A guide to doubleface manufacture17 February 2003
An English version of the book 'Technology and Manufacturing of Doubleface' has been published by Ediciones Díaz de Santos SA of Madrid. Dr Ramón Palop, leather chemical divisional manager for Spanish leather chemical manufacturers, Cromogenia-Units, writes the book, which is also available in Spanish. The 100-page book is broken down into eight easily digestible chapters beginning with the selection of raw materials through the doubleface manufacturing process to finishing. The book is intended for leather technicians in general and for those specifically producing suede shearling (doubleface) in particular. It is most useful for pupils in technical schools, as there are few books which tackle this subject in depth. The book's contents include a comprehensive look at the chemical and mechanical processes which are described with accompanying colour graphs, figures and photographs. There are a total of 28 photographs and graphics but many of these consist of two or three different graphs or pictures. There are also four tables. Special attention is paid to colourimetry and to its use in colour reproduction. Chapter one covers the types of skins used for doubleface, state of preservation of the raw skin, the morphology of the wool and the chemical composition of wool. Chapter two gives a general diagram of the process with sections on installations, soaking, washing wool, wet-process mechanical operations, pickling and bating and, finally, degreasing. Chapter three lists the most usual tanning agents in woolskin or fur processing; there are sections on chromium salts, aluminium salts, aldehydes, mixed tanning agents and mechanical operations in wet-blue condition. Chapter four covers neutralisation, fatliquoring, mechanical operations on crust, conditioning the wool and buffing. Chapter five contains sections on wool dyeing, acid dyestuffs, metal-complex dyestuffs, influence of tanning, influence of the prior ironing, conclusions and snow top dyeing. Chapter six explains about leather dyeing, factors which influence the dyeing, dyeing of leather with wool reserve and mechanical operations on colour. Chapter seven is divided into colourimetry, basic principles, colour measurement and specification, applications in quality control and colour duplication. Chapter eight details finishes for leather, nappalan finish and miscellaneous finishes. The book is completed by the bibliography. Dr Palop has spent most of his professional career carrying out research on the technology of leather manufacturing, particularly on doubleface. He was technical manager of CIESA, one of the leading tanners in the field for 18 years. He currently works as the applied research laboratory manager for the leather department at Cromogenia-Units SA. He has written extensively on technical subjects related to the manufacture of leather and has read papers at several symposia. Ramón Palop won the 10th Ramon Paniker prize for his research work on wool dyeing on doubleface leathers. In his prologue he says the idea for writing the book occurred to him out of a need to express the knowledge and experience acquired during more than 25 years of professional activity. He states: 'I feel privileged in this respect, since life has at each turn in this career afforded me the opportunity to learn, study and apply a highly specific technology, and one about which very little has been written (which is why the reader will find few bibliographical references in the course of the work. 'Much of the book has been written in different places and situations: in planes and hotel rooms, in La Garriga (Spain), Buenos Aires, Istanbul etc. The writing of it has been a true pleasure and source of enjoyment. 'I believe that doubleface is an article in which considerable equilibrium has to be maintained; we should remember that any chemical or mechanical process which is good for the wool is bad for the leather, and vice versa, so that the technician is always subject to a dual pressure, and his ability to resolve this duality can also serve him well when it comes to bringing harmony to a large number of dual situations we face in life itself.'