Vacuum Thermoforming Process: an Approach to Modeling and Optimization Using Artificial Neural Networks
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A Low Cost Vacuum-Forming System1
A LOW COST VACUUM-FORMING SYSTEM1 James P. O'Leary, M.S.2, Edward A. Bianchi, B.S.2, and Richard A. Foulds, M.S.2 Vacuum-forming is an excellent method for molding sheets of plastic into complicated shapes. It is just beginning to be used in the field of re habilitation medicine where the need to make devices that fit the human form is great. This article describes a new, inexpensive apparatus which enables orthotists and prosthetists to use the vacuum-forming process in their work with a very small outlay of capital. Very little training is required to use the apparatus, and it is now being made available in limited quantities. In the vacuum-forming process a sheet of hot, pliable plastic is drawn either into or around a mold with the use of suction provided by a vac uum pump. When the plastic cools and hardens, it retains the shape caused by the mold. An example of the usefulness of a molded orthosis is Fig. 1. A molded ankle-foot orthosis (left) is contrasted shown in Figure 1. to the conventional metal and leather orthosis that it The process, though simple, when adapted to replaces. Besides being lighter in weight, the plastic the needs of mass-production, requires very ex orthosis requires no modification to the shoe. This pensive machinery. Until recently only industrial feature makes it possible for the patient to interchange shoes easily. vacuum-forming equipment was available, with prices ranging from $4,000 to over $125,000. Because of the large investment in money and space required to obtain and use the machines With these thoughts in mind we designed and designed for mass production, very few medical built a vacuum-forming apparatus called the facilities have made use of the vacuum-forming "Bracemaker" (Fig. -
Thermoforming
APPLICATION GUIDE: Thermoforming TIME REQUIRED COST SKILL LEVEL By Brian Sabart, Stratasys Inc. and Jeff Gangel, Formech International, Ltd. OVERVIEW Vacuum Forming Materials: Thermoforming is a relatively simple manufacturing process that is inexpensive when compared to other - ABS plastic molding and forming methods. Although thermoforming is often associated with manufacturing - Polyvinylchloride (PVC) of packaging items such as blister packs and disposable coffee cup lids, the cost and time advantages - Polycarbonate (PC) are realized in a broad spectrum of products in an equally broad range of industries. When using a Fortus - Polyethylene (PE) 3D Production System with FDM technology to construct thermoforming tooling, the process becomes - Low Density Polyethylene (LDPE) simpler, more efficient and increasingly cost-effective. - High Density Polyethylene (HDPE) - Polypropylene (PP) - Polystyrene (PS) PROCESS DESCRIPTION - Polyphenylene Oxide (PPO) Thermoforming is a collection of manufacturing methods that heat and form sheets of extruded plastic. - Polyphenylene Ether (PPE) Thermoforming processes include drape, vacuum and pressure forming. - Polymethyl-Methacrylate (PMMA) - Acrylic Drape forming relies on gravity to pull the sheet against the tool. Vacuum forming, as the name implies, - Closed Cell Foam Polyester (PBT, PET) draws the heated sheet against the tool with the assistance of a vacuum. Pressure forming combines - Polyester Copelymer (PETG) vacuum and pressure to simultaneously pull and push the plastic sheet to the contours of the tool. - Thermoplastic Olefin (TPO) - Thermoplastic Elastomer (TPE) This process guide documents the steps for vacuum forming since it is the most common thermoforming - Thermoplastic Rubber (TPR) method. However, many of the details presented may also be applied to drape and pressure forming. -
Radel® PPSU, Udel® PSU, Veradel® PESU & Acudel® Modified PPSU
