STUDY CONCERNING THE QUALITY OF SOME LIGNIN-BASED ADHESIVE COMPOSITIONS FOR GLUED LAMINATED BEECH WOOD

Anca-Maria VARODI
PhD.Eng. - Universitatea "Transilvania" din Brasov - Facultatea de Industria Lemnului
Address: B-dul Eroilor nr. 29, 500036 Brasov, Romania
E-mail: anknel@yahoo.com

Valeriu PETROVICI
Prof.Dr.Eng. - Universitatea "Transilvania" din Brasov - Facultatea de Stiinte Economice
Address: Bd. Eroilor 29, 500036 Brasov, Romania
Tel: +40 268 412921/int. 166. Fax: +40 268 415315.
E-mail: petrovic@unitbv.ro

Abstract:The main objective of this paper is the comparative study of some adhesive compositions based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type, compared to a classic urea resin of URELIT R type, using the same addition amount of rye flour or technical lignin of PROTOBIND type, at 2 and 4 hours pressing time. The determination of the quality for such adhesive compositions was achieved through determination of the gluing shearing strength of some beech samples, in dry state, as well as under diverse climatic exposure conditions according to STAS 5114-85. It was established that the gluing shearing strength of all adhesive compositions mostly depends on four influencing factors, namely: type of resin, type of dilution-plastifying material, pressing time and type of applied treatment. Regarding the influence of the resin type, it was shown that the gluing shearing strength for the adhesive compositions based on mixed furan resin with furfurylic alcohol are superior to the ones which use the classic URELIT R type urea resin. Regarding the influence of the dilution-plastifying material, the best results were obtained when instead of the rye flour, a technical lignin of PROTOBIND type was used. Regarding the pressing time, it was found that the gluing shearing strength increases with the pressing duration, the values obtained at 4h pressing time being much higher than at 2h pressing time. Regarding the influence of the applied treatment, it was found that the gluing shearing strength is much higher in case of the dry treatment and the order of decreasing values for the five analysed wet treatments was also established. As an overall conclusion of the performed study, it was found that the use of the adhesive composition based on mixed furan resin with furfurylic alcohol of FC-2 URELIT type allows the reduction of the specific glue consumption by ca. 45%.

Key words: furan resin, technical sulphate lignin, gluing shearing strength, urea resin.

REFERENCES
PETROVICI, V.; VARODI, A.M.; PIRNUTA, O.A.; COLCEA, G.; CRACIUN, V.; SCURTU, E.; BORZEA, I. (2006). Cercetari privind gelificarea si rezistenta incleierii la forfecare a rasinii furanice mixte cu alcool furfurilic tip URELIT FC-2 (Research Concerning the Jellification and Shearing Streangth of Joints Glued With Furan Resin Mixed With Furfurilylic Alcohol of the FC-2 URELIT Type). In: Proceedings of the 5th International Symposium, Wood Structure and Properyies'06, September 3-6, Slovakia, pp.337-342.
PETROVICI, V.; VARODI, A.M.; SALCA, E.A. (2007). Study Upon the Gluing Shearing Strength of Some Adhesive Compositions Based on Lignin and Mixed Furan Resin with Furfurylic Alcohol of FR-2 URELIT Type. Proceedings of ALL DIVISION 5 IUFRO Conference FOREST PRODUCT AN ENVIROVMENT: A PRODUCTIVE SYMBIOSIS, 29th October - 9nd November Taipei, TAIWAN.
PETROVICI, V.; VARODI, A.M.; BORZEA, I. (2005). Noi aspecte privind caracterizarea unor rasini furanice cu intarire la rece fabricate in Romania. (New Aspects Concerning the Characterisation of Some Furanic Resins with Cold Setting made in Romania) In: Proceedings of National Conference "Wood Science and Engineering in the Third Millenium",Brasov, Romania, pp.149-158.
VARODI, A.M. (2006). Studiul privind caracterizarea si utilizarea actuala a rasinilor furanice. (Study Regarding the Furan Resin Characterization and Actual Use). Referat de doctorat, Universitatea Transilvania din Brasov, Facultatea de Industria Lemnului, Brasov
VARODI, A.M.; PETROVICI, V. (2008). Studiu privind rezistenta incleierii la forfecare a unor compozitii adezive pe baza unui amestec de rasina ureica si furanica. (Study Upon the Gluing Shearing Strength of Some Adhesive Compositions Based on a Mixed Ureic and Furanic Resin). PRO LIGNO 4(1):31-39.
*** Fisa tehnica (Technical Sheet) nr. 7/2004, URELIT R, S.C. VIROMET S.A. Victoria
*** STAS 12593/1-87. Rasina furanica cu intarire la cald pentru abrazivi (Hot Cure Furan Resin for Abrasives).