Design Formulas For Plastics Engineers

Although designing machines and dies for plastics processing is routinely done with the help of computer modeling and design programs, the results don't always hold up in industrial application. Therefore, it is essential for the designer to have an understanding of the underlying mathematical concepts and their limitations when working with these programs and/or trying to improve their output. This book presents a summary of the most important formulas and their applications to solve design and processing problems with plastics materials. Numerous practical examples guide the reader step-by-step through the computational routine of designing polymer machinery. The approach is unassuming and very practical to enable every engineer to apply these concepts in their daily work and improve their equipment and stabilize their processes. Contents: - Formulas of Rheology - Thermodynamic Properties - Formulas of Heat Transfer - Designing Plastics Parts - Designing Extrusion Equipment - Designing Injection Molding Equipment.

Design formulas and the mathematical models they yield are widely used in creating today's computer programs for designing machines and industrial dies. However the predictions of these programs do not always agree with the practical results. It is therefore essential that engineers have access to the formulas on which mathematical models are based in order to improve existing computer programs or develop entirely new ones. Plastics engineers in particular need a simple way to search for appropriate equations since they often deal with several different fields of engineering. By drawing together formulas from these fields, this book makes it easier to write computer design programs and to change existing ones in order to obtain a better fit with experimental results. The formulas are classified according to subject: rheology, thermodynamics, heat transfer, and part design. Each chapter covers the relevant relations in a particular field. A separate chapter is devoted to the practical equations for designing extrusion and injection molding equipment. Numerous thoroughly worked-out problems illustrate the use of the formulas.

The plastics engineer working on the shop floor in a plastics manufacturing plant often needs quick answers to questions such as why the extruder output is low or whether he can expect better quality product by changing the resin or if the die pressure can be lowered. Applying state-of-the art numerical software to address these issues is time-consuming and costly. Starting from practical design formulas which are easily applicable, and yet take the resin rheology into account, this guide provides answers to these questions quickly and effectively by guiding the user step by step through the computational procedures on the basis of illustrative technical examples. Problems related to melt fracture, homogeneity of the melt, effect of screw geometry on the quality of the melt and the effect of die pressure on the pellet surface and their troubleshooting are only few of the topics among many that are dealt with in detail. All the calculations involved can be handled by pocket calculators and hence can be performed right on the site where the machines are running. This guide is a valuable tool not only to troubleshoot but also to estimate the effect of design and process parameters on the product quality in plastics processing.

• A comprehensive book which collates the experience of two well-known US plastic engineers.• Enables engineers to make informed decisions.• Includes a unique chronology of the world of plastics. The use of plastics is increasing year on year, and new uses are being found for plastics in many industries. Designers using plastics need to understand the nature and properties of the materials which they are using so that the products perform to set standards. This book, written by two very experienced plastics engineers, provides copious information on the materials, fabrication processes, design considerations and plastics performance, thus allowing informed decisions to be made by engineers. It also includes a useful chronology of the world of plastics, a resource not found elsewhere.

The plastics engineer working on the shop floor in a plastics manufacturing plant often needs quick answers to questions such as why the extruder output is low or whether he can expect better quality product by changing the resin or if the die pressure can be lowered. Applying state-of-the art numerical software to address these issues is time-consuming and costly. Starting from practical design formulas which are easily applicable, and yet take the resin rheology into account, this guide provides answers to these questions quickly and effectively by guiding the user step by step through the computational procedures on the basis of illustrative technical examples. Problems related to melt fracture, homogeneity of the melt, effect of screw geometry on the quality of the melt and the effect of die pressure on the pellet surface and their troubleshooting are only few of the topics among many that are dealt with in detail. All the calculations involved can be handled by pocket calculators and hence can be performed right on the site where the machines are running. This guide is a valuable tool not only to troubleshoot but also to estimate the effect of design and process parameters on the product quality in plastics processing.

This book provides a simplified and practical approach to designing with plastics that funda mentally relates to the load, temperature, time, and environment subjected to a product. It will provide the basic behaviors in what to consider when designing plastic products to meet performance and cost requirements. Important aspects are presented such as understanding the advantages of different shapes and how they influence designs. Information is concise, comprehensive, and practical. Review includes designing with plastics based on material and process behaviors. As de signing with any materials (plastic, steel, aluminum, wood, etc.) it is important to know their behaviors in order to maximize product performance-to-cost efficiency. Examples of many different designed products are reviewed. They range from toys to medical devices to cars to boats to underwater devices to containers to springs to pipes to buildings to aircraft to space craft. The reader's product to be designed can directly or indirectly be related to product design reviews in the book. Important are behaviors associated and interrelated with plastic materials (thermoplastics, thermosets, elastomers, reinforced plastics, etc.) and fabricating processes (extrusion, injec tion molding, blow molding, forming, foaming, rotational molding, etc.). They are presented so that the technical or non-technical reader can readily understand the interrelationships.

An outstanding and thorough presentation of the complete field of plastics processing Handbook of Plastic Processes is the only comprehensive reference covering not just one, but all major processes used to produce plastic products-helping designers and manufacturers in selecting the best process for a given product while enabling users to better understand the performance characteristics of each process. The authors, all experts in their fields, explain in clear, concise, and practical terms the advantages, uses, and limitations of each process, as well as the most modern and up-to-date technologies available in their application. Coverage includes chapters on: Injection molding Compression and transfer molding Sheet extrusion Blow molding Calendering Foam processing Reinforced plastics processing Liquid resin processing Rotational molding Thermoforming Reaction injection molding Compounding, mixing, and blending Machining and mechanical fabrication Assembly, finishing, and decorating Each chapter details a particular process, its variations, the equipment used, the range of materials utilized in the process, and its advantages and limitations. Because of its increasing impact on the industry, the editor has also added a chapter on nanotechnology in plastics processing.