MODIFIED PROCESS FOR SETTING THE STABLE STATE OF FORMALDEHYDE EMISSION DETERMINED BY THE FLASK METHOD IN WOOD-BASED PANELS

摘要

The invention relates to a process for determining the emission of formic aldehyde released by wood-based panels glued with adhesives based on aminic resins containing free formic aldehyde. According to the invention, the process consists in determining the stable state of formaldehyde emission by the flask method, within a time interval of 172 h, on separate test sample sets arranged in packs, at equal gaps of 1 mm from one another, by using a power-type function of the form Y= a+b/xfor the temperature of 25°C or 40°C, and another function of the same type, of the form Y=a.b.xfor the temperature of 60°C and by the control of the stable state of the formaldehyde emission, by using the inequation [(C-C) /C] ≤ sigma, where the variables are the formic aldehyde concentrations at moments within the set time interval and σ is a coefficient having the value ≤ 0.02 for the chipboards and 0.05 for plywood, respectively, both products being glued with adhesives based on aminic resins containing free formic aldehyde.