The Effects of Process Parameters In Injection Moulding On Surface Quality Of A Polypropylene (PP) Component.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJUK: The Effects of Process Parameters in Injection Moulding On Surface Quality of a Polypropylene (PP) Component
SESI PENGAJIAN: 2010/11 Semester 2 Saya MUHAMMAD AIMAN BIN YUSOF
mengaku membenarkan Laporan PSM ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut: 1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan
untuk tujuan pengajian sahaja dengan izin penulis.
3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan pertukaran antara institusi pengajian tinggi.
4. **Sila tandakan (√)
SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia yang termaktub di dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
Alamat Tetap:
1, Lot 8842, Kg. Perak Spg. Tiga, 34200 Parit Buntar,
Perak Darul Ridzuan. Tarikh: 18 MAY 2011
Disahkan oleh:
PENYELIA PSM
Tarikh: 18 MAY 2011
** Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai SULIT atau TERHAD.
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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
THE EFFECTS OF PROCESS PARAMETERS IN INJECTION
MOULDING ON SURFACE QUALITY OF A POLYPROPYLENE
(PP) COMPONENT
This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering
(Manufacturing Process)
by
MUHAMMAD AIMAN BIN YUSOF B050710130
FACULTY OF MANUFACTURING ENGINEERING 2011
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DECLARATION
I hereby, declared this report entitled “The Effect of Process Parameter in Injection Moulding on Surface Quality of Polypropylene (PP) Component” is the results of my
own research except as cited in references.
Signature : ………....
Author’s Name : MUHAMMAD AIMAN BIN YUSOF
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APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Manufacturing Process). The members of the supervisory committee is as follow:
……… Supervisor
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ABSTRAK
Kajian yg bertajuk “The Effect Of Process Parameter In Injection Moulding On Surface Quality Of Polypropylene (PP) Component” ini adalah untuk mengenalpasti proses parameter dalam „injection moulding‟ yang mempengaruhi kualtiti permukaan bahan Polypropylene (PP). Proses „injection moulding‟ telah dipelajari secara menyeluruh dalam usaha untuk membuat produk plastik pada kualiti bahan yg terbaik. Mesin „Arburg Injection Moulding‟ adalah instrumen yang digunakan untuk proses menghasilkan spesimen Bekas Sabun dan spesimen 'Dog Bone' sebagai produk kajian. Beberapa parameter „injection moulding‟ yang mempengaruhi kuality permukaan bahan kerja seperti „Injection Pressure‟, „Mould Temperature‟, „Packing Pressure‟, „Melt Temperature‟ serta proses parameter lain seperti „injection speed‟, dan ,‟cooling time‟ juga diuji dalam kajian ini. „Design of Experiment‟ digunakan untuk tujuan mendapatkan susunan parameter yang terbaik dan mengurangkan bilangan ujikaji yang perlu dijalankan. „Taguchi Method‟ adalah yang paling sesuai dan dipilih untuk melakukan kajian ini. Kaedah ini dapat mengenalpasti proses parameter yang sangat memberi kesan dan mempengaruhi kualiti permukaan produk. Ciri-ciri kecatatan permukaan yang dipilih adalah kekasaran permukaan dan kualiti permukaan akhir. Kekasaran permukaan dapat diukur dengan menggunakan „Surface Roughness Tester‟. Selain itu, sifat kekuatan daya tarik bahan Polypropylene (PP) juga diukur dengan menggunakan „Universal Testing Machine‟ (UTM). Nilai maksimum dari kekuatan daya tarik ini akan dikenalpasti mengikut proses ujian. Parameter proses yang memberi kesan paling ketara terhadap kualiti permukaan produk dan kekuatan daya tarik mampu dioptimumkan dan berjaya mendapat parameter proses yang terbaik untuk bahan polypropylene (PP) ini.
