EVALUATION OF FINISHED PRODUCT QUALITY DEPEDING ON PAPER PROPERTIES AND BINDING TECHNIQUE

Perfect bound book is certainly the most used type of book product on the market. The quality of this kind of product can be identified with the binding strength of the book block. There is only one standardized method for book block strength determination and it refers to the static testing of interrupted tensile force required to separate precisely defined leaves within a test sample. In this paper, six groups of book block were investigated, different with regard to paper composition, i.e. the share of primary and recycled fibres and thus the content of ash and calcium carbonate. Furthermore, two binding techniques were used, but all other parameters – volume, format, pressure and drying time, temperature and humidity, were always same and strictly controlled. Based on obtained results, evaluation of finished product quality was performed, depending on paper properties, as well as evaluation of the used binding techniques. By calculating coefficients of variation, a binding technique that allows a more uniform application and guarantees reliability and repeatability of the quality results was chosen, regardless the paper composition