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. Along with the increase in population, the need for building materials, namely wood, will increase, thus triggering rampant illegal logging, which will cause floods, landslides, and global warming. One of the efforts made to reduce the use of wood is to make gypsum composite boards. This study aims to utilize mahogany wood waste and jati wood powder as gypsum board fillers. Research has been carried out on processing waste sawdust from mahogany and jati wood as a filling material for making gypsum ceilings with polyvinyl alcohol adhesive by mixing and compacting using a hot compressor at 70 o C. Good quality with a density value of 0.82 g /cm 3 and absorption capacity of 38.4% complied with SNI 03-2105-2006. Mechanical properties with variations in impact strength (95:5:10) of 19.014 J/m 2 , flexural strength of variation (95:5) of 395, 446 N/m 2 , and fracture strength of variation (95:5:5) of 1.7758 N/m 2 . A Gypsum board was obtained, which did not meet SNI 03-6384-2000 on the gypsum board specification for the results of testing for flexural strength and fracture strength


INTRODUCTION
Along with the increasing population and the rapid development of technology, especially in the property sector, such as housing, hotels, office buildings, shops, and high-rise buildings, the need for building construction materials is also increasing. Wood is a building material widely used to construct housing, hotels, office buildings, shops, and multi-story buildings. Considering that the higher price of wood triggers illegal logging in the forest, it harms the environmental ecosystem in the forest, such as soil erosion resulting in landslides, floods, air pollution, and global warming (Kho, 2014). One of the efforts made to reduce the use of wood as a building construction material is to make gypsum composite boards. Composite is a polymeric material formed from a combination of two or more constituent materials

Liver Iman Putra Zai et all | Processing of Sawdow Waste of Mahoni and Jati Wood as a Material Gypsum Ceiling Fillers with Polivinyl Adhesive Alcohol
through a non-homogeneous blending process, which has different physical properties, namely as a filler or reinforcing material and matrix as a binding material. Composite materials generally have strong, tough, and heatresistant advantages. Natural fibers are an alternative composite filler for various polymer composites because of their superiority over synthetic fibers. Natural fibers are easy to obtain at low prices, easy to process, low density, environmentally friendly, and biodegradable (Minah, et al, 2017). Gypsum (CaSO4.2H2O) is one of the raw materials for making ceilings. It is widely used as a building construction material because it has advantages in terms of its mechanical properties: fire retardant, good finishing, lightweight, fast processing, and drying easily. Gypsum board is widely used for ceilings, particle wall elements, and decorative ceiling trim in residential rooms, hotels, office buildings, shops, and high-rise buildings. The ceiling is a building construction material widely used as a ceiling between the roof and the room below; it serves to place electrical installations, muffle loud and noisy sounds when it rains, and keep the temperature conditions in the room cool due to the intense sunlight. Illuminating the roofs of houses and hot steam and adding to the aesthetics of the building (Rizki et al., 2018). So far, the manufacture of gypsum board is still dominated by using gypsum or other materials as reinforcing materials. Currently, the use of gypsum board is still limited. This is because the availability of gypsum board on the market still needs to improve in strength, not as plywood, and the nature of gypsum board is brittle and not waterproof. Commercial gypsum ceilings that are widely circulated among the public have weaknesses in terms of poor physical properties such as low density (density) and high water absorption resulting in poor mechanical properties resulting in compressive strength, flexural strength, impact strength, very low tensile strength, and price. Expensive (Yang et al., 2013). The unfavorable properties of gypsum board can be corrected by adding fiber to its production. In general, the fibers often used as fillers are artificial fibers such as glass fiber, carbon, and graphite. Using natural fibers, namely hibiscus skin fiber, as a substitute for artificial fibers will reduce production costs. This can be achieved because of the low cost required for processing natural fibers compared to artificial fibers. One of the natural fibers that can be used as a composite filler to manufacture gypsum ceilings is sawdust from mahonia and jati wood (Widiarta et al., 2018). Sawdust of mahoni and jati wood has yet to be utilized optimally, mostly used as boiler fuel or burned without utilization, causing significant environmental damage. So far, the utilization of sawdust of mahoni wood waste (Swietenia macrophylla king) and jati (Tectona grants lf) has already been done, namely its utilization as alternative energy by pyrolysis method (Abdurachman, 2018;Rabiatul, 2017). Mahoni sawdust is a type of sawdust widely used in Indonesia's wood processing industry. The structural components of sawdust of mahonia wood are 47.26% cellulose, 27.37% hemicellulose, 74.63% holocellulose, and 25.82% lignin (Abdurachman, 2018). Jati wood produces sawdust waste which is widely used for making paper. Teak sawdust also contains 47.5% cellulose, 29.9% lignin, 14.4% pentosan, 1.4% ash content, 0.4% silica, solubility in cold water 1.2%, solubility in hot water 11.1%, solubility in alcohol benzene 4.6% and solubility in NaOH 1% 19.8% (Martawijaya, 1999)

Tools and Materials
The equipment used in this study includes analytical balance, a set of matrix printers and hot presses, and a set of test kits. The materials used in this study were gypsum flour, mahogany sawdust, and teak wood polyvinyl alcohol adhesive.

