Docslide.us Ceramic Tiles From Crassostrea Iredalei Oyster Shells

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CERAMIC TILES FROM Crassostrea iredalei (OYSTER) SHELLS

____________________________

A Research Paper presented to the Faculty

of the Department of Physical Sciences

Philippine Normal University

____________________________

In partial fulfillment of the requirements for the degree of

Bachelor of Secondary Education

Major in Chemistry

____________________________

by

April Mae V. Agbayani

Allen A. Espinosa

November 2006

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CERTIFICATE OF APPROVAL

This research paper entitled CERAMIC TILES FROM Crassostrea iredalei

(OYSTER) SHELLS by April Mae V. Agbayani and Allen A. Espinosa in partial

fulfillment of the requirements for the degree Bachelor of Secondary Education Major in

Chemistry, has been examined and recommended for acceptance and approval.

VIC MARIE I. CAMACHO

Research Adviser

NELSON GARCIA ADOLFO P. ROQUE

Panel Panel

REBECCA C. NUEVA ESPAA

Chair

This research paper is accepted and approved in partial fulfillment of the

requirements for the degree of Bachelor of Secondary Education Major in Chemistry.

MARIE PAZ E. MORALES

Date Head, Department of Physical Sciences

PHILIPPINE NORMAL UNIVERSITY

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ACKNOWLEDGEMENT

We wish to thank the following persons and institutions that, in one way or

another, helped make this research study a success:

Dr. Rebecca C. Nueva Espaa, our Chemical Research mentor and chair of the

board of panelist, for sharing her expertise in Chemical Research and the research process

as well.

Prof. Vic Marie I. Camacho, our research adviser, for her guidance and assistance

while in the process of doing our research.

Prof. Nelson Garcia, our panel, for his guidance and assistance while doing our

methodology or experimentation. For always reminding us of a certain lesson in life, that

is, there are ideas that are possible and that there are also ideas which are not possible and

that we have to think critically before pursuing something and the ones we done wrong

should serve as a lesson so we might not repeat it.

Prof. Adolfo P. Roque, our panel, for sharing his ideas regarding our research.

Engr. Benito D. Shea of the Department of Mining, Geology and Ceramics

Engineering of Adamson University for sharing his knowledge and for guiding us in our

methodology.

Prof. Cecilia F. Reynales, Senior Science Research Specialist of the Materials

Science Division of the Department of Science and Technology for explaining to us what

had happened to our research.

Prof. Antonio G. Dacanay, our statistics mentor, for lending us statistics book.

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Genelita P. Gallenito and Antonio V. Lumbo III, student assistants of the

Department of Mining, Geology and Ceramics Engineering of Adamson University for

patiently assisting us in the ceramics engineering laboratory.

Mr. Ronnel Pantig, SRC technician, for patiently providing materials and

chemicals needed in our experimentation.

Dr. Susan R. Arco and Dr. Florian R. del Mundo of the Institute of Chemistry of

the University of the Philippines and Prof. Gilbert U. Yu of the Department of Chemistry

of the Ateneo de Manila University for giving ideas and possible topics for research

while in the process of searching for a subject for research.

Ma. Jesusa O. Araneta, our classmate, for sharing her Bato-Balani journal which

has been a great help to the researchers.

Reinier Augustus S. Isidro and Sherryl R. Jamito, our kuya and ate, for providing

us a soft copy of their research paper about concrete blocks.

The family of April Mae V. Agbayanis husband, Allan Ray Berganos, especially

Mr. Loloy Berganos for helping us do some of the laborious parts.

Leah Mae G. Cariquitan, Christina C. Cuevas, Lea B. Florendo, Vivian Mary S.

Palma and Carla Mari A. Pareja, our dear classmates, for helping us transport our

research materials from PNU to AdU and vice versa.

Department of Science and Technology - Industrial Technology Development

Institute Library for providing us lots of information regarding ceramic tile making.

University of the Philippines College of Science Library for providing us lots of

information about Crassostrea iredalei (oyster) shell.

Our dear classmates, for the friendship and encouragement.

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Our family, for the unconditional love, understanding and support they extended

to us.

Our Creator, for giving us life, for us to experience the sweetness and bitterness of

living which have certainly made us better persons.

A. M. V. A

A. A. E

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ABSTRACT

This research study entitled Ceramic Tiles from Crassostrea iredalei (Oyster)

Shells aimed to investigate the feasibility of the Crassostrea iredalei (oyster) shell as

base for ceramic tile making. The Crassostrea iredalei (oyster) shell were substituted to

silica sand in 40%, 50%, 60%, 100% and 0% substitution respectively. Slip casting was

the forming method used in producing the tile body. Three firing procedures were utilized

using the bisquit and glost firing. The produced tiles were subjected to impact strength

and porosity tests. In the one-way ANOVA used in the study for comparing the said

physical properties of the produced tiles with that of the commercial tiles, it shows that

tile C3 is the most feasible among all the experimental tiles. Meaning, it is the only tile

that is comparable with the commercial tiles in terms of impact strength and porosity.

This also shows the feasibility of producing tile with 60% concentration of calcium

carbonate and with a bisquit firingglazingglost firingproduct firing procedure.

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TABLE OF CONTENTS

Title Page i

Approval Sheet ii

Acknowledgement iii

Abstract vi

List of Figures ix

List of Tables x

List of Appendices xii

Chapter

1 Introduction 1

Objectives of the Study 2

Significance of the Study 2

Scope and Limitations of the Study 3

Definition of Terms 3

2 Crassostrea iredalei (Oyster) Shell: Chemical Components and Uses 4

Ceramic Tile Production 7

Physical Properties of Ceramic Products on the Fired State 13

Local Studies

Nata de Coco Reinforced Styrofoam as Tiles 18

Feasibility of Foam Polystyrene and Powdered

Talaba Shells as Tiles 19

3 Materials and Reagents 21

Research Design 22

Phase I: Preparation of Ceramic Tiles from Oyster Shells

Gathering of Samples 23

Mold Making 23

Preparation of Mixtures 24

Molding and Drying 24

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Glaze Preparation 25

Glaze Application 25

Firing Technology 25

Phase II: Tests on Physical Properties

Test for Impact Strength 26

Test for Porosity 27

4 Results and Discussions 28

5 Conclusion and Recommendations 46

Bibliography 48

Appendices

A Raw Data and Computations for Impact Strength Test 50

B Raw Data and Computations for Porosity Test 58

C Research Pictorials 66

Curriculum Vitae 70

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LIST OF FIGURES

Figure

2.1 Crassostrea iredalei (oyster) shell

2.2 Decomposition of calcium carbonate (CaCO3) into calcium oxide (CaO)

and carbon dioxide (CO2) at a very high temperature

2.3 Pulverized Crassostrea iredalei (oyster) shell

2.4 Process of ceramic tiles production

3.1 The schematic diagram of the entire research

3.2 The dimensions of the tile molder

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LIST OF TABLES

Table

2.1 Chemical Components of Crassostrea iredalei (Oyster) Shell

4.1 Description of Mixtures, Molding and Drying

4.2 Firing Technology

4.3 Result of Impact Strength Test for Control Tiles F and G

4.4 Result of Impact Strength Test for Mixture A

4.5 Summary of one-way ANOVA applied to tile A2 versus tile F or G

4.6 Result of Impact Strength Test for Mixture B

4.7 Summary of one-way ANOVA applied to tile B3 versus tile F or G

4.8 Result of Impact Strength Test for Mixture C

4.9 Summary of one-way ANOVA applied to tile C3 versus tile F or G

4.10 Result of Impact Strength Test for Mixture E

4.11 Summary of one-way ANOVA applied to tile E1 versus tile F or G

4.12 Result of porosity test (in percent apparent porosity, %Pa) for control tiles

F and G

4.13 Result of porosity test (in percent apparent porosity, %Pa) for mixture A

4.14 Summary of one-way ANOVA applied to tile A2 versus tile F

4.15 Result of porosity test (in percent apparent porosity, %Pa) for mixture B

4.16 Summary of one-way ANOVA applied to tile B1 versus tile F

4.17 Result of porosity test (in percent apparent porosity, %Pa) for mixture C

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4.18 Summary of one-way ANOVA applied to tile C3 versus tile F

4.19 Result of porosity test (in percent apparent porosity, %Pa) for mixture E

4.20 Summary of one-way ANOVA applied to tile E1 versus tile F

4.21 Summary of results for the best tiles produced

4.22 Cost of materials utilized in the study

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LIST OF APPENDICES

Appendix

A Raw Data and Computations for Impact Strength Test

B Raw Data and Computations for Porosity Test

C Research Pictorials

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Chapter 1

INTRODUCTION

Building commercial and residential infrastructures in our country is fast growing.

