SlideShare ist ein Scribd-Unternehmen logo
1 von 34
IOT
DEPARTMENT OF TEXTILE AND GARMENT ENGINEERING
Non woven fabric manufacturing seminar on
wet-laid web preparation
HAWASSA,ETHIOPIA
To:Mr. Metasebia.G By peer-I members
TABLE OF CONTENTS:
R.No TITLE SLIDE
1 Introduction 3
2 Raw material 8
3 Production machineries
4 Process description 13
5 Process model 15
6 Special features of the wet laid process and
products
17
7 Miscellaneous Topics 20
8 Defects of wet-laid web fabric 23
9 Merits and demerits 26
10 Application 27
11 Conclusion 28
2
INTRODUCTION
Historical perspective:
 The wet-lay nonwoven process is known to be
derived from the wet-laid paper making process.
 H. Fourdrinier developed a papermaking machine
that has been the basis for the most modern
papermaking machines employing very short
fiber.
3
CONTINUED…
wet-laid paper making process:
 The wood pulp and water in the ratio of 0.003-
0.007 (w/w) are mixed to make a good quality
suspension of fibers and water.
 The suspension is then pumped to the headbox
which has a small opening, often called as slice.
 Through the slice, the fibre-water suspension is
dropped onto the moving perforated Fourdeinier
wires. These wires contain a lot of perforations
through which the water gets drained to the
vacuum and the fibres, deposited on the moving
wires, formed a web. In this way, the wet-laid
paper is formed 4
MODIFIED FORM OF THE MACHINE
 By using the previous version of the machine it
was not possible to process relatively long fibers
as the mentioned dilution ratio results in
inadequate fiber dispersion in water.
Measures taken to solve the problem:
 The ratio of weight of fiber pulp and weight of
water should be around 0.0005-0.00005.
 The inclination of the forming wire to the base
is required to be equal to 20°.
 The machine was made to have large headbox
(slice) opening
5
CONTINUED…
 This machine has been used to make papers from
long fibres and subsequently the basis for
making nonwovens also.
The modified:
6
NON WOVEN TEXTILES
Non woven production general sequence:
7
• Selecting
based on
compatibility
Fiber
preparation
•Wet laid
•Dry laid
•Spun laid
•Melt blown
Web
preparation • mechanical
• Thermal
• Chemical
Web bonding
• Mechanical
• Chemical
Finishing
We will see
wet laid
web here!
PAPER AND TEXTILES
Two fundamental reasons account for physical
property differences between paper and textiles:
1-difference in the raw materials each process uses.
Paper: fibers being short and fine are able to pack
together into a dense structure
Textiles : fibers tend to be longer, stronger, and
relatively inert
2-the structure and the way individual fibers are
arranged by the process to make a finished product.
Paper: the fibers overlap randomly and pack densely.
Textiles: there is a repeating unit structure which
provides some extensibility in all directions 8
CONTINUED…
 In light of the characteristics of these raw
materials and structure, one would expect
9
Paper to be
Textile to be
• weak
• Stiff
• Inextensible
• Smooth
• dense
• strong
• softer,
• bulkier
• more drape able,
• less smooth and
• more porous.
RAW MATERIALS
 In theory, any natural or synthetic fiber could
be used in the production of wet-laid nonwovens.
However, there are practical limitations on the
use of many fibers (cost, availability, priorities).
 wood pulp is used in virtually all wet-laid
nonwovens because of its ease of handling, low
cost, opacity, and chemical reactivity.
 Some natural fibers - such as cotton linters,
manila hemp and cellulose staple fibers - are also
used in wet-laid process(2-30 mm in length).
10
CONTINUED…
 Synthetic fibers provide specialized properties,
uniformity, and constancy of supply which cannot
be achieved by natural fibers.
Reasons for their limited application:
o They are 20 to 50% more expensive than the
same fiber in the form of textile staple.
o Flocculation(they entangle ).
11
CONTINUED…
Flocculation:
 is incapability to disperse in water due to longer
length and flexibility they have.
 Increases with an increase in length to diameter
ratio(L/D) of fiber.
Tt = fiber fineness in dtex
12
CONTINUED…
Several approaches have been developed to
overcome this problem:
o Synthetic fiber manufacturers offer fibers with
proprietary chemical surface treatments, which
improve dispersion.
o The general strategy for reducing flocculation
of synthetic fiber furnishes is to increase the
dilution (decrease the "consistency" of weight
percent of fiber in the suspension).
13
COMPATIBILITY OF THE MATERIAL
WITH THE PROCESS
 Whether or not a fiber is suitable for use in the
web process depends on its ability to disperse in
an aqueous medium.
The dispersion behavior of a fiber depends largely
on the following factors:
 The degree of fineness calculated from the
length and thickness of the fiber
 The stiffness of the fiber in an aqueous medium
(web modified)
 The kind of crimping
 The wettability
 The cutting quality of the fiber 14
PRODUCTION MACHINERIES
There are three characteristic stages in the process
• Swelling and dispersion of the fiber in water;
transport of the suspension on a continuous
traveling screen
• Continuous web formation on the screen as a
result of filtration
• drying and bonding of the web
15
CONTINUED…
Some of machines used in the process:
Web forming device with
inclined wire screen
Wet-laid web-making machine
with cylinder drier
16
PROCESS DESCRIPTION