Radel ® | Udel ® | Veradel ® | Acudel ® Radel® PPSU, Udel® PSU, Veradel® PESU & Acudel® modified PPSU Processing Guide SPECIALT Y POLYMERS 2 \ Sulfone Polymers Processing Guide Table of Contents Introduction ............................. 5 Part Ejection . 14 Draft . 14 Ejector pins and/or stripper plates . 14 Sulfone Polymers........................ 5 Udel® Polysulfone (PPSU) . 5 Injection Molding Equipment ............. 15 ® Veradel Polyethersulfone (PESU) . 5 Controls . 15 ® Radel Polyphenylsulfone (PPSU) . 5 Clamp . 15 ® Acudel modified PPSU . 5 Barrel Capacity . 15 Press Maintenance . 15 Resin Drying . .6 Screw Design . 15 Rheology................................ 8 Screw Tips and Check Valves . 15 Viscosity-Shear Rate ..................... 8 Nozzles . 16 Molding Process . 16 Resin Flow Characteristics . 9 Melt flow index . 9 Polymer Injection or Mold Filling . 16 Spiral flow . 9 Packing and Holding . 17 Injection Molding . .10 Cooling . 17 Molds and Mold Design .................. 10 Machine Settings ....................... 17 Tool Steels . 10 Barrel Temperatures . 17 Mold Dimensions . 10 Mold Temperature . 18 Mold Polishing . 10 Residence Time in the Barrel . 18 Mold Plating and Surface Treatments . 10 Injection Rate . 18 Tool Wear . 10 Back Pressure . 18 Mold Temperature Control . 10 Screw Speed . 18 Mold Types . 11 Shrinkage . 18 Two-plate molds . 11 Three-plate molds . 11 Regrind ............................... 19 Hot runner molds . 11 Cavity Layout . 12 Measuring Residual Stress ............... 19 Runner Systems . 12 Extrusion............................... 22 Gating . 12 Sprue gating . 12 Edge gates . 13 Predrying ............................. 22 Diaphragm gates . 13 Tunnel or submarine gates . 13 Extrusion Temperatures ................. 22 Pin gates . 13 Screw Design Recommendations . 22 Gate location . 13 Venting . 14 Sulfone Polymers Processing Guide / 3 Die Design ............................. 22 Extruded Product Types . 23 Wire . 23 Film . 23 Sheet . 23 Piping and tubing . 23 Start-Up, Shut-Down, and Purging ....... -
M.ENGG. Syllabi
DEPARTMENT OF POLYMER AND PETROCHEMMICAL ENGINEERING SEMESTER SYLLABI OF COURSES FOR M.ENGG. (POLYMER ENGINEERING) PROGRAMME NED UNIVERSITY OF ENGINEERING & TECHNOLOGY, KARACHI-75270 PAKISTAN Compulsory and elective courses for M. Engg. (Polymer Engineering) Compulsory Courses: Credit hours PP-511: Mathematical Methods in Polymer Engineering 3 PP-512: Advanced Polymer Processing 3 PP-513: Polymer Reactor Engineering 3 PP-514: Rheology of Complex Fluids 3 PP-515: Polymer Structure-Property Relationships 3 Elective Courses: PP-525: Advanced Polymer Composites 3 PP-526: Fibre Technology 3 PP-527: Polymer Adhesives and Coatings 3 PP-528: Polymer Product Design 3 PP-529: Specialty and Functional Polymer Materials 3 PP-530: Rubber Technology 3 PP-532: Polymer Degradation, Stability and Recycling 3 PP-531: Polymer Characterization 3 ME-530: Project Management 3 PP-600: Independent Study project 6 PP-601: Dissertation 9 PP-401: Introduction to Polymeric Materials NC Compulsory Courses PP-511: Mathematical Methods in Polymer Engineering Linear Algebra: Algebra of matrices, inverse, rank, system of linear equations, symmetric, skew- symmetric and orthogonal matrices, Hermitian, skew-Hermitian, unitary matrices, eigenvalues and eigenvectors, diagonalisation of matrices, Cayley-Hamilton Theorem. Vector Calculus: Gradient, divergence and curl, vector Identities, directional derivatives, line, surface and volume integrals, Stokes, Gauss and Green’s theorems applications. Tensors: Tensor operations, vector operations using index notation, principal -
Plastics Guidebook Cover
PLASTICS INDUSTRY ENERGY BEST PRACTICE GUIDEBOOK Plastics Energy Best Practice Guidebook Provided By: Funding for this guidebook was provided by Focus on Energy. Focus on Energy, a statewide service, works with eligible Wisconsin residents and businesses to install cost-effective energy efficiency and renewable energy projects. We provide technical expertise, training and financial incentives to help implement innovative energy management projects. We place emphasis on helping implement projects that otherwise would not get completed, or to complete projects sooner than scheduled. Our efforts help Wisconsin residents and businesses manage rising energy costs, protect our environment and control the state’s growing demand for electricity and natural gas. With: Science Applications International Corporation Center for Plastic Processing Technology, UW-Platteville Envise, LLC CleanTech Partners, Inc. Tangram Technology Ltd. July 2006 Special thanks to the American Chemistry Council who provided printing and distribution through a grant by the U.S. Department of Energy, administered by CleanTech Partners, Inc. TABLE OF CONTENTS FORWARD ………........................................................................................................ 3 Are you a World Class Energy User?............................................................... 3 What Others Say about the Guidebook............................................................ 3 Development of the Guidebook........................................................................ 4 -
