Randu (Ceiba pentandra (L) Gaertn.) wood is one of the fast-growing species which has low density. Wood modification by microwave (MW) treatment were conducted to improve its quality. The aim of this work was to evaluate the effect of microwave treatment on the characteristics (physical properties, wood discoloration, and wettability) of Randu wood. Microwave treatment for 0.5 and 1 minute were applied for Randu wood. The evaluation of wood discoloration, wettability, and physical properties include moisture content, specific gravity, swelling, and anti-swelling efficiency (ASE) were measured. Wood discoloration and wettability of untreated and treated sample were measured. The results showed that microwave treatment was reduce the swelling, wettability and cause discoloration. Microwave treatment not significantly affected moisture content and specific gravity of treated wood. Microwave treatment increased contact angle than untreated, and 0.5 minutes microwave treatment caused significant discoloration than 1 minutes microwave treatment and untreated sample. The MW treatment indicated to increase the hydrophobicity of Randu wood.
Keywords: discoloration, microwave, randu, wettability.
ABSTRAK
Kayu randu (Ceiba pentandra (L) Gaertn.) merupakan salah satu jenis kayu cepat tumbuh yang memiliki kerapatan rendah. Modifikasi kayu dengan perlakuan microwave (MW) dilakukan untuk meningkatkan kualitasnya. Tujuan dari penelitian ini adalah untuk mengevaluasi pengaruh perlakuan microwave terhadap karakteristik (sifat fisik, perubahan warna kayu, dan keterbasahan) kayu Randu. Perlakuan microwave selama 0.5 dan 1 menit diaplikasikan pada kayu randu. Pengujian yang dilakukan yaitu perubahan warna kayu, keterbasahan, dan sifat fisis yang meliputi kadar air, berat jenis, pengembangan, dan anti-swelling efficiency (ASE). Hasil penelitian menunjukkan bahwa perlakuan microwave mengurangi pengembangan, keterbasahan dan menyebabkan perubahan warna. Perlakuan microwave tidak berpengaruh nyata terhadap kadar air dan berat jenis kayu. Perlakuan gelombang mikro meningkatkan sudut kontak dibanding kontrol, dan perlakuan microwave 0.5 menit menyebabkan perubahan warna yang signifikan dibanding microwave 1 menit dan tanpa perlakuan. Perlakuan MW dapat meningkatkan hidrofobisitas kayu randu.
Katakunci: keterbasahan, microwave, randu, perubahan warna.