 The fibres are mixed with water and it forms
fibre-water suspension.(two mixing tanks for
preparation of better fibre-water suspension.)
 This suspension is then pumped through the
headbox to the perforated wire.
 The water is drained through the perforations
and the fibres are laid on the moving wire to
form a web.
 The wet-laid web is then dried and bonded by
using binder. It is again dried and finally wound
on a roll.
17
CONTINUED…
• mixing
• Prepare
suspension
Stage
1
Suspension
via head
box to
perforated
wire
Stage
2
Dehydration
and web
formation.
Stage
3
18
CONTINUED…
The schematic diagram of a typical wet-lay process
for making nonwovens :
19
PROCESS MODEL
 It is often necessary to calculate process
parameters in advance with an aim to obtain a
specific structure of wet-laid nonwovens.
Because of this, it is often necessary to model
the wet- lay process.
20
CONTINUED…
21
CONTINUED…
The velocity of water in relation to the velocity
of wire determines the structure of the web.
 When both the velocities are equal then the
fibre lay-down is found to be practically
random.
 When the velocity of wire is higher than the
velocity of water then fibres are found to be
preferentially orientated in the machine
direction.
 when the velocity of wire is lower than the
velocity of water then fibres are found to be
preferentially orientated in the cross direction. 22
SPECIAL FEATURES OF THE WET-LAID
PROCESS AND ITS PRODUCTS:
Compared to dry web making process and its
product:
 Since short fibers are required the web
structure is closer, stiffer and less strong.
 The fibers in the web may be randomly or
longitudinally arranged.
 The basis weight (grams/square meter) can be
varied within broad limits.
 It’s highly productivity and have wide range of
application
23
MISCELLANEOUS TOPICS
Water removal from web:
 Water removal on drying is one of the most
important steps in the wet-laid process.
Pressure, vacuum, and heat are used to remove
water from the sheet.
 The efficiency of the methods are determined
by the machine speed, sheet weight, and fiber
compositions of the sheet
24
CONTINUED…
Calendaring:
 Calendars are often used on the product to make it
dense and smooth the sheet. Creping devices are used to
soften sheets by controlled bond breakage.
Aperturing and water-jet entanglement:
 Apertures are regularly spaced holes, and can
be selected for aesthetics or for performance.
 One method of aperturing uses a course forming
wire, so that the sheet is formed around the
protruding "knuckles" in a regular pattern.
 Another method uses high- pressure water
showers and patterned cylinders to rearrange
the fiber into the desired pattern.
25
FABRIC DEFECTS
There exist three types of defects in the wet-
laid nonwoven fabrics:
 logs, ropes, and dumbbells
26
CONTINUED…
Logs:
 are characterized by bundles of fibres with
aligned cut ends that are never dispersed.
 considered to be a fibre supply problem or can
be the result of remarkably low under agitation
of the initial dispersion.
Ropes:
 are characterized by assemblages of fibres, with
unaligned ends, that are clearly more
agglomerated than in the general dispersion.
 re formed when fibres are encountered a vortex
that facilitates in entangling the fibres to form
ropes.
27
CONTINUED…
Dumbbells:
 are characterized by paired clumps of fibres
connected by one or more long fibres.
 Their formation requires an excessively long
fibre and a snag in the system piping.
 The good quality of dispersion of fibres
in water is a key to the good quality of
wet-laid webs.
28
MERITS AND DEMERITS
The merits of wet-lay nonwoven process are:
 High through-put rate.
 Isotropic as well as anisotropic structures can
be created.
 Too brittle fibres, generally not suitable for
textile applications, can be processed.
The demerits of wet-lay nonwoven process are:
 High capital intensive process.
 High energy intensive process.
 High fiber quality requirements.
29
APPLICATIONS:
 They have applications in diversified areas,
namely surgical clothing and drapes, bed linen,
table linen, cloths, and napkins, towels, kitchen
wipes.
 In addition, the wet-laid technical nonwovens are
found to be used in many specialized
applications, including glass fibre roofing
substrate, glass fibre mat for flooring, glass
fibre mat for printed circuit boards, wall
covering, insulation materials, battery
separators, RFI shielding veils.
30
CONCLUSION:
 The system was thought to be applied for any
types of fiber. However in practice the system is
found to be applied for those fibers capable of
dispersing in the fluid. Moreover the application
is constrained by different factors.
 To prepare the web different machineries are
applied having their own way of performing the
sub operations.
 The main advantage of the system is its
capability to process too brittle fibers that
mayn’t be processed in other systems. The high
energy intensives needed may make it limited.
 The products have application in different areas
including industrial and apparel uses.
31
OUR SOURCES:
 Non woven manufacturing technology lecture,
NPTEL.
 Web formation methods, Textile school.
 Literatures of the same title prepared for
students, Bahir-Dar university, ETHIOPIA.
32
PEER-I MEMBERS
R.No Name ID
1 Melkamu Kenito TECH/0750/09
2 Meron Tebikew TECH//09
3 Azeb Mekonin TECH//09
4 Abdulkerim Nesru TECH//09
5 Selamawit Asalfew TECH//09
33
THIS IS ALL WE HAVE…
THANK YOU!34

