composite fabrication by filament winding
TRANSCRIPT
Composite Fabrication By Filament Winding
1. Introduction
Technological advances in various sectors have created the demand
for newer materials, which can perform in stringent conditions of high
pressure and temperature, highly corrosive environment, with high strength
requirement. Conventional materials failed to service these conditions. This
has triggered the need to develop engineered materials to cater customised
needs. Industries have recognised the ability of composite materials to
produce high quality, durable, cost –effective products.
Filament winding is a major manufacturing process in the fabrication of
high performance composites, allowing the process of filament winding to be
the most efficient and least expensive method to construct the basic
infrastructure system of 21st century.
AEC/MECH/2009 1
Composite Fabrication By Filament Winding
2. About Composites
A ‘composite ‘is a heterogeneous combination of two or more materials
differing in form or composition on macro scale. The combination results in
material that maximises specific performance properties. The constituents do
not dissolve or merge completely and therefore exhibit an interface between
one another. In this form both reinforcing agents and matrix retain their
physical and chemical identities, while producing a combination of properties
that cannot be achieved with either of the constituents acting alone.
Composites are classified based on type of matrix used –polymer, metallic
and ceramic.
The unique properties of composites are:
1. Composite materials are 30-40% lighter than aluminium structures
designed for the same functional requirements.
2. Pipes and cylinders made up of composites have lower weight
compared to the metallic ones and can be withstand high internal
pressure.
3. Composites have excellent corrosion resistance.
4. Appropriate inhibitors and additives can impart good fire retardation.
properties to composite.
5. Improved torsional stiffness and impact resistance properties.
6. Higher fatigue endurance limit.
7. Design flexibility- composites can be tailored to meet performance
needs and complex design requirement.
8. Composites exhibit higher internal damping capacity.
9. Composites have better dimensional stability.
10. Improved appearance.
Composite applications have revolutionised all industries including,
1. Aerospace 4. Chemicals
2. Pharmaceutical 5. Marine
3. Electrical 6. Transportation
AEC/MECH/2009 2
Composite Fabrication By Filament Winding
3. Composite Manufacuring Techniques
There are variety of processing techniques for fabricating composite
parts and structures. They are resin transfer moulding, pultrusion and filament
winding. Some of them are explained bellow in brief:
3.1. Resin Transfer Moulding (RTM):
This is a low pressure, closed mould, semi-mechanised process. In
RTM several layers of dry continues strand mat, woven roving or cloth are
placed in the bottom half of a two part closed mould, and a low viscosity
catalysed liquid resin is injected under pressure into the mould cavity, which is
subsequently cured. Instead of using flat reinforcing layers, such as strand
mat, the starting material in RTM can be a ‘preform‘that already has a shape
of desired product. The potential advantages of RTM can be summarised as:
Manufacture of large complex structures.
Good surface finish.
Design flexibility.
Capability of integrating large number of components into one
part.
APPLICATIONS:
RTM process is mainly used for moulding parts like,
1. Cabinet walls
2. Chairs or bench sheets
3. Hoppers
4. Water tanks
5. Bath tubs
6. Boat hulls
AEC/MECH/2009 3
Composite Fabrication By Filament Winding
3.2. Pultrusion:
Pultrusion is a continuous, automated process. Due to uniformity in
cross section, resin dispersion, fibre distribution and alignment, excellent
composite structural materials can fabricate by pultrusion. The process
involves pulling of fibres through a bath of resin, blended with catalyst and
then into a performing fixture, where the section is partially pre- shaped and
excess resin is removed. Then it is passed through a heated die, which
determines the sectional geometry and finish of the final products.
Common pultruded parts are solid rods, hollow tubes, flat sheets and
various types of beams including angles, channels and wide flanged beams.
Advantages of pultrusion process are:
Cost effective for high volume production.
Uniform cross section products can be manufactured.
APPLICATIONS:
1. Industrial grating
2. Walk ways
3. Cable trays
4. Handrails
5. Ladder
AEC/MECH/2009 4
Composite Fabrication By Filament Winding
4. Filament Winding Method
4. 1. THE EVOLUTION:
In 1964, authors Rosate D.V. and Grove C.S. in their book ‘filament
winding: It’s Development, Manufacture, Applications and Design’ defined it
as a technique that produces high strength and lightweight products; consist
basically of two ingredients; namely, a filament or tape type reinforcement and
matrix or resin.
The equipment that was designed in1950’s was very basic, performing
the simplest tasks using only two axes of motion (spindle rotation and
horizontal carriage). Machine design consisted of a beam, a few legs and cam
rollers for support. The simplistic design was sufficient to create the first
filament wound parts -rocket motor cases.
