drilling of natural fiber particle reinforced polymer composite material

International Journal of Advanced Engineering Research and Studies E-ISSN2249 – 8974

IJAERS/Vol. I/ Issue I/October-December, 2011/134-145

Research Article

DRILLING OF NATURAL FIBER PARTICLE REINFORCED

POLYMER COMPOSITE MATERIAL D. Chandramohan

* K.Marimuthu

Address for Correspondence Ph.D., Research Scholar, Department of Mechanical Engineering, Anna University of Technology-

Coimbatore,Coimbatore, Tamilnadu, India

Associate Professor, Department of Mechanical Engineering, Coimbatore Institute of Technology-

Coimbatore, Tamilnadu, India

Abstract An effort to utilize the advantages offered by renewable resources for the development of biocomposite materials based on

biopolymers and natural fibers has been made through fabrication of Natural fiber powdered material (Sisal (Agave sisalana),

Banana (Musa sepientum), and Roselle (Hibiscus sabdariffa)) reinforced polymer composite plate material by using bio epoxy

resin. The present work focuses on the prediction of thrust force and torque of the natural fiber reinforced polymer composite

materials, and the values, compared with the Regression model and the Scheme of Delamination factor / zone using machine

vision system, also discussed with the help of Scanning Electron Microscope [SEM]. The Electron Dispersive X-Ray Thermo

detector [EDX] machine Model was used to study the composition of the microstructure of composites specimens.

KEY WORDS: Natural fibers, Bio epoxy resin, Thrust force, Torque, Regression Model, SEM, EDX

1. INTRODUCTION

A judicious combination of two or more materials

that produces a synergistic effect. Composites:

materials, usually man-made, that are a three-

dimensional combination of at least two chemically

distinct materials, with a distinct interface separating

the components, created to obtain properties that cannot

be achieved by any of the components acting alone.

Composites are combinations of two materials in which

one of the materials, called the reinforcing phase, are in

the form of fibers, sheets, or particles, and are

embedded in the other materials called the matrix

phase. The reinforcing material and the matrix material

can be metal, ceramic, or polymer. Typically,

reinforcing materials are strong with low densities

while the matrix is usually a ductile, or tough, material.

If the composite is designed and fabricated correctly, it

combines the strength of the reinforcement with the

toughness of the matrix to achieve a combination of

desirable properties not available in any single

conventional material. The downside is that such

composites are often more expensive than conventional

materials. Examples of some current application of

composites include the diesel piston, brake shoes and

pads, tires and the Beechcraft aircraft in which 1800%

of the structural components are composites.

A material system composed of two or more physically

distinct phases whose combination produces aggregate

properties that are different from those of its

constituents.

2. PREVIOUS RESEARCH

2.1 STUDIES IN INDIA

N.S. Mohan, A. Ramachandra and S.M. Kulkarni

(2005) presented a paper on the title: ‘Influence of

process parameters on cutting force and torque during

drilling of glass–fiber polyester reinforced composites’

The authors observed that specimen thickness, feed

rate, speed and diameter are significant parameters of

cutting thrust. Further by the observation interaction

among the parameters, the combined effect of thickness

and drill size, feed and drill size are more significant

than any other combination influence on average S/N

response for cutting thrust. Among the thrust significant

parameters, speed and drill size are more significant

than the specimen thickness and the feed rate. Among

the torque significant parameters, specimen thickness

and drill size are more significant than the specimen

speed and the feed rate. Among process parameters,

thickness and drill size is more dominant factor together

than any other combination for torque characteristic. It

is also observed that the minimum torque observed in

the smaller specimen thickness region.

K. Palanikumar and J. Paulo Davim (2006)

presented a paper on the title: ‘Mathematical model to

predict tool wear on the machining of glass fibre

reinforced plastic composites’. In their work a

mathematical model has been developed to predict the

tool wear on the machining of GFRP composites using

statistical analysis in-order-to study the main and

interaction effects of machining parameters namely

cutting speed, work piece (fibre orientation) angle,

depth of cut and feed rate. This technique is convenient

to predict the effects of different influential

combinations of machining parameters by conducting

minimum number of experiments. Cutting speed was

the factor, which has great influence on tool wear,

followed by feed rate. The accuracy of the developed

model can be improved by including more number of

parameters and levels.

2.2 STUDIES IN ABROAD

Paul Wambua, Jan Ivens and Ignaas Verpoest

(2003) presented a paper on ‘Natural fibres: can they

replace glass in fibre-reinforced plastics?’ They tested

and compared the mechanical properties of the different

natural fibre composites. In most cases the specific

properties of the natural fibre composites were found to

compare favourably with those of glass. They suggested

that the tensile strength and modulus increases with

increasing fibre volume fraction. Among all the fibre

composites tested, coir reinforced polypropylene

composites registered the lowest mechanical properties

whereas hemp composites showed the highest.