Weitere ähnliche Inhalte

Was ist angesagt? (20)

Bicomponent
BicomponentBicomponent
Bicomponent
 
non woven
non wovennon woven
non woven
 
Technical textiles and their applications
Technical textiles and their applicationsTechnical textiles and their applications
Technical textiles and their applications
 
Technical textiles
Technical textilesTechnical textiles
Technical textiles
 
3. filtration textiles
3. filtration textiles3. filtration textiles
3. filtration textiles
 
Ring spun yarn
Ring spun yarnRing spun yarn
Ring spun yarn
 
Needle punch nonwoven applications
Needle punch nonwoven applicationsNeedle punch nonwoven applications
Needle punch nonwoven applications
 
Narrow fabrics
Narrow fabricsNarrow fabrics
Narrow fabrics
 
Filtration in Textile
Filtration in TextileFiltration in Textile
Filtration in Textile
 
Drawing and texturising
Drawing and texturising Drawing and texturising
Drawing and texturising
 
Fabric weight calculation in GSM
Fabric weight calculation in GSMFabric weight calculation in GSM
Fabric weight calculation in GSM
 
Web stitching & stitch bonding warp knitt
Web stitching & stitch bonding warp knittWeb stitching & stitch bonding warp knitt
Web stitching & stitch bonding warp knitt
 
Heat setting
Heat settingHeat setting
Heat setting
 
Non woven presentation by Lucky vankwani & Asad Jafri
Non woven presentation by Lucky vankwani & Asad JafriNon woven presentation by Lucky vankwani & Asad Jafri
Non woven presentation by Lucky vankwani & Asad Jafri
 
wet laid web preparation
wet laid web preparationwet laid web preparation
wet laid web preparation
 
Buildtech
BuildtechBuildtech
Buildtech
 
Packtech
PacktechPacktech
Packtech
 
Crimp & Crimp Interchange
Crimp & Crimp Interchange Crimp & Crimp Interchange
Crimp & Crimp Interchange
 
Lining and interlining
Lining and interliningLining and interlining
Lining and interlining
 
Winding process
Winding processWinding process
Winding process
 

Ähnlich wie wet laid web preparation

Abhi rana)5. wet laid nonwovens
Abhi rana)5. wet laid nonwovensAbhi rana)5. wet laid nonwovens
Abhi rana)5. wet laid nonwovensAbhishek Rana
 
Spunlace (hydroentanglement)
Spunlace (hydroentanglement)Spunlace (hydroentanglement)
Spunlace (hydroentanglement)Himanshu Gupta
 
Non woven fabrics - Non woven technology
Non woven fabrics - Non woven technologyNon woven fabrics - Non woven technology
Non woven fabrics - Non woven technologyAkansha Choudhary
 
Bdft ii, non-woven fabric, tmt, unit-iii
Bdft ii, non-woven fabric, tmt, unit-iiiBdft ii, non-woven fabric, tmt, unit-iii
Bdft ii, non-woven fabric, tmt, unit-iiiRai University
 
