Application Of Bio-Glycol To Inhibit Natural Pressure Loss In Automotive Type.
Master of Science in Manufacturing Engineering
Faculty of Manufacturing Engineering
APPLICATION OF BIO-GLYCOL TO INHIBIT NATURAL
PRESSURE LOSS IN AUTOMOTIVE TYPE
Raguvaran a/l Jayahkudy
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APPLICATION OF BIO-GLYCOL TO INHIBIT NATURAL PRESSURE LOSS IN AN AUTOMOTIVE TYRE
RAGUVARAN A/L JAYAHKUDY
A thesis submitted
in fulfillment of the requirements for the degree ofMaster of Science in Manufacturing Engineering
Faculty of Manufacturing Engineering
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
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DECLARATION
I declare that this thesis entitled “Application of Bio-Glycol to Inhibit Natural Pressure Loss in Automotive Tyre” is the result of my own research except as cited in the references. The thesis has not been accepted for any degree and is concurrently submitted in candidature of any other degree.
Signature : ……… Name : Raguvaran a/l Jayahkudy Date : 14/7/2016
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APPROVAL
I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms of scope and quality for the award for the award of Master of Science in Manufacturing Engineering.
Signature : ………..
Supervisor Name : Prof. Ir. Dr. Sivarao Subramonian Date : 14/7/2016
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DEDICATION
This thesis is dedicated to my beloved parents, for all the continuous support that you have given to me.
To my beloved friends,
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i ABSTRACT
Automotive tyre plays an imperative aspect in ensuring safety, economical and performance of a motor vehicle which indeed the only medium that merge the contact between a car and asphalt. According to studies and statistics by giant tyre manufacturers, one of the primary reasons for major road accidents which often leads to loss of life is the catastrophic tyre failure caused by vehicles running with improper tyre pressure due to lack of attention on tyre maintenance. The phenomena where tyre loses pressure naturally and contracts over time is called air permeation, which is identified to be the main cause of tyre to deflate but rarely can be realised by naked eyes. Properly inflated tyres can safe tyre life up to 20% which is equivalent to nine months of its life span, save fuel from 4% to 10%, increase braking efficiency up to 20%, lightens steering system and ease self-steer. Since the day pneumatic tyres were invented, sudden losses of air acts as a major problem associated with tyres and are still being treated by professional tyre researchers. Besides external punctures which cause tyre deflation, other crucial factors which contribute to natural pressure loss are investigated in this study such as the properties of inflated air, pressure leak through mechanical fittings and ultimately excessive tyre operating temperature which promotes air permeability over time. Fundamental experimentation to study the behaviour and characteristic of pressure loss of a normal tyre was conducted in both static and dynamic conditions where they were also tested with and without loaded situation to extract precise data of the pressure loss. It is noticed that a normal tyre losses 5kPa to 10kPa of pressure a month at static condition and 15kPa to 20kPa at dynamic condition. Nowadays, usage of tyre sealants which contains Ethylene Glycol or Propylene Glycol as a countermeasure to curb the issue becomes an ideal solution and current trend but reflects several drawbacks namely on the performance, properties and characteristic of the sealant. In order to improvise the currently available solution, a relevant bio-based additive sealant that tailor to the situation have been initiated using Bio-Glycol as a way forward total solution suiting a wide range of tyres used on domestic cars sequentially sustaining the tyre pressure and further reducing the natural air permeation rate to stop tyre deflation by means of controlling the tyre operating temperature. The proposed solution have been further tested comprehensively in a dynamic condition along other available solution in the market with aid of Tyre Pressure Monitoring System (TPMS), which then leads to the development of a data logging structure of each tyre pressure and temperature using LabVIEW graphical user interface. Concurrently, the physical and chemical properties of the solution have been generated as a validation to reflect its basic performance. Finally, the proposed solution shows promising result in controlling tyre temperature and ultimately reducing tyre pressure loss over time subsequently meeting the standard regulation of a proper tyre sealant.