However, coir composites displayed higher impact

strength than jute and kenaf composites.



S. Panthapulakkal, A. Zereshkian and M. Sain

(2006) presented a paper on ‘Preparation and

characterization of wheat straw fibers for reinforcing

application in injection molded thermoplastic

composites’. They prepared wheat straw fibres by

chemical and mechanical processes and were

characterized for their potential to reinforce

thermoplastics for manufacturing structural composite

materials. Fibers were characterized with respect to

their chemical constituents, surface morphology, and

physical, mechanical and thermal properties. Fibers

prepared by chemical process were free from surface

irregularities and showed better mechanical properties.

Thermal properties showed the suitability of the

processing of wheat straw fibers with thermoplastic

polyolefins.

Craig M. Clemons and Daniel F. Caulfield (1994)

presented a paper on “Natural fibers”. The aim of their

study is to present a various properties, availability,

chemical contents, dimensions, and various applications

of the natural fiber reinforced composites.

M. Zampaloni, F. Pourboghrat, S.A. Yankovich

(2007) done a research on ‘Roselle natural fiber

reinforced polypropylene composites: A discussion on

manufacturing problems and solutions’ was carried out

to suggest the optimum method of manufacturing the

Roselle reinforced composite materials.

A.M. Abrao, P.E. Faria, J.C. Campos Rubio, P. Reis

and J. Paulo Davim (2006) presented a paper on

‘Drilling of fiber reinforced plastics: A review’ the

paper aims to present a literature survey on the drilling

operation of glass and carbon fibre reinforced plastics

(GFRP and CFRP respectively). Attention will be

focused on tool material and geometry and their effect

on the damage caused on the hole produced, thrust

force and torque and related parameters (power and

specific cutting pressure).

The principal factors used to evaluate the performance

of the process are undoubtedly the damage caused at

the drill entry or exit and the roughness on the wall of

the hole produced. In spite of the fact that this damage

is frequently measured in terms of delamination,

techniques employed to measure the effect of the

cutting parameters cutting speed and feed rate on this

damage differ considerably: while a group of

researchers tend to measure the damage directly (using

parameters such as damage width, delaminated area or

delamination factor), a second group of authors

measure the damage indirectly through thrust force,

torque or power.

U.A. Khashaba, M.A. Seif and M.A. Elhamid (2006)

presented a paper on ‘Drilling analysis of chopped

composites’. The main objective of the present study is

to investigate the effects of the cutting variables, speed

and feed, on the thrust force, torque, and delamination

in drilling chopped composites with different fiber

volume fractions. Based on the results from this

investigation, empirical formulas are developed.

Although it is known that the thrust force and torque

increases with the increase of the feed, this work

provides quantitative measurements of such

relationships for the present composite materials. On

the other hand, increasing the cutting speed reduces the

thrust force and the torque. Empirical formulas that

determine the cutting forces based on fiber volume

fractions, feeds, and speeds are obtained using

multivariable linear regression analysis.

C.C. Tsao and H. Hocheng (2007) presented a paper

on Title: ‘Evaluation of Thrust Force and Surface

Roughness in Drilling Composite Material Using

Taguchi Analysis and Neural Network’. An

experimental approach to the evaluation of thrust force

and surface roughness produced by candlestick drill

using regression analysis of experiments and RBFN

were proposed in their study. The authors found the

feed rate and the drill diameter are recognized the most

significant factors affecting the thrust force, while the

feed rate and spindle speed are seen to make the largest

contribution to the surface roughness. In the

confirmation tests, RBFN is demonstrated more

effective than multi-variable regression analysis for the

evaluation of drilling-induced thrust force and surface

roughness in drilling of composite material.

Marta Fernandes and Chris Cook (2006) presented a

paper on ‘Drilling of carbon composites using a one

shot drill bit - Part II: empirical modeling of maximum

thrust force’. It has been shown that Shaw’s simplified

equations can be used to provide good estimates of

maximum thrust force and torque for drilling of carbon

composites using a new ‘one shot’ drill bit. It has also

been shown that Shaw’s equation for thrust force does

not hold for older drill bits and has to be corrected for

the effect of tool wears. Furthermore, the tool wear

correction is dependent on the thickness of the work

piece. A mathematical model has been developed which

successfully estimates maximum thrust force and torque

produced during drilling of carbon fibre using a one-

shot drill bit.

S.C. Lin and IK. Chen (2005) presents a paper on the

title: ‘Drilling carbon fiber-reinforced composite

material at high speed’. A series of experiments were

conducted to study the effects of cutting speed as wel1

as other cutting parameters on drilling characteristics,

including cutting forces and tool wear when drilling

carbon fiber-reinforced composite materials at high

speed. Based on the experimental results, the authors

concluded that the average thrust force increases as

cutting speed increases for both multifacet dril1 and

twist drill. Tool wear is one of the major reasons for

these changes in force. Tool wear is mainly affected by

cutting speed and drilled length within the range

examined. Tool wear increases significantly as cutting

speed increases. Therefore, more suitable tool materials

should be adopted for cutting carbon fiber-reinforced

composite materials at such high speeds.

