Collagen Materials – Collagen Processing. Technical Freedom and Scientific Challenges when Transforming Collagen into Final Materials

Skins are used to manufacture leather, casings and gelatine, soluble collagen for cosmetic purposes as well as medical devices like hemostyptic sponges, threads, films and matrices for cell culture. All of these materials are manufactured from the same biological polymer collagen. However, the skin as tissue is a natural product, a complex system far from being homogenious compared to most industrial products. Already its basic structure the collagen triple helix consists of different protein chains, there are different collagen types, the protein chains are naturally crosslinked, varying with sex, age and species, the collagen fibrils and fibre bundles vary in form, length, thickness and fiber angle over the crossection of the skin and over its area. Nevertheless, some processing steps are common for most final materials as unhairing, liming, crosslinking, and drying. But order and intensity of these steps, the addition of some further processing stages as well as small amounts of additives are of utmost importance for the proerties of the final materials. The lecture will give an overview on the state of the art of collagen processing and some resulting materials. The strategies to adjust final properties will be discussed with regard to known changes of the collagen structure, and open questions upon structure changes during processing will be touched.