Nonwoven textiles - characteristics, production methods, uses
Nonwoven textiles - characteristics, production methods, usesNonwoven textiles - characteristics, production methods, uses
Nonwoven textiles - characteristics, production methods, usesMagdalena Georgievska
 
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICS
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICSANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICS
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICSIRJET Journal
 
Recent development in needle punching nonwoven manufacturing
Recent development in needle punching nonwoven manufacturingRecent development in needle punching nonwoven manufacturing
Recent development in needle punching nonwoven manufacturingVijay Prakash
 
Nonwoven technologies: A critical analysys by Vignesh Dhanabalan
Nonwoven technologies: A critical analysys by Vignesh DhanabalanNonwoven technologies: A critical analysys by Vignesh Dhanabalan
Nonwoven technologies: A critical analysys by Vignesh DhanabalanVignesh Dhanabalan
 
Dry laid nonwoven
Dry laid nonwovenDry laid nonwoven
Dry laid nonwovendevisweety
 
Innovative Nonwovens
Innovative NonwovensInnovative Nonwovens
Innovative Nonwovensinbound101
 
Recent advances in chemical processing edited.pptx
Recent advances in chemical processing edited.pptxRecent advances in chemical processing edited.pptx
Recent advances in chemical processing edited.pptxNazmaShaik17
 
Nano Finishing of Textiles
Nano Finishing of TextilesNano Finishing of Textiles
Nano Finishing of Textileskibria36
 
Abhi rana)4. dry laid non woven fabrics
Abhi rana)4. dry laid non woven fabricsAbhi rana)4. dry laid non woven fabrics
Abhi rana)4. dry laid non woven fabricsAbhishek Rana
 

Ähnlich wie wet laid web preparation (20)

Abhi rana)5. wet laid nonwovens
Abhi rana)5. wet laid nonwovensAbhi rana)5. wet laid nonwovens
Abhi rana)5. wet laid nonwovens
 
Non woven Process
Non woven ProcessNon woven Process
Non woven Process
 
Spunlace (hydroentanglement)
Spunlace (hydroentanglement)Spunlace (hydroentanglement)
Spunlace (hydroentanglement)
 
Non woven fabrics - Non woven technology
Non woven fabrics - Non woven technologyNon woven fabrics - Non woven technology
Non woven fabrics - Non woven technology
 
Non woven
Non wovenNon woven
Non woven
 
Nonwoven web formation rajesh
Nonwoven web formation   rajeshNonwoven web formation   rajesh
Nonwoven web formation rajesh
 
Bdft ii, non-woven fabric, tmt, unit-iii
Bdft ii, non-woven fabric, tmt, unit-iiiBdft ii, non-woven fabric, tmt, unit-iii
Bdft ii, non-woven fabric, tmt, unit-iii
 
Nonwoven textiles - characteristics, production methods, uses
Nonwoven textiles - characteristics, production methods, usesNonwoven textiles - characteristics, production methods, uses
Nonwoven textiles - characteristics, production methods, uses
 
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICS
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICSANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICS
ANALYSIS OF JUTE AND POLYPROPYLENE NON-WOVEN FABRICS
 
WEB FORMATION
WEB FORMATIONWEB FORMATION
WEB FORMATION
 
Recent development in needle punching nonwoven manufacturing
Recent development in needle punching nonwoven manufacturingRecent development in needle punching nonwoven manufacturing
Recent development in needle punching nonwoven manufacturing
 
Nonwoven technologies: A critical analysys by Vignesh Dhanabalan
Nonwoven technologies: A critical analysys by Vignesh DhanabalanNonwoven technologies: A critical analysys by Vignesh Dhanabalan
Nonwoven technologies: A critical analysys by Vignesh Dhanabalan
 
Dry laid nonwoven
Dry laid nonwovenDry laid nonwoven
Dry laid nonwoven
 
Manufacture of composites
Manufacture  of  compositesManufacture  of  composites
Manufacture of composites
 
Manufacture of composites
Manufacture  of  compositesManufacture  of  composites
Manufacture of composites
 
Innovative Nonwovens
Innovative NonwovensInnovative Nonwovens
Innovative Nonwovens
 
Recent advances in chemical processing edited.pptx
Recent advances in chemical processing edited.pptxRecent advances in chemical processing edited.pptx
Recent advances in chemical processing edited.pptx
 
Nano Finishing of Textiles
Nano Finishing of TextilesNano Finishing of Textiles
Nano Finishing of Textiles
 