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ABSTRACT
This project is to study “The Effect of Process Parameter in Injection Moulding on Surface Quality of Polypropylene (PP) Component”. This injection moulding process was studied extensively in attempt to create plastic component at the highest quality possible. The Arburg Allrounder Injection Moulding was the instrument used for the moulding process to produce the „Soap Container‟ and „Dog Bone‟ Specimen as a product. There are various parameter of injection moulding involve such as Injection Pressure, Packing Pressure, Clamping force, Melt Temperature as well as other processing parameter such as injection speed and cooling time were tested. In order to optimum the parameter setting with the least amount of experiments, the theories of the Design of Experiment (DOE) is used. Selection of The Taguchi Method is applied to perform screening experiments to identify the important significant process parameters affecting quality of the surface moulding product. The process parameter has selected to use in the injection moulding process base on Taguchi Method that applied. The surface quality characteristics chosen are surface roughness and surface finish. Surface roughness can be measured by using Portable Surface Roughness tester. Tensile properties of the Polypropylene (PP) were measure by using the Universal Testing Machine (UTM) were determined. Maximum value of the tensile strength will be find base on the tensile testing process. The process parameter has a significant effect to surface quality and tensile strength was able to optimize and successful for this polypropylene (PP) material.
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ACKNOWLEDGEMENT
Bismillahirrahmanirrahim,
Alhamdulillah, thanks to Allah with all His Gracious and His Merciful for giving me a chance to finish up my final project report until this end of point. First of all, I would like to take the utmost opportunity to express my sincere and gratitude to my supervisor, Dr. Nur Izan Syahriah Binti Hussein who is always giving me supports and guidance in completing this „Projek Sarjana Muda‟. I am very grateful with the co-operation given from all of my friends. Besides, thanks a lot to all lecturers and staffs of Faculty of Manufacturing Engineering.
The greatest thanks to my beloved parents and family who always pray and give the encouragement while pursuing my research and project. Their sacrifices are never being forgotten.
Last but not least, to all BMFP‟s members for their never ending social support and always lending a helping hand whenever I need them. I really thankful and appreciate it.
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DEDICATION
To my beloved parents, my Father, Yusof Bin Hj Awang and my Mother, Nor Lela Binti Hj Yahaya, thankful for your full support and give me an advice.
For UTeM lecturers and staffs who were involved in this thesis especially to my supervisor lecturer, Dr Nur Izan Syahriah Bt. Hussein for help and guide.
For my adored friends, Azri Safwan Bin Abdul Halim, Mohamed Azuan Bin Elias, Muhammad ammar bin Hassan, Mohd Kamarul Shaufi Bin Rasidi and all BMFP‟s members for their never ending social support and always lending a helping hand whenever I need them, thank you.
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TABLE OF CONTENT
Abstrak i
Abstract ii
Acknowledgement iii
Dedication iv
Table of Content v
List of Tables ix
List of Figures xi
List of Abbreviations xiii
1. INTRODUCTION 1
1.1 Introduction 1
1.2 Background of Problem 2
1.3 Problem Statement 3
1.4 Objectives of Project 3
1.5 Scope of Project 3
1.6 Overview of Thesis 4
1.7 Activity Planning 5
2. LITERATURE REVIEW 6
2.1 Introduction 6
2.2 Injection moulding 6
2.2.1 Machine component 7
2.3 Mould 10
2.4 Polypropylene 12
2.5 Process Parameter 13
2.5.1 Temperature 13
2.5.2 Pressure 14
2.5.3 Time 14
2.5.4 Distance 14
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2.6 Type of Defect 17
2.6.1 Cause and Effect Diagram for Injection Moulding 17
2.6.2 Understanding the Defect 17
2.7 Surface Texture and Roughness 20
2.8 Measuring Mechanical Properties of Material 21
2.8.1 Tensile Test 21
2.9 Summary 22
3. METHODOLOGY 23
3.1 Introduction 23