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ii ABSTRAK
Tayar memainkan peranan yang amat penting bagi memastikan pemanduan yang selamat, ekonomikal dan prestasi kenderaan bermotor dimana ianya merupakan satu-satunya medium yang bersentuhan dengan permukaan jalanraya. Merujuk kepada pengkajian dan statistik oleh pengeluar tayar terkemuka, antara faktor utama yang mengakibatkan kemalangan jalanraya sehingga menyebabkan kematian adalah berpunca daripada kenderaan yang beroperasi tanpa tekanan tayar yang betul akibat kelalaian pengguna yang mengabaikan kepentingan tekanan tayar. Fenomena dimana tayar mengalami kehilangan tekanan secara semula-jadi berkadar masa dipanggil kebolehtelapan angin dan ia dikenalpasti sabagai punca utama tayar kempis dimana ia susah untuk disedari dengan hanya memerhati menggunakan mata kasar. Tekanan angin yang mencukupi dalam tayar dapat memanjangkan hayat tayar sehingga 20% (bersamaan dengan 9 bulan), menjimatkan penggunaan bahanapi daripada 4% ke 10%, meningkatkan kecekapan brek sehingga 20% dan meringankan stering dan sistem balasnya. Sejak bermulanya era penggunaan tayar, kehilangan tekanan angin menjadi masalah utama tayar dan masih dalam penyelidikan oleh para pengkaji tayar sehingga ke hari ini. Selain daripada faktor tindakan luar yang mengakibatkan tayar kempis, beberapa punca utama mengakibatkan kehilangan tekanan angin secara semula-jadi telah dikaji antaranya komposisi kandungan angin dalam tayar, kehilangan angin melalui kelengkapan mekanikal dan terutamanya suhu operasi tayar yang tinggi. Eksperimentasi asas bagi mengkaji ciri-ciri sesebuah tayar telah dibuat dalam kedua-dua situasi iaitu statik dan dinamik dibawah pengaruh beban untuk mengekstrak data kehilangan tekanan angin secara tepat dan jitu. Berdasarkan esxperimen tersebut, tayar biasa mengalami kadar kehilangan angin daripada 5kPa ke 10kPa sebulan dalam situasi statik manakala 15kPa ke 20kPa sebulan dalam situasi dinamik. Penggunaan ‘sealant’ tayar yang mengandungi samaada “Ethylene Glycol” atau “Propylene Glycol” sebagai agen untuk menangani masalah kehilangan tekanan angin tayar amat berleluasa pada masa kini tetapi ia juga terdapat kekurangannya tersendiri dari segi prestasi dan ciri-cirinya. Rumusan baru telah dicipta iaitu ‘sealant’ berdasarkan bahan tambahan-bio menggunakan “Bio-Glycol”bagi mengatasi kekurangan prestasi ‘sealant’ tayar yang sedia ada dengan hanya mengawal suhu operasi tayar. Rumusan ini kemudiannya dikaji dalam situasi dinamik bagi mendapatkan perbezaan dengan rumusan yang sediaada dengan bantuan alat yang dipanggil sistem pengawasan tekanan angin tayar (TPMS) yang menjurus kepada ciptaan suatu sistem bagi merekod data tekanan angin dan suhu tayar menggunakan perisian grafik “LabVIEW”. Justeru itu, ciri-ciri fizikal dan kimia solusi tersebut telah dikaji sebagai pengesahan kebolehgunaan solusi tersebut. Akhir sekali, solusi yang telah dicipta menunjukkan prestasi yang amat memuaskan dalam mengawal suhu operasi tayar sekaligus mengurangkan kehilangan angin dalam tayar selaras dengan standard yang ditetapkan bagi penghasilan sesebuah ‘sealant’ tayar.
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iii
ACKNOWLEDGEMENTS
First and foremost, I would like to take this opportunity to express my sincere gratitude to my principal supervisor Professor Ir. Dr. Sivarao Subramonian and my co-supervisor Professor Dr. Qumrul Ahsan from the Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka (UTeM) for their indispensable guidance, assistance and encouragement.
I would also like to assert my genuine appreciation to the top management of UTeM, namely Vice Chancellor, Deputy Vice Chancellor (Research & Innovation) as well as Deputy Vice Chancellor (Academic & Internationalization) where the same is extended to the Dean of Centre of Graduate Studies, Associate Professor Dr. Zulkifilie Bin Ibrahim and the Director of Centre for Research and Innovation Management (CRIM), Associate Professor Dr. Badrul Hisham Bin Ahmad and not forgetting the Ministry of Higher Education for awarding MyBrain KPT scholarship which enabled the successful progression of this critical research.
