WOOD RESEARCH Volume 70, Number 3, 2025
NUR DZAKIRA SAHBANI, ANDI DETTI YUNIANTI, SUHASMAN S, Kidung Tirtayasa Putra Pangestu, GUSTAN PARI, and LISNA DEVIYANTI

EFECTIVENESS OF SAPPAN WOOD DYE MICROPARTICLES IN THE DYEING OF CANDLENUT AND GMELINA WOOD WITH ALUM AND SODA ASH MORDANTING PRETREATMENT

The aesthetic appearance of wood, especially for handicrafts, is greatly influenced by color. Dyeing is an important method to improve the aesthetics of wood. This research focuses on the effectiveness of wood staining using natural dyes from sappan wood, which has the color-giving compound brazilin. However, natural colorants are often less effective due to their low affinity to wood. Therefore, this study aimed to determine the effectiveness of micro-particles of sappan wood natural dye on candlenut wood and gmelina wood. The pretreatment given during the dyeing process is mordanting using alum and soda ash to improve color absorption and durability. The results showed that mordanting pretreatment with a combination of alum and soda ash (5 g/l : 5 g/l) provided optimal dye penetration depth in both types of wood. FTIR analysis confirmed the interaction between the colorants and the wood components. Candlenut wood showed deeper dye penetration than gmelina wood, which is thought to be due to differences in the anatomical structure of the wood.

WOOD RESEARCH Volume 68, Number 4, 2023
ANDI DETTI YUNIANTI, Kidung Tirtayasa Putra Pangestu, Sahriyanti Saad, Citra Oktapiani, Ratih Damayanti, and Heriyanto

Color Improvement of Pretreated Gmelina Wood by Impregnation of Natural Dyes

The purpose of this research was to improve the appearance of pretreated gmelina wood (Gmelina arborea) by coloring with a natural dye. The dyes used in this research were obtained from sappan (Caesalpinia sappan) and tegeran (Cudrania javanensis) wood waste with a size of 20-40 mesh. The anatomical characteristic that determined the permeability of the gmelina wood was investigated referring to International Anatomist Wood Association (IAWA), while the characteristic of the dye was analyzed using X-ray diffraction (XRD). The wood was colored by immersing in dye mixture (ratio dye and water of 1:5 wt/wt) at room temperature during 72 h. The results showed that the lumen diameter of vessel, fiber, and pit of gmelina observed were 159 μm, 23 μm, and 6 μm, respectively. The XRD analysis showed that the structure of sappan was more amorphous than tegeran, which led to penetrate deeper into the wood. The pretreated wood provided more dyes penetration compared to the untreated wood due to the removal extractives from the wood. The pretreatment on gmelina wood would facilitate the natural dye to be impregnated into the wood cell resulting in more attractive color of the wood.