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.

COMPARISON OF FIBER QUALITY AND ANATOMICAL STRUCTURES OF ACACIA MANGIUM FROM BREEDING ACTIVITIES

This study aimed to analyze the effect of a tree breeding program on the fiber quality and anatomical structure of 10-year-old Acacia mangium wood. There are three trees in each breeding generation, namely the first generation (F0) and the second generation (F1). The results showed the average fiber dimensions of all populations were as follows: First generation has 966.05 µm length, 19.84 µm diameter, and 3.78 µm cell wall thickness, while Second generation has 1046.23 µm fiber length, 20.23 µm fiber diameter, and 3.56 µm cell wall thickness. The genetic improvement treatment showed significant improvement in the fiber dimension. According to the quality classification grade for pulp and paper raw materials, all populations belong to quality class II. Based on the list of the International Association of Wood Anatomists (IAWA), it can be ascertained that the wood anatomical structures of all populations showed no microscopic differences

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.