3.2 Research Flow 25
3.3 Raw Material 25
3.3.1 Propylene Resin 25
3.3.2 The Characteristic of Polypropylene 26
3.4 Injection Moulding Process 27
3.4.1 The Injection Moulding Machine 27
3.4.2 Moulding Process 28
3.5 Mould 31
3.6 Injection Moulding Process Parameter 33
3.7 Surface Roughness 33
3.7.1 Surface Roughness Characteristics 34
3.7.2 Method to Analyze Surface Roughness 35
3.7.3 Portable Surface Roughness Tester 35
3.7.4 Surface Roughness Test Process Flow 37
3.8 Tensile Strength Testing 38
3.8.1 Method to Analyze Tensile Strength 39
3.8.2 Universal Tensile Machine (UTM) 40
3.8.3 Tensile Test Process Flow 41
3.9 Machining of Locating Ring 42
3.10 Design of Experiment 43
3.10.1 Taguchi Method 43
3.10.2 Selection Parameter 43
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3.10.4 Orthogonal Array Design 44
4. RESULT AND DICUSSION ON SURFACE QUALITY 45
4.1 Introduction 45
4.2 Design of Experiment (DOE) 45
4.3 Control Factor 46
4.4 Result of Experiment 47
4.4.1 Visual Inspection 49
4.5 Discussion on Surface Quality of Product 49
4.5.1 Introduction to Product Defect 49
4.5.2 Sprue Sticking 50
4.5.3 Part Sticking 51
4.5.4 Flashing 52
4.5.5 Blush 53
4.5.6 Sink Mark 54
4.5.7 Nozzle Drolling 55
5. RESULT AND DISCUSSION ON SURFACE ROUGHNESS AND
TENSILE STRENGTH 57
5.1 Surface Roughness Analysis 57
5.1.1 Generate Main Effect Result 57
5.1.2 Main Effect Plot for S/N Ratios 58
5.1.3 Main Effect Plot for Means 60
5.1.4 Analysis of Variance for Means (ANOVA) 52
5.1.5 Predicted Value of Surface Roughness 63
5.2 Tensile Strength Analysis 65
5.2.1 Result of Tensile Strength Test 65
5.2.2 Main Effect Plot for Means S/N Ratios 67
5.2.3 Main Effect Plot for Mean 69
5.2.4 Predicted Value of Tensile Strength 70
6. CONCLUSION 72
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6.2 Summary of Research Finding 72
6.3 Conclusion 74
6.4 Recommendation for Future Work 75
REFERENCES 76
APPENDICES
Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F
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LIST OF TABLES
2.1 The Control Factor and Level of optical lenses 15
2.2 Parameter Change versus property Effect 16
2.3 Troubleshooting of plastic injection moulding 17
3.1 Material Properties of Polypropylene (PP) 26
3.2 Specification of machine ARBURG ALLROUNDER 420C 28
3.3 Process Parameter of Polypropylene (PP) 33
3.4 Specification of Portable Surface Tester 36
3.5 Dog Bone Specimen Dimension 39
3.6 Universal Testing Machine (UTM) Specification 41
3.6 Selected Variable Parameter 44
3.7 Design of Experiment Orthogonal array Matrix 44
4.1 Control Factor of Process Parameter and Their Level 46
4.2 Design of Experiment Orthogonal Array Matrix 46
4.3 Result of Experiment 47
5.1 Response Table for Signal to Noise Ratio: Smaller-is-Better 58
5.2 Response Table for Means 60
5.2 Predicted Value of Surface Roughness 63
5.4 Factor Levels for Predictions 63
5.5 Tensile Strength Result 65
5.6 Dog Bone Specimen Dimension 66
5.7 Tensile Test Result of Dog Bone 1 66
5.8 Tensile Test Result of Dog Bone 2 66
5.9 Tensile Test Result of Dog Bone 3 66
5.10 Tensile Test Result of Dog Bone 4 66
5.11 Tensile Test Result of Dog Bone 5 66
5.12 Tensile Test Result of Dog Bone 6 66
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5.14 Tensile Test Result of Dog Bone 8 67
5.15 Tensile Test Result of Dog Bone 9 67
5.16 Response Table for Signal to Noise Ratio 67
5.17 Predicted Value of Tensile Strength 70
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LIST OF FIGURES
2.1 Injection Moulding Machine Stage 7
2.2 A Single Screw Injection Moulding Machine for Thermoplastics 8 2.3 Feeding, transition, and metering zone of a reciprocating screw 9
2.4 Nozzle processing position 9
2.5 The moulded system includes a delivery system and moulded parts 10 2.6 Typical mould base showing the various components 11
2.7 Structure of Polypropylene 12
2.8 Categories of Parameter 13
2.9 Response Diagram of Surface Roughness 15
2.10 Defect Factors in Injection Moulding 17
2.11 Surface Roughness Characteristics 20
2.12 Test specimen under axial tension load 22
3.1 Process Flow Chart of Experiment 24
3.2 Polypropylene Resin 26
3.3 The machine ARBURG ALLROUNDER 420C 27
3.4 A Typical Injection Moulding Process 29