I would also like to express my sincere recognition and gratitude to the Dean; Associate Professor Dr. Mohd Rizal Bin Salleh and Deputy Dean; Associate Professor Dr. Hambali Bin Arep @ Ariff from the Faculty of Manufacturing Engineering. Exclusive credit goes to Mr.Damien Hallez Gozard from Michelin Tyres Group of Technical Communication, Mr.Noorez Devraj from Lyna Manufacturing Incorporation, Dr. Letchumi Thannimalay
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from SIRIM Berhad; and not forgetting the entire staff and technician for their continuous advice along with crucial technical support.
Last but not least, special thanks to all my peers and postgraduates for their unceasing moral support aid in completing this valuable research.
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v
TABLE OF CONTENTS
PAGE DECLARATION APPROVAL DEDICATION ABSTRACT i ABSTRAK ii ACKNOWLEDGEMENTS iii
TABLE OF CONTENTS v
LIST OF TABLES vii
LIST OF FIGURES viii
LIST OF APPENDICES xii
LIST OF ABBREVIATIONS xiii
LIST OF PUBLICATIONS xvi
CHAPTER
1. INTRODUCTION 1
1.1 Background 1
1.2 Problem Statement 2
1.3 Research Objectives 4
1.4 Research Scope 4
1.5 Thesis Organization 4
2. LITERATURE REVIEW 5
2.1 Tyre History 5
2.2 Tyre Structure 7
2.3 Tyre Materials 8
2.4 Tyre Safety 9
2.5 Proper Tyre Inflation 11
2.6 Tyre Air Permeation 13
2.6.1 Temperature which Promotes Air Permeability 15 2.6.2
2.6.3
Properties of Inflated Air
Pressure Leaks through Mechanical Fittings
18 25
2.7 Tyre Sealant 26
2.7.1 Ethylene Glycol 31
2.7.2 Propylene Glycol 32
2.7.3 Bio-Glycol 32
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3. METHODOLOGY 34
3.1 Tyre Inner Liner Porosity Observation 36
3.2 Characterization of Tyre Sealants and Glycols 38
3.3 Tyre Air Permeability Test 40
3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 Static-Unloaded Condition Static-Loaded Condition Dynamic-Loaded Condition
Dynamic-Loaded Condition (without additive) Preparation for Sealant Solution
Generation of Sealant Properties (Physical and Chemical) Dynamic-Loaded Condition (with additive)
40 41 42 46 46 48 48
3.4 Experimental Validation 49
3.5 Summary 50
4. RESULTS AND DISCUSSION 51
4.1 Analysis of Tyre Inner Liner Porosity 51
4.2 Analysis of Tyre Sealants and Glycols Characterization 55 4.3 Results of Tyre Air Permeability on Static-Unloaded Condition 61 4.4 Results of Tyre Air Permeability on Static-Loaded Condition 62 4.5 Results of Tyre Air Permeability on Dynamic-Loaded Condition
(without additive)
64 4.6
4.7 4.8
Analysis of Prepared Sealant Solutions
Analysis of Physical and Chemical Properties of Solution
Analysis of Tyre Air Permeability on Dynamic-Loaded Condition (with additive)
71 72 73
4.9 Performance Validation 85
4.10 Summary 86
5. CONCLUSION AND RECOMMENDATIONS FOR FUTURE RESEARCH
88
5.1 Conclusion 89
5.2 Recommendations 89
REFERENCES 91 APPENDICES 105
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vii
LIST OF TABLES
TABLE TITLE PAGE 2.1 Air Permeability Literature Values of Various Inner-Liners 18 2.2 Prescribed Dosage of Tyre Sealant per Wheel 27
2.3 Type of Glycols Used in Tyre Sealant 30
3.1 Type of Experiments to Generate Sealant Properties 48 4.1 Information on Tyre Sealant Ingredients Based on MSDS 55 4.2 Observed Pressure Losses over Months in Static-Unloaded Condition 61 4.3 Observed Pressure Losses over Months in Static-Loaded Condition 62
4.4
Comparison of Tyre Pressure for Dynamic-Loaded Condition (without additive)
69
4.5
Comparison of Physical and Chemical Properties of Original Tyre Sealant “B” and Tyre Sealant “B” with Bio-Glycol
72
4.6
Tyre Pressure Over Days Throughout the Dynamic-Loaded Condition (with additive)
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viii
LIST OF FIGURES
FIGURE TITLE PAGE
2.1 Evolution of Pneumatic Tyre 6
2.2 Cross-Section View of a Radial Tyre Structure 7
2.3 Ingredient Fractions of a Radial Tyre 9
2.4
Statistical Observations (a) Increase of Road Fatalities over the Years and (b) Primary Crash Contributing Factors of Recorded 439 Cases in 2012
