/69
Saturation bonding
Whole batt is wetted with adhesive
It is carried out undersurface of the bonding agent
In this case batt has wide pores, need care to avoiddistortion
Thin batt is produced due to pressure duringsqueezing
Such fabrics are compact
Fibers are crushed and spin back Drying is done on dryers having perforated conveyor
-
7/30/2019 Non Woven Products and Production
44/69
ContFabric is quite compact, all fibers are covered
Sheet is possible
Strong enough to withstand under higher stretching
One of the major uses of saturation bondedfabric turns this apparent disadvantage
Such fabric is used as interlining fabric for textileclothing and as filter fabrics
-
7/30/2019 Non Woven Products and Production
45/69
Foam bonding
Foam reduces the demand of water
Air is used to make foam and then bat isimpregnated
-
7/30/2019 Non Woven Products and Production
46/69
Foam Impregnating
[1]
-
7/30/2019 Non Woven Products and Production
47/69
Print Bonding
It is printing of designs with adhesive on batt
Batt is wetted then printed with any bindingagents
Print-bonded fabrics are quite flexible and soft
Fabric is weaker as compared to other fabrics
Such fabrics are used as disposable/protectiveclothing, cover stock and wiping cloths, dustingmaterial
-
7/30/2019 Non Woven Products and Production
48/69
Print Bonded Fabric
-
7/30/2019 Non Woven Products and Production
49/69
Spray bonding
Latex binders are sprayed instead of printing withthe help of compressed air
It could be spray after laying another batt, or onboth sides of batt
It reduces the thickness
Finally drying and curing is done
Fnal product is a thick, open and lofty fabric
Used as filling in quilted fabrics, for bedding for some upholstery and also for some types of filters[1]
-
7/30/2019 Non Woven Products and Production
50/69
Thermal bondingBecoming popular due to easy and high production
No drying and curing is required
Less energy is demanded
Suitable for:Same types of fibers fibers can be bonded together by using partial binding or fully bonding due makingit a sheetBlend of fibers, some fibers bonded together but fewremains free, it make fabric soft and flexibleSpecial fibers having different polymer in surroundingand in the core. External fibers are melted and inner remained intact
-
7/30/2019 Non Woven Products and Production
51/69
Thermal bonding without
pressureIn this case batt is processed withoutpressure,
Fibers are kept open and thick and highly
porous products are possible
Uniform bonding, more liberty in thicknessand porosity
Formula 1 cars fuel tanks are made by usingsuch fabric
-
7/30/2019 Non Woven Products and Production
52/69
Thermal bonding with some
pressureSame as previous but the difference ispressure
Product is used filters and packing
More stiff and can have precise thickness
Thermal bonding is used also in book bindings, lamination with the help of thermal
-
7/30/2019 Non Woven Products and Production
53/69
Thermal bonding with point contact
Similar to printing or spraying
Not whole batt is bonded
Some selected area is bonded
Fabric becomes flexible and soft feel
Less strong than whole bonded
Engraved calenders rolls are used for pointed binding
It may be less than 5% of the whole areaUsed as geo textile, filters, tufted carpets , homeproducts, covers
-
7/30/2019 Non Woven Products and Production
54/69
-
7/30/2019 Non Woven Products and Production
55/69
Powder bonding
Thermoplastic powders can be added toany batt to produce thermal bonding incertain areas
Flexible fabric and having higher porosity
Low strength
Used as covers
-
7/30/2019 Non Woven Products and Production
56/69
Solvent bonding
Not much popular
Needs more care to handle solvents
Solvent can be recycled
Less energy is required
More eco friendly
Solvent gas can be used
Latent solvent are used, which becomes solvents at higher temperature
Batt is impregnated in solvent then passed through a chamber at higher temperature, cooling is done to recover the solvent
Special fabrics are produced by using this technique
-
7/30/2019 Non Woven Products and Production
57/69
Mechanical Bonding
Needle felting
Hydro entanglement
Fiber entanglements due to friction
-
7/30/2019 Non Woven Products and Production
58/69
Needle FeltingBatt is put between two stationary plates
Batt is penetrated by a large number ofneedles
Needles have cuts to create moreentanglement
Needles are long enough to create a
uniform entanglement
Needle
-
7/30/2019 Non Woven Products and Production
59/69
Needlepunching [1]
-
7/30/2019 Non Woven Products and Production
60/69
Needle FeltingNeedle creates vertical loops, which are not sufficient
Much align fabric is not suitable
Need batt having vertical arrangement of fibers for
horizontal loops, which are required for high strengthArrangement between needle movement andconveyor movement determines the amount ofentanglement
Number of needles per unit area of plate plays acrucial role in strength of fabric
-
7/30/2019 Non Woven Products and Production
61/69
ContiThere are two ways to increase production:
Increase of number of needlesIncrease speed of conveyor
There are more than 5000 types of needles available
Needle felt has high breaking tenacity and high tear strength
Poor extensibility
Some binding chemicals are used for better stability
Major advantage is that whole fabric ishomogeneous ,
-
7/30/2019 Non Woven Products and Production
62/69
ContNeedle felt fabric is used:
gas filtration, wet filtration
-
7/30/2019 Non Woven Products and Production
63/69
-
7/30/2019 Non Woven Products and Production
64/69
Needle punching line
Stit h b di
-
7/30/2019 Non Woven Products and Production
65/69
Stitch bonding
Idea developed in Czechoslovakia
Lot of variation in process is possible like:Batt bonded by threads
Stitch bonding without threadsStitch bonding to produce a pile fabricBatt looped through a supporting structureLaid yarns sewn together with binding
threads
-
7/30/2019 Non Woven Products and Production
66/69
Hydro entanglement
Hydro entanglement is a process similar toneedle loom
Invented by by Du Pont in 1960sMuch need is required to avoid turbulence
Jet are at 90 angle to the perforated conveyor,extra water is collected
Fibers become twisted together or entangled bythe turbulence in the water
-
7/30/2019 Non Woven Products and Production
67/69
Conti
Common use of such fabrics:
wipes, surgeons gowns, disposableprotective clothing and backing fabrics for
coating
Wipes produced are guaranteed lint free,loose fibers are washed away
Light and heavy weight fabrics can beprocessed
R f
-
7/30/2019 Non Woven Products and Production
68/69
References
[1] Smith, P.A., Technical fabric structures,Nonwoven fabrics , in Handbook of TechnicalTextiles A.R. Horrocks, Anand, S. C., Editor 2000, Woodhead Publishing Ltd Cambridge.
[2] Source: CSIRO Textiles & Fibre Technology
[3] The Australian Technical Textiles &Nonwovens Industry Profile May 2006
[4] http://nonwovenbagmachines.com/non-wovensectors.html
-
7/30/2019 Non Woven Products and Production
69/69