3.5 Plastifying Cylinder and Mould 30
3.6 Soap Container Cavity and Core Side 31
3.7 Core and Cavity of „Soap Container‟ mould 32
3.8 „Dog Bone‟ Mould 32
3.9 Measuring Surface Roughness with Stylus 34
3.10 Surface Roughness Characteristic 35
3.11 Portable Surface Roughness Tester SJ-301 36
3.12 Surface Roughness Tester Process Flow 37
3.13 Stress-Strain Curve 38
3.14 Tensile Testing Specimen Load 40
3.15 Universal Tensile Machine (UTM) 40
3.16 Tensile Test Experiment Process Flow 41
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4.1 Sprue Sticking 50
4.2 Part Stuck at Core Side 51
4.3 Part Stuck at Cavity Side 52
4.4 Part Flash 53
4.5 Blushing at End Area of Sprue 54
4.6 Sink Mark near Sprue of Part 55
4.7 Nozzle Drolling 56
4.8 Purging Material after Remove by Using Wire Brush 56 5.1 Main Effect Plot for Signal to Noise Ratio Graph 58
5.2 Main Effect Plot for Means Surface Roughness 60
5.3 Analysis of Variance for Means 62
5.4 Mean Effect Plot for Signal to Noise Ratio Graph 67
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LIST OF ABBREVIATIONS
ANOVA - Analysis of Variance
DF - Degree of Freedom
DOE - Design of Experiment
F - F Statistics
FKP - Fakulti Kejuruteraan Pembuatan
MS - Mean Squares
PP - Polypropylene
P - P Value
PE - Polyethylene
PVC - Polyvinyl chloride S/N - Signal to Noise Ratio
SS - Summation of Squares between Group UTeM - Universiti Teknikal Malaysia Melaka UTM - Universal Testing Machine
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CHAPTER 1
INTRODUCTION
1.1 Introduction
Injection moulding is a practical technique used in manufacturing for mass producing plastics parts quickly and inexpensively. Nowadays injection moulding is the most important method of processing of consumer and industrial goods, and is performed everywhere in the world. As plastic parts have become more popular and critical in modem engineering applications, demand for quality has increased.
The principle of injection moulding is very simple. Injection moulding is process in which a plastic material is heated until it becomes soft enough to force into a closed mould at which point the material cools to solidify and from a specific product. The action that takes place is much like the filling of jelly donut. A reciprocating screw style cylinder and nozzle inject the heated plastic into an opening creates in closer container (mould). The material is allowed to harden, a finished part is ejected and the cycle is represents as often as necessary to produce the total number of pieces required.
This project conducts to study and investigate the effect of process parameter in injection moulding. This project also to carry out optimize of setting parameter in plastic injection moulding to get the good surface quality of Polypropylene (PP) component. For the injection moulding process, the parameters include injection speed, injection pressure, barrel and nozzle temperature, mould temperature, mould clamp force, dwell time, cooling time, and material properties. However, for this study only three parameters (melt temperature, injection pressure and injection speed) were varied while the rest were held constant.
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The material will be use in this project is polypropylene. This material has a different properties and parameter from other material. The accurate result for polypropylene can be finding and can conclude of the quality of product. The surface roughness of the specimen must be measured by using Surface Roughness Tester. The tensile test of the product produced must be carry on and analysis the result of the test using the Universal Tensile Machine (UTM). One of the major activities of manufacturing engineering is the assessment of the effects of changing process parameter values on part characteristics.
The primary use of process models is to predict these effects. Often process models are inadequate for this task, usually because the process is very complex or because accurate material behavior descriptions at processing conditions are unavailable. So the defect of from the result produce should be analyze and try to improve the surface quality of the product. Outcome of the defect will be defined to produce the better parameter.