10
2.5 Monitored Tyre Pressure via TIC in Hamilton, UK 2002 12 2.6 Effect of Various Inflation Pressure on the Tyre-Road Contact 13
2.7 Air Permeability in the Tyre Compound 14
2.8 Tyre Pressure Loss Operation Cycle upon Excessive Heat 15
2.9
Thermo-Graphic Images of Tyres Operating with Decreased Air Pressure
17
2.10
Contour Plot of Average Temperature of the Tread and Sidewall during Dynamic Condition
17
2.11 Tyre Section Measurements 22
2.12 Corroded Rim Flange and Valve 25
2.13 Rubber-Type Valve Stem Cracks 26
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2.15 Total Percentage of Type of Glycols Used in Tyre Sealant 31
3.1 Flow Chart of Research Methodology 35
3.2 Butyl Inner Liners 36
3.3 Coated Inner Liner Samples using Mini Sputter Coater 37 3.4 Setup of a Scanning Electron Microscopy (SEM) Machine 37
3.5 Types of Tyre Sealant 38
3.6 Types of Pure Glycols 39
3.7 Setup of a Fourier Transform Infrared Spectroscopy (FTIR) Machine 39
3.8 Static-Unloaded Test Rig 41
3.9 Setup of a Static-Loaded Condition 41
3.10 Basic TPMS Setup on a Vehicle 42
3.11 TPMS Sensor and Receiver Specifications 43 3.12 Flow Chart of the Developed Data-Logging System 44
3.13 Setup of a Dynamic-Loaded Condition 45
3.14 Sealants with Glycol Additives 47
3.15 Setup of Sealants in a Shaking Incubator 47
4.1 Magnification of Tyre New Inner Liner 52
4.2 Magnification Inner Liner Operated After 2500km 53 4.3 Magnification Inner Liner Operated After 5000km 54
4.4 FTIR Spectrum of Pure Ethylene Glycol 56
4.5 FTIR Spectrum of Pure Bio-Glycol 57
4.6 FTIR Spectrum of Pure Propylene Glycol 57
4.7 FTIR Spectrum of Tyre Sealant “A” 58
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4.9 FTIR Spectrum of Tyre Sealant “C” 60
4.10 Tyre Pressure Losses over Months in the Static-Unloaded Condition 61 4.11 Tyre Pressure Losses over Months in a Static-Loaded Condition 63 4.12 Layouts of Inserted Sealants on Respective Tyres 64 4.13 Tyre Operating Temperature vs. Time (1st Attempt) 65 4.14 Tyre Operating Pressure vs. Time (1st Attempt) 65 4.15 Tyre Operating Temperature vs. Time (2nd Attempt) 66 4.16 Tyre Operating Pressure vs. Time (2nd Attempt) 67 4.17 Tyre Operating Temperature vs. Time (3rd Attempt) 68 4.18 Tyre Operating Pressure vs. Time (3rd Attempt) 68 4.19 Respective Sealant Capabilities of Coating Tyre Inner Liner 70 4.20 Processed Solutions without Sedimentation or Separation 71
4.21
Layouts of Formulated Sealant Solutions Inserted on Respective Tyres
74
4.22
Tyre Operating Temperature vs. Time (1st Attempt) Dynamic-Loaded Test with Additive
75
4.23
Tyre Operating Pressure vs. Time (1st Attempt) Dynamic-Loaded Test with Additive
75
4.24
Tyre Operating Temperature vs. Time (2nd Attempt) Dynamic-Loaded Test with Additive
77
4.25
Tyre Operating Pressure vs. Time (2nd Attempt) Dynamic-Loaded Test with Additive
77
4.26
Tyre Operating Temperature vs. Time (3rd Attempt) Dynamic-Loaded Test with Additive
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xi 4.27
Tyre Operating Pressure vs. Time (3rd Attempt) Dynamic-Loaded Test with Additive
79
4.28
Tyre Operating Temperature vs. Time (4th Attempt) Dynamic-Loaded Test with Additive
81
4.29
Tyre Operating Pressure vs. Time (4th Attempt) Dynamic-Loaded Test with Additive
81
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A MSDS of Tyre Sealant “A” 103
B MSDS of Tyre Sealant “B” 108
C MSDS of Tyre Sealant “C” 113
D MSDS of Pure Ethylene Glycol 116
E MSDS of Pure Bio-Glycol 123
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xiii
LIST OF ABBREVIATIONS
oC - Degree Celsius oF - Degree Fahrenheit
% - Percentage
A - Surface area
ASCII - American Standard Code for Information Interchange ASTM - American Society for Testing and Materials
BG - Bio-Glycol
BIIR - Bromo-butyl
cc - Cubic centimetres
cm - Centimetre
COM-Port - Communication Port
cP - Centipoises
D - Coefficient of diffusion EG - Ethylene Glycol
FTIR - Fourier Transform Infrared Spectroscopy
