Mechanical Properties of Chopped E-Glass Fiber Reinforced ...No.2(2020)/247-256.pdf · Chopped strand mats are arbitrarily situated, give good strand, great wettability, and scattering,

Journal of Mechanical Engineering Research and Developments

ISSN: 1024-1752

CODEN: JERDFO

Vol. 43, No. 2, pp. 247-256

Published Year 2020

247

Mechanical Properties of Chopped E-Glass Fiber Reinforced

Epoxy Resin

Ethar Mohamed Mahdi Mubarak†, Rawaa Hamid Mohammed Al-Kalali†, Emad Ali

Husein‡ & Bahaa Sami Mahdi‡

†Middle Technical University –Institute of Technology –Baghdad

‡Technology University/Baghdad

E-mail: [email protected]

ABSTRACT: One of the aims for the utilizing of random composite materials is to improve the product design.

In this time with fast technological progress, it is often necessary to manufacture machine components and

engineering structure, using fiberglass (E-glass) particles (from chopped E-glass fibers). The exceptional

properties needed for most applications like large strength and low weight. Five different types of composites

are fabricated using fiber reinforced by chopped E-glass with epoxy resin within ratios 10% wt/wt, 20% 40%,

60%, and 80%. Tensile test, Hardness test and SEM investigation are done to these specimens for observing the

influence of contain ratios on the properties of mechanical fiber reinforced by chopped E-glass in the matrix if

epoxy and to analyze the fracture surface respectively. From this study, many observations were concluded that

the best manufacturing of a fiber reinforcement by chopped glass with various epoxy ratios are done by simple

hand lay-up technique and it concluded that the maximum elongation occurs at 10wt% and the minimum

elongation at 20wt%, the hardness for 10wt% composite is higher compared to other ratios. SEM examinations

of fracture region were made to investigate the incorporation of chopped E-glass with epoxy at different ratio.

Also its observed voids and dislocation due to the manufacturing process. The results shown that the

incorporation of chopped E-glass with epoxy at different ratio has an important influence onto composites’

mechanical properties.

KEYWORDS: Random composite material; E-glass fiber chopped; SEM; tensile test; Resin; Epoxy; Hardness

test

INTRODUCTION

Composite materials are a significant type of materials which are presently accessible to humankind in huge

amount. Lately, many glass reinforced by fiber composite materials are broadly utilized in the aviation and car

businesses. Composite materials are significant for mechanical, chemistry and structural architects, material

researchers for utilizing them on a lot of building and different applications. These materials have turned into

the option of customary basic materials, for example, steel, wood or metals in numerous applications [1]. The

technological development has increased on advances in the materials field. A random composite material is

one, which consists of mixing the particles of the materials working together to produce new metal have

properties which are dissimilar to the properties of singular material that they possess. It contains the most

important characteristic that the materials are not soluble to each other. Likewise, the random composite

material assume the role of the advancements designing material because of their fantastic mechanical

properties while being low weight, minimal cost, and profoundly adaptable. Composite essentially comprises a

matrix which around the reinforce in this way the strength and durability is existed that is important in a

specific field of utilization. Chopped strand mats are arbitrarily situated, give good strand, great wettability, and

scattering, and show even strength thought every which way. A researcher examined the investigation of

mechanical properties of E-Glass fiber chopped strand material with epoxy resin nanoclay composites, the point

of this work is to dissect the impact of nanoclay effect on the mechanical conduct of chopped strand E-glass

fiber, strengthened in the matrix of epoxy with filler of nanoclay [2]. Three distinct kinds of composites are

created utilizing 1wt% nanoclay, 5wt% nanoclay and 7wt% nanoclay with 30% wt fiber, resin of epoxy and

Mechanical Properties of Chopped E-Glass Fiber Reinforced Epoxy Resin

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hardener. The resin and hardener are blended in 10:1 weight proportion. The outcomes of this investigation

demonstrate that the nanoclay significantly affects the mechanical conduct of composites. Another researcher

considered the examination the properties of tension and compression of the chopped strand material E-Glass

fiber reinforcement with epoxy matrix [3]. The points of this work is to get ready E-glass fiber reinforcement

composite with variety in fraction of volume of glass fiber substance such as 1%, 2% and 3% with Bi-sphenol

as matrix metal. Tension and compression investigation are directed on the preparation of composite materials.

A scholar explored the mechanical properties of chopped E-glass and empty natural product bundle palm

reinforcement the composites with polylactide acid [4]. Composites are created by arrangement throwing

pursued by palletization and hot pressure. Fiber fraction of volume of 20% was used with fluctuating

proportions of chopped E-glass and empty bundle palm fibers. Expansion of chopped E-glass filaments

improvement the strength and execution of composites materials. A researcher examine the impact of filler of

aluminum oxide on crack strength properties of chopped strand material E-Glass fiber reinforcement with

matrix of epoxy resin was assessed utilizing a specimen of tensile indicated by the standard ASTM D5045 [5].

