Pemanfaatan, Karakteristik dan Pengolahan Hasil Hutan
Joko Sulistyo
Bagian Teknologi Hasil Hutan Fak. Kehutanan UGM Pengantar Ilmu Kehutanan
Pemanfaatan Hasil Hutan
Fungsi Hutan
1. Perlindungan keanekaragaman hayati 2. Habitat bagi satwa liar
3. Paru-paru dunia 4. Pengendali air 5. Pengendali iklim
6. Sumber makanan dan obat 7. Tempat wisata
8. Produksi hasil hutan kayu dan non kayu
Pengantar Ilmu Kehutanan
Pembangunan Hutan Tanaman di Indonesia
Falcataria moluccana
Teak Pinus
A. mangium Pengantar Ilmu Kehutanan
Silvikultur intensif
tanam jalur jenis-jenis fast growing meranti di hutan alam
Pengantar Ilmu Kehutanan
Tegakan hutan jati JPP
Pengantar Ilmu Kehutanan
Jati JPP non-teresan
Jati JPP teresan
Hutan rakyat
Pengantar Ilmu Kehutanan
Fotosintesis
Energi matahari
Karbon
dioksida + Air à Oksigen + Glukosa Glukosa
Proses yang mengkombinasi air dan karbon dioksida dalam daun pada pohon hijau, menggunakan energi dari sinar matahari untuk membentuk
glukosa dan berbagai gula sederhana, dengan oksigen sebagai produk
sampingan.
Glukosa digunakan pohon untuk membentuk daun, kayu dan kulit.
(H2O) (CO2)
(O2)
Pengantar Ilmu Kehutanan
Pengantar Ilmu Kehutanan
Pembentukan Kayu
Kayu penyimpan karbon
Jati – 65 tahun JenisLambatTumbuh (Slow growing species)
Sengon – 5 tahun Jenis Cepat Tumbuh (Fast growing species)
Pengantar Ilmu Kehutanan
Elemen % berat kering
Karbon (C) 49
Hidrogen (H) 6
Oksigen (O) 44
Nitrogen (N) Sangat rendah
Abu 0,1
•Bahan alami yang bersifat terbarukan dari hasil reaksi biokimia antara penyerapan karbon dari udara dan air dari dalam tanah memanfaatkan energi sinar matahari.
•Kayu merupakan penyimpan karbon
Jenis Selulosa Hemiselulosa Lignin
(% berat kering)
Kayukeras (hardwood) 40 – 44 15 – 35 18 – 25 Kayulunak (softwood) 40 – 44 20 – 32 25 – 35
Wood industry
Paper mill
Pyrolysis
Power generation
Paper Furniture Housing
Biomass (residue)
Pemanfaatan hasil hutan yang lestari
Pengantar Ilmu Kehutanan
• Efisien
• Produktivitas
• Ramah lingkungan
• Inovatif
Pohon Tua Mati
- Kayu membusuk dan tidak termanfaatkan - Terjadi emisi karbon
Pengantar Ilmu Kehutanan
Pengantar Ilmu Kehutanan
Pemanfaatan Kayu
Produk dari Rayon Kayu
Energi Pengolahan Berbagai Bahan
. KWH/metrik ton.
Kayu, termasuk penebangan 1,000
Semen 1,400
Gelas 3,900
Baja 4,000
Plastik 28,000
Aluminium 71,000
Pengantar Ilmu Kehutanan
Hasil Hutan Indonesia
Persebaran Produksi Kayu Bulat
Sumatera : 31,1 juta m3(63,32%) - Akasia : 26,7 juta m3(87,76%) - Ekaliptus : 3,1 juta m3(9,97%)
Jawa : 5,1 juta m3(10,49%)
- Sengon : 3,7 juta m3(73,02%) - Jati : 0,5 juta m3(9,65%)
Kalimantan : 10,96 juta m3(22,31%) - Akasia : 4,37 juta m3(39,89%) - Meranti : 3,97 juta m3(36,26%)
- Rimba campur : 1,5 juta m3(13, 74%) Papua & Maluku : 1,68 juta m3(3,43%) - Meranti : 0,96 juta m3(56,74%) - Rimba campur : 0,46 juta m3(27,54%)
Sulawesi : 0,8 juta m3(0,36%)
- Rimba campur : 0,07 juta m3(43,66%) - Meranti : 0,02 juta m3(14,33%)
Hasil Hutan Non Kayu
Karakteristik Hasil Hutan
(Kayu)
Log from Production Site in Natural Forest
Hutan hujan tropis Hutan Tanaman
Pemanenan
Hutan Produksi
Struktur Pohon
Flowering plants
Trees
Trees are large-sized plants that contain wood, a tissue impregnated with a substance called lignin, which makes it rigid. Some species of trees are conifers, such as the fir, but most, such as the oak, belong to the flowering plants group.
Deciduous trees, naked in winter, are distinct from trees with persistent leaves, which are always green.