g - Gram
IRTAD - Malaysian International Traffic Safety Data and Analysis Group
K - Kelvin
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xiv
km - Kilometre
km/h - Kilometre per hour
kPa - Kilopascal
l - Tyre inner-casing material thickness
LabVIEW - Laboratory Virtual Instrumentation Engineering Workbench
M - Molecules
MIROS - Malaysian Institute of Road Safety Research
ml - Millilitre
mm - Millimetre
MSDS - Material Safety Data Sheet
N2 - Nitrogen
n ’’ - Rate of outward flux inflation
n - Number of moles
NHTSA - U.S. National Highway Traffic Safety Administration
NR - Natural Rubber
O2 - Oxygen
P - Pressure
Pa - Pascal
PG - Propylene Glycol
PN2 - Permeability of Nitrogen
PO2 - Permeability of Oxygen psi - Pounds per square inch
Q - Permeability
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S - Solubility
SEM - Scanning Electron Microscopy STP - Standard Temperature and Pressure
T - Temperature
TIC - Trinity Inclusive Curriculum
tm - Number of seconds in a month
TPMS - Tyre Pressure Monitoring System
V - Volume
Vm - Volume of mole
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xvi
LIST OF PUBLICATIONS
1. Way Forward to Halt Pressure Loss in Automotive Tyres. Applied Mechanics and
Materials, 761 (2015), pp.510-514. (SCOPUS Indexed - Published)
2. Air Permeability Investigation towards Automotive Tyre Pressure Sustainability and Life Saving. ARPN Journal of Engineering and Applied Sciences, 10 (10), pp.4404-4412. (SCOPUS Indexed - Published)
3. Design of Novel Pressure Replenishing System to Sustain Automobile Tyre Pressure without Human Intervention. International Journal of Applied Engineering Research, 10 (10), pp.26295-26306 (SCOPUS Indexed - Published)
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1 CHAPTER 1
INTRODUCTION
This chapter describes the background of the research and explains briefly the problem statements, objectives and scope of this research. This chapter also includes the organization of the thesis report.
1.1 Background
Automotive tyres are basically made of natural and synthetic rubber and their hybridization provides comfort, as well as ensures safety in different types of road conditions and operational temperature. The only medium that transfers the whole lot of vehicle load onto the road is the tyre. As tyres are supported by the wheels, they provide a cushion between the road and the vehicle suspension. Besides, they also provide traction for both acceleration and braking; resist lateral forces for safe cornering, stability and better handling. With the assistance of the air pressure inside them, tyres are responsible in providing support for the overall weight of a vehicle as claimed by Haraguchi (2006).
Automobile tyres naturally undergo gas escapism due to several causes, which then require regular inflating to replace the air loss and to sustain proper tyre pressure. Tyre pressure drops mainly due to pressure loss or air escapism from the tyre. Beside tyre quality and tyre materials, improper tyre pressure is the main factor that leads to catastrophic tyre failure and eventually resulting in major road accidents as stated by Dosjoub (1988) and Litchfield (2001). Furthermore, Sivarao et al. (2009) clarify that every
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2
20 kilopascal pressure drop in a tyre is equivalent to adding a virtual 70 kilogram person into the car which indirectly results in excessive tyre wear and serious road accidents due to poor control and stability of the car. Micro molecular gases can easily escape to the atmosphere from a pressurized vessel through the interface fittings and absorption through porous materials. Sivarao et al. (2009) found that an automobile tyre naturally releases about 10kPa to 20kPa of pressure every month regardless of tyre brand used. Excessive tyre operating temperature is noticed to be one of the primary factors affecting natural tyre pressure loss which is also known as air permeation (Karmarkar et al. 2010).