One of the building materials is ceramic tile that is used as floorings in bathrooms, dining

area, function halls, etc. Because of this, there is a demand of ceramic tiles and its

industry is booming.

On the other hand, every year, various solid wastes in our country have been a

great problem to our government. One example is the shells of Crassostrea iredalei

commonly known as oyster found near the seashores. It makes the seashore looks grimy

and its foul odor when fresh is disgusting which is not inviting local and foreign tourists

to visit tourist spots like beaches. It also serves as silt for reproduction of flies and other

oil-causing insects, which are carriers of disease-causing bacteria and viruses.

These shells are known fossil that contains ninety seven and a half percent

(97.5%) calcium carbonate (CaCO3)1, which is a good source of calcium oxide (CaO)

that made these shells rigid and firm. The presence of calcium carbonate (CaCO3) would

make it an ideal component for tiles.

This information brought the idea to the researchers to use the Crassostrea

iredalei (oyster) shells as raw material for ceramic tile making. Due to its high

concentration of calcium carbonate (CaCO3), the proponents therefore would like to

substitute it for the main material in ceramic tile making.

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Objectives of the Study

The main objective of the study is to investigate the feasibility of the Crassostrea

iredalei (oyster) shell as base for ceramic tile making. Specifically, it aims to:

a. Utilize Crassostrea iredalei (oyster) shells as substitute to silicon dioxide (silica

sand) in ceramic tile making;

b. Test the physical properties of the produced ceramic tiles:

i. Impact Strength;

ii. Porosity: and

c. Compare the ceramic tile made of Crassostrea iredalei (oyster) shells to

commercially available ones such as the Mariwasa Ceramic Tiles and Floor

Center Ceramic Tiles in terms of impact strength and porosity.

Significance of the Study

This study was conducted to eliminate solid waste pollution caused by

Crassostrea iredalei (oyster) shells on the seashores by recycling it. Moreover, it can also

prevent the rapid growth of population of insects like mosquitoes living in the shells,

which are carriers of disease-causing bacteria and viruses. In addition, new product

means new opportunity for export and new hope for economic progress.

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Scope and Limitations of the Study

The focus of the study is on the utilization of Crassostrea iredalei (oyster) shells

as raw material for ceramic tiles. The process of ceramic tile making including tests on

properties such as impact strength and porosity are therefore incorporated in the study.

Definition of Terms

Ceramic tile is the tile made from Crassostrea iredalei (oyster) shell and some basic

components of a commercially available ceramic tile.

Impact Strength is the ability of ceramic material to bear crushing loads.

Oyster shells are the shells derived from Crassostrea iredalei.

Porosity is the penetration of liquids and vapors through the material that usually

causes structural damage.

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Chapter 2

REVIEW OF RELATED LITERATURE

This section includes literature concerning the topic that the researchers deemed

important and relevant. It encompasses some background on Crassostrea iredalei

(oyster) shells and the process of ceramic tile making. Also, it includes local studies on

tiles made from locally available materials.

Crassostrea iredalei (Oyster) Shell: Chemical Components and Uses

According to studies, ninety seven and a half percent (97.5%) of the chemical

components of Crassostrea iredalei (oyster) shell are calcium carbonate (CaCO3) or

limestone.1 It is embedded between the layers of an organic substance known as

conchiolin.2 Calcium carbonate (CaCO3) is a compound used in brick making for its high

compressive strength and boiling point.3 The presence of calcium carbonate (CaCO3) in

the shells indicates that it could be used as a source of calcium oxide (CaO), which was

shown to strengthen blocks and dental fillings.

Figure 2.1 Crassostrea iredalei (oyster) shell

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Table 2.1 Chemical Components of Crassostrea iredalei (Oyster) Shell1

CaCO3 (calculated from Ca) 97.5 % Boron 1400 ppm

Calcium 39.00 % Titanium 100 ppm

Silica as SiO2 (calculated from Si) < 0.01 % Lead less than 15 ppm

Sodium 9200 ppm Copper 9 ppm

Magnesium 1400 ppm Lithium less than 10 ppm

Iron 430 ppm Arsenic less than 2.50 ppm

Strontium 1400 ppm Nickel 75 ppm

Manganese 430 ppm Heavy metals as Pb less than 20 ppm

Aluminum 3500 ppm

On a physical analysis done, calcium carbonate is found to have a dry brightness

of 92.1, moisture at 105C of 0.084%, oil absorption of 18.9g oil per 100g of oil,

specific surface area of 0.423m2/g, weight/solid per gallon of 23.1lbs, specific gravity of

2.71, pH of 9.8, hexagonal particle shape, and density of 1.1 g/cm3. Its general uses

includes synthetic/cultured marble, ceramic floor tiles, stucco, caulking compound,

building products, polishing compound, grouting and thin set mortars, abrasive in

powdered cleansers, sealants, adhesives, putty, and glues, paints (water-based), animal

feeds, insecticides, plastics, PVC pipes, carpet underlays and paper.4

Other than being a good ingredient in strengthening tiles, researchers in Florida,

USA and Korea have developed and successfully tested a new process to convert waste

oyster shells into a compound that cleanses water of phosphorus, a common pollutant in

urban, agricultural and industrial runoff. Heating the shells at very high temperatures in a

nitrogen-rich atmosphere for about an hour efficiently converts their contents into a form

of calcium oxide (CaO). Crushed-up oyster shell forces the phosphorus to leave the

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solution, become small particles and precipitate out, or fall to the bottom of the tank,

where it can then be collected and discarded.5

CaCO3(s) CaO(s) + CO2(g) Hrxn = 178.1 kJ/mol Figure 2.2 Decomposition of calcium carbonate (CaCO3) into calcium oxide (CaO)

and carbon dioxide (CO2) at a very high temperature.

Moreover, oyster shells are processed and made into oral calcium supplement

tablets because of its high calcium content. Studies shown that thirty nine percent (39%)

of the chemical components of oyster is calcium.1, 6

Furthermore, oyster shells are crushed into fine particles to be used as an organic

fertilizer. Studies shown that finely crushed oyster shells raises pH in acidic soils. It also

has other nutrients and micronutrients, which keeps the natural balance of the soil.7

Figure 2.3 Pulverized Crassostrea iredalei (oyster) shell.

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Ceramic Tile Production

Tiles are similar to bricks. They differ in uses, in shapes, and in finishing. While a

brick is in the form of a block, a tile is in the form of a sheet. Both are made from the

same process and materials but the tile may go through glazing which can give it a

smooth finish. Tiles are used for walls and flooring.8 Figure 2.4 shows the schematic

diagram of ceramic tile production.

Ceramics is defined as products made out of clay and other earth materials that

can be formed or molded into various shapes, then dried and fired into hardness at a

given temperature.9 Ceramic tile is made of clay. After the formation of the tile body, it

goes through a firing process.10

Basic ceramic raw materials include clay, feldspar and

silica. Clay is an earth material that forms a sticky mass when mixed with water. When

wet, this mass is readily moldable, but when dried, it becomes hard and brittle and retains

its shape. When heated to redness, it becomes still harder and is no longer susceptible to

the action of water. Such a material clearly lends itself to the making of articles of all

shapes. Clays can be classified into kaolin/white clay and ball clay. Kaolin/white clay is

the white-burning clay because of its low iron content. Because of its relative purity, it is

more refractory than other clays. It is the base to which other ingredients are added to

develop the desirable properties. Its strength varies almost directly with plasticity. 9

In a

chemical analysis, kaolin is found to contain 46.87% SiO2, 37.60% Al2O3, 0.27% Fe2O3,

0.85% TiO2, 0.56% CaO, 0.09% Na2O, 0.10% K2O and 13.7% LOI.11

Ball Clays are

extremely plastic clays that fire nearly white though is often black in the raw state. They

usually contain slightly more impurities than kaolin, but are used to increase the plasticity

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and workability of the body. In a chemical analysis, ball clay is found to contain 56.74%

SiO2, 26.94% Al2O3, 1.53% Fe2O3, 1.26% TiO2, 0.25% CaO, 0.64% MgO, 3.42% K2O,

0.41% Na2O and 8.81% LOI.12

Feldspars are used as flux in ceramic bodies. When the

body is fired, the feldspar melts and forms a molten glass that causes the particles of clay

to cling together. When this glass solidifies, it provides strength and hardness to the body.