46
THE STRUCTURE OF A TREE
A tree has an underground part, the roots, and two aboveground parts, the trunk and the crown. The trunk is a single woody stem that ramifies into limbs at a certain height. The limbs, which are also woody, ramify into branches and twigs, which bear all the tree’s leaves, called the foliage.
The crownincludes all the limbs, branches, twigs, and foliage.
The trunkis the main part of the tree, located between the ground and the first branches.
The tree’s root system typically develops more horizontally than vertically.
rootlet
main root A limbis a ramification
directly from the tree trunk.
A limb ramifies into branches.
The peak of the crown is called the top.
Twigsare the smallest ramifications of a branch.
foliage branches
Plants made of wood
Kayu perkakas Kayu pulp Kayu bakar
Kayu
Kayu merupakan material yang unggul, renewable (terbarukan) dan eco-friendly (ramah lingkungan)
Sengon (varietas solomon)
Nangka
The Advantageous of Wood
1. Wood as a raw material is very easy to process
Wood can be sawn into a board, peeled into a finer, chopped into particles, separated into fibers, ground into flour or decomposed into its chemical components.
(T.Listyanto)
FROM LOG TO VENE,ER
1'\ nce its bark is stripped away, a log
\J .un be cut into veneer in one oi three rvays: saw cutting, rotary cutting or flat slicing. Saw cutting, which goes back to the early 19th Centi"rry, employs huge circular saws to rip strips of veneer from logs. Although not as efficient as other techniques, saw cutting is still used to produce some crotch veneers from irregularly grained or dense woods such as ebony.
Rotary cutting and flat slicing can produce veneers as thin as 7s to l,/r zo inch and as long as I B feet. In rotary cutting, a log mounted in a huge lathe rotates against a presslu€bar while a razor-sharp knife oeels off a continuous sheet of veneeithe length of the log. Fir plp,vood, as well as some decorative veneers such as bird's-eye maple, are normally rotary cut. Half-round, rift and back cutting are variations that produce veneer from half-loss rather than whole ones.
In flat slicing, a half-log is held onto a frame that swings r-rp and down against a stationary horizontai knife; a slice of veneer is removed with every down- stroke. FIat slicing produces crown-cut veneers. A type of flat slicing known as quarter-clrt slicing is used on woods that display a striking figure when quarter- sawn, as in sapeie, white oak or lacewood.
Flat-sliced sheets of verteer move nlortg tt conveyor for drying tud
storage hr n vetreer .fnctory.
VENEER-CUTTING METH(lDS
Rotary autting Used Lo cut con' etruction plywood and eome decora' tive veneera guch ao btrd'o-eye maple
Half-round autting A method used for burla and aome decorattve apectea
Eack cutting A rotary cutting method that. yielde buLL and croLch veneer9
Flat eliaing
Uaed to make crown- cut veneer?; pro' ducea veneera wiLh repeatinq figure thaL facrltLaf,ea book' matching and oLher decorative effects
Quarber-aui aliaing Uaed to cut decora- f,tve veneerg, auch ae ribbon, atripe and flake, that are obtarned from quar' Lereawn loqe
Ri{t cutting
Yielde veneer wtth the raye at rou7hly 45" to the eurface;
uoed primarily on whiLe oak
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2. Wood processing into final products require only very little energy
The Advantageous of Wood (2)
• When people are looking for ways to utilize solar energy, wood is an example of a product that is entirely derived from the conversion of solar energy.
• A little extra energy is needed to process wood products, which can be obtained from forests and wood waste.
Solar panel untuk energi listrik terbarukan
Stok karbon tersimpan dalam kayu
Element % Dry Weight
Carbon (C) 49
Hidrogen (H) 6
Oxygen (O) 44
Nitrogen (N) Very low
Ash 0,1
Electricity Oil Gas Solid Fuels Total % (mtoe) (mtoe) (mtoe) (mtoe) (mtoe)
TOTAL CONSUMPTION 395 1 362 491 280 2 528 100
inclusive of
TOTAL INDUSTRY 166 246 202 208 822 33
including:
Iron and steel 20 9 20 92 141 6
Chemicals: 34 131 57 14 236 9
Feedstocks - 112 10 - 122 5
Food & tobacco 10 15 16 6 47 2
Pulp, paper & printing1/ 18 15 14 12 59 2
Wood & wood products1/
3 2 1 1 7 0.3
FAO, 1983
Total Konsumsi Energi Industri
3. The processing and use of wood has a very low impact on the environment compared to other materials such as metals, plastics and cement
The Advantageous of Wood (3)
Due to the low energy needed in wood processing, and providing many benefits to the environment.
Wood
approx. 5,000 kg Concrete
approx. 20,000 kg
C C C C
C
(Prof. Nam-Hun.Kim)
4. Timber harvesting products are renewable
The Advantageous of Wood (4)
Timber originating from sustainably managed forests with appropriate forest management ensure a sustainable supply as long as the forest is sustainable.
