Wrinkle Resistant Finishing

Why do creases form in fabrics? This free online course in textile finishing begins by explaining why and how wrinkles form. It compares the properties of different fabrics and describes the structure of cellulosic fabrics, like cotton. Cellulosic fibres are made from cellulose, which is a starchy carbohydrate. They are used to create a wide range of fabrics, from heavy denim to lightweight corduroy and even delicate muslin and organza. These fabrics crease when bent or folded repeatedly, whereas wool doesn't crease easily. This course analyzes why this is so. Cellulosic fibres are characterised by the presence of a ‘hydroxyl group’ - you will understand the role of these functional groups in the treatment of a fabric for wrinkle resistance. You will also gain knowledge of the nature of intermolecular bonds, such as weak hydrogen bonds and strong covalent bonds, and their role in defining the characteristics of fabrics like cotton or wool. The course describes the reason certain fabrics have more resistant to creasing and better recovery from bending, thus being more resilient. Does the ‘resilience’ of a fabric imply its resistance to deformation or its recovery from deformation? You will gain an understanding of the meaning of resilience of fabric and how its resistance to creasing can be improved.

Next, this tutorial will introduce you to the compounds or urea-based, nitrogenous crosslinking agents that can be used for treating cellulosic fabrics to make them wrinkle resistant. Crosslinking is the formation of chemical links between molecular chains to form a three-dimensional network of connected molecules. It occurs when the hydroxyl groups with weak hydrogen bonds of different molecules in the cellulosic fibres, connect together by formation of a strong covalent bond, leading to a heightened resistance to wrinkle formation. Crosslinking agents enable the formation of covalent bonds between the molecules of cellulosic fibres via an acid-catalysed reaction. You will understand the basic principle of crosslinking reactions that help any fabric to overcome the strain of bending and resultant creasing, and also learn about the limitations of various nitrogenous crosslinking agents. This course describes in detail the application process of the ‘pad-dry-cure’ method and the role of specialist stenter machines in the production of wrinkle-resistant fabric. You will also gain an understanding of the methods of evaluating this process in a simple, easy-to-understand language.

Wrinkle-resistant cotton is the product of varied research by cotton chemists and physicists across the world from the 1800s to the early 20th century by using either zinc chloride or formaldehyde. There have been continuous developments in textile chemistry as a result of persistent research and collaboration to solve problems. This course offers you an opportunity to learn a specialised branch of science that uses the principles of organic and physical chemistry to offer a practical application of certain chemicals, resulting in a useful solution to the problem of creasing. By the end of this course, your understanding of the science behind wrinkle resistance in fabrics will be enhanced and useful for textile production, fashion design or research chemistry.