Therefore, tyre sealants are widely used by vehicle owners not only to seal any external punctures but also used as a laminating medium to reduce pressure loss through the tyre. Most of the sealants produced are glycol-based; they either use Ethylene Glycol or Propylene Glycol which act as heat transfer fluids to reduce the air loss from the tyre by means of controlling excessive tyre operating temperature. A totally new Bio-based additive sealant using Bio-Glycol which is derived totally from corn has been initiated as a solution to improvise currently available sealant performance by controlling excessive tyre operating temperature and ultimately reducing tyre pressure loss. Nevertheless, this proposed solution is non-toxic and fully bio-degradable. Besides, it has non-petroleum content and corrosion inhibited sealant which downsizes the performance gap between the tyre sealant using Ethylene Glycol and Propylene Glycol thus suiting a wide range of tyres used on domestic cars.
1.2 Problem Statement
Under inflated tyres lead to excessive load concentrated on it. Investigations by giant tyre manufacturers reveal that underinflated tyres are virtually overloaded in the
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3
absence of passengers in the car thus increasing the fuel consumption, reducing braking efficiency and tyre life. The improper tyre inflation hazard does not stops here; it goes a step ahead where the excessive heat generated due to the overloaded condition between the road is dissipated to the tyre. This heat accumulation then leads into the fatigue region and exposes the tyre to the risk of explosion hence resulting in accidents due to loss of control (Abdullah et al., 2013). Since automobile tyres are not able to sustain pressure for a longer period due to natural pressure losses, tyre sealants have become a popular solution and are in demand nowadays. The usage of glycol-based tyre sealants for the purpose of sustaining tyre pressure has begun since 1969. Two primary types of glycol based tyre sealants are either from Ethylene Glycol or Propylene Glycol. Unfortunately, both these glycol reflect several drawbacks namely on the performance, properties, cost and characteristics of the sealant (Dianyi, 2007). Ethylene Glycol based sealant contains a high toxicity level which is harmful to users but it is cheap and performs better than Propylene Glycol. On the other hand, Propylene Glycol contains lower toxicity level but is expensive and performs less efficient than Ethylene Glycol. Since, controlling excessive tyre temperature has high potentials in sustaining tyre pressure, a scientific approach is to be formulated to investigate systematically with elements involving experimentation, optimization, and validation in order to provide the industry with an improvised outcome in tyre sealant quality.
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xiv
km - Kilometre
km/h - Kilometre per hour
kPa - Kilopascal
l - Tyre inner-casing material thickness
LabVIEW - Laboratory Virtual Instrumentation Engineering Workbench
M - Molecules
MIROS - Malaysian Institute of Road Safety Research
ml - Millilitre
mm - Millimetre
MSDS - Material Safety Data Sheet
N2 - Nitrogen
n ’’ - Rate of outward flux inflation
n - Number of moles
NHTSA - U.S. National Highway Traffic Safety Administration
NR - Natural Rubber
O2 - Oxygen
P - Pressure
Pa - Pascal
PG - Propylene Glycol PN2 - Permeability of Nitrogen
PO2 - Permeability of Oxygen
psi - Pounds per square inch
Q - Permeability
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S - Solubility
SEM - Scanning Electron Microscopy STP - Standard Temperature and Pressure
T - Temperature
TIC - Trinity Inclusive Curriculum tm - Number of seconds in a month TPMS - Tyre Pressure Monitoring System
V - Volume
Vm - Volume of mole
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xvi
LIST OF PUBLICATIONS
1. Way Forward to Halt Pressure Loss in Automotive Tyres. Applied Mechanics and Materials, 761 (2015), pp.510-514. (SCOPUS Indexed - Published)
2. Air Permeability Investigation towards Automotive Tyre Pressure Sustainability and Life Saving. ARPN Journal of Engineering and Applied Sciences, 10 (10), pp.4404-4412. (SCOPUS Indexed - Published)
3. Design of Novel Pressure Replenishing System to Sustain Automobile Tyre Pressure without Human Intervention. International Journal of Applied Engineering Research, 10 (10), pp.26295-26306 (SCOPUS Indexed - Published)
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1
CHAPTER 1
INTRODUCTION
This chapter describes the background of the research and explains briefly the problem statements, objectives and scope of this research. This chapter also includes the organization of the thesis report.
