Kekuatan Sambungan Kotak (Box Joint) Pada Kayu Jati Berdasarkan Jumlah Gigi | Box Joint Strength in Teak Wood Based on Number of Teeth

Kayu jati (T. grandis) merupakan kayu yang memiliki kelebihan kuat, awet, dan mudah diolah. Pemanfaatan kayu jati beragam diantaranya sebagai bahan baku pembuatan furnitur seperti lemari dan rak penyimpanan yang didalamnya terdapat sambungan kotak. Perlu dilakukan pengujian kekuatan untuk membandingkan kualitas sambungan kayu jati (T. grandis) di 3 usia berbeda yaitu muda (15-24 tahun), panen (25-35 tahun), dan tua (>35 tahun) dengan penggunaan variasi jumlah gigi pada sambungan kotak 4, 8, dan 12. Sebanyak 54 sampel dengan sambungan yang direkatkan menggunakan perekat poliuretan pada masing-masing sampel yang digunakan. Penelitian ini dilakukan dengan pengujian sifat fisis berupa kadar air dan kerapatan sampel serta pengujian mekanis sambungan kotak berupa pengujian momen tarik dan tekan. Pada sifat fisis, diperoleh rata-rata tertinggi kadar air dan kerapatan kayu jati senilai 15,36% dan 0,66 g/cm3. Pada sifat mekanis diperoleh rata-rata tertinggi momen tarik dan tekan sambungan kotak kayu jati berturut-turut senilai 100,03 N.mm dan 45,57 N.mm.

Teak wood (T. grandis) is a wood that has the advantages of being strong, durable, and easy to process. The utilization of teak wood varies, including as raw material for making furniture such as cabinets and storage shelves in which there are box joints. It is necessary to conduct strength testing to compare the quality of teak (T. grandis) joints at 3 different ages young (15-24 years), harvest age (25-35 years), and old (>35 years) with the use of variations in the number of teeth in the box joint 4, 8, and 12. 54 samples with joints glued using polyurethane adhesives in each sample used. This research was conducted by testing the physical properties in the form of moisture content and sample density as well as mechanical testing of box joints in the form of tensile and compressive moment test. In physical properties, the highest average moisture content and density of teak wood were obtained at 15.36% and 0.66 g/cm3. In mechanical properties, the highest average tensile and compressive moment of teak wood box joints is 100.03 N.mm and 45,57 N.mm respectively.