3. MATERIALS AND METHODS

Composite preparation

Materials Used

The specimen used in this study is a cylindrical rod of

60x40 mm made of natural fiber reinforced composite

material. The composite is made of natural fibers.

Commercially available natural fibers are taken.



The materials used in this project are (as shown in fig

5.1 Specimens arranged in Left to Right 1, 2, 3, listed

below)

1. Banana fibre reinforced composite

2. Sisal fibre reinforced composite

3. Roselle fibre reinforced composite

Fig 3.1 Specimens (60x40 mm)

FABRICATION OF COMPOSITES

The natural fibre reinforced composites are fabricated

using mould method. The design of mould is shown in

figure 4.1. General-purpose polyester resin is used as a

matrix.

Chemical Treatment

• The fibers are cut to the required size of 1 cm.

• Then the fibers are cleaned normally in clean

running water and dried.

• A glass beaker is taken and 6% NaOH is

added and 80% of distilled water is added and

a solution is made.

• After adequate drying of the fibers in normal

shading for 2 to 3 hours the fibers are taken

and soaked in the prepared NaOH solution.

• Soaking is carried out for different time

intervals depending upon the strength of fiber

required.

• For our project the fibers are soaked in the

solution for three hours.

• After the soaking process is complete the

fibers are taken out and washed in running

water and dried for another 2 hours.

• Now the fibers are taken for the next

fabrication process namely the

PROCASTING process.

Advantages of chemical treatment

• First and foremost chemical treatment with

NaOH will remove moisture content from the

fibers thereby increasing its strength.

• Secondly the chemical treatment also enhances

the flexural rigidity of the fibers.

• Thirdly this treatment clears all the impurities

that are adjoining with the fiber material and

also stabilizes the molecular orientation.

• Manufacturing process

• A mould of 60 mm length and 40 mm

diameter and is created using GI sheet mould.

• An OHP Sheet is taken and Releasing agent is

applied over it and fitted with the inner side of

the mould and allowed to dry it.

• A glass beaker and a glass rod or a stirrer is

taken and cleaned well with running water and

then with warm water.

• Then calculated quantity of PMMA Resin is

added and measured quantity of Accelerator is

added and the mixture is stirred for nearly 15

minutes.

• The reason behind this stirring is to create a

homogeneous mixture of resin and accelerator

molecules.

• Then after the mixing is over, calculated

quantity of fibers are added and stirring

process is continued for the next 45 minutes.

• After the complete mixing of fiber and resin

materials is over measured quantity of catalyst

is added and stirred for a short while.

• Then the mixture is poured into the mould and

rammed mildly for uniform settlement.

• Then the mould is allowed to solidify for

nearly 3 to 4 hours.

Figure 3.2 Classifications of Natural Fibres



Table 3.1 Properties of Natural fibres

EXPERIMENTAL SETUP

A number of drilling experiments are carried out on a

CNC machining center (Maxmill) using HSS twist

drills for the machining of natural fibre reinforced

polyester composites. A two-component drill tool

dynamometer is used to record the thrust force and

torque. Conventional high-speed steel twist drills are

used as much as cemented tungsten carbide drills.

Tool geometry is a relevant aspect to be considered in

drilling of fibre-reinforced plastics, particularly when

the quality of the machined hole is critical.

FACTORIAL DESIGN

A 33 full factorial design with a total of 27

experimental runs are carried out. The thrust force

and torque were the response variables recorded for

each run. The effect of the machining parameters is

another important aspect to be considered. It can be

seen that cutting speeds from 20 to 60 m/min are

usually employed, whereas feed rate values lower

than 0.3 mm/rev are frequent. Cutting speed is not a

limiting factor when drilling polymeric composites,

particularly with hard metals, therefore, the use of

cutting speeds below 60 m/min may be explained by

the maximum rotational speed of conventional

machining tools, since drill diameters above 10mm

are rarely reported. Another reason for keeping

cutting speeds below 60 m/min may reside in the fat

that higher cutting speed values lead to higher cutting

temperature, which in turn may cause the softening of

the matrix. The use of feed rates below 0.3 mm/rev

may be associated to the delamination damage caused

when this parameter is increased. Table shows the

detail of variables used in the experiment.

Table 3.2 Assignment of the levels to the factors

Level Drill size,

d (mm)

Revolution,

n (rpm)

Feed rate,f

(mm/rev)

1 3 600 0.1

2 4 900 0.2

3 5 1200 0.3

PREDICTION TECHNIQUES

REGRESSION MODEL

The statistical tool, regression analysis helps to

estimate the value of one variable from the given

value of another. In regression analysis, there are two

types of variables. The variable whose value is

influenced or is to be predicted is called dependent

variable and the variable, which influences the values

or used for prediction is called independent variables.