It is also a good source of soda and potash. Chemically, the feldspars are silicates of

aluminum, containing sodium, potassium, iron, calcium, or barium or combinations of

these elements. Silica or silicon dioxide in the form of quartz, is used in nearly all

ceramic bodies for three reasons: to reduce the drying shrinkage and thus help prevent

cracking of the piece, to give firing qualities by reduction of the firing shrinkage and to

act as a sort of skeleton to hold the shape of the piece in the kiln. 8

Silica, along with

alumina (silica-alumina), forms a major part of the crystal lattice of clay minerals. These

decompose on firing and form part of the microstructure of clay based ceramics such as

earthenware, stoneware and porcelain.13

The proportion of clay (kaolin and ball clay),

feldspar and silica sand is 40%:30%:30%.14

Raw materials like clays, talc and other minerals of ceramic tile are quarries and

refined. Great care is taken in the proper mixture of these materials, as one is critical to

the success, quality and characteristics of the product produced. Once the raw materials

are quarries prepared, and properly mixed, the tiles may now be formed. There are few

common means of forming the tile. First is dust press, wherein an almost dry mixture of

clays, talc, and other ingredients are pressed into a mold at extremely high pressures.

Second is extrusion, wherein the ingredients are slightly wetter and are forced through a

nozzle to form the desired tile shape. Third is slush mold or wet pour, wherein a much

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wetter mixture of ingredients is poured into a mold to form the desired shape. Fourth is

rampress, which is very similar to dust press method, except that the size of the tile

shapes are generally much larger.10

Pressing is a kind of hand forming method in which

the clay must be soft enough to flow into the cavity of the mold while under pressure.

Pressed ware is commonly handled immediately after pressing and must be strong

enough to retain its shape. 9

Slip casting method of forming the tile body includes the procedure in where

sodium silicate is added to the clay mixture as a defloculant which is added to obtain

good fluidity. Sodium silicate is added 0.3-0.6% of the total weight of the clay mixture on

the other hand 30-45% of the total weight is water. The specific gravity of the mixture

should fall within the range of 1.6-1.8. The mesh sieve number of particles should fall

from 60-80. Plaster of paris (CaSO4 0.5H2O) is commonly used as a molder. 9

In general, there are essentially three basic production cycles to which the entire

range of different types of ceramic floor and wall tile can be referred. The first of these

three production cycles, based on single firing technology, is used to manufacture

unglazed tile. The types of unglazed tile produced with this production technology are

cotto, red stoneware, porcelain stoneware and clinker (klinker). The second of these is

based on double-firing technology, which obtains its name from the fact that two distinct

firing treatments are employed, i.e. one to consolidate the tile body and the other to

stabilize the glazes and decorations applied onto the fired tile body.

This production cycle is used for the manufacture of the

majolica, cottoforte, and earthenware (white body). The third of these cycles is based on

single-firing technology. The glazes and decorations are applied onto the dried, but still

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unfired, tile body. Then it is subjected to a single heat treatment single-firing. During this

firing, consolidation of the tile body and stabilization of the glazes takes place at the same

time. This production cycle is use for the manufacture of single-fired whiteware and

redware (monocottura and monoporosa) and glazed klinker.15

Glazes constitute an important element of ceramics. It maybe defined as a glassy

coating melted in place on a ceramic body which may render the body smooth, non-

porous and of desired color or texture. The primary function of glazes is to give strength

and durability of products. Likewise, glaze protects ceramic wares from contamination,

from the action of acids and alkaline and from scratching. They are also used for

decoration purposes. Lime or calcium oxide (CaO) is an example of a glaze material. Its

sources are pure calcium carbonate, whiting, limestone, dolomite and anorthite. Lime is a

principal flux in medium and high temperature glazes but it is not very effective at lower

temperatures. It contributes stability, hardness and durability.9

In the preparation of glaze, the universal method is to mix the glaze ingredients with

water to form a suspension or slip. Weighing of glaze batches should be done in scales of

good construction. Sensitive and precise to the smallest quantities required. Small

quantity of glaze batch is prepared in mortar and pestle while in large quantity, pebble

milling is introduced. 9

There are several ways of applying glaze slip on ceramic wares. One is dipping which

involves having a small receptacle filled with glaze into which the ceramic piece is

immersed into the glaze shaken vigorously to remove surplus of glaze. Another is

pouring on which a quantity of glaze is poured into a ceramic piece until the surface of

ware is covered with it. Brushing in which the application is done with the use of soft

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brush, even strokes are required to attain a good finish. Then, spraying in which the

application is done with the use of air compressor and spray gun. 9

Bisquet firing is a technique where the dried ware should be fired to strengthen

the body's resistance to strain and stress. Firing of wares depends on the product required.

Porcelain, stoneware, and other wares to be glazed are fired at temperature of 800-900

degrees Celsius; for bricks, roof tiles, and other earthenware that do not need to be

glazed, firing temperatures should reach at least its semi-vitreous state at about 900

degrees Celsius to 1200 degrees Celsius. Firing state should be normal and slow due to

water smoking, dehydration, and other chemical and physical reactions undergone by the

body from a dried state to its maturing state. Usually, firing is under an oxidizing flame. 9

Glost Firing is a technique where bisquet fired walls are glazed and then fired.

Temperature for glost firing depends on the glaze used. Temperature ranges from 800-

1050 degrees Celsius; for stoneware and porcelain, temperature ranges from 1150-1380

degree Celsius. Oxidizing and reducing atmospheres inside the kiln depend on the glaze

used, tone effect and product required. Usually, the glazed wares are first fired in an

oxidizing atmosphere up to 1100 degrees Celsius, the wares are fired in reducing flame;

lastly, the firing becomes slightly reducing or neutral. This step is called reducing firing.

There are bodies which could be glaze on its green or dried state, then fired. This is called

monofiring. 9

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Figure 2.4 Process of ceramic tiles production14

Pre-mix Clay Body

Weighing

Blunging

Forming (Slip Casting)

Retouching

Drying

Bisquit Firing

Glaze Application

Glost Firing

Quality Control

Packaging

+ water defloculant

underglaze decoration application

brushing, spraying, pouring

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Physical Properties of Ceramic Products on the Fired State

Compressive Strength9

The compressive strength of a ceramic material is a measure of its ability

to bear crushing loads. Since ceramics normally break under tension, its true

compressive strength is difficult to measure. For a correct measurement of the

compressive strength of a ceramic material, more care in simple preparation

should be done. In particular, the specimen facing the bearing load must be

absolutely flat and parallel. If this criterion is not met, the load will be carried

unevenly by the specimen causing failure at low loads thus giving low

compressive strengths. Cushioning materials are often used to distribute the load

uniformly over the bearing surfaces.

The compressive strength (Sc) is represented by the equation:

Sc = P / A

where: P = the crushing load at failure (kg)

A = the cross sectional area of the test sample (cm2)

Hardness9

Hardness is one of the most important properties of ceramics, but because

of brittleness of ceramic materials hardness is also one of the most difficult

properties to measure. Several methods have been developed which give fairly

reliable results. Usually, a diamond stylus is forced into the surface of a ceramic

specimen under a standard load and depth of penetration is measured. The test is

run on polished samples employing a forty-five kilograms (45kg) load on the

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diamond stylus. Although the numerical difference between alumina samples of

various compositions is small, the test results are quite reliable.

The second method and one of the most common tests used for hardness is

the Mohs scale. This scale uses ten standard minerals, each of which will scratch

all minerals below it on the scale. Ceramics are rated on this scale by scratch trials

with the standards: 1) Talc, 2) Gypsum, 3) Calcite, 4) Fluorite, 5) Apatite, 6)

Orthoclase, 7) Quartz, 8) Topaz, 9) Corundum and 10) Diamond.

Modulus of Rupture (MOR) 9

The modulus of rupture is the fracture strength of the materials under a

bending load. It is one of the quality control tests for the measurement of strength.

The MOR measurement is made on a long bar of either a rectangular or

circular cross section; supported near its ends, with a load applied to the central

portion of the supported span. Any standard testing machine of suitable capacity

may be used, so long as the specimen is properly mounted. In order to yield

correct results, the bar must fracture at the center. The MOR is represented by the

equation:

MOR= 3/2 (PL/bd2)

where:

P= the load required to break the bar (kg)

L= the span, distance between the outer supports (cm)

b= the width of the bar (cm)

d= the depth of the bar (cm)

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Using cylindrical bar, the MOR is given by the equation:

MOR = 8PL / D3

where: D= the diameter of the cylindrical bar (cm)

Such a test assumes the pieces to be uniformly strong through all cross

sections, which is not strictly true. To average out the variations, ten specimens

are used for the test and individual values with more than 20% variation from the

average are discarded. The most important factors in the MOR determinations are

the rate of loading, the ratio of span to specimen thickness, and the specimen

alignment. The specimen should be carefully aligned in the specimen holder so

that the latter will not twist during the operation.