By mid-70’s machine design once again made a dramatic shift. This
time the advancement of servo technology entered the real of machine
design. High speed computers allow smoother motion and greater fibre
placement accuracy. Increasingly, function that historically was controlled
through the use of belts, gears, pulleys and chains was eventually being
controlled through the use of computers.
1980’s and 90’s saw the increased use of computer technology.
Machine speed control was greatly improved, and computer control system
could track position and velocity with increased accuracy. At the same time a
number of different companies began to experiment with notion and
development of pattern generation software (CADWIND). By creating pattern
software, more complex configurations such as taper shaft T-shaped parts
and non symmetric parts could be successfully wound.
AEC/MECH/2009 5
Composite Fabrication By Filament Winding
4. 2. PROCESS TECHNOLOGY:
To begin with, a large number of fibre rovings are pulled from series of
creels into bath containing liquid resin, catalysts and other ingredients such as
pigments and UV retardants. Fibre tension is controlled by guides or scissor
bars located between each creel and resin bath. Just before entering the resin
bath the rovings are usually gathered into a band by passing them through a
textile thread board or stainless steel comb.
At the end of resin tank, resin –impregnated rovings are pulled through
a wiping device that removes excess resin from the rovings and controls the
resin coating thickness around each roving. The most commonly used wiping
device is a set of squeezed rollers in which the position of the top roller is
adjusted to control the resin content as well as the tension in fibre rovings.
Another technique for wiping the resin impregnated rovings is to pull each
roving separately through an orifice. The latter method results in better control
of resin content. Once the rovings have been thoroughly impregnated and
wiped, they are gathered together in a flat band and positioned on the
mandrel. Band formation can be achieved by passing through a stainless
steel comb and latter through the collection eye. The transverse speed of the
carriage and the winding speed of the mandrel are controlled to create the
desired winding angle patterns.
After winding, the filament wound mandrel is subjected to curing and
post- curing operations during which the mandrel is continuously rotated to
maintain the uniformity of resin content around the circumference. After
curing, the product is removed from the mandrel, either by hydraulic or
mechanical extractor.
AEC/MECH/2009 6
Composite Fabrication By Filament Winding
Figure 1: Filament Winding Machine & Processes
Figure 2:
Schematic Representation of the wet filament Winding Process
AEC/MECH/2009 7
Composite Fabrication By Filament Winding
4. 3. MATERIALS OF FABRICATION:
Filament winding requires continuous fibre reinforcement and resin
system to bind things together. There are many types of materials that can be
used in this process. The choice of material for a particular product depends
upon the economics, environmental resistance, corrosion resistance, weight
limitations and strength performance requirements.
4.3.1. Reinforcement type:
Continuous fibre reinforcement provides structural performance
required of the final product. A fibre is a primary contributor to the stiffness
and strength of the composite. The dominant commercially available fibres
are
E –Glass
S –Glass
Aramid
Carbon /
graphite
Their common characteristics are,
1. Good tensile strength and stiffness
2. Widely used in commercial and industrial products.
4.3.2. Resins:
The resin matrix provides the load transfer mechanism
between fibres that are wound on to the structure. In addition to
binding the composite structure together, the resin matrix provides
corrosion resistance, protects fibre from external damage and
contributes to the overall toughness from surface impact, cuts,
abrasion and rough handling. A few major resin matrix families of
interest to the filament winders are,
General purpose polyester
Improved polyester
Epoxy
Vinyl ester
Bisphenol
AEC/MECH/2009 8
Composite Fabrication By Filament Winding
The common characteristics are,
1. Low cost system
2. Widely used in industry 3.Applicable for room
temperature
4.3.3. Additives:
By using various additives liquid resin systems can be made
suitable to provide specific performance. Specific purpose
additives include,
1. Ultraviolet radiation screens for improved
weatherability.
2. Antimony oxides for flame retardation.
3. Pigments for colouration
4. 4. WINDING METHODS:
There are two different winding methods:
4.4.1 Wet winding, in which the fibres are passed through a resin
bath and wound onto a rotating mandrel to get the final product.
4.4.2 Pre-preg winding, in which pre-impregnated fibre tows are
placed on the rotating mandrel to get the final product. In this
process is in pre-pregged form, so a resin bath is not needed.
Material is heated as it is wound on the mandrel, a process known
as curing ‘on the fly’. the pre- preg is heated, layed down,
compacted and cooled in a single continuous operation.
Among these winding methods, wet winding is more
commonly used for manufacturing fibre reinforced thermosetting
matrix composite cylinders. Compared with pre-preg winding, wet
winding has several advantages like
Low cost
Short winding time
AEC/MECH/2009 9
Composite Fabrication By Filament Winding
The resin formulation can be easily varied to meet
specific requirements.
