Automotive Painting Technology

Automotive Painting Technology

Kimio Toda Abraham Salazar Kozo Saito Editors Automotive Painting Technology A Monozukuri-Hitozukuri Perspective 1 3

Editors Mr. Kimio Toda Asahi Sunac Corporation Owariasahi, Aichi Japan Dr. Abraham Salazar Institute of Research for Technology Development College of Engineering University of Kentucky Lexington, KY USA Prof. Kozo Saito Institute of Research for Technology Development College of Engineering University of Kentucky Lexington, KY USA ISBN 978-94-007-5094-4 ISBN 978-94-007-5095-1 (ebook) DOI 10.1007/978-94-007-5095-1 Springer Dordrecht Heidelberg London New York Library of Congress Control Number: 2012952151 Springer Science+Business Media Dordrecht 2013 No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Foreword: Monozukuri-based Automotive Painting Science and Technology I would like to send my sincere congratulations to the 10th anniversary of the University of Kentucky s Painting Technology Workshop directed by Professor Kozo Saito and his hard working and talented IR4TD staff members. I very much welcome a special publication of an anniversary volume: Monozukuri-based automobile painting technology to celebrate this occasion. My company, Asahi Sunac has been working on innovative solutions to global environmental and energy problems through spray paint equipment and technology development for the past 55 years. When looking back at the past 55 years, we have made technology developments mainly based on our experience, by accumulating a series of experiments and a large collection of data; largely through our own small continuous effort, known as Kaizen, since we could not find resources and help available in lectures or scientific research from academic institutions around the world. That unfortunate trend eventually came to end when we found that the University of Kentucky had initiated the first Painting Technology Workshop (PTW 2000) in the year 2000. I have been thrilled to find the new and exciting scientific research results that PTW has produced. I had the good fortune to invite Professor Saito for Asahi Sunac s 50th anniversary lecture, and followed with collaborative research on spray painting technology conducted at the Institute of Research for Technology Development (IR4TD) at the University of Kentucky. I am also very pleased to see Mr. Toda, an internationally recognized expert in automobile painting technology who has played a key role in production engineering at Toyota and NUMMI, became a regular lecturer for PTW. In his introduction, Mr. Toda addresses automobile painting technology based on his extensive knowledge and experience. Then, in later sections, IR4TD researchers bring a scientific approach to the experience based technology, making this book very unique and valuable. Mr. Toda also played an important role as a facilitator in making IR4TD s scientific research available to solve industry problems in automobile painting processes, systems and equipment. I am confident that this unique book will help engineers, researchers and students interested in learning both basics and applications of automobile painting technology. Masahiko Amari President of Asahi Sunac Corp. Japan v

Preface The University of Kentucky s Institute of Research for Technology Development (IR4TD) operates through interdependent and sustainable partnership with industry. This unique institute is a good example of University of Kentucky s (UK) effort to seek a new and better way of doing research, education, and service. At IR4TD, we began a series of scientific studies on automobile coating technology around 1993 in response to a request from Toyota which is interested in finding scientific reasoning for the largely experience-based automobile painting technology area, as explained by Kimio Toda in his chapter in this book. I was totally unfamiliar with automobile painting technology at that time, since my research background was scale modeling and combustion. Therefore, I needed to visit a newly opened Toyota Georgetown plant to ask questions: What are the scientific principles to support a rotary bell sprayer, why so much over-sprayed paint fumes are created? How to collect these over-sprayed fumes? Why they need such a large size spray paint booth? What is the paint film thickness and how many different layers of paint is required and why? These are all questions coming from a totally novice point of view but they helped us to create a baseline for our scientific research. Following the Genchi-Genbutsu principle, I made a frequent visit to the automobile plant to collect various data and obtain discussions with engineers and operators, then conducted simple scale model laboratory experiments at the University of Kentucky. During this initial three year phase, we formed a small research team consisting of a graduate student, an industrial extension engineer and myself as a faculty researcher and head of the team. Around 1996, Abraham Salazar joined our team, accelerating this research with his expertise in CFD (Computational Fluid Dynamics) model calculations analyzing the airflow pattern containing paint particles and the capturing mechanism of typical conventional wet scrubbers used by automobile manufacturers to capture over-sprayed paint. It was our first breakthrough to quantitatively estimate energy usage, relative efficiency, and fluid dynamics of particle capturing of existing wet scrubbers. Our next task was focused on how to improve the performance of wet scrubbers. This task required new ideas through thinking outside-the-box and a paradigm shift. We learned from nature that sand dune structure in a desert can be the most efficient vii