The outcome demonstrated that the tensile strength of 4wt% filled of aluminum oxide composite is high

contrasted with 2wt%, 6wt%, 8wt%, 10wt% and neat composite. The toughness of fracture of arbitrary chopped

composite material were resolved. A group of researchers considered the inter-laminate shear strength, tension,

impact and flexural of chopped plain weave E-glass composites [6]. Fiber fraction of volume of 22%, 26%, and

30% were received. The outcomes demonstrate that lamination with three layers of plain weave materials

displayed better inter-laminate shear strength, tension, and flexural. Hence the laminations with two layers of

chopped strand materials and one layer of plain weave materials demonstrated improvement impact effect.

Also, SEM was utilized to investigate the fracture in the surface. A researcher studied chopped E-glass fiber-

reinforcement with epoxy resin (10%, 30% and 50%) were fabricated and their mechanical and tribological

behavior was investigated [7]. Performing the three points bending tests according to the ASTMD790 and tests

of tensile were performing as indicated by the ASTMD638 standards. Impact tests and hardness measurements

of the composites were also carried out. Wear behavior of composites was studied using pin on disc wear

testing device. The design of experiments approach, using Taguchi method, was employed to analyze the

results. The influence of parameters on the wear rate and coefficient of friction are determined by signal to

noise ratio and the analysis of variance. A previous researcher studied of mechanical and tribological

properties of hybrid composite material e-glass/epoxy with carbon powder, the aim of this work is to analyze

mechanical and wear behavior of chopped strand material E-glass fiber, reinforcement by epoxy matrix with

filler of carbon powder [8]. Three unique sorts of composites are manufactured utilizing 10% carbon,

20%carbon and 30% carbon with resin of epoxy and hardener. The resin of epoxy and hardener are mixed in

10:1 weight ratio. It shows that incorporation of carbon filler into E-glass fiber epoxy reinforcement composites

modifies the hardness compressive and properties of wear of the composites when compared with unfilled E-

glass epoxy composite. In the present paper the aims for the utilizing of random composite materials is to

improve the product design. Five different types of composites are fabricated using chopped E-glass fiber

reinforcement with epoxy resin with ratios 10% wt/wt, 20% 40%, 60%, and 80%. Tensile test, Hardness test

and SEM investigation are done to these specimens.

USED MATERIALS

In this paper, the used materials are: Fiberglass (E-glass) particles (from chopped E-glass fibers) reinforcement

with epoxy resin.

The epoxy resin is a DCP quickmast 105, manufactured in Jordan, and its properties illustrated in Table 1.

Table 1. General Properties Epoxy resin

Property Value

Compressive strength (Mpa) 70 @ 25C

Flexural strength (Mpa) ≥ 45 @ 25C

Tensile strength (Mpa) ≥ 25

Density (g/cm3) 1.1 ± 0.05

Viscosity (poise) 3 - 5 @ 25C

E-Glass Particles

Fiberglass (or E-glass) has weight light, amazingly solid, and vigorous material. Despite the fact that quality


249

properties are to some degree lower than carbon fiber and it is less stiff, the material is ordinarily far less brittle,

and the crude materials are substantially less costly. Its mass quality and weight properties are likewise truly

ideal when contrasted with metals, and it very well may be effectively framed utilizing molding forms,

Common employments of fiberglass incorporate boats, cars, showers, hot tubs, water tanks, material, funnels,

cladding, and outside entryway skins. Common properties of E-glass are recorded in table. 2.

Table 2. E-glass Mechanical Properties

Property Value

Specific gravity 2.54

Young’s modulus 72.40 Gpa

Ultimate tensile strength 3447 Mpa

Density 2 g/cm3

Chopped E-glass fibers were bought from a local market, and then were chopped to particles. Visual

comparison between normal Chopped E-glass fibers and Particles that were chopped from the (chopped fiber).

MANUFACTURING THE COMPOSITE SPECIMENS

The specimen is manufactured using Fiberglass (E-glass) particles (from chopped E-glass fibers) as shown in

Fig. (1), reinforced with epoxy resin.

Figure 1. Chopped E-glass fibers

Figure 2. The first trials compression method

The die used to manufacture the specimen was made of wood with smooth surfaces inside, the first attempts

were based on the idea of leaving the upper die cover open and to compress the paste inside the die then level it

with spatula and then close it with a cover as shown in Fig (2).

But this method led to a specimens manufacturing problems. The first trials were a disappointment and

produced bad specimens, the shape was not uniform and there was no smoothness and had many voids when

the specimen was to be cut, the specimen shown in Fig.(3) is a bad specimen production from the first trails.


