Abstract

Natural leather is traditionally a high-quality material that is widely used for vehicle interior materials (e.g., automobiles, trains and airplanes) and fashion items (e.g., handbags, shoes and gloves). However, it is heavier than materials such as various fibres and synthetic leather, which makes it unsuitable for modern applications that prioritise lightness, portability and fuel efficiency. In addition, animal skins used as raw materials are structured with collagen protein, which limits the ability to ability to reduce the weight by altering the thickness and chemicals used in its preparation. In this study, we investigated the penetration, fixation, and foaming methods of thermally expandable microcapsules (TEM) in leather manufacturing procedures to reduce the weight of natural leather. Dyeing and fatliquoring were suitable processes for applying TEM to leather, and the combined use of acryl polymers enabled TEM to attach efficiently to the leather tissue. The manufacture of foamed leather under conditions of 20% TEM and 3% fixing agent resulted in an increase in the thickness by >20% and enabled the production of foamed leather with excellent physical properties.