Resin Infusion Molding

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IINNTTRROODDUUCCTTIIOONN

Composites are fibrous materials infused with a tough and durable plastic.

Composite material is a technology that is being used to make many items in

today’s world stronger and lighter. These materials are starting to be

incorporated into the armor of combat vehicles and soldiers. When these

panels are made in the most economical way, they are inferior to those that

take much more time and money to construct. Developing a method that is

fast and reliable is critical. A controlled setup must be designed in order to

get optimized infusion. The experimental process in which infusion is

accomplished is called Vacuum Assisted Resin Infusion Molding (VARIM).

In this process a vacuum pulls resin in from a feed tube to distribute it

evenly into the preform.

Vacuum-assisted resin infusion molding (VARIM) has become a very

attractive fabrication technology in recent years because of its low-cost

tooling and its scalability to very large structures. It minimizes the void

contents inside the molded composites, reduces VOC emissions and results

in less scrap than other molding techniques. VARIM has been used

primarily with resin systems that cure at room temperature, such as vinyl

ester and epoxies. High-temperature polymer matrix composites for high-

performance applications that require cure at high temperature are currently

produced by this technique. This process is cost effective and is applicable to

small-size as well as large-size structures. The potentials of VARIM for

fabricating high-temperature polymer composite structures with properties

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and quality that match those of the autoclave/prepreg molded ones are

widely unexplored.

To define VVaaccuuuumm AAssssiisstt RReessiinn IInnffuussiioonn MMoollddiinngg the process is briefly

described as :-

Fiber reinforcement is placed in a mold. Then the vacuum is applied

on the reinforcement against the mold. After this the mold is heated. The resin

is then injected into the reinforcement. The motive force in VARIM is

pressure. Therefore vacuum applied on the mold and the reinforcement acts as

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the motive force, and the pressure in the mold cavity is lower than atmospheric

pressure.

The Vacuum Assist Resin Infusion Molding (VARIM) is a vacuum-assisted

resin transfer molding process that produces parts excellent for marine,

aerospace, transportation, and infrastructure applications. The process is a

proven method of producing high-quality composite parts made from a wide

range of fiber and resin combinations. All commercial fibers, core materials,

and any resin in the range of 50 centipoise to 1000 centipoise will “VARIM”

with outstanding results. The process can be run at room or elevated

temperatures. VARIM can produce large (2,000 sq. ft.) parts, using both

single skin and cored construction, and highly complex three-dimensional

trussed parts weighing up to 3,000 lbs. The resulting composite material

properties directly compare to properties that had only been achievable in

highly controlled expensive autoclave processes.

When considering molding options for composites production,

there are several possibilities. In the case of high volume production, the

compression molding process produces low cost parts, but requires a high

capital investment in presses, infrastructure and tooling and maintenance also.

At the other end of the spectrum, infusion molding requires very low capital

investment, but produces cycle times similar or slower than traditional open

molding. Vacuum Assist Resin Infusion Molding (VARIM) stands in the gap -

able to produce mid-range volumes of parts at a moderate capital investment.

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A closed form solution for the flow of resin in the vacuum-assisted

resin infusion molding (VARIM) process is used extensively for affordable

manufacturing of large composite structures. During VARIM processing, a

highly permeable distribution medium is incorporated into the preform as a

surface layer. During infusion, the resin flows preferentially across the

surface, simultaneously through the preform, to a complex flow front. The

analytical solution presented here provides insight into the scaling laws

governing fill times and resin inlet placement as a function of the properties

of the preform, distribution media, and resin. The formulation assumes that

the flow is fully developed and is divided into two areas: (1) a saturated

region with no cross flow, and (2) a flow front region, which moves with a

uniform velocity, where the resin is infiltrating into the preform from the

distribution medium.

The VARIM process is inherently repeatable. Once equilibrium resin

content is achieved (55% to 60% fiber volume, depending on fabric

architecture), the process stops. Aerospace grade quality is ensured by first

eliminating all air voids before the resin is infused, enabling the fabric pre-

form to act as an effective breather layer. As the resin is infused, it travels in

controlled waves that work to completely wet out the reinforcing fibers and

eliminate any voids that could be created by the volatile organic compounds

(VOCs) emitted by the resin during the cure cycle. The process has been

used to infuse laminates up to 6 inches thick with the same high-quality

results as a simple 1/8 inch laminate.

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Some areas of application of VARIM are marine, aerospace, transportation,

wind turbine blades and infrastructure applications :-

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RRAAWW MMAATTEERRIIAALLSS

A) REINFORCEMENT MATERIALS:

Following material & material forms are normally used for the VARIM

process:

Forms of E glass type fibre glass reinforcements:

VARIM grade chopped strand mat

Needled mat

Woven roving

Woven cloth

UD reinforcements/continuous rovings

UD-CSM combination (Stitched/needled/powder bonded mat

configurations)

Texturised rovings

Continuous strand mat

Stitched mat

Carbon / Kevlar / Fibreglass hybrid reinforcements in the form of :

Woven roving

Woven cloth

UD CSM form

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Surface veils (to improve surface finish)

Fibreglass surface mat

Polyester veil fabric-woven

Polyester non-woven fabrics

Glass fibre

B) RESINS

Polyester resins - GP/Isophthalic/Vinyl ester/Bisphenolc

Epoxy resins

Phenolic resins and other thermoset resins

C) FILTERS & ADDITIVES

Low profile additives, internal release agents (used in case of hot

moulds), Lubricants, viscosity modifiers or surface tension relievers/

UV Stabilizers, etc.

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Powder, calcium carbonate, Quartz powder, Alumina - Trihydrate,

Titanium dioxide, Fine silica, etc. (added for requirements of cost

reduction / insulation / part surface quality / to reduce shrinkage /

flame retardancy, etc.)

Pigment pastes - Polyester/Epoxy/Pigments of various colours,

shades.

D) AUXILLARY MATERIALS

Mould release films (Wax & PVA) & coatings, Semi permanent release

agents, permanent coatings (like PTFE/Silicone rubbers, etc.).

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MMOOLLDD AANNDD MMAACCHHIINNEE PPAARRTTSS

Aluminum-FRP Mould

Vacuum Pumps

Small Parts Mould

Resin and Mixing Machine

Sawing and Drilling Machine

Painting Cabins

Heating Coils/Piping Systems

Temperature Measuring System

Guide pins, release pins, air release channels

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VVAARRIIMM PPRROOCCEESSSS

STEP 1

Cleaning of Mould and application of releasing agent.

STEP 2

To adhere Peel ply on Mould, Double-sided Tape is used.

STEP 3

Then, glass fabric layers are laid according to the design. CSM is laid on edge throughout the Mould.

STEP 4

Balsa, Foam and other supporting materials are laid on the mould

STEP 5

Rubber profile is put on the edges of the mould for the easy flow of the resin.

STEP 6

Then put Peel Ply on the fabrics.

STEP 7

Then put Perforated Sieve.

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STEP 8

Then lay Distribution Net according to the design.

STEP 9

Then we place Spiral Tube and Injection T for the transportation of resin in the glass fabric.

STEP 10

After that the Absorbent material is placed along the Flange over Vacuum points.

STEP11

Tissue Paper is put across the Mould between 2 successive Vacuum points all along the Mould.

STEP12

Then Tacky Tape is placed outside the Vacuum point all along the Flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside, another Vacuum plastic is placed to protect the inner one.

STEP13

Inner Vacuum is applied with the help of Vacuum pump to maintain a certain pressure. A little tolerance in drop of Vacuum is allowed for a certain period of time.

STEP14

Similarly a little tolerance of pressure is allowed for fixed time in outer Vacuum Plastic.

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STEP15

Now we apply Epoxy Resin system (Resin + Hardener) using 100:32 each by proportion.

STEP16

Once the infusion is completed , Vacuum is dropped to a certain value fixed by the designer.

STEP17

Then the mould is heated first for two hours. Once the Exotherm is completed heating is provided for a period of 4 hours and the temp is gradually raised for cure to complete.

STEP20

After cooling for certain hours, the Product is released with the help of clamps.

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DDIIAAGGRRAAMM OOFF PPRROOCCEESSSS

Figure showing Vacuum Assist Resin Infusion Molding

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AADDVVAANNTTAAGGEESS OOFF VVAARRIIMM The inherent economic and environmental advantages of a vacuum-assisted

resin infusion molding (VARIM) composite manufacturing process have

caused an increase in the number of applications and generated research

activity within the industry. Some of them are :-

It can be used with most resin systems (polyester, vinylester and

epoxy).

It can also be used with most woven, stitched, knitted, braided or

random fabrics.

It has relatively low tooling costs for high-performance components.

The process uses the injection of resin in combination with a vacuum

and captured under a bag to thoroughly impregnate the fiber

reinforcement. Thus resin fully wets the fibres, making it more strong

and free of dry patches to produce large structural shapes that are

virtually void-free.

