Evaluasi Cacat Pengeringan Dan Pemesinan Pada Empat Jenis Kayu Cepat Tumbuh Termodifikasi Panas

Abstract

Heat treatment is one method that can improve the quality of wood including for fast-growing wood species. However, this treatment can cause some drying defects as well as the change of machining properties after applying that heat treatment. The purpose of this study was to evaluate the effect of wood species and heating time on the drying and machining defects. The fast-growing wood species used were teak, mangium, jabon, and sengon. The heat treatment was carried out at a temperature of 165°C with variation in time were 0 (control), 2, and 6 hours. The result showed that the moisture content and wood density decreased after heat treatment. Heat treatment was succeeded to decrease the moisture content of 57% and caused a decreasing of density until 20% compared with control wood. The drying defects of end checks in teak, mangium, jabon and sengon increased after 2 and 6-hour heat treatment. In the other hand, the surface checks defect of teak, mangium, sengon and jabon were decreased. The defects after applying machining activities i.e. the defects of sanding, planing, shaping, and boring were decreased in teak, mangium, jabon and sengon after heat treatment of 2 and 6-hour. Jati was the best wood species in term of machining quality followed by jabon, mangium, and sengon after heat treatment. At the temperature of 165°C in 2 hours could be considered as the appropriate time for heat treatment in term of obtaining minimal defects of drying and machining. ABSTRAKPerlakuan panas merupakan salah satu metode yang dapat meningkatkan kualitas kayu termasuk untuk kayu cepat tumbuh. Namun perlakuan tersebut dapat menyebabkan cacat pengeringan serta perubahan sifat pemesinan setelah perlakuan panas. Tujuan penelitian ini untuk mengevaluasi pengaruh variasi jenis kayu dan waktu pemanasan terhadap adanya cacat pengeringan dan pemesinan kayu cepat tumbuh. Jenis kayu cepat tumbuh yang digunakan adalah jati, mangium, jabon dan sengon. Perlakuan panas dilakukan pada suhu 165ºC dengan variasi waktu 0 jam (kontrol), 2 jam dan 6 jam. Hasil penelitian menunjukkan bahwa kadar air dan kerapatan kayu menurun setelah perlakuan panas. Perlakuan panas berhasil menurunkan kadar air 57% dan menyebabkan penurunan kerapatan kayu hingga 20% dibandingkan dengan kayu kontrolnya. Cacat pengeringan retak ujung pada jati, mangium, jabon dan sengon meningkat setelah perlakuan panas selama 2 dan 6 jam. Di sisi lain, cacat retak permukaan pada jati, mangium, sengon dan jabon berkurang. Cacat setelah menerapkan kegiatan pemesinan yaitu cacat pengamplasan, penyerutan, pembentukan, dan pengeboran menurun pada jati, mangium, jabon dan sengon setelah perlakuan panas 2 dan 6 jam. Jati adalah spesies kayu terbaik dalam hal kualitas pemesinan setelah perlakuan panas diikuti oleh jabon, mangium, dan sengon. Pada suhu 165°C dalam 2 jam dianggap sebagai waktu yang tepat untuk perlakuan panas dalam hal memperoleh cacat minimal pengeringan dan pemesinan. Kata kunci : Jati, jabon, perlakuan panas, sengon.

Improvement on Several Physical and Mechanical Properties of Jati Utama Nusantara Wood by Thermal Compression Treatment

“…The use of high temperatures to improve the quality of young teak wood has been carried out by several researchers (Garcia, Lopes, Nascimento, & Latorraca, 2014;Lopes, Garcia, & Nascimento, 2018;Adzkia, Priadi, & Karlinasari, 2019;Pasaribu & Sisilia, 2021;Martha et al, 2021). According to the research results of Adzkia et al (2019), the best machining quality can be obtained by using a temperature of 165ºC for 2 hours. However, Pasaribu and Sisilia (2021) reported that temperatures up to 170ºC for 2 hours and compacted by 25% will still experience a dimension change at room temperature.…”