Tannin adhesive made from snakeskin fruit and its application for laminated wood

Snakeskin fruit called Salak is one type of tropical fruit that is widely grown in Indonesia. Salak fruit peels are known to contain a certain amount of tannin. This research explores the potential of rind salak fruit as the latest alternative adhesive. The extract from the rind had a tannin content of 1.85% and Stiasny number 76.67%. The results showed that the tannin extract of rind salak fruit was reactive to formaldehyde. Characteristics of Tannin Resorsinol Formadehyde (TRF) adhesives with variation in resorcinol concentration have a significant effect on its viscosity, gelatinization, and solid content. Utilizitaion of recorcinol 15% in TRF adhesive formula resulting a highest bonding strength of produced laminated wood. The value was 67.85 kg/cm3 with 53.3% wood failure on laminated wood. Those result indicated that utilization of tannin based adhesive from skin of salak fruit is very potential as an alternative raw material for bio adhesive.