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Figure 3. A bad specimen production from the first trials

It’s obvious that there is no smoothness and the shape is not uniform and there are parts of the mold is ripped

off with the specimen ,this method was conducted with many trials for few weeks changing the lubrication

method and the method of compounding, but all changes lead to the same result. A newer way to manufacture

the specimen was conducted, this is done by closing all sides of mold leaving only one side open (the narrow

side), this method improved the product improving, the specimen shown in Fig.(4) is a sample of improved

manufacturing procedure were the shape was uniform about 98% but still has no smoothness, and still had

many voids when the specimen was to be cut.

Figure 4. The process of taping and oiling Figure 5. The process of enclosing the die

After few months of trials, the problem was analyzed and the solution was found, which can be summarized in

3 problems:

1. The mold had to be taped inside.

2. The mold must be oiled with car motors oil only.

3. The mold must be closed in all the directions and only opened from one of the narrow sides.

The following procedure explains how the mold must be made and used:

1. The mold must be taped and oiled with car oils; the tape makes the surface of the specimen extremely

smooth and also to be insulating layer between the mold and the specimen, while the car oil makes the

operation of taking of the specimen from the mold very easy.

2. The cover of the mold must be closed after step (no. 1) from all direction leaving the narrow side opened,

where the paste is to be compressed through this part as shown in Fig. (5)


251 0.00 0.50 1.00 1.50 2.00 2.50 3.00Strain (%)

0

5

10

15

20

25

30

35

40

45

Str

ess [M

Pa

]

Figure 6. The injection process

After the calculations of fiber to matrix ratio are completed and the paste is ready, the paste is to be injected

through the narrow part of the mold with a stick with continues compression of the paste as shown in Fig. (6),

once the paste is all inside the mold, a small piece of wood with the same width and thickness of the opened

side and with specified length is to be placed and then hammered to close the gap and compress the paste inside

the mold.

The final product is homogenous, isotropic, smooth, gaps free and has the exact dimensions inside the mold, as

shown in Fig.(7).

Figure 7. E-glass/epoxy Tensile specimens

Tensile Test Result

The fundamental motivation behind this test is to discover the conduct of the specimens in the stress-strain

curve that the efficiency of the arbitrary composite and extreme tensile stress is determined as appeared in

Fig.(8).


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Figure 8. Stress – Strain curves for random composite material with different weight ratio

The universal testing machine with 5 tons capacity was using as shown in Fig. (9). The test sample is set up as

per ASTM D 638-03 standard as appeared in Fig. (7). Fig. (10) shows tensile specimens after testing, the

fracture pattern of tensile samples having different ratios, fracture occurs near the tabbing region (Fig.10-a).

When the load increases the specimen gets elongated and max stress occurs below the tab in the specimen.

Fig. (8) demonstrates the outcomes for tensile investigation. The outcomes demonstrate that the strength of

tensile increments with 10 wt% that arrives at greatest worth. Hence, further increment in wt of E-glass

chopped, caused decreasing in the strength of tensile. Young’s modulus were obtained from the tensile test and

listed in the table 3, also poisons ratio was measured for each tensile specimen and calculated and are listed in

the table 3.

(a) (b)

Figure 9. Tensile test device Figure 10. Tensile specimens after testing

Table 3. Young’s Modulus and Poisson’s ratio for Composites

Item Young Modulus [Gpa] Poisson’s ratio

10% wt/wt 1.66 ν = 0.24

20% wt/wt 1 ν = 0.22

40% wt/wt 1.11 ν = 0.2

60% wt/wt 2 ν = 0.251

80% wt/wt 2 ν= 0.256

THE HARDNESS TEST

Hardness for each type of specimen was measured using a Rockwell B type machine. The weights were

mounted by the device (100 kg.f), which is the standard load for Rockwell B Type of test, the specimen was

centered on the holder and then the device wheel was screwed to the point where the specimen is in contact

with the rounded tip of the device, once there, the wheel is to be screwed very carefully until the reading on the

small gauge is pointed to “ Set “, then the large gauge is to be set to zero at the red scales, which represent

Rockwell B settings, once all these procedures are successfully completed, the lever of the device is to be

released to apply the load on the specimen, once the gauge is settled after few seconds, the lever is to be lifted

and the reading was taken from the gauge, seven readings were taken on each specimen then the average value

was obtained. The values of hardness were measured listed in table 4.