The tool, regression can be extended to three or more

variables. If two variables are taken into account, then

it is called simple regression. The tool of regression

when extended to three or more variables is called

multiple regressions.

SPSS

SPSS (originally, Statistical Package for the Social

Sciences) was released in its first version in 1968.

SPSS is among the most widely used programs for

statistical analysis in social science. It is used by

market researchers, health researchers, survey

companies, government, education researchers,

marketing organizations and others. In addition to

statistical analysis, data management (case selection,

file reshaping, creating derived data) and data

documentation (a metadata dictionary is stored with

the data) are features of the base software.

Statistics included in the base software:

• Descriptive statistics: Cross tabulation,

Frequencies, Descriptives, Explore,

• Descriptive Ratio Statistics

• Bivariate statistics: Means, t-test, ANOVA,

Correlation (bivariate, partial, distances),

Nonparametric tests.

• Prediction for numerical outcomes: Linear

regression

• Prediction for identifying groups: Factor

analysis, cluster analysis (two-step, K means,

hierarchical), Discriminant

Statistical output is to a proprietary file format (*.spo

file, supporting pivot tables) for which, in addition to

the in-package viewer, a stand-alone reader is

provided. The proprietary output can be exported to

text or Microsoft Word. Alternatively, output can be

captured as data (using the OMS command), as text,

tab-delimited text, HTML, XML, SPSS dataset or a

variety of graphic image formats (JPEG, PNG, BMP

and EMF).

Regression equations:

Thrust = k * d a * n b * f c

Torque = k * d a * n b * f c

Wear = k * d a * n b * f c

Where

d = Drill diameter in mm

n = Speed in rpm

f = Feed rate in mm/rev

a, b & c = Regression constants

Density Water

absorption

Modulus of

Elasticity

Fibre Type

Kg/m3 % E(GPa)

Tensile Strength

(MPa)

Sisal 800-700 56 15 268

Roselle 800-750 40-50 17 170-350

Banana 950-750 60 23 180-430

Date Palm 463 60-65 70 125-200

coconut 145-380 130-180 19-26 120-200

Reed 490 100 37 70-140



Table 3.3 Regression equations for thrust force Material Thrust force R2

Sisal 1.479916792 X d ^ 1.695179761 X n ^ 0.218422665 X f ^ 0.927436761 0.93614

Banana 3.072028878 X d ^ 1.347046253 X n ^ 0.233186110 X f ^ 0.886143709 0.89341

Roselle 3.023946833 X d ^ 1.094546824 X n ^ 0 .324203073 X f ^ 0.951921753 0.88378

Table 3.4 Regression equations for torque Material Thrust force R2

Sisal 2.849305728 X d ^ 1.099468559 X n ^ -.066603083 X f ^ 0.962428131 0.87688

Banana 2.187147307 X d ^ 1.138389699 X n ^ -.037946866 X f ^ 1.061918604 0.88161

Roselle 1.534106581 X d ^ 1.348045235 X n ^ -.09453993 X f ^ 0.772847627 0.88963

DELAMINATION

The advantage of the composite materials over

conventional materials is that they possess high specific

strength, stiffness, and fatigue characteristics, which

enable structural design to be more versatile. Owing to

the inhomogeneous and anisotropy nature of composite

materials, their machining behavior differs in many

respects from metal machining. In recent years,

customer requirements have put greater emphasis on

product development, with new challenges to

manufacturers, such as machining techniques.

Machining of composite materials requires the need for

better understanding of cutting process with regard to

accuracy and efficiency. Though near net shape process

have gained a lot of attention, more intricate products

need secondary machining to achieve the required

accuracy.

Induced delamination occurs both at the entry and exit

planes of the work piece. These delaminations could be

correlated to the thrust force during the approach and

exit of the drill. Delamination is one of the major

concerns in drilling holes in composite materials. To

understand the effects of the process parameters on

delamination, numerous experiments have to be

performed and analyzed mathematical models have to

be built on the same. Modeling of the formation of

delamination is highly complex and expensive. Hence,

statistical approaches are widely used over the

conventional mathematical models.

Types of Delamination

Peel-up Delamination

Peel-up occurs at the entrance plane of the work piece.

This can be explained as follows. After cutting, the

edge of the drill makes contact with the laminate, and

the cutting force acting in the perpendicular direction is

the driving force for delamination. It generates a

peeling force in the axial direction through the slope of

the drill flute, which results in separating the laminas

from each other forming a delamination zone at the top

surface of the laminate, which mainly depends on speed

and point angle.