viii Preface way to capture paint particles with minimum energy consumption. This approach led our team to invent Vortecone in collaboration with Toyota and Trinity engineers. Vortecone wet scrubber is 30 50 % energy efficient and has a higher capturing capability than other similar products available on the market. Our team s success lies in the combination of the following factors: basic research to understand the capturing mechanisms, thinking outside-the-box, paradigm shift, and Toyota continuous and steady funding support. Without any of the above elements, I doubt this invention would have been possible. In this case, the box was technology, that is, the outcome if human thought combined with engineering principles. We shifted our focus to nature, another source for models of how to make things efficiently. This initial success attracted other companies to pay attention to our automobile coating research, leading to the establishment of UK s Painting Technology Consortium (PTC) in 1999. In the following year, we initiated the annual Painting Technology Workshop with the following aims: (1) to provide a place where industry engineers, government agency regulatory personnel, and academic researchers meet and discuss coating research and technology development; (2) to share common problems in coating technology and seek win-win solutions; and (3) to provide educational and training opportunity. Around 2005, Kimio Toda, an internationally renowned automobile painting technology expert joined PTW as a special lecturer bringing his thirty two years experience at Toyota. Based on this Toda-UK PTW collaboration, we created a two-day special short course on automobile painting technology which produced rich documentation on automobile painting technology. This course led to the idea to publish a more comprehensive book on automobile painting technology. As a result, this book was born. Kozo Saito

Contents 1 Introduction... 1 Kozo Saito Part I Painting Technology The Empirical Approach 2 What Is Spray Coating?... 5 Kimio Toda Part II Painting Technology: Numerical Simulation and Scale Modeling 3 Computational Modeling of Relevant Automotive Rotary Spray Painting Process... 47 Abraham J. Salazar 4 The Use of Scale Model to Study Film Flow in a Rotary Atomizer Cup... 97 Vedanth Srinivasan, Abraham J. Salazar and Kozo Saito Part III Painting Technology Visualization and Characterization 5 Automotive Paint Spray Characterization and Visualization... 121 Nelson K. Akafuah Part IV Painting Technology Research and Education An Integrative Approach 6 Hitozukuri and Monozukuri in Relation to Research and Development in Surface Coating... 169 K. Saito, A. J. Salazar, K. Kreafle and E. Grulke ix

Contributors Nelson K. Akafuah Institute of Research for Technology Development, College of Engineering, University of Kentucky, KY 40506-0503, Lexington, USA e-mail: nkakaf0@engr.uky.edu Eric Grulke Institute of Research for Technology Development, College of Engineering, University of Kentucky, Lexington, KY 40506-0503, USA e-mail: egrulke@engr.uky.edu Ken Kreafle Institute of Research for Technology Development, College of Engineering, University of Kentucky, Lexington, KY 40506-0503, USA e-mail: ken.kreafle@tema.toyota.com Kozo Saito Institute of Research for Technology Development, College of Engineering, University of Kentucky, Room: RGAN 179, Lexington, KY 40506-0503, USA e-mail: saito@engr.uky.edu Abraham J. Salazar Institute of Research for Technology Development, College of Engineering, University of Kentucky, Lexington, KY 40506-0503, USA e-mail: ajsala00@uky.edu V. Srinivasan ANSYS FLUENT, 15915 Katy Freeway, Suite 550, Houston, TX 77094, USA e-mail: Vedanth.Srinivasan@ansys.com Kimio Toda Asahi Sunac Corporation, Asahimae-cho 5050, Owariasahi, 488-8688 Aichi, Japan e-mail: kimio_toda@sunac.co.jp xi