Porosity9

The porosity of a ceramic sample, particularly a fixed ceramic sample,

should be carefully controlled. The greater the porosity of a sample, the more

likely the penetration of liquids and vapors through the materials and usually,

such penetration is accompanied by structural damage to the product. Example:

refractories with high porosity will suffer internal chemical attack as a result of

the penetration of slags into the interior. Also, table-ware that exhibits high

porosity would absorb various substances during use and becomes permanently

stained and unsanitary. There are few ceramic products produced today which do

not have carefully controlled pore structures. Only the open pore volume,

sometimes called the apparent pore volume, can be directly measured. When this

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volume is expressed as a percentage of the bulk volume of the sample, it is called

the percentage apparent porosity

% Pa = Vop / Vb x 100

where: Pa = percentage apparent porosity

Vop = the volume of open pores (cm3)

Vb = the bulk volume of the sample (cm3)

Substituting the weight quantities in the equation, the result is:

% Pa = Wm Wd / Wm Wmm x 100

where: Wm = the unsaturated (dry fired/weight/g,kg)

Wd = the unsaturated weight of the sample ( that is all the open

pores are filled with water)

Wmm = the weight of saturated sample when it is submerged in

liquid for five hours (g, kg)

Percent Water Absorption9

Generally, the absorption test is the best single indicator of the quality of a

ceramic body. It is a measure of the degree of vitrification achieved, in as much

as, when the firing temperature of a body is increased, its absorption steadily

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drops, and, as the absorption decreases, the mechanical strength of the body is

greatly improved.

Percentage water absorption is the ratio of the weight of water absorbed

during saturation to the weight of the sample when it is saturated. It is represented

by the equation:

%WA = Wm-WD/WD x 100

where: WA = percentage water absorption

Wm = the weight of the water-saturated (g, kg)

WD = the weight of unsaturated (dry fired) sample (g, kg)

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Local Studies

This section includes literature on tile making using locally available materials

and the tests conducted to investigate the feasibility of the tiles produced.

Nata de Coco Reinforced Styrofoam as Tiles16

The rise of the nata de coco industry and the many uses of the said food product

prompted a group of students to do research on the said fibrous material. An idea came

up to use the cellulose fibers of nata de coco to reinforce the common Styrofoam.

Nata de coco was placed in a large container then boiled in a 25% sodium

hydroxide solution to remove the noncellulosic material. The mixture was allowed to

settle for 10-15 minutes until the material had separated. The cellulose was then collected

and placed in the drying oven for a few minutes to dry. The oven was occasionally

observed to prevent the sheets from burning. The dried cellulose was then cut into small

pieces and was placed in the Wiley mill for grinding. The powdered cellulose was then

stored until the Styrofoam was ready for mixing. The Styrofoam was placed in a

container and toluene was added to dissolve the material. The powdered cellulose was

mixed with the Styrofoam and toluene. The mixture was stirred until all the Styrofoam

had been dissolved into pure polystyrene.

Four treatments of different ratios of Styrofoam with cellulose were prepared

during the production; the four mixtures were as follows: 10:90, 15:85, 20:80, and 25:75

percent of cellulose with Styrofoam, respectively. Pure Styrofoam and pure cellulose

31

were also held as basis for comparison. The mixtures were mixed very evenly and

carefully. When the cellulose and Styrofoam were mixed completely in each of the

different treatments, the resulting polymer blend was poured into aluminum containers.

The mixtures where then allowed to harden.

Tests were made to examine the quality of the resulting material. Tests on

flexibility, flammability, and water absorption were done. The test on flexibility was

done by noting the expansion of the samples when exposed to the same tension. The

flammability test was based on whether the tiles are easily burned or not. The water

absorption test was done by submerging each sample into water and left there for a

certain time then weighed to note the change in mass. The texture was also observed to

see which appears to be closest to Styrofoam.

Through the flexibility, flammability, and water absorption qualitative test and

with the aid of statistical tests such as Friedmanns statistical test prove that the product

cannot substitute tiles since they do not possess the properties of commercially produced

tiles.

Feasibility of Foam Polystyrene and Powdered Talaba Shells as Tiles17

The study deals with the recycling of polystyrene foam or foam polystyrene more

popularly known as Styrofoam. Foam polystyrene (FPS) was reused as an ingredient in

making tiles. The tiles were made as follows: FPS was mixed with ground talaba shells

after being dissolved in premium gasoline. This mixture was then placed into molds

having 2.54 cm x 2.54 cm x 1.27 cm dimensions and was left to air dry. Three mixtures

of FPS and gasoline with ground talaba shells were prepared. The mixtures have the

32

ratios of 60:40, 50:50, and 40:40. It was then removed from the molds and sanded into

tiles having dimensions of one by 2.54 cm x 3.18 cm. The resulting tiles were tested

(Impact Test) against some commercial tiles involving a test for the breaking of the tiles

upon receiving the impact of a load. The results showed that the experimental tiles were

comparable with the control.

Impact Test

The strength of the tiles will be tested in the following manner. The tiles would be

placed on the floor underneath a piece of metal. A load would be dropped on the metal.

This would be done on each of the tiles with increasing weight. A commercial tile would

also be tested in this manner to compare its strength with that of the experimental tiles.

Height = 0.68 m

Load 1 = 0.587 kg

Load 2 = 1.1567 kg

Load 3 = 1.7577 kg

Rating Scale:

5 no cracks, no damage

4 chipped; few cracks

3 more cracks but did not break into fragments

2 broke into fragments

1 extensive damage; crushed

33

Chapter 3

METHODOLOGY

This section includes the details how the study was conducted, that is, the plans

for different stages, experimentation, tools, special procedures or techniques.

Materials and Reagents

For the pulverization of Crassostrea iredalei (oyster) shells, pounding steel is

used while for the straining of the pounded shells, a metal screen with fine holes (70

mesh sieve) is used.

For the preparation of mixtures, basins are used in the mixing of the pounded

shells with the feldspar, kaolin, ball clay, sodium silicate and water. For further mixing, a

labo mill is used.

For master mold making, plaster of paris and water is used.

For the molding and drying, a mold made of plaster of paris is used.

For glaze preparation, calcium oxide, carboxymethyl cellulose and water is used.

For the firing, a firing machine is used.

For the impact test, a meter stick, loads of different weight and a flat metal are

used.

For the porosity and water absorption test, a triple beam balance and a basin are

used.

34

Research Design

Phase I: Preparation of Ceramic Tiles from Crassostrea iredalei (Oyster) Shells

Figure 3.1 The schematic diagram of the entire research.

Gathering of Crassostrea iredalei (Oyster) Shells

Washing of Impurities by Boiling

Air & Sun Drying

Pounding/Pulverizing & Filtering/Straining

Master Mold Making

Preparation of Mixtures (Slip Casting)

Experimental

2:3 (A)

1:1 (B)

3:2 (C)

1:0 (D)

0:1 (E)

Molding & Drying

Glaze Preparation

Bisquet Firing Final Product

Glaze Application

Glost Firing

Final Product

Impact Strength Porosity

Phase II: Test for Physical Properties

35

Phase I: Preparation of Ceramic Tiles from Crassostrea iredalei (Oyster) Shells

Gathering of Samples

The fifty kilograms (50kg) or one (1) sack of Crassostrea iredalei (oyster) shells

were obtained from the shores of Maragondon, Cavite on August 4, 2006.

After the shells were collected, it was washed of impurities by boiling. It was

done for ten (10) minutes and then air-dried and sun-dried for twenty four (24) hours.

After drying, the shells were pounded using pounding steel. The pounded shells are

subjected to a screen with fine holes (70 mesh sieve) to allow only the passage of finer

shell particles. Shells that were left on the screen will be pounded again until such time

that it pass through the screen with fine holes.

Mold Making

Each mixture of plaster of paris was carefully mixed for three (3) to four (4)

minutes until it is about to start setting. The mixtures composition is three hundred

grams (300g) of plaster of paris added to sixty-seven milliliters (200mL) of water.

The mixture was poured in the master mold. The master mold has a plastic

walling to prevent sticking of the plaster of paris. The mater mold is made up of wood

and is prepared by a carpenter.

36

Preparation of Mixtures

For the experimental group, five (5) different mixtures were made: mixtures A, B,

C, D and E. The composition of each are: 2:3, 1:1, 3:2, 1:0, 0:1 (pulverized shells : fixed

mixture of feldspar, kaolin and ball clay ratio of mass). The composition of the fixed

mixture was 3:2:1 (feldspar : kaolin : ball clay ratio of mass). The composition of mixture

D was 1:1 (pulverized shells : feldspar ratio of mass). The composition of mixture E was

0:1 (pulverized shells: fixed mixture of feldspar, kaolin and ball clay ratio of mass).