Push-down Delamination

Push out is the delamination mechanism occurring as

the drill reaches the exit side of the material and can be

explained as follows. As the drill approaches the end,

thickness of the uncut chip gets smaller and resistance

to deformation decreases. At some point, the thrust

force exceeds the interlaminar bond strength and

delamination occurs. This happens before the laminate

is completely penetrated by the drill, and mainly

depends on the feed rate and drill diameter.

Procedure to calculate the value of delamination

factor:

• Drilling was done in the CNC MAXMILL for

three different drill diameters of 3, 4, and 5

mm, respectively.

• Then, the job was placed in the MACHINE

VISION system to capture the digital image of

the hole drilled. This was done by using

different zoom factors (11x, 67x, 22x, 134x).

Procedure to calculate the value of delamination

factor:

• Drilling is done in the CNC MAXMILL for

three different drill diameters of 3mm, 4mm,

and 5mm respectively.

• Then the job is placed in the MACHINE

VISION system to capture the digital image of

the hole drilled. This is done by using various

zoom factors (11x, 67x, 22x, 134x).

• A circle was drawn using the draw tool

available in the RAPID-I software for both

maximum diameter and nominal diameter.

• From the values of Dmax and Dnom,

delamination factor was calculated using the

following formula:

(Fd ) = Dmax/Dnom ----- (1)

The first part of the equation represents the size of the

crack contribution and the second part represents the

damage area contribution.

Fda = α (Dmax / Dnom) + β (Amax / Anom) ----- (2)

Where, Amax – Maximum area related to the maximum diameter of the

delamination zone.

Anom – Area of the nominal hole.

In this work,

α = (1- β), ----- (3)

β = Amax / (Amax - Anom). ----- (4)

Fda = (1- β)*Fd + ((Amax / (Amax - Anom)*(Fd2- Fd))

----- (5)

Calculations

Delamination factors,

Delamination factor (Fd ) = Dmax/Dnom ----- (6)

Where, Dmax – Maximum diameter corresponding to the Delamination zone.

Dnom – Nominal diameter.

Adjusted Delamination factor

(Fda) = Fd + {(Ad/ (Amax-Ao)) ( Fd2- Fd)} -----(7)

Where, Fda – Adjusted Delamination factor.



Fd – Delamination factor.

Ad – Area of the Delamination zone.

Ao – Nominal area.

SCANNING ELECTRON MICROSCOPE

Introduction

The Scanning Electron Microscope (SEM) is a type of

Electron microscope that images the sample surface by

scanning it with a high-energy beam of electrons in a

raster scan pattern. The electrons interact with the

atoms that make up the sample producing signals that

contain information about the samples surface

topography, composition and other properties such as

electrical conductivity. SEM can produce very high-

resolution images of a sample surface, revealing details

about less than 2 to 5 nm in size. Due to the very

narrow electron beam, SEM micrographs have a large

depth of fielding a characteristic three-dimensional

appearance useful for understanding the surface of a

structure of a sample. For conventional imaging in the

SEM, specimens must be electrically conductive, at

least at the surface, and electrically grounded to prevent

the accumulation of electrostatic charge at the surface.

Metal objects require little special preparation for SEM

except for cleaning and mounting on a specimen stub.

Nonconductive specimens tend to charge when scanned

by the electron beam, and especially in secondary

electron imaging mode, this causes scanning faults and

other image artifacts. They are therefore usually coated

with an ultrathin coating of electricially conducting

material, commonly gold, deposited on the sample

either by low vacuum sputter coating or by high

vacuum evaporation. Conductive materials in current

use for specimen coating include gold, gold/palladium

alloy, platinum, osmium, iridium, tungsten, chromium

and graphite. Coating prevents the accumulation of

static electric charge on the specimen during electron

irradiation. The image may be captured by photography

from a high resolution cathode ray tube, but in modern

machines is digitally captured and displayed on a

computer monitor and saved to a computers hard disc.

All samples must also be of an appropriate size to fit in

the specimen chamber and are generally mounted

rigidly on a specimen holder called a specimen stub.

Several models of SEM can examine any part of a 6-

inch (25cm) semiconductor wafer, and some can tilt an

object of that size to 45°.

Specification of SEM Make : Hitachi

Acc voltage : 0.3 to 30kv

Magnification :5x to 3,0000x

Resolution : 3.0nm (30kv HV mode)

:10nm (3kv HV mode)

:40nm (30kv LV mode)

Standard detection : SE, BSE

Vaccum system :MP/RP based

Specimen :Fully motorized, 100/50 XY movement

Coating unit :Ion sputter coated with gold target

Chamber viewing :IRCCD camera

Detector system : LN2 Free peltier cooled, 139ev

Electron Dispersive X-Ray Thermo detector

The EDX machine Model Hitachi S-3000N was used to

study the composition of the microstructure of

composites specimens.