4. 5. WINDING PATTERNS:
In filament winding, one can vary winding tension, winding
angle and resin content in each layer of reinforcement until
desired thickness and strength of the composite are achieved.
The properties of finished composite can be varied with the type
of winding pattern selected.
4.5.1 Hoop winding:
It is known as girth or circumferential winding. Strictly
spiking, hoop winding is high angle helical ending that approaches
an angle of 90degrees. Each full rotation of mandrel advances the
band delivery by one full band width as shown in fig. 3.
AEC/MECH/2009 10
Composite Fabrication By Filament Winding
Figure 3
Hoop Winding
4.5.2. Helical Winding:
In helical winding, the mandrel rotates at a constant speed
while the fibre feed carriage transverses back and forth at a speed
regulated to generate the desired helical angles as shown in fig.4.
Usually all composite tubes and pressure vessels re produced by
means of helical winding.
Figure 4
Helical Winding
AEC/MECH/2009 11
Composite Fabrication By Filament Winding
4.5.3. Polar winding:
In polar winding, fibres passes tangentially to the polar
opening at one end of the chamber, reverse direction and
passes tangentially to the opposite side of the polar opening at
the other end. In other words, fibres are wrapped from pole to
pole, as mandrel arm rotates about the longitudinal axis as
shown in fig.5. It is used to wind almost axial fibres on domed
end type of pressure vessels. On vessels with parallel sides, a
subsequent circumferential winding is done.
On the above three, helical winding has great versatility.
Almost any combination of diameter and length may be wound
by trading off wind angle and circuits to close the e patterns.
AEC/MECH/2009 12
Composite Fabrication By Filament Winding
Figure 5
Polar Winding
5. Recent Advances
Now a day, most filament windings are numerically
controlled with high degree of freedom to place the fibres at
required positions for meeting the complex design configurations
of the products. Fibre orientation is the decisive factor in the
strength of the composites.
Belgium has developed user –friendly pattern generation
software CADWIND for obtaining custom fibre orientation and
high quality of filament wounds components. CADWIND
calculates from the given strength requirements, the fibre lay-up
AEC/MECH/2009 13
Composite Fabrication By Filament Winding
on the mandrel and automatically generates the part programme
for any winding machine. The laminate structure is reproduces on
the winding machine exactly as calculated by CADWIND. A
CADWIND design software tool creates 3D mandrel models and
also interfaces for input of mandrel models from cad system.
Optimisation of winding angle variation is possible with this
software. Computer numerical controlled multi-axis filament
winding machines using CADWIND software can wind any
irregular shapes with no axis of symmetry.
6. Indian Scenario
In view of the crucial need for developing indigenous
capability in composite technology, the Advanced Composite
Programme was launched by the Department of Science and
Technology (Government of India). Based on the direct exposure
of Technology Information, Forecasting and Assessment Council
AEC/MECH/2009 14
Composite Fabrication By Filament Winding
(TIFAC) to composite applications, the responsibility of
implementing the programme was assigned to this council. The
programme was an attempt to enhance the utilisation and
application of composite as an important performance material in
various sectors and to improve upon the laboratory- industry
linkages towards development and commercialisation.
Assessing the importance of filament winding technology
for novel applications, the following projects have been launched
under the Advanced Composites Programme in collaboration with
industry partners.
6.1. Composite pressure vessels:
The project was launched in March 2002 under the
advanced composite programme of TIFAC in partnership with
Kineco Pvt. Ltd., Panaji and with technological support from IIT
Mumbai. The project aimed at developing filament wound
pressure vessels.
The project aimed at developing filament wound pressure
vessels for the following applications,
1. Under carriage tanks to be fitted to the railway passenger
coaches for water supply to the toilets.
2. For water treatment application.
6.2. Filament wound GRE pipes:
In view of the wide application potential of GRE pipes, a
project on development of glass reinforced epoxy (GRE) pipes by
filament winding technique is being considered by TIFAC. GRE
pipes will be developed as per ASTM standards, using
AEC/MECH/2009 15
Composite Fabrication By Filament Winding
indigenously developed 4 axes CNC filament winding system for
catering to high pressure applications.
GRE pipes offer resistance to highly corrosive fluids at
various pressure and temperatures, and adverse soil and weather
conditions.
The project aimed at developing filament wound GRE pipes
for the following applications,
1. In oil refineries.
2. Offshore flat forms.
3. Chemical and pharmaceutical plant.
4. Sewerage, heating, cooling of fluid lines.
6.3. Filament wound composite pipe fittings:
At present FRP pipe fittings in India are being
manufactured by hand lay –up or by tape winding which cannot
withstand high pressures and temperatures. Due to non uniformity
in fabrication and resultant mechanical properties, the service life
of such pipe fittings is also minimal.