This technique produces parts with higher fibre content than any other

process. Higher fibre volume fraction gives improved mechanical

performance.

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Parts produced using this method is stronger, lighter, and cheaper to

produce.

Furthermore, the process is very environmentally friendly. Volatile

Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs)

are drastically reduced. This also means that the working environment

is greatly improved.

VIP also allows unlimited setup time because the resin is not

catalyzed until all the materials are in place.

The vacuum bag evenly applies pressure, conforming to both simple

and complex shapes.

Application of vacuum provides control of part thickness by

compressing the laminate during cure.

Application of vacuum removes air, excess resin and volatiles

resulting in a good uniform product.

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AAPPPPLLIICCAATTIIOONNSS The Vacuum Assist Resin Infusion Molding (VARIM) is a vacuum-assisted

resin transfer molding process that produces parts excellent for marine,

aerospace, transportation, and infrastructure applications. The process is a

proven method of producing high-quality composite parts made from a wide

range of fiber and resin combinations. Some of the areas of application are

discussed here.

TTrraannssppoorrttaattiioonn Businesses involved in the transportation of goods and services are

continually looking for ways to reduce costs and stay competitive. Whether

it’s people or goods, the cost to move a pound of weight, continues to rise.

This is primarily driven by high-energy costs and by the type of vehicle and

materials used to produce that vehicle. For some, reducing costs may mean

improving fuel mileage or lowering maintenance costs while others are

looking for higher capacity or lower operating expenses.

Railway Coaches

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MMii ll ii ttaarryy AAppppll iiccaattiioonnss

The military forces are designed to respond immediately to deployment and

other reactive situations. Soldiers, supplies and vehicles must be prepared

for any challenge in a moments notice. Heavy vehicles hinder rapid

deployment and put military personnel at risk. VARIM technology addresses

these problems with composite solutions that ensure battle readiness and

increase personnel protection. The main objective is optimizing vehicles for

all war situations through lightweight, durable composite solutions.

VARIM focus on delivering composite solutions for military applicatins

that:

• Significantly reduce weight • Increase vehicle durability • Allow for the integration of other important features, like personnel

protection • Eliminate corrosion • Save the military millions of dollars over the vehicle's life cycle

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VARIM has produced composite materials to address many challenges in

the military. In addition to actively developing composite components for

the Army's tactical wheeled vehicles, VARIM is developing an all

composite cab armored for complete personnel protection, and will be

working on developing a next generation, lightweight all composite vehicle

for the Army.

WWiinndd eenneerrggyy The VARIM process is effectively used in designing and building large scale

wind turbine blades. Since the process is vacuum assisted, the problem of

dry patches is not there as in other techniques where the fibere is not fully

wetted by the resin. As the blade has to suffer various extreme

environmental conditions, it has to be free from points of failures like dry

patches, white patches etc which can only be achieved by this process.

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OOtthheerr AAppppll iiccaattiioonnss

Marine

Aerospace

Automobiles

Large Structural Components

Civil Infrastructure

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WITH THE APPLICATION OF THE VACUUM ASSIST

RESIN INFUSION MOULDING WE ARE GOING TO

DESIGN A PRODUCT WHICH IS ---

BLADE OF WIND ENERGY CONVERTER.

Finished blade

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WWIINNDD EENNEERRGGYY CCOONNVVEERRTTEERRSS

Wind is simply air in motion and the energy produced by this moving air is

called wind energy. The unequal heating of land and water by sun is the

main cause of wind generation on the earth’s surface. Wind is one of the

vital renewable sources of energy. Windmills are technically known as wind

energy converters (WEC’s). WEC’s are the machines used for the

production of electricity. These machines use wind as the source of energy.

WECs are producing energy without any pollution. The sound produced by

these WEC’s is about 40 db, which is not harmful to human ears and comes

in the favorable region.

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MMAAIINN PPAARRTTSS OOFF RROOTTOORR BBLLAADDEE

PREFORM It’s a partially cured layer of Glass Fibres made to give strength & enough thickness at root section SPARBOOM It’s a Glass Reinforced component made by Resin Infusion to give bending strength to the blade as Backbone

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LEADING EDGE GLUE CAP It’s a Glass Reinforced component made by Resin Infusion to form the cap like structure between the Pressure and suction Shell of the blade. TRAILING EDGE GLUE CAP It’s a Glass Reinforced component made by Resin Infusion form a cap like structure at rear part of blade

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Web

It’s a Glass Reinforced ,PVC foam / Balsa sandwiched component made by Resin Infusion, gives support to Suction and Pressure shell from innerside SPOILER It’s a Glass Reinforced ,PVC foam / Balsa sandwiched component made separately by Resin Infusion and is mounted on root side of blade to increase the overall output of Turbine between the Pressure and suction Shell of the blade.

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OOUUTTLLIINNEE OOFF TTHHEE MMAAIINN PPRROOCCEESSSS

1.Blank Blade making.

a) Preform making.

b) Sparboom making.

c) Web making.

d) T/E & L/E Glue Caps making.

e) Spoiler making.

f) Spoiler Web.

g) Spoiler Glue Cap.

h) Balancing chamber.

i) Shell Making.

j) Shell Joining and Releasing.

2. Deburring Process.

3. Sawing and Drilling Process.

4. Spoiler Fixing Process.

5. Finishing Process.

6. Dispatch.

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BBLLAANNKK BBLLAADDEE MMAAKKIINNGG PPRROOCCEESSSS

PREFORM MAKING

MATERIALS USED

a) Glass Fiber (G-2/1/0/1-1169 powder coated).

b) CSM (width of 300/100/250/200 mm used respectively).

PROCESS

STEP 1 Clean the Mould. (Once in 15 days) with the use of Acmosion.

STEP 2 Put G1 + G1 strips offset to radial direction along the Mould.

STEP 3 Table cutting of Layers (50 pieces) and lay them in the Mould according to the design.

STEP 4 Press (iron) out each layer straighten it and hold the layers at their desired positions.

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STEP 5 Apply Vacuum of 1 bar of 60 0 C for 1 hour.

STEP 6 Remove Vacuum gradually by switching off the Vacuum pump.

STEP 7 Switch off the heater and use for Shell making.

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SPARBOOM MAKING

MATERIALS USED

a) Double-sided Tape

b) Peel ply

c) CSM of width 50 mm

d) The Glass Fiber used is R-1/0-1188-M70

e) Balsa and Foam

f) Perforated Sieve

g) Spiral Tube and “T”

h) Tissue Paper

i) Tacky Tape

j) Rubber Profile (15 x 16 , 15 x 10 )

k) Distribution Net.

l) Epoxy Resin System

PROCESS There are two Moulds for Sparboom.

A. Suction and B. Pressure

Same layout is used for the both kinds of Mould.

STEP 1 Cleaning of Suction Mould by using NC-55.

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STEP 2 To adhere Peel ply on Mould, Double-sided Tape is used.

STEP 3 Then, R1 layers of 5 no’s (width 420 mm) are laid according to the design. 50 mm CSM is laid on either edge (Leading & trailing)

throughout the Mould.

STEP 4 Balsa and Foam laying on the mould L/E side : Foam - 10 mm of width 61mm from R 1800 to R 3300. Balsa - 9.5 mm of width 61mm from R 3300 to R 19000.

(Chamfer 150 mm at starting and with lay-up 15mm)

T/E side ::

Foam 16 mm of width 56mm from R 1800 to R 4300. (Chamfer 200 mm at starting and with lay-up 35 mm)

Balsa 15.9 mm from R 4300 to R 6000. Balsa 12.7 mm from R 6000 to R 15000. Balsa 9.5 mm from R 15000 to R 19000.

Balsa 9.55mm from R 19000 to R 22000 (Chamfer at 19000 , 300mm up to 9.5-0 mm) (Chamfer at 22000 , 30mm to 5 mm)

STEP 5 Rubber profile use on T/E side :

15x16mm R 1800 to R 15000 15x10mm R 15000 to R 22000

G1+G1 layer of 100mm width used to cover foam T/E side R 1800 to R 4690

L/E side R 1800 to R 4520

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STEP 6 Rest of 20 layers of R1 is used according to the design.

STEP 7 Put Peel ply from R 1800 to R 22500.

STEP 8 Put Perforated Sieve from R 1800 to R 22500.

STEP 9 Put Distribution Net according to the design.

STEP 10 Place “Injection T “at R 8000 and 12000. Place Spiral Tube at R 2800 to R 8000 and R 8000 to R 12000 and then R 12000 to R 21800.

STEP 11 Place Absorbent material of 30mm is placed along the Flange over Vacuum points.

STEP 12 Tissue Paper is put across the Mould between 2 successive Vacuum points all along the Mould.

