Some characteristics of urea-formaldehyde powder adhesives

Abstract

Urea-formaldehyde (UF) glue resins were the most important type of adhesives in the wood industry last 60 years, especially for the production of wood based panels. More convenient spray dried UF powders went into use last two decades. Small and medium private wood processing plants in Serbia prefer to use such powder adhesives, since they are more convenient for small capacity production. There is no production of UF powder resin in Serbia so necessary quantities are imported from abroad including producers from Asia. However, their characteristics are variable, dependent on syntheses steps and not well known among users. Objective of this research was to determine conveniences and lacks in application of two imported UF powder resins in comparison to domestic UF emulsion.Urea-formaldehidni (UF) adhezivi su najvazniji adhezivi u drvnoj industriji posledljih 60 godina, posebno za proizvodnju ploca na bazi drveta. Od pre dve dekade usli su u upotrebu pogodniji urea-formaldehidni adhezivi u praskastom stanju, proizvedeni rasprsivanjem u vakuumu. Male i srednje privatne fabrike za preradu drveta u Srbiji radije koriste ovakve sprasene adhezive, posto su pogodniji za nisko kapacitetnu proizvodnju. U Srbiji se ne proizvode ovakvi urea-formaldehidni adhezivi, pa se oni uvoze iz inostranstva ukljucujuci i azijske proizvodjace. Medjutim, njihove karakteristike variraju zavisno od postupka sinteze i korisnici nisu dobro upoznati sa njima. Cilj ovog rada bio je odredjivanje pogodnosti i nedostataka primene dva uvezena praskasta urea-formaldehidna adheziva, u poredjenju sa dobro poznatom domacom urea-formaldehidnom emulzijom.