1.2 Background of Problem
Nowadays, quite a variety of different techniques are employed in the forming polymeric material. Injection moulding is the most common method for method for forming plastic polymer. Injection moulding is the most widely used moulding process for thermoplastics and thermosetting. Injection moulding is economical only for large production quantities. Thus, the product of produced using injection moulding have are troubleshooting. Most of the defects of the product have a come from not proper parameter setting in plastic injection moulding. Besides that, in this project also have to optimize the parameter of the injection and determine the accurate value of the parameter. Before this, the parameter is manually setting and don't have the accurate value. The other side, the problem is to minimize of the defect on and improve surface quality of the injection moulding. A through understanding of the moulding process will be help determine the causes.
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1.3 Problem Statement
There are several main points needed to be concentrated and questions need to be answered at the end of the topic:
i. How different processing parameters affected surface quality of polypropylene (PP) material?
ii. How different processing parameters affected tensile strength of polypropylene (PP) material?
1.4 Objectives of Project
Objective of this project is:
1. To study the effect of process parameter in plastic injection moulding of polypropylene (PP).
2. To measure the surface roughness of sample product from optimized process parameter.
3. To determine the maximum tensile strength value of polypropylene (PP).
1.5 Scope of The Project
This project to study the effect of process parameter in plastic injection moulding, so for the started to optimize the parameter, the sequence of the process was:
i. Material selection for polypropylene. Pure polypropylene have been used to investigate the parameter setting in injection moulding
ii. Produce the specimen using Plastic injection Moulding. The parameter should be setting based on the parameter selection.
iii. Measure surface roughness for the produce specimen and other defect involve in surface quality.
iv. Tensile test using Universal Testing Machine (UTM) to find maximum tensile strength of value for each specimen based on different parameter setting.
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v. Analyze the result and find the optimum result for this investigation for parameter setting of Plastic Injection Moulding.
1.6 Overview of the Thesis
Chapter 1 provides the principle of injection moulding and its applications. Overview of the activity and background of this research involve in this study also include in this chapter. Problem statement and objectives of this experimental research are stated based on the task given.
Chapter 2 is more presents a review on the literature about injection moulding, machine component, materials and its properties and its commercial application. Beside, the literature about process parameter of injection moulding also reviews in this chapter. The properties of polypropylene material are also provided in relation to its process parameter, surface roughness, and tensile strength. Summary of literature review is provided at the end of this chapter.
Chapter 3 explains an experimental method of this research including experimental flow, equipment involve and design of experiment. Method and approach in selecting an optimize parameters for this experimental research also stated in this report. Furthermore, design of experiment method that help to run the experiment also describe in this chapter.
Chapter 4 describes the detail result on surface roughness and their quality of each specimen that running based on Design of Experiment (DOE) selected. The produce specimen is investigating and inspect by using Mitutoyo Portable Surface Roughness Tester that available at UTeM Laboratory. The discussion on possible source of error of surface defect and the quality of product also involve in this chapter.
Chapters 5 discuss on analysis of the surface roughness result and tensile strength result of injection moulding sample and specimen. The graph and table is including in this chapter to explain in detail of the analysis and the optimization result can be achieved.
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Chapter 6 is the conclusion sections that will be summarize the study on a achievement of objectives, completion of research, the future work and the suggestion.
1.7 Activity Planning
Gantt chart is used to illustrate the start and finish dates of activity planning. The used of Gantt chart is an effective tool for planning and scheduling operations involving a minimum of dependencies and interrelationships in this experimental research. In addition, the charts are easy to construct and understand, even though they may contain a great amount of information. In general, the charts are easily maintained provided the task requirements are somewhat static. Process monitoring the progress of the project will be easy and smooth by following the schedule that has been set up. Gantt chart of this experimental research is provided in Appendix A.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
This chapter reviews the literature on injection moulding and basic working principle, process parameter, materials, mould and commercial application. In addition, the literature about defect of injection moulding and properties of injected material also review in this chapter. Background knowledge on surface roughness, tensile testing and mechanical properties of propylene material is also provided in relation to its process parameter. Summary of the literature review is outlined at the end of this chapter.
2.2 Injection Moulding
Injection moulding is widely used technique for fabricating thermoplastic and thermosetting material. It also is perhaps the most common and versatile method of forming plastic into plastics. Injection moulding process is a process in which polymer is heated to highly plastic state and forced to flow under high pressure into mould cavity, where it solidifies. Moulding is widely used for manufacturing a variety of parts, from the smallest component. The moulded part called is moulding, is then removed from the cavity.
