STUDY UPON THE SHEARING STRENGTH OF GLUINGS MADE WITH MIXED FURAN RESIN WITH FURFURYLIC ALCOHOL OF URELIT FC-2 TYPE

Valeriu Petrovici
Prof.Eng., PhD – „Transilvania” University of Brasov – Faculty of Wood Industry
Address: B-dul Eroilor nr. 29, 500036 Brasov, Romania
Tel: 0040 268 412921/int. 166. Fax: 0040 268 415315. E-mail: petrovic@unitbv.ro

Anca Maria Varodi
PhD-student, Eng. - „Transilvania” University of Brasov – Faculty of Wood Industry
Address: B-dul Eroilor nr. 29, 500036 Brasov, Romania. E-mail: petrovic@unitbv.ro

Emilia-Adela SALCA
Lecturer Eng., PhD-student - „Transilvania” University of Brasov – Faculty of Wood Industry
Address: B-dul. Eroilor nr. 29, 500036 Brasov, Romania
Tel:0040 268 412921/int.192. Fax: 0040 268 415315. E-mail: emilia.salca@unitbv.ro

Abstract:
Within this paper the authors present the results of their own researches performed at the laboratory phase, regarding the shearing strength of gluings made with mixed furan resin with furfurylic alcohol of URELIT FC-2 type, under the conditions of the resin reticulation at the temperature of 20ºC.
A constant additive of 5% ammonium chloride and hardener of IR type were used as catalyst, each of them as such in solid state and under the form of aqueous solutions with the concentrations of about 20% and 25% respectively.
The shearing strengths of the gluings in dry state and after 24 hours of cold water immersion were determined under the following conditions: the gluing temperature of 20ºC, the pressing time of 4 hours and the specific pressures of 0.4 and 1.2N/mm2. The specific adhesive consumptions resulted were by 46-54% smaller than the ones of the urea resin of URELIT R type which was used as control sample. The specific consumptions were different depending on the catalyst type and state.
When calculated as absolute values at the same specific consumption of the oven-dry applied adhesive, the shearing strengths of the gluings made with mixed furan resin with furfurylic alcohol of URELIT FC-2 type were 29-135% higher in dry stare and 32-85% higher after 24 hours of water immesion at the temperature of 20ºC, all these results being in relation to the same urea resin.
In the case of the furan resin of URELIT FC-2 type, the pressure of 1.2N/mm2 leads to different values of the shearing strength of the gluing than the ones obtained for the pressure of 0.4N/mm2, such as 1.6-2.25 times higher in dry state and 1.73-2.14 times higher after 24 hours of water immersion at the temperature of 20ºC.
The catalysts under the form of aqueous solutions lead to higher values of the shearing strength of the gluing than the ones determined when using them in solid state, a favorable action being obtained when using the ammonium chloride solution with the concentration of 20%.

Key words: furan resin, furfurylic alcohol, adhesive, cold cure, catalyst, shearing strength of the gluing.