4. RESULTS

Table 4.1 Comparison results of Sisal Thrust force and Torque Drill dia Speed Feed Thrust Torque (RM) (RM)

Thrust Torque Sl. No. (mm) (rpm) (mm/rev) (N) (N-m)

(N) (N-m)

1 3 300 0.1 3.86 0.71 3.91441 0.711061

2 3 600 0.1 4.49 0.67 4.554262 0.67898

3 3 900 0.1 4.91 0.66 4.976 0.66089

4 3 300 0.2 7.34 1.38 7.444792 1.385564

5 3 600 0.2 8.54 1.31 8.661723 1.323052

6 3 900 0.2 9.34 1.28 9.463824 1.287801

7 3 300 0.3 10.7 2.03 10.84341 2.046924

8 3 600 0.3 12.45 1.94 12.61589 1.954574

9 3 900 0.3 13.6 1.89 13.78415 1.902497

10 4 300 0.1 6.29 0.97 6.374702 0.975603

11 4 600 0.1 7.32 0.93 7.416716 0.931587

12 4 900 0.1 7.99 0.9 8.103525 0.906766

13 4 300 0.2 11.96 1.89 12.12401 1.901047

14 4 600 0.2 13.92 1.8 14.10581 1.815278

15 4 900 0.2 15.2 1.75 15.41204 1.766912

16 4 300 0.3 17.42 2.79 17.65874 2.808458

17 4 600 0.3 20.27 2.66 20.54525 2.681751

18 4 900 0.3 22.14 2.59 22.4478 2.610299

19 5 300 0.1 9.18 1.24 9.305501 1.246874

20 5 600 0.1 10.68 1.18 10.82659 1.19062

21 5 900 0.1 11.67 1.15 11.82916 1.158897

22 5 300 0.2 17.46 2.41 17.69808 2.429642

23 5 600 0.2 20.31 2.3 20.59102 2.320026

24 5 900 0.2 22.19 2.24 22.4978 2.258211

25 5 300 0.3 25.43 3.56 25.77743 3.589364

26 5 600 0.3 29.59 3.4 29.99103 3.427425

27 5 900 0.3 32.33 3.31 32.76828 3.336105



Table 4.2 Comparison results of Banana Thrust force and Torque

Drill dia Speed Feed Thrust Torque (RM) (RM)


(N) (N-m)

1 3 300 0.1 6.5 0.53 6.631568 0.53347

2 3 600 0.1 7.64 0.51 7.794931 0.519622

3 3 900 0.1 8.4 0.5 8.567898 0.511688

4 3 300 0.2 12.02 1.1 12.25666 1.113729

5 3 600 0.2 14.13 1.07 14.40682 1.084817

6 3 900 0.2 15.53 1.05 15.83544 1.068254

7 3 300 0.3 17.21 1.69 17.55554 1.713067

8 3 600 0.3 20.23 1.65 20.63528 1.668596

9 3 900 0.3 22.24 1.62 22.68153 1.643119

10 4 300 0.1 9.58 0.73 9.770449 0.740183

11 4 600 0.1 11.26 0.71 11.48446 0.720968

12 4 900 0.1 12.38 0.7 12.62329 0.70996

13 4 300 0.2 17.71 1.52 18.05803 1.545285

14 4 600 0.2 20.81 1.48 21.22591 1.50517

15 4 900 0.2 22.88 1.46 23.33073 1.482188

16 4 300 0.3 25.36 2.34 25.865 2.376858

17 4 600 0.3 29.81 2.28 30.40245 2.315155

18 4 900 0.3 32.76 2.25 33.41724 2.279807

19 5 300 0.1 12.94 0.94 13.19644 0.954247

20 5 600 0.1 15.21 0.92 15.51146 0.929475

21 5 900 0.1 16.72 0.9 17.04962 0.915283

22 5 300 0.2 23.91 1.96 24.39005 1.992187

23 5 600 0.2 28.11 1.91 28.66874 1.94047

24 5 900 0.2 30.9 1.88 31.51162 1.910842

25 5 300 0.3 34.25 3.02 34.93452 3.064253

26 5 600 0.3 40.26 2.94 41.06301 2.984706

27 5 900 0.3 44.25 2.9 45.13494 2.939134

Table 4.3 Comparison results of Roselle Thrust force and Torque

Drill dia Speed Feed Thrust Torque (RM) (RM)


(N) (N-m)