STEP 13 Tacky Tape is placed outside the Vacuum point all along the Flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside, another Vacuum plastic is placed to protect the inner one.

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STEP 14 Inner Vacuum is applied with the help of Vacuum pump to maintain a pressure of 1 bar. Tolerance of drop in Vacuum of 30 Milibar is allowed for 10 Minutes.

STEP 15 Similarly tolerance of 30 Milibar is allowed for 3 Minutes in outer Vacuum Plastic.

STEP 16 Once the Quality Dept. approves the Vacuum, then a drop till 50 Milibar is done manually by regulation of valve.

STEP 17 Now apply Epoxy Resin system (Resin + Hardener) using 100:32 each by proportion.

RESIN INFUSION PROCESS IN SPARBOOM

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STEP 18 Once the infusion is completed, Vacuum is dropped to 50 Milibar.

STEP 19 Then the mould is heated to 650 C for two hours. Once the Exotherm is completed heating is provided for a period of 4 hours and the temp is gradually raised to 850 C.

STEP 20 After 4 hours, the Sparboom is released when mould temp down up to 400 - 450 C from the Mould.

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WEB MAKING MATERIALS USED

a) The Glass Fiber used is G1+G1

b) Peel ply

c) CSM

d) Double-sided Tape

e) Balsa and Foam

f) Perforated Sieve

g) Spiral Tube and “T”

h) Vacuum Plastic

i) Tissue Paper

j) Tacky Tape

k) Epoxy Resin System.

PROCESS

Radial position of Web is from R- 2700 to R- 21800.

STEP 1 Cleaning of the Mould with Acmosion.

STEP 2 Placing of double sided tape for Adherence of the subsequent

Peelply.

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STEP 3 Peel ply is placed along the Flange of the Web as,

Layer 1 R 17000 to R 21800 of 300 mm. Layer 2 R 2700 to R 17000 of 200 mm.

STEP 4 Place Layer of G1+G1 (4 No’s) throughout the mould.

Layer 1 R 2700 to R 21800 Layer 2 R 2700 to R 20500 Layer 3 R 2700 to R 17000 Layer 4 R 2700 to R 4800.

STEP 5 Balsa & Foam are placed according to design.

Gap between Balsa & Foam is filled with cotton powder.

STEP 6 120 mm layer of G1+G1 is placed on both sides along the Flange of

Web From R 2700 to R 20500. Another 100mm G1+ G1 layers are placed from R 4800 to R 20500.

STEP 7 CSM is placed all along the above layers.i.e. From R 2700 R 21800.

STEP 8 Spiral Tube is placed 80 – 100 mm from mould Edge. “ T ” position at R 6000 and another at R 12000 for Resin infusion.

Distribution Net start at R 2700 & End at R 21700.

STEP 9 Then 100 mm CSM is placed all along the Spiral Tube and peel-

ply is then laid at R 2900 to R 21600.

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STEP 10 Place Absorbent material of 30mm is placed along the Flange over Vacuum points.

STEP 11 Tissue Paper is put across the Mould between 2 successive

Vacuums point all along the Mould.

STEP 12 Tacky Tape is placed outside the Vacuum point all along the

Flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside, another Vacuum plastic is placed to protect the inner one.

STEP 13 Inner Vacuum is applied with the help of Vacuum pump to

maintain a pressure of 1 bar. Tolerance of drop in Vacuum of 30 Milibar is allowed for 10 Minutes.

STEP 14 Similarly tolerance of 30 Milibar is allowed for 3 Minutes in outer

Vacuum Plastic.

STEP 15 Once the Quality Dept. approves the Vacuum, then a drop till 95

Milibar is done manually by regulation of valve.

STEP 16 Now apply Epoxy Resin system (Resin + Hardener) using 50%

each by proportion.

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STEP 17 Once the infusion is completed , Vacuum is dropped to 75 Milibar.

STEP 18 Once the Exotherm is completed heating is provided for a period

of 4 hours and then cooled subsequently.

A HEATED WEB KEPT FOR COOLING

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LEADING EDGE GLUE CAP MAKING

MATERIALS USED-

a) The Glass Fiber used is R-1/0-1188-M70

b) Peel ply


d) Double-sided Tape

e) Balsa and Foam

f) G1+G1

g) Perforated Sieve

h) Spiral Tube and “T”

i) Tissue Paper

j) Tacky Tape

k) Epoxy Resin System

PROCESS

STEP 1 Cleaning of Suction Mould by using NC-55 & Acmosion.

STEP 2 To adhere Peel ply on Mould, Double - sided Tape is used.

STEP 3 Peel ply is placed all along the Mould according to the design

from R1100 to R 24000.

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STEP 4 Three layer of G1+G1 is placed from

R1100 to R 6500. R1100 to R 6300. R1100 to R 6100.

STEP 5 G1+G1 layer 0f 120mm is placed from

R 6200 to R 19600 R 6000 to R 19750 R 5800 to R 17000.

STEP 6 G1+G1 layer of 85mm is placed from

R 19450 to R 24000 R 19650 to R 24000.

STEP 7 Place R1 layer from R 1950 to R 18700 reducing by 150mm from

both the sides 7 layers subsequently.

STEP 8 Pocket of G2 layer is placed from R 1100 to R 3430.

STEP 9 Aluminum flat strip is placed from R 1350 to R 23995.

STEP 10 85mm G1+G1 is placed over the aluminium strip from R 1750 to R 23745.

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STEP 11 CSM is placed from R 63oo to R 23745.

STEP 12 Peel ply is placed all along the layer.

STEP 13 Perforated film is placed from R1200 to R 24000.

STEP 14 Sieve is placed from R 1200 to R 6300.

STEP 15 Place insulation paper from R 1200 to R 24000.

STEP 16 Spiral Tube is placed over insulation paper.

STEP 17 Injection T is placed at R 2000 and at R 13000.

STEP 18 Vacuum Plastic is done one over the other.


flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside with another Vacuum plastic is placed to protect the inner one.

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STEP 20 Inner Vacuum is applied with the help of Vacuum pump to maintain a pressure of 1 bar. Tolerance of drop in Vacuum of 30 Milibar is allowed for 10 Minutes. Similarly tolerance of 30 Milibar is allowed for 2 Minutes in outer Vacuum Plastic.

STEP 21

Once the Quality Dept. approves the Vacuum, then a drop till 97

Milibar is done manually by regulation of valve.

.

STEP 22 Now apply Epoxy Resin system (Resin + Hardener) using 50% each by

Proportion.

STEP 23 Once the infusion is completed Vacuum is dropped to 75 Milibar.

STEP 24 Once the exotherm is completed heating is provided for a

period of 2 hours.

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TRAILING EDGE GLUE CAP MAKING

MATERIALS USED

a) The Glass Fiber used is R-1/0-1188-M70

b) Peel ply


d) Double sided tape

e) Balsa and Foam

f) G2 layer

g) G1+G1 layer

h) Perforated sieve

i) Spiral Tube and T

j) Tissue paper

k) Tacky tape

l) Epoxy Resin System

PROCESS

STEP 1 Cleaning of the Mould with NC-55 & Flange with Acmosion.

STEP 2 Placing of Double-sided Tape for Adherence of the subsequent Peel ply.

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STEP 3 Three layer of G1 +G1 is placed from

R 1100 to R 10500 R 1100 to R 10300 R 1100 to R 10100

STEP 4 R1 is placed from R 1950 to R 9200. 16 layer of R1 are placed one above the other by reducing 75mm from R 1950 and 150mm from R 9200 for every subsequent layer.

STEP 5 Then 48 pocket of G2 is placed from R 1100 to R 3430.

STEP 6 CSM of 70 mm is placed from R 5000 to the end.

STEP 7 Peel ply is placed from R1100 to R 10000.

STEP 8 Perforated plastic is placed over CSM from R 1100 to

R 9000.

STEP 9 70 mm Net is placed from R 1100 to R 5000.

STEP 10 Insulation paper is placed centrally from R 100 to R 9000.

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STEP 11 Spiral Tube is placed over the insulation paper.

STEP 12 Resin infusion T is placed at R2000 to R 6800.

STEP 13 Place Vacuum flash absorbent all along the Vacuum point.

STEP 14 Inside & outside Vacuum Plastic is placed.

STEP 15 Tissue Paper is placed between two successive Vacuum

points.


flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside with another Vacuum plastic is placed to protect the inner one.


STEP 18 Resin system is allowed to infuse all along the layers up to a

period of two hours.

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SPOILER MAKING

MATERIALS USED

a) Double-sided Tape

b) Peel ply


d) The Glass Fiber used is R-1/0-1188-M70

e) Balsa and Foam

f) G2 Layer

g) G1+G1

h) Perforated Sieve

i) Spiral Tube and “T”

j) Tissue Paper

k) Tacky Tape

l) Epoxy Resin system

PROCESS

STEP 1 Cleaning of Suction Mould by using NC-55 & Acmosion.