Strategies to Support the Plastics Industry in North Central Massachusetts: a Report to the City of Leominster
UNIVERSITY OF MASSACHUSETTS Amherst Boston Dartmouth Lowell Worcester Strategies to Support the Plastics Industry in North Central Massachusetts: A Report to the City of Leominster University of Massachusetts Donahue Institute Strategies to Support the Plastics Industry in North Central Massachusetts: A Report to the City of Leominster A Project of the University of Massachusetts Donahue Institute, Middlesex House, University of Massachusetts at Amherst, Amherst, MA 01003 University of Massachusetts Donahue Institute Steven Landau Steven Ellis William Ennen University of Massachusetts at Lowell Robert Forrant March 2000 i ACKNOWLEDGEMENTS Our work would not have been possible with out the support we received from Mayor Dean J. Mazzarella to conduct an independent investigation of how best to support the plastics industry. The authors gratefully acknowledge the "hands-on" support of the Leominster Office of Planning and Development, particularly Joseph Viola, Plastics Technology Coordinator, Mary Albertson, Director and Trevor M. Beauregard, Economic Development Coordinator. We especially want to thank Joe for the unstinting assistance he provided through the life of this project. As we began our work, we reached out to the North Central Chamber of Commerce and its Plastics Council. Todd Simkus and Dan Curley of the Chamber's staff provided critical assistance in allowing us to involve plastics companies directly in our research. Dan's assistance, working with Joe Viola, was essential in organizing the forums where we discussed the findings and recommendations that emerged from our research. We also want to thank Mark LaVoie for inviting us to meet with the Plastics Council when our effort was getting underway. Staff of the Donahue Institute, Carolyn Mailler, Rebecca Loveland, Ruth Malkin, James Palma, Jennifer Woods, Carlos Gonzales and Irma Bushati, stepped in at critical times with editorial assistance and research. -
Optimizing Thermoforming of High Impact Polystyrene (HIPS) Trays by Design of Experiments (DOE) Methodologies
Optimizing Thermoforming of High Impact Polystyrene (HIPS) Trays by Design of Experiments (DOE) Methodologies Vishal M. Dhagat Department of Electrical & Computer Engineering, UConn Storrs, CT 06269-4157 [email protected] Ravindra Thamma Manufacturing & Construction Management, CCSU 1615 Stanley Street, New Britain, CT 06050 [email protected] Abstract The process of heating and reshaping plastics sheet and film materials has been in use since the beginning of the plastics industry better known as thermoforming. Today this process is very ubiquitous for industrial products including signage, housings, and hot tubs. It also produces much of the packaging in use today including blister packs, cartons, and food storage containers. The process of thermoforming has many advantages over other methods for producing high quality plastic products, with some limitations, which can be resolved by implementing stringent quality control using scientific methods to improve process performance. Two areas of interest in today’s industry of great concerns are lean manufacturing operations and environment. Thermoforming of high impact polystyrene sheets using vacuum forming technique requires technical knowledge on material behavior, mold type, mold material, and process variables. Research on these various subjects is well documented but very limited research is done in process optimization of HIPS (High Impact Polystyrene). Design of Experiments (DOE) approaches like the face-centered cubic central composite design can be used to refine the process and to minimize rejects. In this paper, we present a case study on thermoforming of HIPS single use trays made on a semi automatic machine using three criteria solely based on the FCC Design method. The optimization of tray forming and wall thickness distribution is explored. -
Design Guidelines for the Thermoforming Process 1
