The goal of this book is the modelling of the production process of environmentally friendly fibres and yarns used in the textile industry for tomorrow’s environment. Since the success of production processes in the textile industry depends on good planning and having a clear programme from the raw materials until the final product, the focus of this book is in the modelling of the production process of biodegradable fibres. Fully biodegradable petroleum co-polyester was used to explain the book theory. The biodegradable textiles could be used for different applications, as an alternative to commercial chemical fibres at reasonable cost, leaving no environmental footprint. The present book: • Relates to biodegradable textiles and supports the production of environmentally friendly fibres. • Investigates and simulates the relationships between the fibres/yarn properties and the processing conditions by using factorial experimental design. • Establishes programmed forecasting models and applications in the experimental ranges studied, the forecasting program simulates the production processes of biopolymers, and saves time and cost.