Abhi rana)4. dry laid non woven fabrics
Abhi rana)4. dry laid non woven fabricsAbhi rana)4. dry laid non woven fabrics
Abhi rana)4. dry laid non woven fabrics
 
Nonwoven
NonwovenNonwoven
Nonwoven
 

Mehr von MelkamuKenito

Munsell Color Order System
Munsell Color Order SystemMunsell Color Order System
Munsell Color Order SystemMelkamuKenito
 
flame retardant and proof finish
flame retardant and proof finishflame retardant and proof finish
flame retardant and proof finishMelkamuKenito
 
natural and mordant dyes
natural and mordant dyesnatural and mordant dyes
natural and mordant dyesMelkamuKenito
 
fabric structure and design solution by mk39@
fabric structure and design solution by mk39@fabric structure and design solution by mk39@
fabric structure and design solution by mk39@MelkamuKenito
 
Woven FM II assignment solution
Woven FM II assignment solutionWoven FM II assignment solution
Woven FM II assignment solutionMelkamuKenito
 
Melkamu kenito electronics in knitting
Melkamu kenito electronics in knittingMelkamu kenito electronics in knitting
Melkamu kenito electronics in knittingMelkamuKenito
 
woven fabric manufacturing
woven fabric manufacturingwoven fabric manufacturing
woven fabric manufacturingMelkamuKenito
 
fabric structure and design
fabric structure and designfabric structure and design
fabric structure and designMelkamuKenito
 

Mehr von MelkamuKenito (10)

Munsell Color Order System
Munsell Color Order SystemMunsell Color Order System
Munsell Color Order System
 
Agrotextiles
AgrotextilesAgrotextiles
Agrotextiles
 
flame retardant and proof finish
flame retardant and proof finishflame retardant and proof finish
flame retardant and proof finish
 
natural and mordant dyes
natural and mordant dyesnatural and mordant dyes
natural and mordant dyes
 
fabric structure and design solution by mk39@
fabric structure and design solution by mk39@fabric structure and design solution by mk39@
fabric structure and design solution by mk39@
 
Woven FM II assignment solution
Woven FM II assignment solutionWoven FM II assignment solution
Woven FM II assignment solution
 
Melkamu kenito electronics in knitting
Melkamu kenito electronics in knittingMelkamu kenito electronics in knitting
Melkamu kenito electronics in knitting
 
woven fabric manufacturing
woven fabric manufacturingwoven fabric manufacturing
woven fabric manufacturing
 
fabric structure and design
fabric structure and designfabric structure and design
fabric structure and design
 
Textile Testing
Textile TestingTextile Testing
Textile Testing
 

Kürzlich hochgeladen

The basics of sentences session 2pptx copy.pptx
The basics of sentences session 2pptx copy.pptxThe basics of sentences session 2pptx copy.pptx
The basics of sentences session 2pptx copy.pptxheathfieldcps1
 
Disha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfDisha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfchloefrazer622
 
Measures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and ModeMeasures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and ModeThiyagu K
 
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...fonyou31
 
1029-Danh muc Sach Giao Khoa khoi 6.pdf
1029-Danh muc Sach Giao Khoa khoi  6.pdf1029-Danh muc Sach Giao Khoa khoi  6.pdf
1029-Danh muc Sach Giao Khoa khoi 6.pdfQucHHunhnh
 
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxSOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxiammrhaywood
 
Russian Call Girls in Andheri Airport Mumbai WhatsApp 9167673311 💞 Full Nigh...
Russian Call Girls in Andheri Airport Mumbai WhatsApp  9167673311 💞 Full Nigh...Russian Call Girls in Andheri Airport Mumbai WhatsApp  9167673311 💞 Full Nigh...
Russian Call Girls in Andheri Airport Mumbai WhatsApp 9167673311 💞 Full Nigh...Pooja Nehwal
 
microwave assisted reaction. General introduction
microwave assisted reaction. General introductionmicrowave assisted reaction. General introduction
microwave assisted reaction. General introductionMaksud Ahmed
 
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...Krashi Coaching
 
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxPOINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxSayali Powar
 
APM Welcome, APM North West Network Conference, Synergies Across Sectors
APM Welcome, APM North West Network Conference, Synergies Across SectorsAPM Welcome, APM North West Network Conference, Synergies Across Sectors
APM Welcome, APM North West Network Conference, Synergies Across SectorsAssociation for Project Management
 
Accessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactAccessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactdawncurless
 
Paris 2024 Olympic Geographies - an activity
Paris 2024 Olympic Geographies - an activityParis 2024 Olympic Geographies - an activity
Paris 2024 Olympic Geographies - an activityGeoBlogs
 