Slip Casting was used in the preparation of mixtures. Sodium silicate is added to

the mixtures. It was 0.5% of the total weight of the clay mixture on the other hand 36% of

the total weight is water.

Molding and Drying

The prepared mixtures were poured into corresponding molds with 4 in x 4 in x

0.5 in in dimensions. Fifteen (15) replicates were prepared for each mixture. The

mixtures were left over to dry.

Figure 3.2 The dimensions of the tile molder

4 in 4 in

0.5 in

37

Glaze Preparation

Thirty grams (30g) of lime or calcium oxide (CaO) was mixed with seventy

milliliter (70mL) of water to form a suspension or slip. Three tenths grams (0.3g) of

commercially prepared carboxymethylcellulose (CMC) was added to it. The mixtures

specific gravity is checked using a hydrometer. The specific gravity of the mixture was

1.5.

Glaze Application

Brushing glaze application is used. It was done with the use of a soft brush.

Firing Technology

Four (4) tiles from mixtures A, B, C, and E are subjected to bisquit firing without

glaze at a temperature of 900C. They were referred to as A1, B1, C1, and E1.

Another four (4) tiles from mixtures A, B, C, and E are subjected to glost firing

with glaze at a temperature of 900C. They were referred to as A2, B2, C2, and E2.

The last four (4) tiles from mixtures A, B, C, and E are subjected to bisquit firing

without glaze at a temperature of 900C. The glaze was added to the tile after firing. The

38

glazed tiles were subjected to glost firing at a temperature of 1100C afterwards. They

were referred to as A3, B3, C3, D3 and E3.

Phase II: Tests for Physical Properties

Tests

Impact Strength Test

Two (2) tiles from A1, A2, A3, B1, B3, C1, C2, C3, E1, E2 and E3 and two

commercially available tiles namely Mariwasa Ceramic Tiles and Floor Center

Ceramic Tiles which were referred to as F and G respectively are subjected to

Impact Strength Test.

The tiles would be placed on the floor underneath a piece of metal. A load

would be dropped on the metal. This would be done on each of the tiles with

increasing weight. The weight, height and rating scale is shown below.

Height = 0.68 m

Load 1 = 100 g

Load 2 = 200 g

Load 3 = 500 g

Rating Scale:

50 no cracks, no damage

40 chipped; few cracks

30 more cracks but did not break into fragments

20 broke into fragments

10 extensive damage; crushed

39

Porosity Test

Two (2) tiles from A1, A2, A3, B1, B3, C1, C2, C3, E1, E2 and E3 and two

commercially available tiles namely Mariwasa Ceramic Tiles and Floor Center

Ceramic Tiles which were referred to as F and G respectively are subjected to

Porosity Test.

Each tile was weighed using a triple beam balance to get its dry fired mass

(Wm). After weighing, each tile was dipped in water instantaneously to fill the

open pores then it was weighed again to get its unsaturated mass (Wd). After

weighing, the tiles were submerged in water for five (5) hours and were weighed

again to get its saturated mass (Wmm). To get the percent apparent porosity (%Pa),

the values gathered from weighing was then be substituted to the equation:

% Pa = Wm Wd / Wm Wmm x 100

40

Chapter 4

RESULTS AND DISCUSSIONS

This section includes facts and figures gathered in the experimentation process of

utilizing oyster shells as substitute to silica sand in ceramic tile making. The results of the

study were described in the preceding sections.

The oyster shells were mixed with five (5) treatments, referred to as mixtures A,

B, C, D and E. The proportions of each mixture were 2:3, 1:1, 3:2, 1:0 and 0:1

(pulverized oyster shells : fixed mixture of ball clay feldspar and kaolin ratio of mass)

respectively. Refer to Table 4.1 for the data.

Table 4.1 Description of Mixtures, Molding and Drying

* Pulverized shells: fixed mixture of ball clay, feldspar and kaolin ratio of mass

Mixture Proportion* No. of Tiles

Molded

No. of Tile Body

Formed Description

A

2:3

12

12

When placed in the plaster of

paris mold, it dries, hardens & forms a tile body.

B

1:1

12

12


paris mold, it dries, hardens & forms a tile body.

C

3:2

12

12


paris mold, it dries, hardens

& forms a tile body.

D

1:0

12

0


paris mold, it dries but did

not harden, therefore not

forming a tile body.

E

0:1

12

12


paris mold, it dries, hardens

& forms a tile body.

41

As shown in Table 4.1, mixtures A, B, C and E dries, hardens and forms a tile

body. No cracking occurs when removing it in the plaster of paris mold. The said

mixtures dry because the plaster of paris mold absorbs its water content. On the other

hand, said mixtures harden & become moldable due to the presence of clays (ball clay

and kaolin). Mixture B, however, did not form a tile body because it did not harden and it

did not become moldable, though it dries. Drying of the mixture is due to the plaster of

paris mold, but because it does not contain clays, it did not harden and it did not become

moldable. It cracks when removing it to the plaster of paris mold. Mixture D contains

feldspar only whose function is to provide strength and hardness to the tile body which is

limited to the fired state of the tile.

Firing Technology

Three firing procedures were done. Different subscripts were used to indicate the

firing procedure done on the tile. The subscript 1 indicates that the tile undergone bisquit

firingproduct procedure. In contrast, the subscript 2 indicates that the tile underwent

glazingglost firingproduct procedure. Nonetheless, the subscript 3 indicates that the

tile go through bisquit firingglazingglost firingproduct procedure. Refer to table

4.2 for the data gathered.

42

Table 4.2. Firing Technology

Mixture Groups*

No.

of

tiles

fired

No. of

tiles

produced

No. of

tiles that

broke into

fragments

Description

A

A1 4 4 0 no cracks,

no damage

A2 4 4 0

few cracks,

little

damage

A3 4 4 0

few cracks,

little

damage

B

B1

4 4 0

no cracks,

no damage

B2 4 0 4

broke into

fragments,

extensive

damage

B3 4 4 0

few cracks,

little

damage

C

C1 4 4 0 few cracks,

brittle

C2 4 4 0 few cracks,

brittle

C3 4 4 0 no cracks,

no damage

E

E1 4

4 0 no cracks,

no damage

E2 4 4 0

no cracks,

no damage

E3 4 4 0 no cracks,

no damage

*Firing Procedure: 1 - bisquit firingproduct 2 - glazingglost firingproduct

3 - bisquit firingglazingglost firingproduct

As shown in Table 4.2, all the groups except for B2 yields 100% though referring to

the description of each groups, it is noticeable that almost all have little damage. Group

B2 broke into fragments and exhibits extensive damage. This means that it is not feasible

to make tiles with 50% concentration of calcium carbonate and with a glazingglost

firing product procedure. On the other hand, the presence of feldspar provides strength

43

and hardness to the groups of tiles on the fired state because when the feldspar melts, it

forms a molten glass that causes the particles to cling together. But due to a lesser

concentration of it, qualitatively speaking, the produced tiles do not exhibit much

hardness and strength. The absence of silica sand, however, is substituted by calcium

carbonate which according to studies has the same function as the silica sand. Both silica

sand and calcium carbonate acts as sort of skeleton, reduce firing shrinkage, drying

shrinkage and cracking. But due to its higher concentration in mixtures, A, B and C the

result is the other way around. This means that, higher concentration of calcium

carbonate is not good. Proportions of raw materials should be distributed well.

Test for Physical Properties

The physical properties such as impact strength and porosity of the produced tiles

from oyster shells were tested and compared with commercial ceramic tiles. The

following sections describe the results of said tests.

A. Impact Strength Test

Impact strength is an important property of a ceramic tile on the fired state. It refers to

the ability of ceramic material to bear crushing loads. Impact strength test is done to

measure the capacity of the ceramic tiles produced to bear crushing loads of different

masses. This test is done by dropping three loads of different masses (100g, 200g and

500g) consecutively on the tile 0.68m high.

44

Table 4.3 shows the result of the impact strength test done on the two

commercial/control tiles F and G which will be used to compare with the experimental

tiles.

Table 4.3 Result of Impact Strength Test for Control Tiles F and G

Table 4.3 shows the impact strength test conducted on the control tiles F and G.

The rating 50.0 indicates that the tile has the greatest impact strength while the rating

10.0 indicates that the tile has the lowest impact strength.

Referring to Table 4.3, it shows that the total mean indicates that control tiles F

and G have the same impact strength. The impact strength result for each control tile will

be used in comparing with the best tile for each mixture using one-way ANOVA but

since control tile F and G have the same impact strength rating, either of the two can be

used.

Table 4.4 shows the result of the impact strength test done on mixture A.

