5.1 Introduction

Polymer foams that are made primarily from polyol, isocyanate and water are known as flexible polyurethane foams (FPF). In this chapter, we will discuss both slabstock and moulded FPF with a density of less than about 100 kg/m ³. The goal is to provide a general introduction to the chemistry, manufacturing, testing, and commercial aspects of FPF. Rigid polyurethane foams are covered elsewhere in this book. Readers are encouraged to use the citations to obtain more detailed information in areas of particular interest.

The earliest work on FPF was published in Germany in the 1940s [1]. A viable commercial process was quickly developed, and within a decade there were manufacturing sites in both Europe and North America. By the year 2000, more than three million tonnes of FPF were produced around the globe [2]. The industry continues to grow and expand into new markets, and foam grades are constantly being developed and improved to meet the ever-increasing demands of the end users.