Measures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDMeasures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDThiyagu K
 
Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104misteraugie
 
Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)eniolaolutunde
 
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...EduSkills OECD
 

Kürzlich hochgeladen (20)

Código Creativo y Arte de Software | Unidad 1
Código Creativo y Arte de Software | Unidad 1Código Creativo y Arte de Software | Unidad 1
Código Creativo y Arte de Software | Unidad 1
 
The basics of sentences session 2pptx copy.pptx
The basics of sentences session 2pptx copy.pptxThe basics of sentences session 2pptx copy.pptx
The basics of sentences session 2pptx copy.pptx
 
Disha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfDisha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdf
 
Measures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and ModeMeasures of Central Tendency: Mean, Median and Mode
Measures of Central Tendency: Mean, Median and Mode
 
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
 
1029-Danh muc Sach Giao Khoa khoi 6.pdf
1029-Danh muc Sach Giao Khoa khoi  6.pdf1029-Danh muc Sach Giao Khoa khoi  6.pdf
1029-Danh muc Sach Giao Khoa khoi 6.pdf
 
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptxSOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
SOCIAL AND HISTORICAL CONTEXT - LFTVD.pptx
 
Russian Call Girls in Andheri Airport Mumbai WhatsApp 9167673311 💞 Full Nigh...
Russian Call Girls in Andheri Airport Mumbai WhatsApp  9167673311 💞 Full Nigh...Russian Call Girls in Andheri Airport Mumbai WhatsApp  9167673311 💞 Full Nigh...
Russian Call Girls in Andheri Airport Mumbai WhatsApp 9167673311 💞 Full Nigh...
 
microwave assisted reaction. General introduction
microwave assisted reaction. General introductionmicrowave assisted reaction. General introduction
microwave assisted reaction. General introduction
 
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...
Kisan Call Centre - To harness potential of ICT in Agriculture by answer farm...
 
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptxPOINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
POINT- BIOCHEMISTRY SEM 2 ENZYMES UNIT 5.pptx
 
APM Welcome, APM North West Network Conference, Synergies Across Sectors
APM Welcome, APM North West Network Conference, Synergies Across SectorsAPM Welcome, APM North West Network Conference, Synergies Across Sectors
APM Welcome, APM North West Network Conference, Synergies Across Sectors
 
Accessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactAccessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impact
 
Paris 2024 Olympic Geographies - an activity
Paris 2024 Olympic Geographies - an activityParis 2024 Olympic Geographies - an activity
Paris 2024 Olympic Geographies - an activity
 
Measures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDMeasures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SD
 
Mattingly "AI & Prompt Design: The Basics of Prompt Design"
Mattingly "AI & Prompt Design: The Basics of Prompt Design"Mattingly "AI & Prompt Design: The Basics of Prompt Design"
Mattingly "AI & Prompt Design: The Basics of Prompt Design"
 
Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104
 
Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)Software Engineering Methodologies (overview)
Software Engineering Methodologies (overview)
 
Mattingly "AI & Prompt Design: Structured Data, Assistants, & RAG"
Mattingly "AI & Prompt Design: Structured Data, Assistants, & RAG"Mattingly "AI & Prompt Design: Structured Data, Assistants, & RAG"
Mattingly "AI & Prompt Design: Structured Data, Assistants, & RAG"
 
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...
Presentation by Andreas Schleicher Tackling the School Absenteeism Crisis 30 ...
 

