Proučevanje utrjevanja lepil na osnovi tanina in lignina s sistemom za avtomatizirano vrednotenje zlepljenosti

Brus, Maks (author), Dolenc, Jernej (author), Serženta, Aleš (author), Šernek, Milan (author)

V raziskavi so bile proučevane lepilne mešanice na osnovi lignina in tanina, zamrežene s heksametilentetraminom (HMTA) in heksametilendiaminom (HMDA). Proces utrjevanja lepila je bil raziskan z metodo ABES (Automated Bonding Evaluation System) pri desetih različnih časih stiskanja od 15 do 600 sekund in štirih temperaturah: 125 °C, 150 °C, 175 °C in 200 °C. Dodatno je ugotavljanje strižne trdnosti lepilnega spoja potekalo po EN 12765:2016 in EN 205:2016, pri temperaturi 200 °C in času stiskanja 15 minut, pri taninskem lepilu tudi pri 175 °C in 15 minutah. ABES rezultati so pokazali, da je strižna trdnost lepilnih spojev naraščala s temperaturo in časom stiskanja. Najvišja trdnost okoli 6,4 MPa je bila ugotovljena za lepilni mešanici T-HMDA in L-HMDA pri 200 °C in času stiskanja 10 minut. Lepilni spoj na osnovi lignina je imel nižjo trdnost kot lepilni spoj na osnovi tanina. Najvišja trdnost po standardni metodi je bila ugotovljena za T-HMDA pri 175 °C in je znašala 10,8 MPa, kar zadostuje zahtevam standarda za nekonstrukcijsko rabo v suhih pogojih (C1).

• Language: Slovenian
• Keywords: naravna lepila, taninska lepila, ligninska lepila, ABES
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 29-38
• Numbering: Vol. 75, no. 1
• PID: 20.500.12556/RUL-184488
• UDC: 630*8
• ISSN on article: 2590-9932
• DOI: 10.26614/les-wood.2026.v75n01a02
• COBISS.SI-ID: 284035075
• Publication date in RUL: 08.07.2026

Record is a part of a journal

• Title: Les
• Publisher: Biotehniška fakulteta, Oddelek za lesarstvo, Biotehniška fakulteta, Oddelek za lesarstvo, Založba Univerze v Ljubljani
• ISSN: 2590-9932
• COBISS.SI-ID: 290940672

Licences

• License: CC BY-SA 4.0, Creative Commons Attribution-ShareAlike 4.0 International
• Link: http://creativecommons.org/licenses/by-sa/4.0/
• Description: This Creative Commons license is very similar to the regular Attribution license, but requires the release of all derivative works under this same license.

Secondary language

• Language: English
• Title: Study of the curing of tannin- and lignin-based adhesives using an automated bonding evaluation system

Abstract

This study investigated adhesive mixtures based on lignin and tannin crosslinked with hexamethylenetetramine (HMTA) and hexamethylenediamine (HMDA). Curing was assessed using the ABES (Automated Bonding Evaluation System) at ten different pressing times, ranging from 15 to 600 seconds, and at four temperatures: 125 °C, 150 °C, 175 °C, and 200 °C. Shear strength was evaluated according to EN 12765:2016 and EN 205:2016 at 200 °C with a 15-minute press time, and for the tannin adhesive also at 175 °C with a 15-minute press time. ABES results show that bond shear strength increased with pressing time and pressing temperature. The highest strength achieved with ABES was for T-HMDA and L-HMDA, of around 6.4 MPa at 200 °C and 10-minute press time. The lignin-based adhesive exhibited lower shear strength than the tannin-based adhesive. The highest bond strength obtained by standard testing was for T-HMDA at 10.8 MPa when pressed at 175 °C, which is sufficient for non-structural use in dry conditions (C1).

• Keywords: natural adhesives, tannin adhesives, lignin adhesives, ABES

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P4-0015
• Name: Les in lignocelulozni kompoziti