Fluoropolymer Applications in the Chemical Processing Industries

The Definitive User's Guide and Handbook

Sina Ebnesajjad, Pradip R. Khaladkar

• Publisher: William Andrew
• Year: 2017
• Print ISBN:
  9780323447164
• Edition: 2
• eBook ISBN:
  9780323461153
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Fluoropolymer Applications in Chemical Processing Industries: The Definitive User's Guide and Handbook, Second Edition, contains the most extensive collection of data and information on fluoropolymer applications in chemical processing industries. Because of their superior properties, fluoropolymers have been rapidly replacing metal alloys for corrosion inhibition in chemical processing equipment. This book is a complete compendium of information about fluoropolymer lining materials and structural piping and tubing. Fluoropolymer surfaces preserve purity of processing streams in the chemical processing, plastics, food, pharmaceutical, semiconductor, and pulp and paper industries. Updated to reflect major changes since 2004, this book contains practical, problem-solving tools for professionals in those industries. Equipment manufacturers, plant operators, and product design and manufacturing engineers all will benefit from the in-depth knowledge provided. This new edition includes new fluoropolymer grades and new examples of the fluoropolymer role in preventing corrosion. New fabrication techniques have been added, and additional emphasis has been placed on adhesion and welding techniques. New sections have been added on inspection of new linings, and in-service inspection – including inspection frequency, acceptance criteria, fitness for service evaluation, and reparability. - Includes extensive guidelines for the selection of fluoropolymers for corrosion control - Features a detailed 'how-to' on processes that convert fluoropolymers into shapes and parts - Discusses fabrication techniques to finish the fluoropolymer components before exposure to harsh chemical environments - Includes laboratory techniques to determine the cause of part failure, and a modeling methodology to predict and analyze failure of fluoropolymer parts

1

Introduction to Fluoropolymers

Abstract

Carbon and fluorine are the major elements that form polytetrafluoroethylene (PTFE) homopolymers. The C

F bond is the main reason these plastics have many special properties surpassing those of most other polymers. These properties span mechanical, electrical, and thermal characteristics of the fluoropolymers in addition to their chemical resistance.

This book describes fluoropolymers in chemical processing industries. These industries often handle chemicals, usually corrosive, during the manufacturing of diverse products. Examples of important industries include chemical manufacturing, plastics manufacturing and processing, semiconductor manufacturing, pharmaceutical and biopharmaceutical industries, and food processing.

Keywords

Fluorinated ethylene propylene; Fluoropolymers; Perfluoropolymers; Polytetrafluoroethylene; Teflon; Tetrafluoroethylene

1.1. Introduction

Carbon and fluorine are the major elements that form polytetrafluoroethylene (PTFE) homopolymers. The C

F bond is the main reason these plastics have many special properties surpassing those of most other polymers. These properties span mechanical, electrical, and thermal characteristics of the fluoropolymers in addition to their chemical resistance.

This book describes fluoropolymers in chemical processing industries. These industries often handle chemicals, usually corrosive, during the manufacturing of diverse products. Examples of important industries include chemical manufacturing, plastics manufacturing and processing, semiconductor manufacturing, pharmaceutical and biopharmaceutical industries, and food processing.

Fluoropolymers replace stainless steel and exotic alloys such as Hastelloy in processes involving highly reactive chemicals. This plastic family has successfully met the requirement of purity, which is essential in semiconductor, food, and biopharmaceutical production. The nonstick surface and extreme temperature characteristics of fluoropolymers have reserved a special place for them in the world of equipment construction materials. This chapter offers a brief history of the discovery and the evolution of fluoropolymers, their applications, and the introduction of various types of this plastic family.

Inception of fluoropolymers began with a small incident that did not go undetected by the careful and observant Dr. Roy Plunkett of DuPont Company [1]. In 1938, he had been at DuPont for 2 years, concentrating mostly on the development of fluorinated refrigerants. He was experimenting with tetrafluoroethylene (TFE) for synthesis of a useful refrigerant tetrafluorohydrochloro ethane (CClF₂

CHF₂) [2]. The objective was to create safe, nonflammable, nontoxic, colorless, and odorless refrigerants. On the morning of April 6, 1938, when Plunkett checked the pressure gauge on a full cylinder of TFE, he found no pressure. The cylinder, however, had not lost weight. Removal of the valve and opening the cylinder yielded a few grams of a waxy white powder—the first polymer of TFE [2].

Plunkett analyzed the white powder, which was conclusively proven to be PTFE. He could not dissolve the slippery PTFE in any solvent, acid, or base. After melting, it formed a stiff clear gel with no tendency to flow [3,4]. Later, researchers were able to fabricate parts from PTFE by processing techniques similar to those used to make parts from metal powders. At the time, the Manhattan Project was seeking new corrosion-resistant materials for gaskets, packings, and liners for uranium hexafluoride (UF₆) handling. PTFE provided the answer because of its extreme resistance to chemicals. The US Government maintained a veil of secrecy over the PTFE project until the end of World War II.

Large-scale monomer synthesis and controlled polymerization were technical impediments to be overcome. Intense research resolved these problems, and small-scale production of Teflon (trademark, 1944) began in 1947. In 1950, DuPont scaled up the commercial production of Teflon in the Uni...

Table of contents

• Cover image
• Title page
• Table of Contents
• Series Page
• Copyright
• Dedication
• Preface
• Acknowledgments
• 1. Introduction to Fluoropolymers
• 2. Materials of Construction
• 3. Properties of Neat (Unfilled) and Filled Fluoropolymers
• 4. Selecting Fluoropolymers for Corrosion Control
• 5. Manufacturing of Parts From Tetrafluoroethylene Homopolymers
• 6. Manufacturing Parts From Melt-Processible Fluoropolymers
• 7. Fabrication Techniques of Fluoropolymers
• 8. Design and Construction of Linings and Vessels
• 9. Operation, Inspections, Maintenance, and Repairs
• 10. Failure Analysis of Fluoropolymer Parts
• 11. Cost Analysis
• 12. Safety, Health, Environmental, Disposal, and Recycling
• 13. Future Trends
• Index