wet laid web preparation

  • 1. IOT DEPARTMENT OF TEXTILE AND GARMENT ENGINEERING Non woven fabric manufacturing seminar on wet-laid web preparation HAWASSA,ETHIOPIA To:Mr. Metasebia.G By peer-I members
  • 2. TABLE OF CONTENTS: R.No TITLE SLIDE 1 Introduction 3 2 Raw material 8 3 Production machineries 4 Process description 13 5 Process model 15 6 Special features of the wet laid process and products 17 7 Miscellaneous Topics 20 8 Defects of wet-laid web fabric 23 9 Merits and demerits 26 10 Application 27 11 Conclusion 28 2
  • 3. INTRODUCTION Historical perspective:  The wet-lay nonwoven process is known to be derived from the wet-laid paper making process.  H. Fourdrinier developed a papermaking machine that has been the basis for the most modern papermaking machines employing very short fiber. 3
  • 4. CONTINUED… wet-laid paper making process:  The wood pulp and water in the ratio of 0.003- 0.007 (w/w) are mixed to make a good quality suspension of fibers and water.  The suspension is then pumped to the headbox which has a small opening, often called as slice.  Through the slice, the fibre-water suspension is dropped onto the moving perforated Fourdeinier wires. These wires contain a lot of perforations through which the water gets drained to the vacuum and the fibres, deposited on the moving wires, formed a web. In this way, the wet-laid paper is formed 4
  • 5. MODIFIED FORM OF THE MACHINE  By using the previous version of the machine it was not possible to process relatively long fibers as the mentioned dilution ratio results in inadequate fiber dispersion in water. Measures taken to solve the problem:  The ratio of weight of fiber pulp and weight of water should be around 0.0005-0.00005.  The inclination of the forming wire to the base is required to be equal to 20°.  The machine was made to have large headbox (slice) opening 5
  • 6. CONTINUED…  This machine has been used to make papers from long fibres and subsequently the basis for making nonwovens also. The modified: 6
  • 7. NON WOVEN TEXTILES Non woven production general sequence: 7 • Selecting based on compatibility Fiber preparation •Wet laid •Dry laid •Spun laid •Melt blown Web preparation • mechanical • Thermal • Chemical Web bonding • Mechanical • Chemical Finishing We will see wet laid web here!
  • 8. PAPER AND TEXTILES Two fundamental reasons account for physical property differences between paper and textiles: 1-difference in the raw materials each process uses. Paper: fibers being short and fine are able to pack together into a dense structure Textiles : fibers tend to be longer, stronger, and relatively inert 2-the structure and the way individual fibers are arranged by the process to make a finished product. Paper: the fibers overlap randomly and pack densely. Textiles: there is a repeating unit structure which provides some extensibility in all directions 8
  • 9. CONTINUED…  In light of the characteristics of these raw materials and structure, one would expect 9 Paper to be Textile to be • weak • Stiff • Inextensible • Smooth • dense • strong • softer, • bulkier • more drape able, • less smooth and • more porous.
  • 10. RAW MATERIALS  In theory, any natural or synthetic fiber could be used in the production of wet-laid nonwovens. However, there are practical limitations on the use of many fibers (cost, availability, priorities).  wood pulp is used in virtually all wet-laid nonwovens because of its ease of handling, low cost, opacity, and chemical reactivity.  Some natural fibers - such as cotton linters, manila hemp and cellulose staple fibers - are also used in wet-laid process(2-30 mm in length). 10
  • 11. CONTINUED…  Synthetic fibers provide specialized properties, uniformity, and constancy of supply which cannot be achieved by natural fibers. Reasons for their limited application: o They are 20 to 50% more expensive than the same fiber in the form of textile staple. o Flocculation(they entangle ). 11
  • 12. CONTINUED… Flocculation:  is incapability to disperse in water due to longer length and flexibility they have.  Increases with an increase in length to diameter ratio(L/D) of fiber. Tt = fiber fineness in dtex 12
  • 13. CONTINUED… Several approaches have been developed to overcome this problem: o Synthetic fiber manufacturers offer fibers with proprietary chemical surface treatments, which improve dispersion. o The general strategy for reducing flocculation of synthetic fiber furnishes is to increase the dilution (decrease the "consistency" of weight percent of fiber in the suspension). 13
  • 14. COMPATIBILITY OF THE MATERIAL WITH THE PROCESS  Whether or not a fiber is suitable for use in the web process depends on its ability to disperse in an aqueous medium. The dispersion behavior of a fiber depends largely on the following factors:  The degree of fineness calculated from the length and thickness of the fiber  The stiffness of the fiber in an aqueous medium (web modified)  The kind of crimping  The wettability  The cutting quality of the fiber 14
  • 15. PRODUCTION MACHINERIES There are three characteristic stages in the process • Swelling and dispersion of the fiber in water; transport of the suspension on a continuous traveling screen • Continuous web formation on the screen as a result of filtration • drying and bonding of the web 15
  • 16. CONTINUED… Some of machines used in the process: Web forming device with inclined wire screen Wet-laid web-making machine with cylinder drier 16