Generally injection moulding has four stage starting the filling, packing, cooling and finally ejection. According to Bozdana et al. (2002) is said injection moulding
process is a cyclic process. Four significant stages of the process are filling, packing, cooling and ejection. The first stage is the "filling stage" in which the mould cavity is
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filled with hot polymer melt at injection temperature. After the cavity is filled, in the "packing stage", additional polymer melt is packed into the cavity at a higher pressure to compensate the expected shrinkage as the polymer solidifies. Next, the mould is cooled until the part is sufficiently rigid to be ejected, and this stage is the "cooling stage". The last one is the "ejection stage" in which the mould is opened and the part is ejected, after which the mould is closed again to begin the next cycle. For thermoplastic materials, the injection moulding machine converts granular or pelleted raw plastic material into final moulded parts via melting, injection, packing, cooling and ejection cycle. Polypropylene is tough and flexible material and used for containers, polyethylene, and polyvinyl chloride or PVC is more common in extrusions as used for pipes, window frames, or as the insulation on wiring where it is rendered flexible by the inclusion of a high proportion of plasticize as reported by Osswald et al. (2002).
Figure 2.1: Injection Moulding Machine Stage (Strong, 1996).
2.2.1 Machine Component
The injection system consists of a hopper, a reciprocating screw and barrel assembly, and an injection nozzle, as shown in Figure 2.2. This system confines and transports
Mould system Injection
system Clamping system
Heater system
Nozzle Moul d syste
m
Tie Bar
system Clamping Unit Ejector system Stationary Platen system Movable
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The material will be use in this project is polypropylene. This material has a different properties and parameter from other material. The accurate result for polypropylene can be finding and can conclude of the quality of product. The surface roughness of the specimen must be measured by using Surface Roughness Tester. The tensile test of the product produced must be carry on and analysis the result of the test using the Universal Tensile Machine (UTM). One of the major activities of manufacturing engineering is the assessment of the effects of changing process parameter values on part characteristics.
The primary use of process models is to predict these effects. Often process models are inadequate for this task, usually because the process is very complex or because accurate material behavior descriptions at processing conditions are unavailable. So the defect of from the result produce should be analyze and try to improve the surface quality of the product. Outcome of the defect will be defined to produce the better parameter.
1.2 Background of Problem
Nowadays, quite a variety of different techniques are employed in the forming polymeric material. Injection moulding is the most common method for method for forming plastic polymer. Injection moulding is the most widely used moulding process for thermoplastics and thermosetting. Injection moulding is economical only for large production quantities. Thus, the product of produced using injection moulding have are troubleshooting. Most of the defects of the product have a come from not proper parameter setting in plastic injection moulding. Besides that, in this project also have to optimize the parameter of the injection and determine the accurate value of the parameter. Before this, the parameter is manually setting and don't have the accurate value. The other side, the problem is to minimize of the defect on and improve surface quality of the injection moulding. A through understanding of the moulding process will be help determine the causes.
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1.3 Problem Statement
There are several main points needed to be concentrated and questions need to be answered at the end of the topic:
i. How different processing parameters affected surface quality of polypropylene (PP) material?
ii. How different processing parameters affected tensile strength of polypropylene (PP) material?
1.4 Objectives of Project
Objective of this project is:
1. To study the effect of process parameter in plastic injection moulding of polypropylene (PP).
2. To measure the surface roughness of sample product from optimized process parameter.
3. To determine the maximum tensile strength value of polypropylene (PP).
1.5 Scope of The Project
This project to study the effect of process parameter in plastic injection moulding, so for the started to optimize the parameter, the sequence of the process was:
i. Material selection for polypropylene. Pure polypropylene have been used to investigate the parameter setting in injection moulding
ii. Produce the specimen using Plastic injection Moulding. The parameter should be setting based on the parameter selection.
iii. Measure surface roughness for the produce specimen and other defect involve in surface quality.
iv. Tensile test using Universal Testing Machine (UTM) to find maximum tensile strength of value for each specimen based on different parameter setting.
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v. Analyze the result and find the optimum result for this investigation for parameter setting of Plastic Injection Moulding.
