Pengaruh posisi radial Kayu Bawang (Dysoxylum sp) jenis Filler dan derajat kelembutannya terhadap keteguhan rekat

LOIWATU, Mery, Prof.Dr.Ir. T.A. Prayitno, M.For

2005 | Tesis | S2 Ilmu Kehutanan

Kayu Bawang (Dysoxylum sp) termasuk kayu non komersial yang dijumpai cukup banyak di Pulau Seram (Propinsi Maluku) dengan diameter pohon yang cukup besar. Pemanfaatan kayu bawang sebagai bahan baku industri kayu lapis belum banyak diteliti. Oleh sebab itu, perlu penelitian pengembangan teknologi perekatannya seperti pengaruh filler dan derajat kelembutan yang tepat sebagai komposisi adonan perekat. Tujuan penelitian ini yaitu mengetahui pengaruh posisi radial, jenis filler dan derajat kelembutan terhadap keteguhan rekat, persentase kerusakan, delaminasi, sifat fisik pelengkap (kadar air, penyusutan, kerapatan kayu lapis, wetabilitas dan ekstraktif) serta viskositas dan emisi formaldehida. Penelitian ini mengggunakan Rancangan Acak Lengkap (CRD) dalam percobaan faktorial 2 x 3 x 3 dengan 3 ulangan. Faktor A yaitu posisi radial kayu (a1= dekat kulit dan a2 = dekat hati; faktor B yaitu jenis filler (b1 = ampas sagu, b2= campuran serbuk kayu dan b3 = batok kelapa serta faktor C yaitu derajat kelembutan filler (c1= -100/+140 mesh, c2 = -140/+180 mesh dan c3 = -180 mesh. Untuk mengetahui hubungan antara keteguhan rekat dan persentase kerusakan terhadap beberapa sifat fisik kayu lapis digunakan analisis multiregresi. Hasil penelitian menunjukkan bahwa interaksi faktor A, B dan C berpengaruh sangat nyata terhadap keteguhan rekat dan persentase kerusakan kayu lapis pada kondisi basah dan kondisi kering. Keteguhan rekat dan persentase kerusakan kondisi basah tertinggi pada perlakuan a1b1c3 (22,54 kg/cm2 dan 26,32 %) sedangkan keteguhan rekat dan persentase kerusakan kayu lapis kondisi kering terdapat pada perlakuan a1b1c3 (24,62 kg/cm2 dan 86,89 %). Keteguhan rekat dan delaminasi kayu lapis yang dihasilkan memenuhi standar JAS, 1973. Nilai rata-rata kadar air, penyusutan dan kerapatan kondisi basah dan kering masing-masing (10,71-12,77%; 0,0267- 0,0630 %; 0,52-0,6 g/cm3 dan 0,46-0,54 g/cm3). Nilai wetabilitas tertinggi pada posisi radial dekat kulit (a1 =1620,494) dan jenis filler ampas sagu (b1) = 1229.589. Viskositas tertinggi pada b3c3 = 23,1 poise. Kandungan ekstraktif tertinggi untuk posisi radial yaitu pada posisi dekat hati (a2 = 4,93 %) dan jenis filler batok kelapa (b3 = 4,20%). Emisi formaldehida kayu lapis yang dihasilkan pada posisi dekat kulit terhadap jenis filler ampas sagu, campuran serbuk kayu dan batok kelapa masing-masing (0,223 ppm; 0,221 ppm dan 0,217 ppm) sedangkan dekat hati (0,220 ppm, 0,216 ppm dan 0,211 ppm) dengan nilai rata-rata antara 0,211 ppm – 0,223 ppm. Analisis multiregresi kadar air (X1) dan penyusutan (X2) kayu lapis terhadap keteguhan rekat kondisi basah (Y1) menghasilkan nilai r = 0,948 dan keteguhan rekat kondisi kering menghasilkan nilai r = 0,965 sedangkan untuk persentase kerusakan kayu lapis kondisi basah (Y2) menghasilkan nilai r = 0,900 dan persentase kerusakan kondisi kering dengan r = 0,911.

Wood bawang (Dysoxylum sp) is one of non commercial timber species that found quite numerous in Seram Island (Province of Mollucas) with large tree diameter. The utilized of Dysoxylum sp as raw material of plywood industry is not intensified. This research objective was to find out the effect of radial position, filler type and particle size to the adhesion strength, wood failure, delamination and several physic properties (water content, shrinkage, density, wettability, extractive), viscosity and formaldehyde emission. This research as arrange Complete Randomized Design (CRD) in factorial experiment analysis 2 x 3 x 3 with 3 repetition. Factor A that was radial position of wood (a1 = near to the bark and a2 = near to the pith); factor B that was filler type (b1 = sago waste, b2 = sawdust and b3 = coconut shell) and factor C that was particle size of filler (c1 = -100/+140 mesh, c2 = -140/+180 mesh and c3 = -180 mesh). To identify the relationship between the adhesion strength and the wood failure to several physical properties (water content and shrinkage of plywood) was used multi regression analysis. The result revealed interaction A, B, and C indicate very significant relationship to adhesion strength and wood failure of plywood on the wet and dry condition. The adhesion strength and wood failure with the highest wet condition are presented on a1b1c3 treatment (22,54 kg/cm2 and 26,32%) while the adhesion strength and wood failure of plywood on dry condition are presented in a1b1c3 treatment (24,62 kg/cm2 and 86,89%). The adhesion strength and delamination of plywood yielded have fulfill the JAS standard, 1973. The average value to water content, shrinkage, density in dry air and oven dry condition (10,71-12,77 %; 0,0267- 0,0630 %; 0,52-0,6 g/cm3 and 0,46-0,54 g/cm3). The highest wettability value in the radial position near to the bark (a1 = 1620,494) and filler type of sago waste (b1) = 1229,589. The highest viscosity are on b3c3 = 23,1 poise. The highest extractive content for radial position that is position near to the heart (a2 = 4,93%) and filler type of coconut shell (b3 = 4,20%). Formaldehyde emission of plywood resulted in position near to the bark toward filler types of sago waste, sawdust and coconut shell (0,223 ppm; 0,221 ppm and 0,217 ppm) respectively whereas near to the heart (0,220 ppm, 0,216 ppm and 0,211 ppm) with average value about 0,211 ppm – 0,223 ppm. A multiregression analysis of water content (X1) and shrinkage (X2) of plywood to the adhesion strength of wet condition (Y1) resulted in value r = 0,948 and the adhesion strength of dry condition resulted in value r = 0,965 whereas to wood failure of plywood on wet condition (Y2) resulted in value r = 0,900 and the wood failure on dry condition with r = 0,911.

Kata Kunci : Industri Perkayuan, Kayu Lapis, Adhesion Strength, formaldehyde emission, sago waste, sawdust, coconut shell.Perekatan.