Abstract: Disclosed herein is a process for bringing amino-type compounds such as amines, amides, imines and proteins, containing --NH.sub.2 and .dbd.NH groups, into liquid form, usually a solution, by reaction with glyoxals. The resulting liquids, which can dissolve further materials such as natural and synthetic fibres, are especially useful as hardeners for collageneous materials used in the preparation of films such as sausage casings. An especially preferred preparation for this purpose comprises an animal hide fibre composition and a precondensate formed from collagen scrap, e.g. waste skin casing or leather scraps, dissolved in a solution of glyoxal.

Abstract: A preparation is disclosed herein which may be used for making shaped articles, particularly for making tubular films for the packaging of sausages. The preparation comprises collagen and a precondensate, which precondensate comprisesA. one or more structural units derivable from a compound containing at least one amine group, andB. one or more structural units derivable from a compound containing at least one aldehyde group and/or one or more structural units derivable from a polyhydroxy compound.Also disclosed are a process for making the preparation, a method of making a shaped article from the preparation, and shaped articles so made. The collagen used is advantageously contained in an animal hide fibre composition.