Optimization Of Injection Molding Process On Name Tag Plastic Product

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UNIVERSITI TEKNIKAL MALAYSIA MELAKA

OPTIMIZATION OF INJECTION MOLDING PROCESS ON

NAME TAG PLASTIC PRODUCT

This report is submitted in accordance with the requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor of Manufacturing Engineering

Technology (Product Design) with Honours.

by

STUDENT NAME: LIM CUI FEN MATRIX NUMBER: B 071310502

IC NUMBER: 930512-02-5764

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UNIVERSITI TEKNIKAL MALAYSIA MELAKA

BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA

TAJUK: Optimization of Injection Moulding process on Name Tag Plastic Product

SESI PENGAJIAN: 2016/17 Semester 1

Saya LIM CUI FEN

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 sebagaimana yang termaktub dalam AKTA RAHSIA RASMI 1972)

(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi / badan di mana penyelidikan dijalankan)

AlamatTetap:

62A, Taman Lam Sun,

05200 Alor Setar, Kedah Darul Aman.

Tarikh: _____________________

Disahkanoleh:

Cop Rasmi:

Tarikh: _______________________

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DECLARATION

I hereby, declared this report entitled “Optimization Of Injection Molding Process On Name Tag Plastic Product” is the results of my own research except as cited in

references.

Signature : ……… Author’s Name : LIM CUI FEN

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APPROVAL

This report is submitted to the Faculty of Engineering Technology of UTeM as a partial fulfilment of the requirements for the degree of Bachelor of Manufacturing Engineering Technology (Product Design) with Honours. The member of the supervisory is as follow:

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i

ABSTRAK

Proses pengacuan suntikan adalah satu proses yang digunakan secara meluas

untuk pembuatan kompleks berbentuk produk polimer. Proses pengacuan suntikan

terdiri daripada empat peringkat utama: proses plastifikasi, proses suntikan, proses pek

& tahan dan proses pelemparan. Selepas proses pelemparan, menyedari bahawa dimensi

bahagian adalah berbeza dari dimensi acuan yang dikehendaki, saiz produk telah

menjadi lebih kecil. Pengecutan adalah satu fenomena yang berlaku semasa pemejalan

bahan plastik lebur, tetapi ia juga boleh menjadi masalah utama yang sering dihadapi

oleh industri plastik jika ia adalah berlebihan disebabkan oleh faktor-faktor proses

parameter tanpa pengoptimuman. Kajian ini telah dibangunkan untuk menentukan faktor

utama yang menjejaskan sebahagian pengecutan, dan juga untuk mengoptimumkan

faktor proses parameter untuk produk tag nama. Faktor-faktor yang terlibat dalam kajian

ini ialah Tekanan Suntikan, Tekanan Ketahanan, Masa Ketahanan dan Masa Penyejukan.

Bahan yang dipilih untuk kajian ini adalah Acrylonitrile Butadiene Styrene (ABS) bahan

plastik. Kajian ini telah direka dengan menggunakan kaedah Taguchi, pendekatan

berstruktur yang biasa digunakan untuk menentukan kombinasi input yang "terbaik"

untuk menghasilkan satu produk plastik. Selepas menentukan keadaan operasi bagi

setiap parameter dan tahap (minimum, semasa dan maksimum), sebuah ortogon Array

(OA) yang sesuai telah dipilih untuk menghasilkan bilangan minimum percubaan untuk

menganggarkan kesan utama. 9 ujian telah dijalankan dan 10 sampel telah diambil dari

setiap percubaan. Pemeriksaan dimensi telah dibuat dengan menggunakan Mesin

Pengukuran Koordinat (CMM), untuk mendapatkan nilai purata tepat untuk mengira

nilai pengecutan. Nilai pengecutan digunakan untuk mencari Nisbah Isyarat-Hingar (SN)

dengan menggunakan Minitab, plot kesan utama bagi nilai purata dan nisbah SN telah

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ii pengecutan. Satu set faktor proses parameter yang telah dioptimumkan pada akhir

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iii

ABSTRACT

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iv

DEDICATION

This thesis is dedicated to my beloved family, my supervisor En Salleh bin Aboo Hassan and all my fellow friends for their guidance and help to complete the Final Year Project

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ACKNOWLEDGEMENT

Firstly, I would like to express my sincere appreciation to my supervisor, Encik Salleh bin Aboo Hassan for his guidance, patience and encouragement. Thanks for spending your precious time to teach me and guide me for the project. A special thank to my friend, Ivy King Chien Chien who always helped me, guided me and supported me all the time although she was also busy in her final year project. Without Encik Salleh and Ivy, I would never able to complete this project on time.