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Table 4. Hardness test result for Composites

Item Rockwell B

10% wt/wt 67.5

20% wt/wt 64.07

40% wt/wt 60.75

60% wt/wt 45

80% wt/wt 49.42

SEM RESULTS

Fig (11) illustrated the apparatus of SEM, was utilized to specify the conduct of mechanism of fracture for the

materials. Figs.(12)-(16) illustrated the SEM images of the fracture region with weight ratio 10, 20, 40, 60, 80

% respectively. The interface zone was obviously watched for each sort of blended. A mechanical interlock

mechanism is the jointing component between the chopped E-glass and epoxy resin, with no cavities. Hence,

the bonding mechanism was achieved by a Vannder Waals forces. The huge applied pressure came about in a

fixed built in along the interface zone with no gaps. Fig.(12) observed the fracture region of composite material

with 10% weight with magnification 500µm, Fig.(13) with 20% weight and 200µm ,100µm and 500µm

magnification, Fig.(14) with 40% weight and 200µm ,100µm and 500µm magnification, Fig.(15) with 60%

weight and 200µm ,100µm and 500µm magnification and Fig.(16) with 80% weight and 200µm ,100µm and

500µm magnification. It can be seen that there are voids, which occurred during the manufacturing process.

Also it can be observed the dislocation because of weak bonding of matrix and reinforcement.

Figure 11. SEM device


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-a - -b- -c-

Figure 12. Composite material with 10% weight (a) magnification 500µm (b) magnification 500µm (c)

magnification 500µm

-a - -b- -c-



-a - -b- -c-

Figure 14. Ccomposite material with 40% weight (a) magnification 2mm (b) magnification 200µm (c)



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-a - -b- -c-

Figure 15. Composite material with 60% weight (a) magnification 2mm (b) magnification 100µm (c)


-a - -b- -c-



CONCLUSIONS

The composite of chopped E-glass with epoxy resin is set up with various wt% viz 10wt %, 20wt%, 40wt%,

60wt% and 80wt%. From the study, following observations were concluded:

1. The effective manufacture of a chopped glass fiber reinforcement by epoxy resin with various proportion

has been done by simple hand lay-up technique.

2. The strength of tensile for 10wt% composite is higher contrasted with different proportions. It is seen that

the maximum elongation occurs at 10wt% and the minimum elongation at 20wt%.

3. The hardness for 10wt% composite is higher compared to other ratios.


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4. The present work shows that incorporation of Chopped E-glass with epoxy reinforced composites modifies

the tensile and hardness properties of the composites.

5. SEM examinations of fracture region were made to investigate the incorporation of chopped E-glass with

epoxy at different ratio. Its observed voids and dislocation due to the manufacturing process.

REFERENCES

[1] S.S. Mathapati, B. Suresh. “Experimental Investigation and Failure Analysis of Glass Fibre Reinforced

Epoxy Composite”, International Journal of Science and Research (IJSR), Vol. 4, no. 12, 2015.

[2] P.K. Palani, M.N. Andakumar, “Analysis of Mechanical Properties of Chopped Strand Mat E-Glass Fiber

Epoxy Resin Nanoclay Composites”, Vol. 2, no. 2, pp. 185-189, 2013.

[3] S.S. Mathapati, T.T. Hawal, P.P. Kakamari, R. Nikhil, “Analysis and characterization of Tensile and

Compressive Properties of the Chopped Strand Mat E-Glass Fiber Reinforced Epoxy Composites”,

Advanced Engineering and Applied Sciences: An International, vol. 4, no. 3, pp. 29-33, 2014.

[4] K.Y. Tshai, A.B. Chai, I. Kong, M.E. Hoque, K.H. Tshai, “Hybrid fibre polylactide acid composite with

empty fruit bunch: chopped glass strands,” Journal of Composites, Article ID 987956, pp. 7, 2014.

[5] M.S. Ravikumar, S. Prasad, “Fracture Toughness and Mechanical Properties of Aluminum Oxide Filled

Chopped Strand Mat E-Glass Fiber Reinforced–Epoxy Composites”, International Journal of Scientific

and Research Publications, Vol. 4, no. 7, 2014.

[6] S.S. Heckadka, S.Y. Nayak, K. Narang, K.V. Pant, “Chopped Strand/Plain Weave E-Glass as

Reinforcement in Vacuum Bagged Epoxy Composites”, Hindawi Publishing Corporation, Journal of

Materials, Volume 2015, Article ID 957043, pp. 7, 2015.

[7] N. Ozsoy, M. Ozsoy, A. Mimaroglu, “Mechanical and Tribological Behaviour of Chopped E-Glass Fiber-

Reinforced Epoxy Composite Materials”, Acta Physica Polonica A, Vol. 132, No. 3-II, pp. 852-856, 2017.

[8] V. Lokesh, T. Basava, J. Nithin, “Study of Mechanical and Tribological Properties of Hybrid Composite

Material E-Glass/Epoxy with Carbon Powder”, International Journal of Engineering Sciences &

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Documents

Mechanical Properties of Chopped E-Glass Fiber Reinforced ...No.2(2020)/247-256.pdf · Chopped strand mats are arbitrarily situated, give good strand, great wettability, and scattering,