Making Gypsum Ceiling from a Combination of Sawdust of Mahoni and Jati Wood before Addition of Polyvinyl Alcohol Adhesive (PVA)
Gypsum flour and a combination of mahoni & jati wood sawdust were weighed according to a predetermined composition variation (% b/b) 95:5, 93:7, and 90:10. Then mixed into one for each composition variation and stirred using a spatula in the container manually until homogeneous. Then the mixture is poured into a mold evenly coated with aluminum foil. The mixture is then pressed/pressed using a hot compressor for 30 min at a temperature of 90 o C. Then it is removed from the mold. The printed sample is divided into several parts to carry out tests, both physical and mechanical properties, FTIR test.

Making Gypsum Ceiling from a Combination of Mahogany and Teak Wood Powder after Adding Polyvinyl Alcohol Adhesive (PVA)
Gypsum flour and a combination of mahoni & jati and PVA sawdust were weighed according to a predetermined composition variation (% b/b) 95:5:5, 95:5:7.5 and 95:5:10. Then mixed into one each composition variation and stirred using a spatula in a container manually until homogeneous. Then the mixture is poured into a mold that has been evenly coated with aluminum foil. The mixture is then pressed / pressed using a hot compressor for 30 min at a temperature of 90 o C. Then it is removed from the mold. The printed sample is divided into several parts to carry out tests, both physical and mechanical properties, FTIR test.

RESULTS AND DISCUSSION
Several tests and analyses have been carried out on samples of gypsum board ceilings by utilizing sawdust of mahoni and jati wood as filler for gypsum board using polyvinyl alcohol (PVA) as an adhesive, with variations in the ratio of the composition of gypsum and fillers without the addition of adhesive (95:5,93:7, and 90:10) and variations in the ratio of the composition of gypsum and fillers with polyvinyl alcohol (PVA) adhesives namely (95:5:5, 95:5:7,5, and 95:5:10).

Figure 1. Relationship between Gypsum Ceiling Density and Mahoni and Jati
Powder Filler.
So adding sawdust of mahoni and jati as a filler by reducing the composition of the gypsum produces a much smaller sample density. With the addition of mahonia and jati sawdust as fillers, the density value of the material tends to decrease; this is because mahogany and teak sawdust have a lower density, so when adding fillers to the mixture, it will reduce the density of the mixture (Parinduri, 2013).

b. After Addition of PVA
Density values range from 0.975 g/cm 3 to 0.995 g/cm 3 , indicating that adding PVA tends to lower the density values. This shows that the smaller the density of a gypsum board, the better it is used as a ceiling because it is lighter and safer for the user in the event of damage. (Salon, 2009). Based on Figure 3, the graph shows that the percentage for pure gypsum is 45.5%. The maximum percentage of water absorption in the 95:5 variation is 43.0%, while the minimum percentage in the 90:10 variation is 38.4%. From the graph of Figure 4.3, it can be seen that the addition of mahoni and jati sawdust tends to reduce the water absorption value in the test sample where the minimum composition of mahoni and jati wood is 90:10 the water absorption is around 38.4%, while the maximum composition of mahoni and jati wood powder is 95: 5 which is 43.0% water absorption. The 90:10 composition is the optimum composition for water absorption in the sense that the ability to absorb water decreases (Salon, 2009).   -2105 (2006), the results of this study are still by the standard, where the maximum permissible water absorption limit is 50%, except for the 95:5:10 variation (Rahmadi Indra, 2011).

Liver Iman Putra Zai et all | Processing of Sawdow Waste of Mahoni and Jati Wood as a Material Gypsum Ceiling Fillers with Polivinyl Adhesive Alcohol
The impact strength of gypsum ceilings ranges from14,960J/m 2 -19.014 J/m 2 , where optimum results were obtained on the composition of gypsum and sawdust of mahoni and jati with a ratio of (95:05:10) 19.014 J/m 2 . The results show that adding PVA adhesive increases the impact strength value. The existence of empty cavities that are not filled with PVA adhesive will affect the impact strength of the resulting gypsum ceiling, where the more amount of adhesive is distributed, the impact strength of the gypsum ceiling will increase (Purnama et al., 2013). In addition, adding fiber to the composite can disrupt the bonds between the matrices in the polymer.