STEP 3 Peel ply is placed over the Mould from R 2200 to R 11500.

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STEP 4 Leading side G1+G1 100mm is placed from R 2200 to R 11500.

STEP 5 G2 layer is placed from R 2200 to R 11500.

STEP 6 G1 layer of 100 mm is placed from R 2200 to R 11500.

STEP 7 G1 of 80 mm is placed over leading side from R 2200 to

R 11500.

STEP 8 Foam 140 mm and 120 mm are placed above one another

across the Root side of Length 1200mm starting from R 2200.

STEP 9 Balsa of 9.5mm is placed from R 2270 to R 10350 according to the

design.

STEP 10 G1 of 100mm is placed on leading side from R 2200 along

the profile.

STEP 11 G2 layer is placed from R 2200 to R 11500.

STEP 12 Spoiler drilling edge Glue Cap is placed from R 2254 to R 8000.

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STEP 13 Peel ply is placed all over the lay out.

STEP 14 Perforated plastic is placed over peel ply.

STEP 15 Mosquito net is placed from R 2270 to R 11300.

STEP 16 Insulation Tape is placed centrally from the trailing edge at 735mm

from R 2270 to R 11000.

STEP 17 Spiral Tube is placed over the insulation Tape using T pipe at

R 2400.

VACUUM APPLICATION BEFORE INJECTION OF RESIN

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STEP 18 Tacky Tape is placed outside the Vacuum point all along the Flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside with another Vacuum Plastic is placed to protect the inner one.


STEP 20 After Resin infusion all along the layers heating at stage one

(400 C) Is continued till 30 minutes. After 30 minutes, stage two heating is given (700 C) for a period of one hour. In stage three heating is given then onwards for a period of one hour.

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SPOILER WEB CAP MAKING MATERIALS USED

a) Peel ply

b) CSM of width 50 mm

c) Double-sided Tape

d) Foam

e) G1+G1 fibre

f) Insulation paper

g) Spiral Tube

h) Tissue Paper

i) Tacky Tape

j) Epoxy Resin system

PROCESS


STEP 2 Placing of double sided tape for Adherence of the subsequent

Peelply.

STEP 3 Place Peel ply all over the Mould.

49

STEP 4 Place G1+G1 layer all over the Mould.

STEP 5 Put 10 mm Foam as per design. Gaps are filled with Cotton flock.

STEP 6 Again G1+G1 layer placed.

STEP 7 Insulation paper is placed centrally.

STEP 8 Spiral Tube is placed over insulation paper as per the design.

STEP 9 Place Injection T. The injection point is taken centrally.

STEP 10 Tacky Tape is placed outside Vacuum point all along the Flange

to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside ,another Vacuum Plastic is placed to protect the inner one.

STEP 11 Inner Vacuum is applied with the help of Vacuum pump to

maintain a pressure of 1 bar. Tolerance of drop in Vacuum of 30 Milibar is allowed for 10 Minutes.


50



each by proportion.


STEP 16 Once the exotherm is completed heating is provided for a period of 2 hour.

51

SPOILER GLUE CAP MAKING

MATERIALS USED

a) Peel ply

b) CSM of width 50 mm

c) Double sided tape

d) G1+G1 fabric

e) Tissue paper

f) Tacky Tape

g) Vacuum Plastic

h) Epoxy Resin System

PROCESS


STEP 2 Placing of double sided tape for Adherence of the subsequent Peelply.

STEP 3 Three layers of G1+G1 Error! Not a valid link.is placed from R 2254 to R 8000. STEP 4 Re-enforcement layer for crane transport. Three G1+G1 layer

(Length400mm, and width 100mm) are placed starting from R 4950 to R 5000 and R 5050 respectively.

52

STEP 5 Put CSM layer over the one side of layers laid leaving a gap of 200

mm on either side of the Mould.

STEP 6 Place Vacuum flash absorbent all along the Vacuum point.

STEP 7 Inside & outside Vacuum Plastic is placed .

STEP 8 Tissue Paper is placed between two successive Vacuum points.


Flange to have a Vacuum plastic over the Mould. This is referred as inside Vacuum. Outside with another Vacuum Plastic is placed to protect the inner one.





each by proportion.

53


STEP 15 Once the exotherm is completed heating is provided for a period of 2 hour.

HEATING OF SPOILER GLUE CAP

54

SHELL MAKING

MATERIALS USED-

1. The Glass Fiber used are R-1/0-1188-M70 , G-1/1/0/1-114

M100 , G2-/1/0/1-1169 ,G1 + G 1, G2-/1/0/1-1169 powder

coated.

2. Peel ply

3. CSM of different width

4. Double-sided Tape

5. Masking tape

6. Balsa and Foam

7. Perforated Sieve

8. Spiral Tube and “ injection T”

9. Vacuum plastic

10. Tissue Paper

11. Tacky Tape

12. Epoxy Resin System.

E_48/1 Blade Manufactured in two parts.

A. Suction Shell and

B. Pressure Shell.

55

A. SUCTION SHELL MAKING STEP 1 Cleaning of Suction Mould by using Acmosion at Flange area and

NC-55 on Shell surface.


STEP 3 Peel ply is placed over the Mould at

• L / E and T/ E 200 mm width from R1100 to R 5800

• Peel ply over Spoiler area 100mm width.

• Peel ply 25 mm width for bonding of V profile R11500 to R

24000.

• Peel ply on outer surface from R 1100 to R 2200.

STEP 4 Shell Lamination

a. Two layer of CSM apply over FRP strip from R 1100 to R1900 (Which is used for Resin transfer) at middle of the Mould having the width of 100 mm and 200 mm width up to R 3000.

b. One surface layer apply width of 500 mm (Apply leading side to trilling side at 100 mm step).

c. Outer G2 sub pocket apply. � Layer 1 width 420 mm � Layer 2 width 450 mm � Layer 3 width 480 mm

d. Apply Special G1 layer (G-1/1/0/1-114 M100) throughout the Mould.

56

e. Outer G2 pocket apply (G2-/1/0/1-1169) � Layer 1 R 1100 to R 8800 (T/E side)

R 1100 to R 7600 (L/E side)

� Layer 2 R 11oo to R 7600 (T/E side) R 1100 to R 6400 (L/E side)

� Layer 3 R 1100 to R 6400 (T/E side) R 1100 to R 5200 (L/E side)

f. Three layer of R1 apply. (R-1/0-1188-m70, 100mm width) � Layer 1 R 6700 to R 21200 � Layer 2 R 7000 to R 20100 � Layer 3 R 7600 to R19000

g. Preform apply from R 1100 to R 3900. h. One layer of CSM width 700 mm from R 1100 to R 22500. i. Sparboom apply from R 1800 to R 22000. j. CSM apply throughout the Sparboom.

STEP 5 Foam and Balsa Placing.

� L/E side a. Balsa of 9.5mm from R 1800 to R15000.

(Chamfering 150mm at R 1800, Chamfering 30 0 at R 15000)

b. Foam 5mm from R 15000 to R 23900. (Chamfering 130mm at R 23900) � T/E side

a. Balsa of 15.9mm from R 1800 to R 6000 (Chamfer 300 at R 6000)

b. 14 mm Foam from R 6000 to R15000 (Chamfering both end 40mm)

c. Foam 8mm from 15000 to R 17500. (Chamfering both end 300)

d. Foam 5 mm from 17500 to 22000.

57

STEP 6 Apply R1 layer at T/E side.

� Layer 1 R 7900 to R 21900 � Layer 2 R 8200 to R 21350 � Layer 3 R 8500 to R 20800 � Layer 4 R 8800 to R 20250.

STEP 7 Inside G2 pocket apply (G2-/1/0/1-1169)

� Layer 1 R 1100 to R 8200(L/E)side � Layer 1 R 1100 to R 8200(T/E) side � Layer 2 R 11oo to R 7000(L/E) side � Layer 2 R 1100 to R 7000(T/E) side � Layer 3 R 1100 to R 5800 (L/E) side � Layer 3 R 1100 to R 5800 (T/E) side � Layer 4 R 1100 to R 4600 (L/E) side � Layer 4 R 1100 to R 4600 (L/E) side.

STEP 8 Last (G2-/1/0/1-1169 layer )

1) R 1100 to R 10200 (throughout the Mould) G2 apply (G2-/1/0/1-1169) 2) R 10200 to R 24000 (throughout the Mould) G1+ G1 layer.

STEP 9 Five layer of G1+ G1 (at tip side)

� Layer 1 180.x 340 � Layer 2 160x 320 � Layer 3 140x300 � Layer 4 120x280 � Layer 5 100x260.

STEP 10 Inside G2 (G2-/1/0/1-1169) sub pocket

� Layer 1 Width 420 mm � Layer 2 Width 450 mm � Layer 3 Width 480 mm

58

STEP 11 Apply peel ply through out the mould.