1.1 Background
Automotive tyres are basically made of natural and synthetic rubber and their hybridization provides comfort, as well as ensures safety in different types of road conditions and operational temperature. The only medium that transfers the whole lot of vehicle load onto the road is the tyre. As tyres are supported by the wheels, they provide a cushion between the road and the vehicle suspension. Besides, they also provide traction for both acceleration and braking; resist lateral forces for safe cornering, stability and better handling. With the assistance of the air pressure inside them, tyres are responsible in providing support for the overall weight of a vehicle as claimed by Haraguchi (2006).
Automobile tyres naturally undergo gas escapism due to several causes, which then require regular inflating to replace the air loss and to sustain proper tyre pressure. Tyre pressure drops mainly due to pressure loss or air escapism from the tyre. Beside tyre quality and tyre materials, improper tyre pressure is the main factor that leads to catastrophic tyre failure and eventually resulting in major road accidents as stated by Dosjoub (1988) and Litchfield (2001). Furthermore, Sivarao et al. (2009) clarify that every
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2
20 kilopascal pressure drop in a tyre is equivalent to adding a virtual 70 kilogram person into the car which indirectly results in excessive tyre wear and serious road accidents due to poor control and stability of the car. Micro molecular gases can easily escape to the atmosphere from a pressurized vessel through the interface fittings and absorption through porous materials. Sivarao et al. (2009) found that an automobile tyre naturally releases about 10kPa to 20kPa of pressure every month regardless of tyre brand used. Excessive tyre operating temperature is noticed to be one of the primary factors affecting natural tyre pressure loss which is also known as air permeation (Karmarkar et al. 2010).
Therefore, tyre sealants are widely used by vehicle owners not only to seal any external punctures but also used as a laminating medium to reduce pressure loss through the tyre. Most of the sealants produced are glycol-based; they either use Ethylene Glycol or Propylene Glycol which act as heat transfer fluids to reduce the air loss from the tyre by means of controlling excessive tyre operating temperature. A totally new Bio-based additive sealant using Bio-Glycol which is derived totally from corn has been initiated as a solution to improvise currently available sealant performance by controlling excessive tyre operating temperature and ultimately reducing tyre pressure loss. Nevertheless, this proposed solution is non-toxic and fully bio-degradable. Besides, it has non-petroleum content and corrosion inhibited sealant which downsizes the performance gap between the tyre sealant using Ethylene Glycol and Propylene Glycol thus suiting a wide range of tyres used on domestic cars.
1.2 Problem Statement
Under inflated tyres lead to excessive load concentrated on it. Investigations by giant tyre manufacturers reveal that underinflated tyres are virtually overloaded in the
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3
absence of passengers in the car thus increasing the fuel consumption, reducing braking efficiency and tyre life. The improper tyre inflation hazard does not stops here; it goes a step ahead where the excessive heat generated due to the overloaded condition between the road is dissipated to the tyre. This heat accumulation then leads into the fatigue region and exposes the tyre to the risk of explosion hence resulting in accidents due to loss of control (Abdullah et al., 2013). Since automobile tyres are not able to sustain pressure for a longer period due to natural pressure losses, tyre sealants have become a popular solution and are in demand nowadays. The usage of glycol-based tyre sealants for the purpose of sustaining tyre pressure has begun since 1969. Two primary types of glycol based tyre sealants are either from Ethylene Glycol or Propylene Glycol. Unfortunately, both these glycol reflect several drawbacks namely on the performance, properties, cost and characteristics of the sealant (Dianyi, 2007). Ethylene Glycol based sealant contains a high toxicity level which is harmful to users but it is cheap and performs better than Propylene Glycol. On the other hand, Propylene Glycol contains lower toxicity level but is expensive and performs less efficient than Ethylene Glycol. Since, controlling excessive tyre temperature has high potentials in sustaining tyre pressure, a scientific approach is to be formulated to investigate systematically with elements involving experimentation, optimization, and validation in order to provide the industry with an improvised outcome in tyre sealant quality.