Modification of polycondensation adhesives with animal proteins. Part III. Industrial trials and results. The effort of authors is to determine the possibility of ecological and effective application of animal biopolymers into polycondensation adhesives used in woodworking industry. Modification of condensation adhesives with animal proteins were directed to urea-formaldehyde (Diakol Ml) and phenol-formaldehyde (Fenokol A) resins, with the aim to verify the influence of biopolymers on mechanical properties of plywood. The supposed source of biopolymers is solid waste from leather production (e.g. chromium shavings and chippings, hypodermic and adipose ligament, leather chippings, gelatine production and food packing). The aim of the research was the preparation and optimisation of technology for biopolymer production and following utilisation into adhesive mixtures with the application in woodworking industry in industrial conditions of Bučina Zvolen, a.s.. The solution of the problem of processing and application of animal biopolymers will be improved ecology at leather tanning and also in woodworking industry in the field of adhesive application and utilisation for furniture products.