Table 4.4 Result of Impact Strength Test for Mixture A

Tile Trial 1 Trial 2

Mean

Total Rank Loads Loads

1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

F 50.0 50.0 30.0 43.3 50.0 50.0 30.0 43.3 43.3 1.5

G 50.0 50.0 30.0 43.3 50.0 50.0 30.0 43.3 43.3 1.5


Mean


1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

A1 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 3

A2 40.0 30.0 20.0 30.0 30.0 30.0 20.0 26.7 28.4 1

A3 40.0 20.0 20.0 26.7 40.0 20.0 20.0 26.7 26.7 2

45

Table 4.4 shows the impact strength test conducted on experimental tile A. The

rating 50.0 indicates that the tile has the greatest impact strength while the rating 10.0

indicates that the tile has the lowest impact strength.

Referring to Table 4.4, it shows that the total mean indicates that tile A2 have the

greatest impact strength while tile A1 have the lowest impact strength. For this reason, tile

A2 is selected to be compared with control tiles F and G.

Table 4.5 shows the summary of the one-way ANOVA applied in comparing tile

A2 versus control tiles F or G.

Table 4.5 Summary of one-way ANOVA applied to tile A2 versus tile F or G

Source of

variation

Sum of

Squares

df Mean

Squares

F ratio Interpretation

Between

Groups 223.5 1 223.5

111.8 Significant Within

Group 3.800 2 1.9

Total 227.3 3

As shown in Table 4.5, the F-ratio is more than the critical value, 13.51, then the

null hypothesis, which is, the 2 groups of tiles do not differ in terms of impact strength,

will be rejected. Meaning, tile A2 differ significantly with that of the control tile F or G in

terms of impact strength. Since the mean value of the result of impact strength test done

on experimental tile A2 is less than the mean value of the result of impact test done on

control tile F or G, tile A2 is more fragile compared with the control tiles. This indicates

that it not feasible to make tiles with 40% concentration of calcium carbonate and with a

bisquit firingproduct procedure if the impact strength is the only physical property to

be considered.

46

Table 4.6 shows the result of the impact strength test done on mixture B.

Table 4.6 Result of Impact Strength Test for Mixture B

Table 4.6 shows the impact strength test conducted on experimental tile B. The



Referring to Table 4.6, it shows that the total mean indicates that tile B3 have the

greatest impact strength while tile B1 have the lowest impact strength. For this reason, tile

B3 is selected to be compared with control tiles F and G.

Table 4.7 shows the summary of theone-way ANOVA applied in comparing tile

B3 versus control tiles F or G.

Table 4.7 Summary of one-way ANOVA applied to tile B3 versus tile F or G

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 43.56 1 43.56

-54.45 Not

Significant Within

Group -1.600 2 -0.8

Total 42.00 3

As shown in Table 4.7, the F-ratio is less than the critical value, 13.51, then the


will be accepted. Meaning, tile B3 do not differ with that of the control tile F or G in

terms of impact strength. This indicates that it is feasible to make tiles with 50%

concentration of calcium carbonate and with a bisquit firingglazingglost


Mean


1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

B1 40.0 30.0 20.0 30.0 40.0 20.0 20.0 26.7 28.4 2

B3 50.0 40.0 20.0 36.7 50.0 40.0 20.0 36.7 36.7 1

47

firingproduct procedure if the impact strength is the only physical property to be

considered.

Table 4.8 shows the result of the impact strength test conducted on experimental

tile C.

Table 4.8 Result of Impact Strength Test for Mixture C

Table 4.8 shows the impact strength test conducted on experimental tile C. The



Referring to Table 4.8, it shows that the total mean indicates that tile C3 have the

greatest impact strength while tile C1 have the lowest impact strength. For this reason, tile

C3 is selected to be compared with control tiles F and G.


C3 versus control tiles F or G.

Table 4.9 Summary of one-way ANOVA applied to tile C3 versus tile F or G

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 24.50 1 24.50

12.89 Not

Significant Within

Group 3.800 2 1.900

Total 28.30 3

As shown in Table 4.9 the F-ratio is less than the critical value, 13.51, then the


Tile Trial 1 Trial 2 Mean


1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

C1 40.0 20.0 20.0 26.7 40.0 20.0 20.0 26.7 26.7 3

C2 40.0 40.0 20.0 33.3 40.0 40.0 20.0 33.3 33.3 2

C3 50.0 50.0 20.0 40.0 50.0 40.0 20.0 36.7 38.4 1

48

will be accepted. Meaning, tile C3 is comparable to control tile F or G in terms of impact

strength. This indicates that it is feasible to make tiles with 60% concentration of calcium

carbonate and with a bisquit firingglazingglost firingproduct procedure if the

impact strength is the only physical property to be considered.

Table 4.10 shows the result of the impact strength test conducted on experimental

tile E.

Table 4.10 Result of Impact Strength Test for Mixture E

Table 4.10 shows the impact strength test conducted on experimental tile E. The



Referring to Table 4.10, it shows that the total mean indicates that tile E1 have the

greatest impact strength while tile E2 have the lowest impact strength. For this reason, tile

E1 is selected to be compared with control tiles F and G.


E1 versus control tiles F or G.

Table 4.11 Summary of one-way ANOVA applied to tile E1 versus tile F or G

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 223.5 1 223.5


Group 3.800 2 1.900

Total 227.0 3


Mean


1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

E1 40.0 30.0 20.0 30.0 40.0 20.0 20.0 26.7 28.4 1

E2 20.0 20.0 20.0 20.0 20.0 20.0 10.0 16.6 18.3 3

E3 40.0 20.0 10.0 23.3 40.0 20.0 10.0 23.3 23.3 2

49



will be rejected. Meaning, tile E1 differ significantly with that of the control tile F or G in

terms of impact strength. Since the mean value of the result of impact test done on

experimental tile E1 is less than the mean value of the result of impact strength test done

on control tile F or G, tile E1 is more fragile compared with the control tiles. This

indicates that it not feasible to make tiles with 0% concentration of calcium carbonate or

silica sand and with a bisquit firingproduct procedure if the impact strength is the only

physical property to be considered.

In general, groups B3 and C3 are the tiles comparable with control tiles F or G in

terms of impact strength.

B. Porosity Test

Porosity is an important physical property of a ceramic tile on the fired state. It

refers to the penetration of liquids and vapors through the material that usually causes

structural damage. The porosity test is conducted to determine how much liquid the

produced ceramic tile will absorb in standard period of time. It is done by measuring the

unsaturated mass of the tile, the liquid-dipped mass of the tile and the saturated mass of

the tile. The resulting masses were then substituted to the equation for percent apparent

porosity.

Table 4.12 shows the result of the porosity test done on the control tiles F and G.

50

Table 4.12 Result of porosity test (in percent apparent porosity, %Pa) for control tiles F

and G


Rank %Pa (%) %Pa (%) (%)

F 48.57 40.00 44.29 1

G 45.46 46.73 46.15 2

Table 4.12 shows the porosity test done on control tiles F and G. It illustrates that

the lesser the percent apparent porosity, the lesser is its susceptibility to be penetrated by

liquids, the better.

As shown in Table 4.12 control tile F has the least percent apparent porosity,

meaning it is less susceptible to be penetrated by liquids while control tile G has larger

percent apparent porosity, meaning it is more susceptible to be penetrated by liquids and

vapors. For this reason, control tile F is selected to be compared with the experimental

tiles.

Table 4.13 shows the results of the porosity test for mixture A.

Table 4.13 Result of porosity test (in percent apparent porosity, %Pa) for mixture A


Rank %Pa (%) %Pa (%) (%)

A1 46.00 45.82 45.91 2

A2 39.90 40.46 40.18 1

A3 47.47 47.74 47.61 3

Table 4.13 shows the porosity test for mixture A. It illustrates that the lesser the

percent apparent porosity, the lesser is its susceptibility to be penetrated by liquids, the

better.

51

Referring to Table 4.13, it shows that tile A2 has the least percent apparent

porosity, meaning it is less susceptible to be penetrated by liquids while tile A3 have the

largest percent apparent porosity, meaning it is more susceptible to be penetrated by

liquids and vapors. For this reason, tile A2 is selected to be compared with control tile F.

Table 4.14 shows the one-way ANOVA applied in comparing tile A2 versus

control tile F.

Table 4.14 Summary of one-way ANOVA applied to tile A2 versus tile F

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 19.38 1 19.38

1.053 Not

Significant Within

Group 36.82 2 18.41

Total 56.20 3


null hypothesis, which is, the 2 groups of tiles do not differ in terms of porosity, will be

accepted. Meaning, tile A2 is comparable with control tile F in terms of porosity. This

indicates that it is feasible to make tiles with 40% concentration of calcium carbonate and

with a bisquit firingproduct procedure if porosity is the only physical property to be

considered.