SUCTION SHELL MAKING

STEP 12 Infusion plan & Vacuum application.

• Resin infusion “ T ” is placed at R1400, R2700& R 15500.

• CSM is place according to design for Resin infusion.

• Peel ply is applied all over the Mould surface.

• Tissue Paper is placed every half-meter at Mould edge

before inside Vacuum.

• Place Vacuum flash absorbent all along the Mould.

• Inside & outside Vacuum Plastic is placed.

59

• Tacky Tape is placed all along the Flange area. Than

Vacuum is applied this is referred as inside Vacuum.

Outside another Vacuum Plastic is placed to protect the

inner one.

• Inner Vacuum is applied with the help of Vacuum pump to

maintain pressure of 1 bar. Tolerance of drop in Vacuum of

30 Milibar is allowed for 10 Minutes.

• Similarly tolerance of 30 Milibar is allowed for 3 Minutes in

outer Vacuum Plastic.

• Once the Quality Dept. approves the Vacuum, then a drop

till 97 Milibar is done manually by regulation of valve.

• Once the infusion is completed Vacuum is dropped to 75

Milibar.

• Once the exotherm is completed heating is provided for a

period of 4 Hour at 600 C.

60

B. PRESSURE SHELL MAKING STEP 1 Cleaning of the suction mould by using Acmosion at flange area and and applying NC-55 on Shell surface.


STEP 3 Peel ply is placed over the Mould at

• L / E and T/ E 200 mm width from R1100 to R 5800. • Peel ply over Spoiler area 100mm width. • Peel ply 25 mm width for bonding of V profile R11500 to R 24000. • Peel ply on outer surface from R 1100 to R 2200.

STEP 4 Shell Lamination

a. Two layer of CSM apply over FRP strip from R 1100 to R1900 (which is used for Resin transfer) at middle of the Mould having the width of 100 mm and 200 mm width up to R 3000.

b. One surface layer apply width of 500 mm. c. Outer G2 sub pocket apply.

� Layer 1 width 420 mm � Layer 2 width 450 mm � Layer 3 width 480 mm

d. Special G1 layer apply (G-1/1/0/1-114 M100) throughout the Mould.

e. Outer G2 pocket apply (G2-/1/0/1-1169)

Layer 1 R 1100 to R 8800 (T/E side)

R 1100 to R 7600 (L/E side)

61

Layer 2 R 11oo to R 7600 (T/E side)

R 1100 to R 6400 (L/E side) Layer 3 R 1100 to R 6400 (T/E side)

R 1100 to R 5200 (L/E side)

f. 5 layer of R1 apply. (R-1/0-1188-m70, 100mm width). � Layer 1 R 6400 to R 22300 � Layer 2 R 6700 to R 21200 � Layer 3 R 7000 to R 20100 � Layer 4 R 7300 to R 19000 � Layer 5 R 7600 to R 17900

g. Preform apply from R 1100 to R 3900. h. One layer of CSM width 700 mm from R 1100 to R 22500 i. Sparboom apply from R 1800 to R 22000. j. CSM apply throughout the Sparboom. k. Balancing Chamber layer

� Start from R15950 � End at R 18050.

STEP 5 Foam and Balsa Placing

� L/E side a. Balsa of 9.5mm from R 1800 to R15000.

(Chamfering 150mm at R 1800, Chamfering 30 0 at R 15000)

b. Foam 5mm from R 15000 to R 23900. (Chamfering 130mm at R 23900) � T/E side

a. Balsa of 15.9mm from R 1800 to R 6000 (Chamfer 300 at R 6000)

b. Foam 14 mm from R 6000 to R15000 (Chamfering both end 40mm)

62

c. Foam 8mm from 15000 to R 17500. (Chamfering both end 300) d. Foam 5 mm from 17500 to 22000.

STEP 6 Apply R1 layer at T/E side. (Trailing edge side)

� Layer 1 R 7900 to R 21900 � Layer 2 R 8200 to R 21350 � Layer 3 R 8500 to R 20800 � Layer 4 R 8800 to R 20250.

STEP 7 Balancing Chamber layer

� Start from R16000 � End at R 18000.

STEP 8 Inside G2 pocket apply (G2-/1/0/1-1169)

� Layer 1 R 1100 to R 8200(L/E) side � Layer 1 R 1100 to R 8200(T/E) side � Layer 2 R 11oo to R 7000(L/E )side � Layer 2 R 1100 to R 7000(T/E) side � Layer 3 R 1100 to R 5800 (L/E) side � Layer 3 R 1100 to R 5800 (T/E) side � Layer 4 R 1100 to R 4600 (L/E) side � Layer 4 R 1100 to R 4600 (T/E) side.

STEP 9 Last (G2-/1/0/1-1169) layer

1) R 1100 to R 10200 (throughout the Mould) G2 apply

(G2-/1/0/1-1169) 2) R 10200 to R 24000 (throughout the Mould) G1+ G1

layer.

63

STEP 10 Five layer of G1+ G1 (at tip side)

� Layer 1 180.x 340 � Layer 2 160x 320 � Layer 3 140x300 � Layer 4 120x280 � Layer 5 100x260.

STEP 11 Inside G2 (G2-/1/0/1-1169) sub pocket

� Layer 1 Width 420 mm � Layer 2 Width 450 mm � Layer 3 Width 480 mm.

STEP 12 Infusion plan & Vacuum application.

• Resin infusion “ T ” is placed at R1400, R2700& R 15500.

• CSM is place according to design for Resin infusion.

• Peel ply is applied all over the Mould surface.

• Tissue Paper is placed every half-meter at Mould edge before

Inside Vacuum.

• Place Vacuum flash absorbent all along the Mould.

• Inside & outside Vacuum Plastic is placed.

• Tacky Tape is placed all along the Flange area. Then Vacuum is

applied this is referred as inside Vacuum. Outside another

Vacuum Plastic is placed to protect the inner one.

• Inner Vacuum is applied with the help of Vacuum pump to

maintain a pressure of 1 bar. Tolerance of drop in Vacuum of

30 Milibar is allowed for 10 Minutes.

64

• Similarly tolerance of 30 Milibar is allowed for 3 Minutes in

outer Vacuum Plastic.

• Once the Quality Dept. approves the Vacuum, then a drop till

97 Milibar is done manually by regulation of valve.

• Once the infusion is completed Vacuum is dropped to 75

Milibar.

• Once the Exotherm is completed heating is provided for a

period of 4 Hour at 600 C.

PRESSURE SHELL MAKING

65

WEB JOINING

MATERIALS USED

a) Epoxy paste

b) Paste applicator

c) G1+ G1 layer

d) Hot Blower

e) Epoxy Resin system

After the curing of Shell following prior activities are to be carried out for

Web joining process.

PROCESS

STEP 1 The Vacuum Plastic, which contain Different items Vacuum film, PVC

Angle, Tacky Tape, Perforated PE, Non-wowing cloth are taken out from the Mould surface.

STEP 2 Injection pipe remove from the Mould surface.

STEP 3 Injection point sanding & lamination.

STEP 4 Peel ply fabric is taken out from the surface of Mould & paste

coating of gluing area.

STEP 5 Epoxy paste place at required glue area with the help of glue applicator.

66

APPLICATION OF EPOXY PASTE

STEP 6 Web put at R 2700 & fix with the help of fixture and End at R 21800

distance between two Webs is 260 mm at R 2700 and at R 21800 is 200 mm.

STEP 7 Flash out paste is removing with the help of glue applicator and brush.

STEP 8 Two G1+ G1 layer of 100 mm width, laminate with Shell.

1). 60 mm with Web & 40 mm with Shell 2). 40 mm with Web & 60 mm with Shell

STEP 9 Remove air with the help of hard roller.

STEP 10 Heating is given for a period of 2 hour at the temperature 700 – 800 C

by using hot water circulation.

67

STEP 11 Fixture is applied for heating.

STEP 12 Hot Blower applies at Root side for further heating.

A JOINED WEB KEPT OPEN TO HOT AIR

68

SHELL JOINING

MATERIALS USED

a) Glue Caps

b) Tip

c) Epoxy paste

d) S.S. 180 mm spokes

e) Paste applicator

PROCESS

After the curing of Shell following prior activities are to be carried out for

Shell joining process.

STEP 1 The Vacuum Plastic, which contain Different items Vacuum film, PVC angle, Tacky Tape, Perforated PE, Non wowing cloth are then taken out from the Mould surface.

STEP 2 Remove injection pipe from the Mould surface.

STEP 3 Injection point lamination.

STEP 4 Balance Chamber made ready & joining on pressure Shell at R 16250 mm.

69

STEP 5 Glue Caps (Leading & Trailing edge) are make ready for joining (Peel ply fabric is taken out from the surface of Glue Caps) & placed on Edges of Mould with the help of S.S. spokes of 180 mm & fiber Washer is used.

