DETERMINATION OF BONDING PERFORMANCES OF MODIFIED POLYVINYLACETATE (PVAc) AND KLEBIT 303 (K.303) ADHESIVES IN DIFFERENT HOT-SURROUNDINGS

In this study, performances of woods bonded with polyvinylacetate (PVAc) and Klebit 303 (K.303) thermoplastics glues and PVAc+UF and K.303+UF thermoset glues that were modified with Urea-fomaldehyde were investiguted at various temperatures. In total, 320 experimental samples were investigated at various temperatures which were prepared from pine wood (Pinus sylvestris L.), beech wood (Fagus orientalis L.) and were bonded with PVAc, K.303, PVAc+UF, K.303+UF glues. After these experimental samples were held for two hours at 20 °C, 40 °C, 60 °C, 80 °C temperature, tensile test was applied according TS EN 205. It was found that the adhesion performance of unmodified PVAc and K.303 bonded samples decreases when temperature increases, moreover, this retuction is smaller in samples bonded with PVAc+UF and K.303+UF in comparison to unmodified glues and in samples of beech wood in comparison to pine wood.

MODÝFÝYE EDÝLMÝÞ POLÝVÝNÝLASETAT (PVAc) VE KLEBÝT 303 (K.303) TUTKALLARININ FARKLI SICAKLIK ORTAMLARINDA YAPIÞMA PERFORMANSLARININ BELÝRLENMESÝ

Bu çalýþmada, termoplastik sertleþen Polivinilasetat (PVAc), Klebit 303 (K.303) tutkallarý ve bunlarýn termoset sertleþen Üre – formaldehit (UF) tutkalý ile modifiye edilmiþ çeþitleri olan PVAc + UF ve K.303 + UF tutkallarý ile yapýþmýþ aðacýn farklý sýcaklýk ortamlarýndaki yapýþma performanslarý araþtýrýlmýþtýr. Bu maksatla, sarýçam (Pinus Sylvestris L.) ve Doðu kayýný (Fagus Orientalis L.) odunlarýndan hazýrlanan toplam 320 adet deney örneði PVAc, K.303, PVAc + UF ve K.303 + UF tutkallarý ile yapýþtýrýlmýþtýr. Örneklere 20 °C, 40 °C, 60 °C, 80 °C’lik sýcak ortamlarda bekletildikten sonra TS EN 205 esaslarýna göre çekme deneyi uygulanmýþtýr. Sonuç olarak, modifikasyonsuz PVAc ve K.303 tutkallý örneklerde ortamýn sýcaklýðý arttýkça yapýþma performansýnýn azaldýðý, bu azalmanýn PVAc + UF ve K.303 + UF tutkallý örneklerde modifikasyonsuzlara ve kayýnda sarýçama göre daha düþük oranda olduðu belirlenmiþtir.