Table 4.15 shows the results of the porosity test for mixture B.

Table 4.15 Result of porosity test (in percent apparent porosity, %Pa) for mixture B


Rank %Pa (%) %Pa (%) (%)

B1 47.54 48.96 48.25 1

B3 49.61 47.29 48.41 2

52

Table 4.13 shows the porosity test for mixture B. It illustrates that the lesser the


better.

Referring to Table 4.13, tile B1 has the least percent apparent porosity, meaning it

is less susceptible to be penetrated by liquids while tile B3 have larger percent apparent

porosity, meaning it is more susceptible to be penetrated by liquids and vapors. For this

reason, tile B1 is selected to be compared with control tile F.


B1 versus control tile F.

Table 4.16 Summary of one-way ANOVA applied to tile B1 versus tile F

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 12.94 1 12.94

0.6890 Not

Significant Within

Group 37.56 2 18.78

Total 50.50 3



accepted. Meaning, tile A2 is comparable with control tile F in terms of porosity. This

indicates that it is feasible to make tiles with 50% concentration of calcium carbonate and

with a glazingglost firingproduct procedure if porosity is the only physical property

to be considered.

Table 4.17 shows the results of the porosity test for mixture C.

53

Table 4.17 Result of porosity test (in percent apparent porosity, %Pa) for mixture C


Rank %Pa (%) %Pa (%) (%)

C1 63.56 64.60 64.08 3

C2 64.06 64.02 64.04 2

C3 59.92 59.47 59.70 1

Table 4.17 shows the porosity test for mixture C. It illustrates that the lesser the


better.

Referring to Table 4.17, tile C3 has the least percent apparent porosity, meaning it

is less susceptible to be penetrated by liquids while tile C1 have larger percent apparent

porosity, meaning it is more susceptible to be penetrated by liquids and vapors. For this

reason, tile C3 is selected to be compared with control tile F.


C3 versus control tile F.

Table 4.18 Summary of one-way ANOVA applied to tile C3 versus tile F

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 234.5 1 234.5

13.21 Not

Significant Within

Group 35.50 2 17.75

Total 270.0 3



accepted. Meaning, tile C3 is comparable with control tile F in terms of porosity. This

indicates that it is somewhat feasible to make tiles with 60% concentration of calcium

54

carbonate and with a bisquit firingglazingglost firingproduct procedure if porosity

is the only physical property to be considered.

Table 4.19 shows the results of the porosity test for mixture E.

Table 4.19 Result of porosity test (in percent apparent porosity, %Pa) for mixture E


Rank %Pa (%) %Pa (%) (%)

E1 29.32 23.26 26.29 1

E2 32.42 30.02 31.22 3

E3 24.44 23.33 23.89 2

Table 4.19 shows the porosity test for mixture E. It illustrates that the lesser the


better.

Referring to Table 4.19, tile E1 has the least percent apparent porosity, meaning it

is less susceptible to be penetrated by liquids while tile E2 have the largest percent

apparent porosity, meaning it is more susceptible to be penetrated by liquids and vapors.

For this reason, tile E1 is selected to be compared with control tile F.


E1 versus control tile F.

Table 4.20 Summary of one-way ANOVA applied to tile E1 versus tile F

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 320.3 1 320.3


Group 1.173 2 0.5865

Total 375.6 3

55



rejected. Meaning, tile E1 differs significantly with control tile F in terms of porosity. But

for this sample, E1 has lesser percent apparent porosity than control tile F. Meaning, tile

E1 is less susceptible to the penetration of liquids than control tile F. This indicates that it

is feasible to make tiles with 0% concentration of calcium carbonate or silica sand and

with a bisquit firingproduct procedure if porosity is the only physical property to be

considered. The hardened clays after firing that make this group resistant to action of

liquids and vapors. But because it does not contain calcium carbonate or silica sand, the

tile is fragile.

In general, tiles A2 B1 and C3 are the tiles comparable with control tile F in terms

of porosity.

Table 4.21 shows the summary of results for the best tiles produced according to

the one-way ANOVA used.

Table 4.21 Summary of results for the best tiles produced

Tile* % Oyster Shells Impact Strength Porosity Decision

A2 40 Not Feasible Feasible Not Feasible

B1 50 Not Feasible Feasible Not Feasible

B3 50 Feasible Not Feasible Not Feasible

C3 60 Feasible Feasible Feasible *Firing Procedure: 1 - bisquit firingproduct 2 - glazingglost firingproduct

3 - bisquit firingglazingglost firingproduct

As shown in Table 4.21, it suggests that tile C3 is the most feasible experimental

tile because it is feasible in both impact strength and porosity test done. This means that it

56

is feasible to make tile with 60% concentration of calcium carbonate and with a bisquit

firingglazingglost firingproduct procedure.

However, as shown in Table 4.21, tiles A2, B1 and B3 are feasible in one physical

property only that is why the decision for its acceptance is not feasible. It is very

important that the produced tile pass all the tests for physical properties to achieve

quality.

It was also observed in the study that the lesser the calcium carbonate added to the

tile, the smaller the porosity. The lesser the percent apparent porosity means that the

susceptibility of the tile to absorb liquid or vapor is less. It is because calcium oxide

(from fired calcium carbonate) easily absorbs liquids like water to form hydroxides.

On the other hand, the greater the amount of calcium carbonate added to the tile,

the greater is the impact strength. The greater the impact strength means that the ability of

the tile to bear crushing load is better. It is because calcium carbonate reduces the drying

shrinkage, prevents cracking of the piece and act as a sort of skeleton to hold the shape of

the piece.

Table 4.22 shows the rough estimate of the costs of chemicals and equipment

utilized in the study.

57

Table 4.22 Cost of materials utilized in the study

Material Quantity Unit Price Price

Ball clay 1.00 kg P 15.00/kg P 15.00

Feldspar 4.20 kg 12.00/kg 50.40

Kaolin 2.00 kg 28.85/kg 47.70

Plaster of paris 18.0 kg 18.75/kg 337.50

Calcium carbonate 0.48 kg 21.50/kg 10.32

Sodium silicate 0.15 L 45.00/L 6.75

CMC 0.25 kg 174.00/kg 43.50

Firing Machine 1 pc 500.00/day 500.00

Total P 1,011.17

Referring at Table 4.22, it shows that the total cost of the study amounted to

roughly one thousand eleven and 17/100 pesos (P1,011.17). This amount was utilized in

the production of 60 pieces of tiles. Dividing the amount used in the study with the

number of tiles will give out 16.85. Meaning, if the tiles were to be sold, its unit price

would be P16.85/piece which is higher than the price of the commercial tiles which is

P12.50/piece. The difference would be P4.35.

The unit price may seem expensive but it should also be considered that the

plaster of paris mold can be used over and over again and the firing machine could fire

more than 60 tiles a day.

58

Chapter 5

CONCLUSION AND RECOMMENDATIONS

The main objective of the study is to investigate the feasibility of the Crassostrea

iredalei (oyster) shell as base for ceramic tile making. Specifically, it aimed to: (a) utilize

Crassostrea iredalei (oyster) shells as substitute to silicon dioxide (silica sand) in ceramic

tile making; (b) test the physical properties like impact strength and porosity of the

produced ceramic tiles; and (c) compare the ceramic tile made of Crassostrea iredalei

(oyster) shells to commercially available ones such as the Mariwasa Ceramic Tiles and

Floor Center Ceramic Tiles in terms of impact strength and porosity via One-Way

ANOVA.

Based on the statistical analysis, it was found out that utilizing Crassostrea

iredalei (oyster) shells as substitute to silicon dioxide (silica sand) in ceramic tile making

at a 60% substitution and with a bisquit firingglazingglost firingproduct firing

procedure is feasible. The produced tile is comparable with the commercial tiles like

Mariwasa Ceramic Tiles and Floor Center Ceramic Tiles in terms of impact strength

and porosity. The other percent substitution of calcium carbonate including the firing

procedure done is not as effective ad the 60% substitution.

To further enhance or modify this research study, the researchers throw the

following recommendations:

59

1) Utilize other test for the physical properties of the best tile produced.

2) The use of other tile body forming method like the dust press method or

the spray drying method;

3) Reformulation of the proportions of the calcium carbonate, ball clay,

feldspar and kaolin used.

