U drvoprerađivačkoj industriji upotrebljavaju se ljepila na bazi formaldehida zato što je taj aldehid jeftin, jednostavan za uporabu, otporan na vlagu i ima posebne mehaničke učinke. Formaldehid ima određenih prednosti i nedostataka. Poznato je da se u ljudi koji rade u drvoprerađivačkoj industriji pojavljuju različite bolesti poput raka pluća, što može biti posljedica ispuštanja formaldehida u zrak tijekom i nakon proizvodnje ploča. Za ovo je istraživanje pripremljena smjesa urea-formaldehidnog ljepila dodavanjem četiriju različitih punila: ekstrakta kore primorskog bora (Pinus pinaster) i brijesta (Ulmus glabra), ekstrakta ljuske lješnjaka (Corylus avellana) i tanina žira u dva različita omjera. Posmična čvrstoća furnirske ploče od borovine (Pinus sylvestris) i smrekovine (Picea orientalis), proizvedene uporabom urea-formaldehidnog ljepila, ispitana je prema normi EN 314-1. Sve furnirske ploče, osim onih s taninom iz žira, zadovoljile su zahtjeve norme. Ispitivanje emisije formaldehida iz furnirskih ploča provedeno je prema normi EN 713-3. Tim je pristupom moguće brzo odrediti emisije formaldehida. Dobiveni su eksperimentalni rezultati za naknadna mjerenja, uključujući ispitivanje u komori. Primijećeno je da je ekstrakt kore brijesta smanjio emisiju formaldehida furnirske ploče od borovine za 40 %, dok su ostala punila smanjila tu emisiju za 3 – 37 %.

Formaldehyde-based adhesives are used in the forestry industry. This is because formaldehyde is inexpensive, easy to use and resistant to moisture; it also has particular mechanical effects. Formaldehyde has both advantages and disadvantages. It is known that various diseases such as lung cancer occur in humans as a result of the release of formaldehyde into the air during and after board production. In this study, a urea formaldehyde glue mixture was prepared by using four different fillers (extract of maritime pine (Pinus pinaster) and elm (Ulmus glabra) bark, extract of hazelnut (Corylus avellana) husk and acorn tannins) at two different ratios. The bonding shear strength of pine (Pinus sylvestris) and spruce (Picea orientalis) plywood produced with urea formaldehyde adhesive was tested according to EN 314-1 standard. All plywood, except the plywood with acorn tannin, met the requirements of the standard. A formaldehyde emission test of the plywood was carried out in accordance with EN 713-3 standard. With this approach, it is possible to quickly determine formaldehyde emissions. Experimental results were obtained for subsequent measurements, including chamber tests. It was observed that the elm bark extract reduced the formaldehyde emission of pine plywood by 40 %, while other fillers reduced it by 3-37 %.