Design guidelines for the thermoforming process 1 Design guidelines for product engineers on the thermoforming process U aangeboden door: Batelaan Kunststoffen BV ● Veerpolder 8 ● 2361KV Warmond T: 071-5613301 ● F: 071-5616701 ● www.batelaan.nl Zonder schriftelijke toestemming van de ProducentenVereniging Thermoplasten (PVT) mag niets uit deze informatiemap worden verveelvoudigd en/of openbaar gemaakt door middel van druk, fotokopie, microfilm of anderszins, hetgeen ook van toepassing is op de gehele of gedeeltelijke bewerking. Deze informatiemap is gebaseerd op de trainingmodules, gerealiseerd in het kader van T-ForM. Voor de eventuele aanwezigheid van (zet)fouten en onvolledigheden kan de PVT geen aansprakelijkheid aanvaarden. PVT, Postbus 420, 2260 AK Leidschendam, [email protected] www.t-form.eu July 2008 1 Design guidelines for the thermoforming process 2 Contents Contents ................................................................................................................................ 1 1. Executive Summary ........................................................................................................... 5 2. Introduction ........................................................................................................................ 9 2.1 Thin Sheet Thermoforming ........................................................................................... 9 2.2 Thick Sheet Thermoforming ....................................................................................... 10 2.3 Tooling ...................................................................................................................... -
POLYMER-PLASTICS TECHNOLOGY and ENGINEERING June 1999 Aims and Scope
rJ 31 CY Ls dM F4 B cnY 0 cc z=8 OE 0 U POLYMER-PLASTICS TECHNOLOGY AND ENGINEERING June 1999 Aims and Scope. The joumal Polymer-Plastics Technology and Engineering will provide a forum for the prompt publication of peer-reviewed, English lan- guage articles such as state-of-the-art reviews, full research papers, reports, notes/communications, and letters on all aspects of polymer and plastics tech- nology that are industrial, semi-commercial, and/or research oriented. Some ex- amples of the topics covered are specialty polymers (functional polymers, liq- uid crystalline polymers, conducting polymers, thermally stable polymers, and photoactive polymers), engineering polymers (polymer composites, polymer blends, fiber forming polymers, polymer membranes, pre-ceramics, and reac- tive processing), biomaterials (bio-polymers, biodegradable polymers, biomed- ical plastics), applications of polymers (construction plastics materials, elec- tronics and communications, leather and allied areas, surface coatings, packaging, and automobile), and other areas (non-solution based polymerization processes, biodegradable plastics, environmentally friendly polymers, recycling of plastics, advanced materials, polymer plastics degradation and stabilization, natural, synthetic and graft polymerskopolymers, macromolecular metal com- plexes, catalysts for producing ultra-narrow molecular weight distribution poly- mers, structure property relations, reactor design and catalyst technology for compositional control of polymers, advanced manufacturing techniques and equipment, plastics processing, testing and characterization, analytical tools for characterizing molecular properties and other timely subjects). Identification Statement. Polymer-Plastics Technology and Engineering is pub- lished five times a year in the months of February, April, June, September, and November by Marcel Dekker, Inc., P.O. Box 5005, 185 Cimarron Road, Monti- cello, NY 12701-5185. -
The Dynisco Extrusion Processors Handbook 2Nd Edition
The Dynisco Extrusion Processors Handbook 2nd edition Written by: John Goff and Tony Whelan Edited by: Don DeLaney Acknowledgements We would like to thank the following people for their contributions to this latest edition of the DYNISCO Extrusion Processors Handbook. First of all, we would like to thank John Goff and Tony Whelan who have contributed new material that has been included in this new addition of their original book. In addition, we would like to thank John Herrmann, Jim Reilly, and Joan DeCoste of the DYNISCO Companies and Christine Ronaghan and Gabor Nagy of Davis-Standard for their assistance in editing and publication. For the fig- ures included in this edition, we would like to acknowledge the contributions of Davis- Standard, Inc., Krupp Werner and Pfleiderer, Inc., The DYNISCO Companies, Dr. Harold Giles and Eileen Reilly. CONTENTS SECTION 1: INTRODUCTION TO EXTRUSION Single-Screw Extrusion . .1 Twin-Screw Extrusion . .3 Extrusion Processes . .6 Safety . .11 SECTION 2: MATERIALS AND THEIR FLOW