60

BIBLIOGRAPHY

1 JEFE (2000). Downloaded on August 10, 2006 from

http://www.jefo.ca/fiches_anglais/oyster_shells.html

2 Britannica, 1978

3 Encyclopedia Britannica, Vol. 4, 1988

4 Jamaica Export Trading Company. Downloaded on October 24, 2006 from

http://www.exportjamaica.org/jetco/click.htm

5 University of Florida News (2004). Downloaded on August 10, 2006 from

http://www.napa.ufl.edu/2004news/oystertip.htm

6 Rx List (2005). Downloaded on August 10, 2006 from http://www.rxlist.com/drugs/drug-

20939Calcium+Oyster+Shell+Oral.aspx?drugid=20939&drugname=Calcium+Oyster+Shell+Oral

7 Planet Natural (2004). Downloaded on August 10, 2006 from

http://www.planetnatural.com/site/oyster-shell-lime.html

8 The World Book Encyclopedia, Vol. 16, 1958

9 Training Manual on Ceramic Artware Production published by the Rural Technology &

Information Division, Industrial Technology Development Institute, Department of

Science and Technology.

10 The Tile Doctor (2003). Downloaded on August 10, 2006 from

http://www.thetiledoctor.com/tile_manufac.cfm

11 Alibaba.com (1999). Downloaded on October 5, 2006 from

http://www.alibaba.com/catalog/11336587/Water_Washed_Lavigated_China_Clay_Kaol

in.html

12 (October 2001). China Raw Ball Clay QY-03 Chemical Analysis. Quezon City: Central

Ceramic Center.

13Wikipedia (2006). Downloaded on October 24, 2006 from

http://en.wikipedia.org/wiki/Silica

14 Production of Ceramic Artwares published by the Rural Technology & Information

Division, Industrial Technology Development Institute, Department of Science and

Technology.

15 Ceramic-tile.com (2003). Downloaded on August 10, 2006 from http://www.ceramic-

tile.com/class.cfm

61

16 Isidro, Reinier Augustus and Sheryll R. Jamito. 2006. Janitor Fishs Skin Reinforced

Concrete Blocks. Manila: Philippine Normal University Research Paper.

17 Camara, Paolo, Janssen Canicula, Rex Capuno, Don dela Cruz and Christopher

Sanguyo. 2001. Feasibility of Foam Polystyrene and Powdered Talaba Shells as Tiles.

Quezon City, Philippines: Philippine Science High School Research Paper.

62

APPENDIX A

Raw Data and Computations for Impact Strength Test

Impact Strength Test

Results of One-Way ANOVA

Group A

X = 143.3

Do the 2 groups of tiles differ in terms of impact strength?

Step 1: Ho = M1 = M2= the 2 groups of tiles do not differ in terms of impact strength

H1 = M1 M2 = the 2 groups of tiles do differ in terms of impact strength

Step 2: .05 level

Step 3: dfb = k-1 2-1 = 1

dfw = N-k = 4-2 = 2

Tile

Trial 1 Trial 2 Mean

Total Loads Loads

1(100g) 2(200g) 3(500g) Mean 1(100g) 2(200g) 3(500g) Mean

A1 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0

A2 40.0 30.0 20.0 30.0 30.0 30.0 20.0 26.7 28.4

A3 40.0 20.0 20.0 26.7 40.0 20.0 20.0 26.7 26.7

B1 40.0 30.0 20.0 30.0 40.0 20.0 20.0 26.7 56.7

B3 50.0 40.0 20.0 36.7 50.0 40.0 20.0 36.7 36.7

C1 40.0 20.0 20.0 26.7 40.0 20.0 20.0 26.7 26.7

C2 40.0 40.0 20.0 33.3 40.0 40.0 20.0 33.3 33.3

C3 50.0 50.0 20.0 40.0 50.0 40.0 20.0 36.7 38.4

E1 40.0 30.0 20.0 30.0 40.0 20.0 20.0 26.7 28.4

E2 20.0 20.0 20.0 20.0 20.0 20.0 10.0 16.6 18.3

E3 40.0 20.0 10.0 23.3 40.0 20.0 10.0 23.3 23.3

F 50.0 50.0 30.0 43.3 50.0 50.0 30.0 43.3 43.3

G 50.0 50.0 30.0 43.3 50.0 50.0 30.0 43.3 43.3

Trial A2 F/G

1 30.0 43.3

2 26.7 43.3

56.7 86.6

63

Step 4: DR: if F 13.51 reject Ho DR: if F < 13.51 accept Ho

X2 = 5361

Step 5: (5.1) total sum of squares

SSt = X2

_ ( X)2

N

= 5361 (143.3) 2

4

= 227.3

(5.2) sum of squares for between groups

SSb = ( X)2 + ( X)

2 - ( X)

2

n1 n2 N

= (30.0)2

+ (26.7) 2

+ (43.3)2

+ (43.3)2

- (143.3)

2

2 2 2 2 4

= 223.5

(5.3) sum of squares for w/in groups

SSw = SSt SSb = 227.3 223.5 = 3.8

(5.4) mean squares

* for between groups * for w/in groups

MSb = SSb MSw = SSw K-1 (2-1) N-k (4-2)

= 223.5 = 3.8

1 2

= 223.5 = 1.9

(5.5) F ratio

F = MSb

MSw

= 223.5

1.9

= 111.8

Trial A2 F/G

1 900 1874

2 713 1874

1613 3748

64

Step 6: Decision: Reject Ho

Step 7: The 2 groups of tiles differ in terms of impact strength

Summary Table

Group B

Trial B3 F/G

1 36.7 43.3

2 36.7 43.3

73.4 86.6

X=160.0




Step 2: .05 level

Step 3: dfb = k-1 2-1 = 1

dfw = N-k = 4-2 = 2


Trial B3 F/G

1 1347 1874

2 1347 1874

2694 3748

x2 = 6442

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 223.5 1 223.5


Group 3.800 2 1.9

Total 227.3 3

65


SSt = X2

_ ( X)2

N

= 6442 (160) 2

2

= 42


SSb = ( X)2 + ( X)

2 - ( X)

2

n1 n2 N

= (36.7)2

+ (36.76) 2

+ (43.3)2

+ (43.3)2

- (160)

2

2 2 2 2 4

= 223.5


SSw = SSt SSb = 42 43.56 = - 1.6

(5.4) mean squares



= 10.9 = 28.7

2 6

= 43.56 = - 0.8

(5.5) F ratio

F = MSb

MSw

= 43.56

-0.8

= - 54.45

Step 6: Decision: Accept Ho

Step 7: The 2 groups of tiles do not differ in terms of impact strength

66

Summary Table

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 43.56 1 43.56

-54.45 Not

Significant Within

Group -1.600 2 -0.8

Total 42.00 3

Group C

Trial C3 F/G

1 40.0 43.3

2 36.7 43.3

76.7 86.6

X=163.3


Step 1: Ho = M1 = M2= M3 = the 2 groups of tiles do not differ in terms of impact

strength

H1 = M1 M2 M3 = the 2 groups of tiles do differ in terms of impact strength

Step 2: .05 level

Step 3: dfb = k-1 2-1 = 1

dfw = N-k = 4-2 = 2


Trial C3 F/G

1 1600 1874

2 1347 1874

2947 3748

x2 = 6695


SSt = X2

_ ( X)2

N

= 6695 (163.3) 2

4

= 28.3

67


SSb = ( X)2 + ( X)

2 - ( X)

2

n1 n2 N

= (40.0)2

+ (36.7) 2

+ (43.3)2

+ (43.3)2

- (163.3)

2

2 2 2 2 4

= 223.5


SSw = SSt SSb =28.3 24.5 = 3.8

(5.4) mean squares



= 24.5 = 3.8

1 2

= 24.5 = 1.9

(5.5) F ratio

F = MSb

MSw

= 24.5

1.9

= 12.89

Step 6: Decision: Accept Ho

Step 7: The 2 groups of tiles do not differ in terms of impact strength

Summary Table

Source of

variation

Sum of

Squares

df Mean

Squares


Between

Groups 24.50 1 24.50

12.89 Not

Significant Within

Group 3.800 2 1.900

Total 28.30 3

68

Group E

Trial E1 F/G

1 40.0 43.3

2 36.7 43.3

76.7 86.6

X=143.3




Step 2: .05 level

Step 3: dfb = k-1 2-1 = 1

dfw = N-k = 4-2 = 2


Trial E1 F/G

1 900 1874

2 713 1874

1613 3748

x2 = 5361


SSt = X2

_ ( X)2

N

= 5361 (143.3) 2

4

= 227.3


SSb = ( X)2 + ( X)

2 - ( X)

2

n1 n2 N

= (30.0)2

+ (26.7) 2

+ (43.3)2

+ (43.3)2

- (143.3)

2

2 2 2 2 4

= 223.5


SSw = SSt SSb =28.3 24.5 = 3.8

69

(5.

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