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TABLE OF CONTENT

Abstrak i

Abstract iii

Dedication iv

Acknowledgement v

Table of Content vi

List of Tables ix

List of Figures x

List of Abbreviations, Symbols and Nomenclatures xii

CHAPTER 1: INTRODUCTION 1

1.0 Overview 1

1.1 Introduction 1

1.2 Project Background 4

1.3 Problem Statement 5

1.4 Research Objectives 5

1.5 Scope 5

CHAPTER 2: LITERATURE REVIEW 7

2.0 Introduction 7

2.1 History of Injection Moulding 7

2.2 Injection Moulding Process 10

2.2.1 Plastification Stage 11

2.2.2 Injection Stage 13

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viii

2.2.4 Ejection Stage 14

2.3 Cold Runner VS Hot Runner 14

2.3.1 Cold Runner 15

2.3.2 Hot Runner 16

2.4 Defects in Injection Moulding process 17

2.4.1 Sink Mark 17

2.4.2 Flash 18

2.4.3 Short Shot 19

2.4.4 Gate Blush 19

2.4.5 Jetting 20

2.4.6 Weld lines 21

2.4.7 Vacuum Voids 21

2.4.8 Splay 22

2.4.9 Warpage 23

2.4.10 Burn Marks 23

2.5 Design of Experiment (DOE) 24

2.5.1 Taguchi Method 25

2.6 Plastic Materials 27

2.6.1 Acrylonitrile Butadiene Styrene (ABS) 27

2.7 Shrinkage 29

CHAPTER 3: METHODOLOGY 31

3.0 Introduction 31

3.1 Flow Chart 31

3.1.1 Planning of Study 33

3.1.2 Define Input Parameter and Variable 33

3.1.3 Apply Taguchi Method (DOE) 35

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ix

3.1.5 Dimension Inspection 38

3.1.6 Data Collection & Analysis 40

3.1.7 Results & Discussion 41

3.1.8 Conclusion & Recommendation 41

3.2 Gantt Chart 41

CHAPTER 4: RESULT & DISCUSSION 43

4.0 Introduction 43

4.1 Operating Conditions for Each Parameter and Levels 43

4.2 Orthogonal Array by Minitab Software 47

4.3 Data Collection 48

4.3.1 Mean and Shrinkage Values 48

4.4 Data Analysis 51

4.4.1 Means and Signal-to-Noise ratios (SNR) 52

4.4.2 Analyzing the Relationship Between Means & SN Ratios 53

4.4.3 Optimizing the Process Parameters 54

4.4.4 Predicted Value 55

CHAPTER 5: CONCLUSION & FUTURE WORK 56

5.0 Introduction 56

5.1 Summary 56

5.2 Achievement of Research Objectives 57

5.3 Problems Encountered 58

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x

LIST OF TABLES

1.1: Overview of Injection Moulding Process 2

2.1: General Properties of ABS. 28

2.2: Processing Characteristics of ABS 28

2.3: Moulding Shrinkage For Each Plastic Materials 29

3.1: Process Parameters of Injection Moulding Machine 34

4.1: Operating Conditions for Each Parameter and Levels 43

4.2: Uncoded L9 orthogonal array. 47

4.3: Sample Data. 49

4.4: Means and SNR values obtained from Taguchi Analysis from Minitab. 52

4.5: The Optimized Process Parameter. 54

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xi

LIST OF FIGURES

1.1: Injection Moulding Machine Overview. 3

1.2: Plastic Pellets for Injection Moulding Process. 3

2.1: Patent Drawings for Henry Injection Moulding Machine 8 2.2: Drawings for Willert Reciprocating Injection Moulding Machine. 9

2.3: Injection Moulding Machine 10

2.4: Diagram of Injection Moulding Process. 10

2.5: Structure of Injection Moulding Machine. 12

2.6: Hopper dryer. 12

2.7: Reciprocating Screw of Injection Moulding Machine. 12

2.8: Flights of Reciprocating Screw. 13

2.9: Check Ring and Thrust Ring. 13

2.10: Two-Plates Mould for Cold Runner. 15

2.11: Three-Plates Mould for Cold Runner. 16

2.12: Hot Runner Moulding System 17

2.13: Sink Mark Defect Sample. 18

2.14: Flash Mark Defect Sample. 18

2.15: Short Shot Defect Sample. 19

2.16: Gate Blush Defect Sample. 20

2.17: Jetting. 20

2.18: Weld Lines Defect Sample. 21

2.19: Voids Defect Sample. 22

2.20: Splay Marks Defect Sample. 22

2.21: Warpage Defect Sample. 23

2.22: Burn Marks Defect Sample. 24

2.23: Flow Chart of a DOE. 25

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3.1: Flow Chart of Research Methodology 32

3.2: ZHAFIR Plastic Machinery VE1200 II Injection Moulding Machine 34 3.3: Taguchi Design of Experiment (DOE) in MINITAB V6 Software. 36 3.4: The Taguchi Design with 3-Level Design and 4 Factors in MINITAB V6 software. 36