STEP 6 L/E & T/E Glue Caps make ready for joining (Peel ply fabric is taken out from the surface of Glue Caps).

STEP 7 Tip connecting with Glue Caps.

STEP 8 Glue gap checking of Mould.

STEP 9 Peel ply fabric of various widths is taken out from the surface of Mould.

STEP 10 Epoxy paste is used for entire joining process, which contains Epoxy Resin G-3, Hardeners for H-137 at Ratio of 100: 45 respectively.

STEP 11 Epoxy paste is applied on Web surface with the help of glue applicator.

STEP 12 Glue Caps leading & trailing edge are placed on edges of Mould & glue with Epoxy paste.

70

STEP 13 The Mould is closed and S.S. spokes pulled with the help of spokes puller by using Air gun than inside flash out paste is remove & heating is given for a period of 6 hour at the temperature 700 - 800 C by using hot water circulation. STEP 14 Hot Blower applies at Root side for further heating.

JOINING OF THE PRESSURE AND SUCTION SHELLS

71

SHELL RELEASING

PROCESS

STEP 1 After getting desired TG (600 C) value stop the heating and open

the spoke puller.

STEP 2 Release Suction Shell with the help of Crain and turning device.

STEP 3 Cool the Mould up to 500 - 550 C in pressure Shell.

STEP 4 Release the Blade with the help of fixture ( cut the flesh out

paste at required radial position for fixture ).

STEP 5 Release the Blade from pressure shell.

RELEASING OF BLADE BY CRANE

72

DDEEBBUURRRRIINNGG PPRROOCCEESSSS

MATERIALS USED

a) G1+G1 layer & (G2-/1/0/1-1169)

b) Paste – 20

c) V shape and D shape.

PROCESS

STEP 1 Flash Cutting.

The paste i.e. flashed out during the joining of two Shells is streamed according to the profile of the Blade.

STEP 2 QA Inspection.

STEP 3 V shape and D shape. V shape is fixed over blade according to design side with the help of Paste – 20 glue & D shape is laminated with 100 mm G1+G1 layer and given a heating of 4 hour respectively with the help of special

heating systems.

STEP 4 Leading & Trailing.

From .R 2000 to R 5000, three layer of G1+ G1 having width of 200 mm each are placed by hand lay-up technique on L/E and T/E side and given a heating of 4 hour with the help of hot blower.

73

STEP 5 Inner and outer. To maintain a thickness of 57 mm of the Root section inner and outer Lamination is done using G2 (G2-/1/0/1-1169) layer by hand lay up technique.

V AND D PROFILE FIXING

74

SSAAWWIINNGG AANNDD DDRRIILLLLIINNGG PPRROOCCEESSSS

MATERIALS & MACHINES USED

a) Sawing and Drilling machine

b) Flange

c) Stud bolt

d) Paste – 20

After completion of the Debarring process the Blade is placed for the sawing

& drilling machine.

PROCESS

STEP 1 Place Blade on fixture.

STEP 2 Sawing is done by Sawing and Drilling machine (100mm from the Root).

STEP 3 Marking for sawing of the Root fixed at R 2100.

STEP 4 Marking is fixed for the drilling as per the design.

75

STEP 5 QA Department checks the marking.

STEP 6 Then drilling is done by machine. The drilling machine drills two kindsof holes. a. Cross holes (O .450 ) b. Longitudinal holes (O .230)

STEP 7 Place Flange on the Root side with the help of Paste – 20 glue & heating is applied for 4 hours.

STEP 8 The stud bolt is placed on Root side with the help of Paste – 20 glue and heating is applied for 4 hours.

SAWING AND DRILLING MACHINE

76

SSPPOOIILLEERR FFIIXXIINNGG

MATERIALS USED

a) Gel coat

b) Resin hardener paste

c) Screw of 2.5 mm

d) Layer of G1+G1

PROCESS

STEP 1 The Spoiler is affixed to the Blade after stud bolt joining.

STEP 2 Fixture for fixing of Spoiler is fixed to the stud bolt so that the Spoiler is fixed at R 2254 location of the Blade.

STEP 3 The Blade is made ready for Spoiler fixing by removing the peelply over the bonding area.

STEP 4 Gel coat is then applied over the D shape.

STEP 5 The Spoiler is trimmed and made ready for fixing on the Blade.

77

STEP 6 Resin hardener paste is applied on the bonding area between the Blade and Spoiler.

STEP 7 Screw of 2.5mm is used to adhere the Blade with the Spoiler.

STEP 8 Layer of G1+G1 of width 200x200mm to the inner edge of Spoiler, so that better adherence of the Blade with the Spoiler takes place.

STEP 9 Heating is provided to the Spoiler Glue for attaining required TG ( 600 C ) value.

BLADE AFTER SPOILER FIXING

78

FFIINNIISSHHIINNGG PPRROOCCEESSSS

MATERIALS USED

a) M5 screw

b) 60 Grid paper, 120 Grid paper

c) Bergolin Paste

d) Kantensutz Paint

e) Aluminum primer

f) Topcoat

PROCESS

After checking TG values of the Blade Viz. Stud Bolt, V profile Spoiler Glue is checked by quality people, and then Blade is allowed to load on finishing stand. STEP 1 The V profile and the Tip are connected to each other by M5 screw. The joint of the FRP and the Tip is strengthen by using counter shock M6 screw (14 No’s) according to the design.

STEP 2 The flesh of L/E is trimmed carefully to match with the profile of Leading Edge.

STEP 3 Using 60 Grid paper full sanding of the surface of the Blade is done. STEP 4 PU paste called as bergolin is used to level the profile Viz. L/E, V profile, and Root surface. This is allowed to 2 hour.

79

STEP 5 Complete sanding of the bergolin is done and the surface is leveled to the Profile of the Blade.

SANDING MACHINE SAND PAPER

SANDING OPERATION

80

STEP 6 Kantensutz is applied from R 14000 to R 24000. It is allowed to cure for four hour.

STEP 7 Aluminum primer is applied from R 11000 to R 24000 and allowed to Cure for 2 hour.

STEP 8 Three coat of primer is then applied to the entire surface of the Blade. Between every coat of primer gap of 45 Minutes is taken for drying the Primer.

APPLICATION OF ALUMINIUM PRIMER

81

STEP 9 Three topcoats are applied to the Blade giving a gap of 45 minutes.

STEP 10 The Blade is then checked by the Quality Dept. for any touch up required.

STEP 11 The Blade is then unloaded and given to Dispatch Dept. for further work.

TOPCOAT BEING APPLIED

82

DDIISSPPAATTCCHH

MATERIALS USED

a) Discharge ring

b) G1+G1 layer

c) Discharge box

d) Stud Paste

e) Polyester Resin Hardener System

f) Brush

PROCESS

STEP 1 Discharge ring is located on the Root section according to design.

STEP 2 Connection of lightening protection is ensured.

STEP 3 Inside cleaning for dust is done.

STEP 4 Lamination at the start of Web is done using G1+G1 layer of 600x150 mm.

STEP 5 Discharge box is connected to the leading edge flat aluminum Plate.

83

STEP 6 Ceiling of the stud paste over the locus of the drilling is done for stud Bolt.

STEP 7 Brush at the edge of the Spoiler is placed to avoid dust from entering the Blade.

STEP 8 Pair of Drainage holes are put at the end of blade on T / E side.

STEP 9 The Blades are now ready for balancing. Momentum of the three Blades is done by pouring lead and Resin hardener system, keeping one of the Blades as reference.

BLADE BALANCING ( TIP SIDE )

84

BLADE BALANCING ( ROOT SIDE )

STEP 10 The QA Department ensures Quality of the Blade. STEP 11 The 0 Deeg. Marking is done on the reference bolt. STEP 12 The three Blades are covered & loaded on the trailer to be dispatch as finished product.

