KARAKTERISTIK KAYU MUDA PADA MANGIUM (Acacia mangium Willd.) DAN KUALITAS PENGERINGANNYA

Abstract

Recently, the availability of wood species from natural forests has run limited and scarce. Consequently, fulfilling public demand of wood is met in part by woods from plantation forest. The problem with the plantation forest is that its woods contain relatively high juvenile wood portions due to the felling or harvesting at relatively younger tree ages (with shorter rotation) than those from natural forest trees.In wood processing the presence of juvenile wood often causes problems with its corresponding products such as defects after drying thereby lowering their qualities. As the relevance, this experiment dealt with characteristics (e.g. anatomy features) and drying qualities of wood with high juvenile wood content. Wood species used in this experiment was 22-year old mangium (Acacia mangium Willd.).The results revealed that the percentage of juvenile wood in mangium as obtained through regression equation was 50% (R 2 = 70%) with particular characteristics such as short fibers, end surface defects, honeycombs and collapses after drying. Therefore, it is suggested that great care should be taken in processing and uses, particularly during the drying by implementing mild schedules (i.e. staged temperature changes).

Radial Variation of Wood Anatomical Characteristics and Maturation Ages of Six Korean Oak Species

“…Recent studies by Hamdan et al [42] and Chen et al [43] have observed that vessel diameter, fiber length, and fiber wall thickness significantly affected the density and mechanical properties of wood. In addition, juvenile and mature wood played a crucial role in determining the anatomical characteristics that will impact the wood quality [17][18][19][20][21][22][23][24][25][26][27][28][29].…”

“…As described by Kozlowski [17], Tsoumis [18], and Moore and Cown [19], juvenile wood forms near the pith and exhibits considerable changes in cell characteristics such as shorter cells, thinner cell walls, narrower cell diameter, and a higher microfibril angle. Therefore, juvenile wood possesses poorer physical [20,21] and mechanical properties than mature wood [22][23][24][25], as well as reduced natural durability [26] and diminished drying quality [27,28]. Therefore, more juvenile wood can significantly impact the overall wood quality [29].…”

PERBANDINGAN KARAKTERISTIK BAHAN BAKU DAN PULP KRASIKARPA (Acacia crassicarpa A. Cunn) UMUR 1 SAMPAI 4 TAHUN

“…Kayu juvenil masih mengalami perubahan sifat pada dimensi serat, kerapatan, dan sifat lainnya. Beberapa penelitian mengenai kayu juvenil di Indonesia diantaranya pada kayu mangium (Lukmandaru, 2012;Rulliaty, 2008), sengon dan jabon (Darmawan, Nandika, Rahayu, & Fournier, 2013), serta samama (Cahyono et al, 2015). Semua penelitian tersebut menyatakan bahwa sampai umur 6 tahun, pada pohon yang diteliti masih terdiri dari kayu juvenil.…”

“…Hal ini dikaitkan dengan pernyataan Fengel & Wegener, (1995) kuat, makanya kadar lignin umur 2 sampai 4 tahun lebih tinggi dibandingkan dengan kadar lignin umur 1 tahun. Bila dibandingkan dengan kayu juvenil pada umumnya, sebagaimana dilaporkan Rulliaty (2008), karakteristik dimensi serat kayu juvenil pada awal pertumbuhan lebih pendek dan dinding sel lebih tipis. Hal ini diduga walaupun dinding sel tipis namun rendahnya persentase lignin menjadikan kadar selulosa lebih tinggi pada umur 1 tahun.…”

“…Hal ini disebabkan oleh serat pada umur 1 tahun memiliki serat pendek, sehingga lolos dalam penyaringan. Menurut Rulliaty (2008) karakteristik dimensi serat kayu juvenil pada awal pertumbuhan lebih pendek dan dinding sel lebih tipis. Sifat kimia kayu dan pulp krasikarpa umur 2 tahun memiliki sifat yang sama dengan beberapa pustaka.…”