3.5: L9 Taguchi Design. 37

3.6: L9 Taguchi Design with Four Factors. 37

3.7: A Sample Product of the Experiment (Name Tag). 38

3.8: CONTURA G2 Coordinate Measuring Machine 39

3.9: UTeM’s Name Tag Product. 39

4.1: Short Shot Defect Sample. 44

4.2: Sink Mark Defect Sample. 44

4.3: Acceptable Sink Mark Sample. 45

4.4: Overpacked Samples due to Overpack Pressure. 45

4.5: Overpacked Part Stuck at the Mould. 46

4.6: Splay Defect Sample. 46

4.7: Coded L9 Orthogonal Array. 47

4.8: MINITAB V6 Software Data Analysis. 51

4.9: Taguchi Analysis Shrinkage versus IP, HP, HT, CT. 52

4.10: Main Effect Plot for Means. 53

4.11: Main Effect Plot for SN Ratios. 53

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LIST OF ABBREVIATIONS, SYMBOLS AND

NOMENCLATURE

ABS Acrylonitrile-Butadiene-Styrene

ANOVA Analysis of Variance

CAB Cellulose Acetate Butyrate

CMM Coordinate Measuring Machine

DOE Design of Experiment

GF Glass Fiber

HDPE High-Density Polyethylene

LDPE Low-Density Polyethylene

OA Orthogonal Array

OAPEC Organization of Arab Petroleum Exporting Countries

PBT Polybutylene Terephthalate

PC Polycarbonate

PEEK Polyetheretherketone

PET Polyethylene Terephthalate

PPO Polyphenylene Oxide

PVC Polyvinyl Chloride

PVC-P Plasticized Polyvinyl Chloride PVC-U Polyvinyl Chloride Unplasticized

SAN Styrene Acrylonitrile

SN ratio Signal-to-Noise ratio

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1

CHAPTER 1

INTRODUCTION

1.0 Overview

This chapter explained about the basic knowledge of injection moulding process and project title. Besides that, this chapter also described the project background, the problem statement, objectives and the scope of this study.

1.1 Introduction

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2 Table 1.1: Overview of Injection Moulding Process

Step 1 The plastic pellets (raw materials) are fed

into the barrel through a hopper. The pellets are then transported forward when the reciprocating screw is turning.

Step 2 The plastic pellets are melted by the

external pressure from the narrow space in barrel, the friction inside the barrel and the additional heat from the heater bands which are surrounded the barrel. The molten material flow into the nozzle, the screw is then pushed forward to inject the molten material into the mould cavity.

Step 3 The reciprocating screw holds and pack s

the molten material in the time set in order to ensure the molten part was completely solidified when the mould opens. The cooling process is then proceed when the holding time ends.

Step 4 After cooling process, the injected

material is fully solidified. The mould opens eject the product by using the ejector pins. One cycle of production completes and repeats to produce the next product.

There are various types of plastic materials used in the injection moulding process, such as Polypropylene, Polystyrene, Polyethylene and other plastic materials. Acrylonitrile-Butadiene-Styrene (ABS) (C8H8)x·(C4H6)y·(C3H3N)z) is one of the

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3 process. It is opaque, high resist to heat and chemicals, and even able to maintain high durability at low temperature. Each material has different physical and chemical properties which may affect the setting of process parameters in an injection moulding machine. The process parameters such as mould temperature, injection pressure and injection speed. Therefore, the process parameters are needed to be optimized based on the material properties in order to produce a part with good quality.

Figure 1.1: Injection Moulding Machine Overview.

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4 1.2 Project Background

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5 1.3 Problem Statement

The reason for this study is to address the need for controlling and minimize the part of shrinkage formation in plastic materials for name tag product. Shrinkage is a major problem when dealing with plastic injection moulding. Shrinkage could affect the quality of moulded product. In this shrinkage study, we focused only on the ABS plastic shrinkage problem which could be affected by many factors which could caused lower quality of product in terms of dimension and well-finished surfaces. There were many process factors that were required to be considered during an injection moulding process, such as barrel temperature, mould temperature, injection speed, holding pressure and more. These factors were analysed and optimized in order to produce a good quality with less shrinkage moulded part.

1.4 Research Objectives

The objectives of this research study are:

i. To determine the significant factors affecting the part shrinkage. ii. To optimize the process parameter factors for name tag product.

1.5 Scope

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7

CHAPTER 2

LITERATURE REVIEW

2.0 Introduction

This chapter had covered the literature review of the project study. In this chapter, the literature review had introduced about the history of injection moulding, and also reviewed the topics such as injection moulding process, plastic defects, plastic material, Taguchi method and part shrinkage.

2.1 History of Injection Moulding

Figure

Table 1.1: Overview of Injection Moulding Process
Table 1 1 Overview of Injection Moulding Process . View in document p.19
Figure 1.2: Plastic Pellets for Injection Moulding Process.
Figure 1 2 Plastic Pellets for Injection Moulding Process . View in document p.20
Figure 1.1: Injection Moulding Machine Overview.
Figure 1 1 Injection Moulding Machine Overview . View in document p.20

References

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