BLADES READY FOR DISPATCH

85

LLIINNEE DDIIAAGGRRAAMM OOFF BBLLAADDEE MMAAKKIINNGG

HEATING

VACUUM & HEATING

curing

MOLD CLEANING & REALEASE AGENT

APLY ON MOLD SURFACE

DRY GLASS FIBRE LAYERS LAY UP ON

MOULD SURFACE

SUCTION SHELL

ONLINE Q.A. CHECK

ONLINE Q.A CHECK

RESIN INJECTION

PREFORM MAKING

SPARBOOM MAKING

1) L/E GLUECAP 2) T/E GLUECAP 3) SET OF WEB 4) BALANCING CHAMBER 5) TIP

ONLINE Q.A CHECK

VACUUM & HEATING

PRESSURE & SUCTION SHELL JOINING

86

T/E & L/E LAMINATION

BLADE RELEASING

FLASH CUTTING AND SLOTING

V & D PROFILE FIXING

& DISCHARGE RING FIXING

SAND BLASTING

V” & D” PROFILE

WELDING

SAWING AND DRILLING

STUD & BOLT FIXING

SPOILER FIXING TO BLADE

FLANGE LAMINATION

Q.A. CHECKING

1.BLADE ANGLE 2. PCD CHECK 3. THICKNESS

GRP COVERING ON ‘T’BOLT SPOILER

MANUFACTURING

87

FINISHING

BLADE BALANCING

Q.A CHECK

FINAL Q.A CHECK

DISHARGE BOX & ADAPTER COVER FIXING

BLADE DISPATCH

88

TTEECCHHNNIICCAALL DDEETTAAIILLSS Rated capacity 800kw Rotor diameter 48 m Cut in wind speed 2 m/sec Rated wind speed 14 m/sec Rotor with Pitch control : Type Up wind rotor with active pitch control Direction of rotation Clockwise No of blades 3 Swept area 1810 m sq. Blade material Fibre glass (reinforced epoxy) with integral Lightning protection Rotor speed variable, 16-31.5 rpm Pitch control three synchronized blade pitch system with battery back up Generator :

Hub rigid Bearings tapered roller bearings Grid feeding : AC-DC-AC through converter inverter Braking system : 3 independent aero brakes with emergency power back up Yaw control active through adjustment gears, friction damping Tower:

Steel tubular 56 m Concrete 74 m

89

CCRRIITTIICCAALL PPAARRAAMMEETTEERRSS

MOULD TEMPERATURE DURING LAY-UP

LAY-UP PROCEDURE

EFFECTIVENESS OF VACUUM

RESIN:HARDENER RATIO

RESIN HARDENER TEMPERATURE DURING INFUSION

MOULD TEMPERATURE DURING INFUSION

FLOW OF RESIN DURING THE PROCESS

TEMPERATURE DURING EXOTHERM AND CURING

PAINTING AND FINISHING OF THE SURFACE

90

MOLD TEMPERATURE DURING LAY-UP

Before starting the lay up procedure of the fibres the primary step is to set

the temperature of the mold to the desired value. The temperature of the

mold can be controlled by the heating system attached to the mould. The

heating system is provided with a small indicator screen that indicates the

temperature of the mold. The operator sets the temperature that is to be

maintained throughout the lay-up process, and the heating system

automatically maintains that temperature during the operation until and

unless someone changes it.

The standard temperature for the lay-up process of the E-48 blade

parts is 40-450 C.

If the temperature, which is mentioned above, is not kept constant and

increased to a higher value then the layers of the glass fibres will get heated.

These layers will not be cooled on the application of the vacuum and when

we infuse the resin and hardener mixture in between these layers, there

would be an early curing of the resin, before the desired time period. Due to

this pre-mature curing, the resin will not cover the whole of the glass fibres

and there would be some dry portions or patches where the resin would not

have reached.

On the other hand, if the temperature is reduced to a little extent,

then the layers will be cooled. These cooled layers will not be affected by

the vacuum application and during the infusion process, when the resin will

pass through these layers, the crystallization of the resin will take place. Due

91

to this crystallization phenomenon coming in to picture, the crystallized

resin would acquire certain portions in the product and would hinder the

distribution of resin to other portions connected to that particular area. As a

result there would be the presence of dry patches or resin free voids in the

final molded product.

So it is clear from the above two factors that the controlling of temperature

during lay up is a very important factor in order to prevent any defect in the

molded product. Therefore any deviation, whether increment or decrement

from the standard temperature would be responsible for the appearance of

dry patches.In order to prevent these dry patches we have to maintain the

recommended temperature constant through out the whole lay up process.

SCREEN SHOWING THE TEMPERATURE OF THE MOULD

92

LAY-UP PROCEDURE

The procedure given previously for each part has to be strictly followed in

order to prevent any disconfirmation from the standard design. Any kind of

deviation, whether in terms of order of lay-up of glass fibres, peel ply,

perforated plastic, distribution net; their dimensions; shape; chamfering of

balsa and foam, would be responsible for the presence of defect in the final

product. So in order to avoid this problem, the workers have to be very

attentive and careful during the lay up process.

Some important factors to be considered during the process of lay up are

given below :-

� The workers while laying should wear hand gloves in order to avoid

any dust or foreign particle entering in between the layers to cause the

dry patches.

� Moreover there is moisture present in the hands, which gets absorbed

to the glass fabric and is entrapped in between the layers. Since

vacuum is applied in the process, so these do not evaporate out to

atmosphere on heating and remain there collected in certain areas.

During the infusion process, these areas do not allow the resin to soak

the glass fabric as a result of which there is absence of resin in these

portions causing the dry patches or white patches to appear on the

surface after the process is complete.

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� The glass fibres should not be kept open to atmosphere as they can

easily acquire moisture and dust particles suspending in the

environment. They should be well covered with a suitable plastic

cover in recommended conditions.

� The lay up should not be done if the humidity is more than 97%.

� The fibres should not be folded too much during the lay-up as some of

the individual fibre may break.

� The laying process of the fibres should be done in a separate area free

from any dust producing environment, such as an area where the

operations like sanding is being done.

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EFFECTIVENESS OF VACUUM

� Inner Vacuum is applied with the help of Vacuum pump to maintain a

pressure of 1000 mbar. Tolerance of drop in Vacuum of 20 mbar is

allowed for 10 minutes.

� Then the outer vacuum is applied. A tolerance of 30 mbar is allowed

for 3 minutes in outer vacuum plastic.

� Once the vacuum is found to be perfect i.e. there are no leakages

detected, and then a drop of 50 mbar is allowed for the infusion

process to occur.

� Once the resin has fully wetted the glass fabric, then the vacuum is

dropped to 500 mbar.

VACUUM PUMP

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The proper application of vacuum is a very important, in order to avoid any

kind of defect in the blade parts. Usually there are some leakages during the

application of vacuum. These leakages if not detected properly and sealed,

can cause air entrapment in the glass fabric layers. When we infuse the resin

in between the layers, the resins do not cover the air-entrapped area. So these

portions in which the resin is not there, naturally contains some dry patches

or resin free voids.

Another cause for the voids is that the vacuum applied is

not sufficient for the resin to flow properly i.e. there is not enough pressure

difference for the resin to fill in the glass fabric layers. Thus there is

inadequate amount of resin to cover the whole of the glass fabric, leaving

some dry patches.

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RESIN-HARDENER TEMPERATURE

DURING INFUSION

The temperature of resin and hardener during the infusion time period is also

an important factor for the occurrence of defects. Normally the temperature

is kept in the desired range, but sometimes it shoots up more than the

allowable range due to the ignorance of the workers.

If we infuse the resin and hardener at temperature more than the

recommended, then the resin and hardener will cure at a much early time

period, without covering the whole of the fabric. Thus we see that there are

some dry patches or areas where the resin has not reached, occurring in the

blade parts.

The standard temperature of resin and hardener during infusion is

30 – 400 C.

The epoxy resin and hardener temperatures have the following positive and

negative effects on usability and the quality of the finished product:

� The mixture loses viscosity as the temperature rises; the mixture

becomes more fluid, which improves the flowing quality of the

components in the pipeline systems.

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� Warm resin mixtures allow for improved wetting of the fibres during

processing. However, the pot life of the resin/hardener mixture

decreases as its temperature rises.

� At low temperatures ( 10-150 C ) some parts of the resin component

can crystallize and sink to the bottom of the container. Removing the

mixture in this state and mixing it with the hardening component

would create an unserviceable epoxy resin mixture.

� The working time ( pot life ) of the mixture increases at low

temperatures, however, when the temperature drops below 150 C the

curing process more or less stops.

HIGH TEMPERATURE ( INCORRECT )

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TEMPERATURE IN THE DESIRED RANGE ( CORRECT )

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TEMPERATURE DURING INFUSION

The temperature during the infusion time period is also an important factor

for the occurrence of some deviations or defects. Normally the temperature

is kept in the desired range, but sometimes it shoots up more than the

allowable range due to the carelessness of the heating system operator or

some fault in the machine.

The standard temperature of the mold during the infusion time

period is kept at 420 C.

The defects in the parts occur if the mould temperature is increased, say to

600 C, then the glass fabric and other supporting materials like distribution net,

CSM etc, will be heated. When the resin will pass through these materials, and

the upper layers of the glass fabric, it will start to get cured. In this way these

upper layers would unnecessarily create a blockage of resin to the lower

layers. So the lower layers would not be fully wetted by the resin in the normal

time period creating some dry patches or white patches on the surface of the

molded product.