1 3 300 0.1 7.12 0.63 7.14454 0.663746

2 3 600 0.1 8.91 0.59 8.944769 0.621645

3 3 900 0.1 10.16 0.56 10.20137 0.598267

4 3 300 0.2 13.77 1.07 13.82074 1.134103

5 3 600 0.2 17.23 1 17.30319 1.062168

6 3 900 0.2 19.66 0.96 19.73401 1.022222

7 3 300 0.3 20.25 1.46 20.33089 1.551473

8 3 600 0.3 25.35 1.37 25.45372 1.453064

9 3 900 0.3 28.91 1.32 29.02957 1.398418

10 4 300 0.1 9.75 0.92 9.788712 0.978194

11 4 600 0.1 12.21 0.86 12.2552 0.916148

12 4 900 0.1 13.92 0.83 13.97686 0.881694

13 4 300 0.2 18.86 1.58 18.93575 1.671381

14 4 600 0.2 23.61 1.47 23.70704 1.565367

15 4 900 0.2 26.93 1.42 27.03751 1.506498

16 4 300 0.3 27.74 2.16 27.85529 2.286479

17 4 600 0.3 34.74 2.02 34.87406 2.141449

18 4 900 0.3 39.62 1.94 39.77332 2.060915

19 5 300 0.1 12.45 1.25 12.49678 1.321491

20 5 600 0.1 15.58 1.17 15.64563 1.23767

21 5 900 0.1 17.77 1.12 17.84359 1.191125

22 5 300 0.2 24.08 2.13 24.17437 2.257951

23 5 600 0.2 30.15 1.99 30.26565 2.114731

24 5 900 0.2 34.38 1.92 34.5175 2.035202

25 5 300 0.3 35.42 2.91 35.56151 3.088917

26 5 600 0.3 44.35 2.73 44.52204 2.89299

27 5 900 0.3 50.58 2.62 50.77669 2.784192



Table 4.4 Delamination Factor (Banana) for d=3mm


S.NO FEED(mm/rev) SPEED( rpm )

DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.235 2.0778

2 0.1 900 1.23 2.0345

3 0.1 1200 1.225 2.0446

4 0.2 600 1.17 1.9081

5 0.2 900 1.16 1.8826

6 0.2 1200 1.155 1.87

7 0.3 600 1.035 1.5798

8 0.3 900 1.0275 1.5625

9 0.3 1200 1.01 1.5226



DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.188 1.95431

0.1 900 1.184 1.94398

3 0.1 1200 1.178 1.92855

4 0.2 600 1.136 1.82233

5 0.2 900 1.128 1.80246

6 0.2 1200 1.124 1.79257

7 0.3 600 1.028 1.56369

8 0.3 900 1.022 1.54992

9 0.3 1200 1.008 1.51806

Table 4.7 Delamination Factor (Roselle) for d=3mm


DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.188 1.95431

2 0.1 900 1.184 1.94398

3 0.1 1200 1.178 1.92855

4 0.2 600 1.136 1.82233

5 0.2 900 1.128 1.80246

6 0.2 1200 1.124 1.79257

7 0.3 600 1.028 1.56369

8 0.3 900 1.022 1.54992

9 0.3 1200 1.008 1.51806



DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.2825 2.20669

2 0.1 900 1.28 2.1998

3 0.1 1200 1.2775 2.19293

4 0.2 600 1.27 2.17237

5 0.2 900 1.265 2.15872

6 0.2 1200 1.2575 2.13834

7 0.3 600 1.21 2.01161

8 0.3 900 1.1835 1.94269

9 0.3 1200 1.16 1.88264

S.NO

FEED

(mm/rev)

SPEED

( rpm )

DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.31333 2.29257

2 0.1 900 1.30667 2.27385

3 0.1 1200 1.29667 2.24593

4 0.2 600 1.22667 2.05561

5 0.2 900 1.21333 2.02037

6 0.2 1200 1.20667 2.00287

7 0.3 600 1.04667 1.60691

8 0.3 900 1.03667 1.58368

9 0.3 1200 1.01333 1.53016





DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.2282 2.05968

2 0.1 900 1.2264 2.0549

3 0.1 1200 1.2246 2.05013

4 0.2 600 1.216 2.02739

5 0.2 900 1.2112 2.01476

6 0.2 1200 1.2066 2.0027

7 0.3 600 1.628 1.88974

8 0.3 900 1.148 1.85235

9 0.3 1200 1.068 1.65707

Table 4.10 Delamination Factor (Sisal) for d=3mm


DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.34167 2.37302

2 0.1 900 1.339 2.36539

3 0.1 1200 1.337 2.35967

4 0.2 600 1.29333 2.23666

5 0.2 900 1.28333 2.20899

6 0.2 1200 1.27 2.17237

7 0.3 600 1.16333 1.89109

8 0.3 900 1.15333 1.86578

9 0.3 1200 1.14 1.83231



DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.2475 2.11132

2 0.1 900 1.2425 2.09788

3 0.1 1200 1.2435 2.10056

4 0.2 600 1.22 2.03795

5 0.2 900 1.215 2.02476

6 0.2 1200 1.205 1.99851

7 0.3 600 1.16 1.88264

8 0.3 900 1.155 1.86999

9 0.3 1200 1.1525 1.86368



DELAMINATON FACTOR

Fd Fda

1 0.1 600 1.32167 2.31608

2 0.1 900 1.315 2.29726

3 0.1 1200 1.30067 2.25708

4 0.2 600 1.26 2.14512

5 0.2 900 1.25 2.11806

6 0.2 1200 1.23667 2.08225

7 0.3 600 1.13 1.80742

8 0.3 900 1.12167 1.78681

9 0.3 1200 1.10833 1.75409

SCHEME OF DELAMINATION FACTOR USING MACHINE VISION SYSTEM

Fig 4.1 delamination zone Fig 4.2 delamination zone Fig 4.3 delamination zone

(for banana 4 mm dia) (for banana 3 mm dia) (for banana 4 mm dia)