PROPERTIES Polymers and Plastics . .15 Thermoplastic Materials . .19 Viscosity and Viscosity Terms . .25 Flow Properties Measurement . .28 Elastic Effects in Polymer Melts . .30 Die Swell . .30 Melt Fracture . .32 Sharkskin . .34 Frozen-In Orientation . .35 Draw Down . .36 SECTION 3: TESTING Testing and Standards . .37 Material Inspection . .40 Density and Dimensions . .42 Tensile Strength . .44 Flexural Properties . .46 Impact Strength . .47 Hardness and Softness . .48 Thermal Properties . .49 Flammability Testing . .57 Melt Flow Rate . .59 Melt Viscosity . .62 Measurement of Elastic Effects . .64 Chemical Resistance . .66 Electrical Properties . .66 Optical Properties . .68 Material Identification . .70 SECTION 4: THE SCREW AND BARREL SYSTEM Materials Handling . -
Introducing Plastic Product Design Into the Machine Design Curriculum
Session 2566 Introducing Plastic Product Design into the Machine Design Curriculum Reginald G. Mitchiner, Ph.D., and John T. Tester Mechanical Engineering / Industrial and Systems Engineering Virginia Polytechnic Institute and State University Blacksburg, VA 24060 Abstract We present our paradigm of plastic product design as a necessary part of the mechanical engineering design curriculum and how these concepts have been a historical part of the mechanical engineering educational agenda, though in other venues. We discuss the practical and accreditation problems associated with incorporating the "new" design features in an existing machine design course. A separate design course, dedicated to plastic product design, is also outlined. This last alternative is likely the best bridge from a machine design curriculum without plastics concepts to one with metallic/nonmetallic product design. 1 Introduction Plastic products† are a dominant part of the manufacturing world. It is very likely that you the reader could, at this moment, reach out and touch a plastic product from where you sit. Yet, mechanical design curricula at universities, as a general rule, do not have plastic product design integral in their construction. The mechanical design curriculum has embedded within it the classical theory associated with metallic products; usually these products are assumed to be manufactured via metal-removal processes, if their manufacture is assumed in any manner at all. As practicing mechanical design engineers, we (the authors) have frequently been required to design products with a plastic component as part of their basic structure. One of the authors' primary functions for several years was to design solely plastic products as part of electronic product packaging. -
Equipment Requirements for Vacuum Forming Aristech Surfaces Acrylic Spas, Tub-Showers, Whirlpool Baths, & Small Marine Craft
TECHNICAL INFORMATION SHEET 4 Equipment Requirements for Vacuum Forming Aristech Surfaces Acrylic Spas, Tub-Showers, Whirlpool Baths, & Small Marine Craft Introduction This Technical Information Sheet was prepared to supplement Aristech Surfaces Technical Bulletins 140, 142, 144, and 152 covering acrylic FRP spas, tub-showers, whirlpool baths, and small marine craft. These bulletins outline the complete process, equipment required and costing information in enough detail to allow a potential manufacturer to design an operating facility provided the technical service offered by the many materials and equipment suppliers is utilized. This document will describe in more detail the equipment required for vacuum forming and supporting the formed unit for fiberglassing. Two types of vacuum forming machines will be specified; a low cost outfit and a higher priced semi-automatic machine. This document is directed to manufacturers of polyester gel coated units who are interested in converting to acrylic surfaced units or wish to add acrylic surfaced units to their current line of products. It is assumed that a manufacturer of gel coated units will not need assistance in fiberglassing the acrylic vacuum formed part once it is jigged since the two processes are nearly identical from that point. After the part is fiberglassed it can be trimmed as gel coated parts are, therefore, no additional information beyond that given in the technical bulletins is supplied. Molds The most economical vacuum forming mold is an exact replica of the finished product made from either tooling grade polyester or epoxy. The master tool used for making Gel Coat molds often will serve as a working vacuum forming mold with minor modifications.