Another possible reason for the occurrence of the defects could be the non-

uniform heating of the mould. The temperature during the infusion process is

controlled by the heating system. Temperature controlled molds usually

employ internal tubing to circulate a temperature-adjusted fluid through the

mold heat sink. The fluid (usually water) maintains the temperature,

sometimes heating and sometimes cooling the mold, while the heat sink acts

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to moderate the temperature and provide a consistent baseline. Temperature

controlled molds provides a molding consistency that promotes quality along

with fast cycle times. The process can be optimized when mold temperature

is properly managed.

But sometimes the mould is not heated uniformly

throughout its entire length. Thus while the infusion process is going on, the

resin is more heated at some places than the other. Thus the place where the

resin is over heated, starts to gets cured before the desired time period and

other places are deprived of the resin showing some resin free voids on the

surface of the molded blade part.

INFUSION PROCESS GOING ON

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FLOW OF RESIN

The proper flow of the resin is another factor for the non-occurrence of the

dry patches or white patches. In the resin flow channel there should not be

any hindrance to cause the accumulation of resin at certain areas. In this case

the importance of supporting materials is realized for helping in the proper

flow of resin to all the glass fabric layers. The spiral tube is the only medium

through which the resin first enters. So the spiral tube has to be given great

importance, besides the other supporting materials.

The standard diameter of spiral tube is 11.50 mm.

This diameter has to be maintained throughout the entire length of the spiral

tube i.e. it should have a uniform cross section. Any deviation from this

standard value would have a direct impact on the resin flow. If at some

places the diameter is reduced, then naturally, less resin would flow from

that area as compared to areas where the diameter is normal.

SPIRAL TUBE

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Some important points, which should be taken into consideration are :-

• The spiral tube should not loose its uniform diameter during the

application of vacuum. It should be hard enough to resist the force

applied by the vacuum pump.

• The spiral tube should be made of the material, which would not deform

and loose its shape at the cross section under the heating conditions,

during the infusion time period. This would create some portions of the

tube thinner than the other causing insufficient flow of resin.

• Likewise all the supporting materials such as distribution net, perforated

film etc, should not loose their properties during the application of heat

and vacuum.

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TEMPERATURE DURING EXOTHERM AND CURING

Temperature rise during the exotherm is a very important consideration for

the occurrence of dry patches. During this time period because of the

exotherm nature of the interaction between the resin/hardener and the glass

fibre, temperature of the system automatically increases. It increases from

400 C at the infusion time to 650 C. it is at this time period that no external

heat is supplied to the mould. If we apply any kind of heat then the resin will

not cure properly and some dry patches would be there.

HEATING SYSTEM

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After the exothermic rise of the temperature, the system is again cooled to

420 C. then after it is heated upto 850 C in about two and half hours. Then

again it is cooled by the heating system. In the heating system the heating

medium is circulated throughout the mould to provide uniform heating. In

case of cooling the mould the heating medium is cooled by slow addition of

small amount of the same cooling medium but at a temperature much lower.

So this process takes a little bit of time as the mould cools slowly and

slowly.

If the heat supplied is very high right from the starting then the resin will

cure at much earlier time and it will not cover the whole of the fabric layers

leaving some dry or white patches in between the portions of the blade parts.

The important point to be taken care of is that the operation should be

carried out only on the specified temperature of each of the steps.

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PAINTING AND FINISHING OF THE BLADE SURFACE

VARIOUS STEPS OF PAINTING AND FINISHING ARE: 1). SANDING :-

Sanding is the very first and important process in the finishing

of rotor blade. Sanding is used for creating roughness on the blade. The

roughness is required to the whole blade for creating the mechanical voids;

these mechanical voids increase the contact area of blade surface to the PU

paste. These are responsible for the bonding of PU paste to the blade surface.

Sanding is done with the help of sand paper. These sand papers are of the

different grits like 60, 80, 120, 240 etc. Sanding is done with the help of

different sand paper for different parts of the blade.

If the sanding operation is not done properly, then there would be inadequate

roughness and also the level will not be smooth, so the painting operation

will suffer. Moreover at some places, if there is too much sanding then the

sand paper would penetrate the surface and would reach the glass fibres,

causing it to break.

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2). CLEANING :-

Cleaning is done for removing the dust from the blade

surface. Cleaning is done with the help of a cotton cloth or a tack cloth. Tack

cloth is actually a glue coated cloth, which helps in proper cleaning of blade

surface.

Improper or inadequate cleaning of the blade surface can cause entrapment

of foreign or dust particles. These particles results in defects like air bubbles,

pin holes, unlevelling, clogging etc.

3). APPLICATION OF PU PASTE :-

PU paste is used for leveling of the

Leading edge profile, V profile and Root surface. PU paste is used for

leveling of the different voids also. PU paste is used as the filler for different

voids appeared on the surface of blade after sanding is done. PU paste is also

used in repairing of different parts of blade.

• After applying PU paste, the paste is allowed for curing. Curing

provide bonding of paste to the blade surface. The curing time for PU

paste is about two hours.

• In the next step we check leading edge profile with the templates.

Templates are actually the apparatus used for checking the profile of

leading edge. The gap between blade surface and templates should be

<1mm. After this, sanding is done for best fit of the template with

abrasive paper grit 120 and eccentric grinder.

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• First sanding is done only at radial position of template. If there is not

enough PU paste, then this position is marked and PU paste is applied

again. The same procedure is performed with the all other profile

checking template.

• The spoiler area should be given the correct shape ( right angle ) at the

trailing edge.

Right Wrong

• There may be there may be some kind of flaws occurring like, air

bubble, holes, pinholes etc. These flaws are occur due to foreign

particles in the paint; improper cleaning (dust remaining on the

surface); improper mixing ratio of resin and hardener (100:175); use

of expired material etc. These flaws are removed with sanding at the

particular place and then applying paste again.

4). APPLICATION OF PRIMER :-

Primer used in the painting application is

a polyurethane based primer. It has excellent adhesion on blade surface. It

provides a bonding between topcoat and blade surface. Usually three coats

of primer are done for best results. The time gap between the coats is 40

minutes. Usually the primer is applied with the help of rollers.

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• The mixing of components in the correct ratio is very important in

order to give the best bonding surface for the paint. The standard ratio

is

o PU based primer 100

o Hardener 66

o Accelerator 03

o Thinner 05

• After the application of primer the wet film thickness of primer is

measured with thickness gauge. The standard thickness after three

coats of primer is 100 microns.

THICKNESS GAUGE IN MICRONS

• Curing time for primer after three coats is at least five hours in

standard conditions. This may vary according to the environmental

conditions.

• When the primer is becomes dry to touch, inspection is done by the

quality assurance department. There may be some flaws like air

bubble, dust, pinholes, and unleveled surface. These flaws occur due

to air entrapment, foreign particle (dust), improper mixing ratio, and

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unskilled work. Flaws can be avoided by proper cleaning of blade

surface, using a proper workspace, proper mixing ratio and

recommended storage conditions. It should be stored between 5oC and

30oC in a dry, well ventilated place away from sources of heat and

direct sunlight, sources of ignition, oxidizing agents and strongly

alkaline and strongly acidic materials.

• For repairing the flaws, first sanding of affected area is done with Grit

240 sanding paper and then paste is applied to the surface. After

applying the paste, primer is applied to that particular area.

5). APPLICATION OF TOP COAT :-

Top coat is the main paint system

applied to blade surface. Top coat has better weather resistance. Top coat is

applied for pore densing and providing smooth surface to the finished blade.

• The mixing of components in the correct ratio is very important in

order to give the best finished surface . The standard ratio for different

components is

o PU based paint 100

o Hardener 100

o Thinner 65

• The application of top coat can be performed by two ways:

By ROLLERS

By SPRAYING

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The rollers are economical but the spraying painting gives a very

smooth surface finish. The time consumption is also very less in case

of spray painting.

• After the application of top coat the wet film thickness of paint is

measured with thickness gauge. The standard thickness after three

coats of paint is 200 microns.

• Curing time for paint after three coats is at least five hours in standard

conditions. This may vary according to the environmental conditions.

• After curing the inspection of blade is done by the quality assurance

department. Defects that are occurring in painting are mainly

unleveled surface, air bubble, dust, roller marks and uncured paint.

These defects occur due to the air entrapment, foreign particle,

unskilled work, improper mixing and improper mixing ratio.

• For repairing these defects, first sanding is done at the particular area

then PU paste is applied. After this primer and then top coat is

applied.

• Taking few precautions like, proper cleaning at the place, proper

mixing and mixing ratio, skilled workers, can avoid defects. Also

paint should be stored between 5oC and 30oC in a dry, well ventilated

place away from sources of heat and direct sunlight, sources of

ignition, oxidizing agents and strongly alkaline and strongly acidic

materials.

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• Finally the surface roughness measurement is done for checking the

smoothness of the finished surface. Surface roughness is measured

with Roughness tester. The Roughness tester used is known as

HOMMEL TESTER T500. The roughness for the finished blade

surface is about 5 microns.

Resin Infusion Molding

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