1.6 Overview of the Thesis
Chapter 1 provides the principle of injection moulding and its applications. Overview of the activity and background of this research involve in this study also include in this chapter. Problem statement and objectives of this experimental research are stated based on the task given.
Chapter 2 is more presents a review on the literature about injection moulding, machine component, materials and its properties and its commercial application. Beside, the literature about process parameter of injection moulding also reviews in this chapter. The properties of polypropylene material are also provided in relation to its process parameter, surface roughness, and tensile strength. Summary of literature review is provided at the end of this chapter.
Chapter 3 explains an experimental method of this research including experimental flow, equipment involve and design of experiment. Method and approach in selecting an optimize parameters for this experimental research also stated in this report. Furthermore, design of experiment method that help to run the experiment also describe in this chapter.
Chapter 4 describes the detail result on surface roughness and their quality of each specimen that running based on Design of Experiment (DOE) selected. The produce specimen is investigating and inspect by using Mitutoyo Portable Surface Roughness Tester that available at UTeM Laboratory. The discussion on possible source of error of surface defect and the quality of product also involve in this chapter.
Chapters 5 discuss on analysis of the surface roughness result and tensile strength result of injection moulding sample and specimen. The graph and table is including in this chapter to explain in detail of the analysis and the optimization result can be achieved.
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Chapter 6 is the conclusion sections that will be summarize the study on a achievement of objectives, completion of research, the future work and the suggestion.
1.7 Activity Planning
Gantt chart is used to illustrate the start and finish dates of activity planning. The used of Gantt chart is an effective tool for planning and scheduling operations involving a minimum of dependencies and interrelationships in this experimental research. In addition, the charts are easy to construct and understand, even though they may contain a great amount of information. In general, the charts are easily maintained provided the task requirements are somewhat static. Process monitoring the progress of the project will be easy and smooth by following the schedule that has been set up. Gantt chart of this experimental research is provided in Appendix A.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
This chapter reviews the literature on injection moulding and basic working principle, process parameter, materials, mould and commercial application. In addition, the literature about defect of injection moulding and properties of injected material also review in this chapter. Background knowledge on surface roughness, tensile testing and mechanical properties of propylene material is also provided in relation to its process parameter. Summary of the literature review is outlined at the end of this chapter.
2.2 Injection Moulding
Injection moulding is widely used technique for fabricating thermoplastic and thermosetting material. It also is perhaps the most common and versatile method of forming plastic into plastics. Injection moulding process is a process in which polymer is heated to highly plastic state and forced to flow under high pressure into mould cavity, where it solidifies. Moulding is widely used for manufacturing a variety of parts, from the smallest component. The moulded part called is moulding, is then removed from the cavity.
Generally injection moulding has four stage starting the filling, packing, cooling and finally ejection. According to Bozdana et al. (2002) is said injection moulding process is a cyclic process. Four significant stages of the process are filling, packing, cooling and ejection. The first stage is the "filling stage" in which the mould cavity is
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filled with hot polymer melt at injection temperature. After the cavity is filled, in the "packing stage", additional polymer melt is packed into the cavity at a higher pressure to compensate the expected shrinkage as the polymer solidifies. Next, the mould is cooled until the part is sufficiently rigid to be ejected, and this stage is the "cooling stage". The last one is the "ejection stage" in which the mould is opened and the part is ejected, after which the mould is closed again to begin the next cycle. For thermoplastic materials, the injection moulding machine converts granular or pelleted raw plastic material into final moulded parts via melting, injection, packing, cooling and ejection cycle. Polypropylene is tough and flexible material and used for containers, polyethylene, and polyvinyl chloride or PVC is more common in extrusions as used for pipes, window frames, or as the insulation on wiring where it is rendered flexible by the inclusion of a high proportion of plasticize as reported by Osswald et al. (2002).
Figure 2.1: Injection Moulding Machine Stage (Strong, 1996).
2.2.1 Machine Component
The injection system consists of a hopper, a reciprocating screw and barrel assembly, and an injection nozzle, as shown in Figure 2.2. This system confines and transports
Mould system Injection
system Clamping system
Heater system
Nozzle Moul
d syste
m
Tie Bar
system Clamping Unit Ejector system
Stationary Platen system
Movable