  • 17. PROCESS DESCRIPTION  The fibres are mixed with water and it forms fibre-water suspension.(two mixing tanks for preparation of better fibre-water suspension.)  This suspension is then pumped through the headbox to the perforated wire.  The water is drained through the perforations and the fibres are laid on the moving wire to form a web.  The wet-laid web is then dried and bonded by using binder. It is again dried and finally wound on a roll. 17
  • 18. CONTINUED… • mixing • Prepare suspension Stage 1 Suspension via head box to perforated wire Stage 2 Dehydration and web formation. Stage 3 18
  • 19. CONTINUED… The schematic diagram of a typical wet-lay process for making nonwovens : 19
  • 20. PROCESS MODEL  It is often necessary to calculate process parameters in advance with an aim to obtain a specific structure of wet-laid nonwovens. Because of this, it is often necessary to model the wet- lay process. 20
  • 22. CONTINUED… The velocity of water in relation to the velocity of wire determines the structure of the web.  When both the velocities are equal then the fibre lay-down is found to be practically random.  When the velocity of wire is higher than the velocity of water then fibres are found to be preferentially orientated in the machine direction.  when the velocity of wire is lower than the velocity of water then fibres are found to be preferentially orientated in the cross direction. 22
  • 23. SPECIAL FEATURES OF THE WET-LAID PROCESS AND ITS PRODUCTS: Compared to dry web making process and its product:  Since short fibers are required the web structure is closer, stiffer and less strong.  The fibers in the web may be randomly or longitudinally arranged.  The basis weight (grams/square meter) can be varied within broad limits.  It’s highly productivity and have wide range of application 23
  • 24. MISCELLANEOUS TOPICS Water removal from web:  Water removal on drying is one of the most important steps in the wet-laid process. Pressure, vacuum, and heat are used to remove water from the sheet.  The efficiency of the methods are determined by the machine speed, sheet weight, and fiber compositions of the sheet 24
  • 25. CONTINUED… Calendaring:  Calendars are often used on the product to make it dense and smooth the sheet. Creping devices are used to soften sheets by controlled bond breakage. Aperturing and water-jet entanglement:  Apertures are regularly spaced holes, and can be selected for aesthetics or for performance.  One method of aperturing uses a course forming wire, so that the sheet is formed around the protruding "knuckles" in a regular pattern.  Another method uses high- pressure water showers and patterned cylinders to rearrange the fiber into the desired pattern. 25
  • 26. FABRIC DEFECTS There exist three types of defects in the wet- laid nonwoven fabrics:  logs, ropes, and dumbbells 26
  • 27. CONTINUED… Logs:  are characterized by bundles of fibres with aligned cut ends that are never dispersed.  considered to be a fibre supply problem or can be the result of remarkably low under agitation of the initial dispersion. Ropes:  are characterized by assemblages of fibres, with unaligned ends, that are clearly more agglomerated than in the general dispersion.  re formed when fibres are encountered a vortex that facilitates in entangling the fibres to form ropes. 27
  • 28. CONTINUED… Dumbbells:  are characterized by paired clumps of fibres connected by one or more long fibres.  Their formation requires an excessively long fibre and a snag in the system piping.  The good quality of dispersion of fibres in water is a key to the good quality of wet-laid webs. 28
  • 29. MERITS AND DEMERITS The merits of wet-lay nonwoven process are:  High through-put rate.  Isotropic as well as anisotropic structures can be created.  Too brittle fibres, generally not suitable for textile applications, can be processed. The demerits of wet-lay nonwoven process are:  High capital intensive process.  High energy intensive process.  High fiber quality requirements. 29
  • 30. APPLICATIONS:  They have applications in diversified areas, namely surgical clothing and drapes, bed linen, table linen, cloths, and napkins, towels, kitchen wipes.  In addition, the wet-laid technical nonwovens are found to be used in many specialized applications, including glass fibre roofing substrate, glass fibre mat for flooring, glass fibre mat for printed circuit boards, wall covering, insulation materials, battery separators, RFI shielding veils. 30
  • 31. CONCLUSION:  The system was thought to be applied for any types of fiber. However in practice the system is found to be applied for those fibers capable of dispersing in the fluid. Moreover the application is constrained by different factors.  To prepare the web different machineries are applied having their own way of performing the sub operations.  The main advantage of the system is its capability to process too brittle fibers that mayn’t be processed in other systems. The high energy intensives needed may make it limited.  The products have application in different areas including industrial and apparel uses. 31
  • 32. OUR SOURCES:  Non woven manufacturing technology lecture, NPTEL.  Web formation methods, Textile school.  Literatures of the same title prepared for students, Bahir-Dar university, ETHIOPIA. 32
  • 33. PEER-I MEMBERS R.No Name ID 1 Melkamu Kenito TECH/0750/09 2 Meron Tebikew TECH//09 3 Azeb Mekonin TECH//09 4 Abdulkerim Nesru TECH//09 5 Selamawit Asalfew TECH//09 33
  • 34. THIS IS ALL WE HAVE… THANK YOU!34