In view of application potential of filament wound pipe
fittings, a project on ‘development of filament wound composite
pipe fittings’ is being considered by TIFAC. Under the project,
there is proposal to fabricate composite pipe fittings using
indigenously developed six axis CNC filament winding system.
AEC/MECH/2009 16
Composite Fabrication By Filament Winding
Figure 6 .Six-Axis Computer-Controlled Filament Winder
The project aimed at developing filament wound composite
pipe fittings for the following applications,
1. Oil exploration and transportation.
2. Refineries.
3. Chemical and pharmaceutical plants.
4. Irrigation.
5. Nuclear and thermal power plant.
6. Fire fittings.
AEC/MECH/2009 17
Composite Fabrication By Filament Winding
7. Advantages & Limitations
Advantageous points of filament winding method as
compared to other manufacturing techniques of composites
are:
This technique offer high speed.
This is precise method for placing many composite
layers.
This is low cost method.
This is the fastest technique for manufacturing fibre
reinforced cylindrical components and high pressure
pipes.
This process is not limited to axis- symmetric structures.
This method is efficient for more complex parts such as
Tee joints, Elbows.
Attractive external appearance of the product.
Cost comparison between composites fabrication methods.
Limitations:
This method is limited for cylindrical, spherical & dome
shaped structures.
AEC/MECH/2009 18
Composite Fabrication By Filament Winding
Setup cost is high.
8. Applications of Filament Winding Method
1) Aerospace-applications include,
Tailcone assemblies
Drive shafts
Masts
Turrets
Rocket Motor Cases
Launch Tubes
Fuel Tanks
2) Corrosion Resistant
Ducting Systems
Underground Storage Tanks
Above Ground Storage Tanks
Piping Systems
Stack Liners
3) Sport’s and recreation
Golf Shafts
Bicycle Tubular Structures
Wind Surfing Masts
Ski Poles
4) Pressure Vessels
Water Heaters
Rocket Motor Casings
CNG (Compresses Natural Gas) Tanks
Solar Heaters
5) Roller Shafts
Paper rollers
Liners
Ducting Systems
Tubular Systems
AEC/MECH/2009 19
Composite Fabrication By Filament Winding
AEROSPACE AND CUSTOM DESIGN APPLICATIONS
AEC/MECH/2009 20
Composite Fabrication By Filament Winding
AEC/MECH/2009 21
Composite Fabrication By Filament Winding
Image no. 8 Image no. 9
ROLLER SHAFT DRIVE SHAFT
AEC/MECH/2009 22
Composite Fabrication By Filament Winding
Image no.10 Pressure vessel
AEC/MECH/2009 23
Composite Fabrication By Filament Winding
9. Conclusion
By using filament wound processes application never
corrode and remain maintained free for decades, competing in
cost and performance with the metallic structures.
Filament wound composite pipe are good replacement for
all steel and metal pipelines in oil, gas and water supply systems.
There is substantial need to renovate and restore all municipal
pipe lines for water and sewerage transportation with composites.
India with an excellent knowledge base in various resins,
catalyst and curing systems with an adequate availability of raw
materials can certainly shape out a role in the emerging
technology of composite fabrication. Commercialising this
technology will bring about a steady growth in Indian economy.
AEC/MECH/2009 24
Composite Fabrication By Filament Winding
10. References
Following are the sources from where the information for
the seminar has been collected:
1) Engineering Materials
(By Budinski)
2) Material Science & Metallurgy
(By Yesudian & Samual)
3) Publisher; Search: The industrial sourcebook.
Edition: January 2004
Page no. From 222 to 232.
WEBSITES:
1. www.compositesworld.com
2.
www.compositetek.com/papers/preformSAMPEPAPER.pdf
3. INCORPORATING ENVIRONMENTAL ISSUES IN A FILAMENT WINDING COMPOSITE MANUFACTURING SYSTEM BY Dawn K. Russell, Phillip A. Farrington, Sherri L. Messier James 4. Metal Prepare Filament Winding Brian Gordon Touchstone Research Laboratory, Ltd., Triadelphia, WV 5. OPTIMAL DESIGN OF FILAMENT WOUND STRUCTURES UNDER INTERNAL PRESSURE BASED ON THE SEMI-GEODESIC PATH ALGORITHM BY Cheol-Ung Kim, Ji-Ho Kang, Chang-Sun Hong and Chun-Gon 6. Economic assessment of Product-Process Innovation in Filament Winding Technology by Daniele Romano and Paola Pedone
AEC/MECH/2009 25
Composite Fabrication By Filament Winding
7. COMPOSITE MANUFACTURING 8. Composite Fabrication by Filament Winding - An Insight Muttana Suresh Babu, Gudavalli Srikanth & Soumitra Biswas
AEC/MECH/2009 26