As producer you have a high regard for maintaining an excellent and stable quality of your product. Tests result that tensil strength of glued connections is mostly determined by the air conditions during the process of gluing. To guarantee a constant tensil strength not only the temperature but also the air humidity is very important.
Mainly polyurethane or hot melt glues react strongly on air humidity. If the air humidity drops under 50%, the glue will harden slower and the optimum tensil strength will never be reached; these glues react strongly to the present humidity. By increasing the air humidity to 65% till 70%, a strong harden will take place.