(for Roselle 3 mm dia) (for Roselle 4 mm dia) (for Roselle 5 mm dia)


(for Sisal 3 mm dia) (for Sisal 4 mm dia) (for Sisal 5 mm dia)

Fig.4.10. SEM of Banana Fig.4.11. SEM of Roselle Fig.4.12. SEM of Sisal

Live Time: 100.0 sec.

Acc.Voltage: 15.0 kV Take Off Angle: 35.0 deg.

Fig 4.15 Composition graph of Banana



Fig 4.16 Composition graph of Sisal

Fig 4.17 Composition graph of Roselle

CONCLUSION

Based on the experimental results obtained, the

following conclusions can be extracted:

Effect of Thrust Force

In general, the thrust and torque parameters will mainly

depend on the manufacturing conditions employed,

such as feed, cutting speed, tool geometry, machine

tool, and cutting tool rigidity. A larger thrust force

occurs for larger diameter drills and higher feed rates.

In other words, feed rate and drill diameter are

recognized as the most significant factors affecting the

thrust force. Worn-out drill may be one of the major

reasons for the drastic increase in the thrust force as

well as for the appearance of larger thrust forces when

using multifacet drill than those when using twist drill

at high cutting speed. Although tools are worn out

quickly and the thrust force increases drastically as

cutting speed increases, an acceptable hole entry and

exit is maintained. We found that the thrust force is

drastically reduced when the hole is predrilled to 0.4

mm or above. The thrust force increases with the

increase in fiber volume fraction. Although it is known

that the thrust force increases with the increase in the

feed, this study provided quantitative measurements of

such relationships for the present composite materials.

In general, increasing the cutting speed will decrease

the thrust force. This work has shown that the cutting

speed has an insignificant effect on the thrust force

when drilling at low feed values. At high feed values,

the thrust force decreases with an increased cutting

speed.

Effect of Torque

It can be observed that thrust force and torque increase

with the drill diameter and feed rate. By examining

these results, it can be concluded that the torque slightly

increases as the cutting speed increases. However, we

found that the increase in torque was much smaller than

that in thrust force, with the increasing cutting speed.

The average torque appearing when using a multifacet

drill was larger than that using the twist drill at low

drilling speed, and the average torque when using a

multifacet drill was smaller than that when using twist

drill at high drilling speed. It was noticed that the

average torque decreased as the drilled length increased

for twist drill. Furthermore, the effect of feed, speed,

and fiber volume fraction on the resulting torque in



drilling the specimen was also observed. The results

indicate that the torque increases as the feed increases.

This increase is owing to the increasing cross-sectional

area of the undeformed chip. The results also indicate

that the torque increases with the increase in the fiber

volume fraction. Increasing fiber volume fraction

increases the static strength, and thus, the resistance of

the composite to mechanical drilling increases. This

leads to the increase in the required thrust force and

torque. The result also indicates that the torque

decreases when increasing the cutting speed.

ACKNOWLEDGEMENT

We express our sincere thanks to my beloved parents

for their invaluable love; moral support and constant

encouragement in my life.We owe immense gratitude to

our principal Prof. Dr. V. Selladurai, Ph.D.,

Coimbatore Institute of Technology, Coimbatore for his

moral support during the course of my Research work.

We sincere thanks to Prof. Dr. G. Sundararaj, Ph.D.,

Professor, Department of Production Engineering,

P.S.G.College of Technology, Coimbatore and Prof.

Dr. I. Rajendran, Ph.D., Professor and Head,

Department of Mechanical Engineering, Dr.

Mahalingam College of Engineering &Technology,

Coimbatore for their valuable guidance and

suggestions.

This research was sponsored by the INSTITUTION

OF ENGINEERS (INDIA), KOLKATA. We wish to

acknowledge their support.

We would like to acknowledge THE CONTROLLER

OF PATENTS & DESIGNS, The Patent office,

Chennai, INDIA for filed this research work

provisional specification [PATENT APPLICATION

NO.2349/CHE//2010].

We would also like to acknowledge Dr. L.

Karunamoorthy, Ph.D., Professor and Head of Central

Workshop at the ANNA UNIVERSITY, CHENNAI for

his help in SEM and EDX Analysis.

We would like to thank the Reviewers of this editorial

system for their valuable inputs and comments.

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