Karakteristik Kayu sebagai Material Eco-Friendly
1.Kayu tersusun atas individual sel dan dengan dinding sel
SOFTWOODS AND HARDWOODS
f rees are roughly divided into soft- I woods and hardwoods, but the terms are inexact: Some hardwoods, such as basswood or aspen, for exam- ple, are softer than North American soft- woods like longleaf pine or Douglas-fir.
The type and shape of a tree's leaves are more accurate indicators of a particular wood's identity. Softwoods include evergreen conifers with needle- like leaves, while hardwoods comprise broad-leaved deciduous, or leaf-shed- ding, trees. But it is at the microscopic level that the true differences between softwoods and hardwoods can be seen.
Softwoods are composed mainly of tra- cheids, dual-purpose cells which con- duct the sap up through the trunk and
provide support. Hardwoods, which are believed to have evolved later, have nar- rowet thicker-walled fiber cells for sup- port and large-diameter thin-walled vessels for sap conduction, These cells determine thi texture of a tree's wood.
In spring, when there is abundant moisture and rapid growth of early- wood, the tracheid cells in softwoods have thin walls and large cavities to con- duct the sap. The result is relatively porous wood. As latewood develops in the latter part of the growing season, the tracheids begin to form thicker walls, creating denser wood.
In hardwoods such as oak or ash, most of the vessels develop in the early- wood, resulting in uneven grain. These
species are called ring-porous. With dif- fuse-porous hardwoods such as maple, the vessels are distributed more evenly in the earlpvood and latewood. Some species, such as walnut, exhibit a more gradual transition from earlpvood to latewood and are termed semi-rine- porous or semi-diffuse-porous.
The differences in cell structure between softwoods and hardwoods become apparent when a stain is applied.
In softwoods, the light, porous early- wood absorbs stain more readily than the dark, denser latewood-in effect reversing the grain pattern like a photo- graphic negative. Hardwoods, however, absorb stain more evenly, enhancing the
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(above, right),the sap is conducted through vessels, a series of tubelike cells stacked one atop the other. Support for the trunk is provided by f iber cells. In the ring-porous hardwood shown, vessels are more prominent in earlywood; f ibers are the pre- dominant cell type in latewood. In both hardwoods and soft- woods, storage cells for carbohydrates and starch make up the remainins non-vascular wood tissue.
CELL STRUCTURE ()F SOFTWOODS AND HARDW()()DS
Latewood
A microscopic view
The differences between softwood and hardwood are readily apparent when viewed under a microscope's magnif ication.
The cell structure of softwoods (above, /eff) is much simpler than that of hardwoods. Almost all softwood cells are long, thin tracheids, which support an unbroken column of sap that can tower more than 200 feet. The tracheids in Iatewood become thrcker-walled than those in earlvwood. In hardwoods
T6
Karakteristik Kayu sebagai Material Eco-Friendly
52 Saka
FIGURE 1 The gross structure of a typical softwood tracheid or hardwood fiber. (Courtesy of Prof. Emer. R. J. Thomas, North Carolina State University, Raleigh, NC.)
wall layers. Instead, the gelatinous layer (G layer) is usually deposited adjacent to the cell lumen (Fig. 2c). The G layer contains little or no lignin and consists mainly of cellulose microfibrils oriented parallel to the fiber axis.
111. CHEMICAL COMPOSITION OF WOOD A. Normal Wood and Reaction Wood
The chemical constituents of wood are well known, and a number of authors have provided an excellent review of this work [4-81. The major cell wall constituents are cellulose, hemicelluloses, and lignin. Other polymeric constituents, present in lesser and often var- ying quantities, are starch, pectin, and ash for the extractive-free wood.
Tables 1 and 2 show comparisons of the chemical composition made by Time11 [9]
for five hardwoods and five softwoods, respectively. Although the cellulose content is more or less the same (43 -t 2%) for both groups, the hardwoods contain less lignin. The lignin content of hardwoods is usually in the range of 18-25%, whereas that of softwoods varies between 25% and 35%. However, tropical hardwoods can exceed the lignin content of many softwoods. The structure of lignin is different between these two groups: softwood lignins are composed mostly of guaiacyl units, whereas hardwood lignins consist of sy- ringyl and guaiacyl moieties [ 101.
The hemicelluloses found in these groups vary both in structure and quality, as shown in Fig. 3. The predominant hardwood hemicellulose is a partly acetylated, glucuronoxylan (O-acetyl-4-O-methylglucuronoxylan), accounting for 20-35%, whereas softwoods con- tain glucuronoarabinoxylan (arabino-4-0-methylglucuronoxylan) in the range of 10%.
Hardwoods contain only a small quantity of glucomannan. In softwoods, however, a partly acetylated galactoglucomannan (0-acetylgalactoglucomannan) makes up as much as 18%.
In addition to these major cell wall components, pectic materials and starch are included in much smaller quantities in both softwoods and hardwoods. Ash usually makes up between 0.1% and 0.5% of wood, but tropical species often exceed this range. Wood
52 Saka
FIGURE 1 The gross structure of a typical softwood tracheid or hardwood fiber. (Courtesy of Prof. Emer. R. J. Thomas, North Carolina State University, Raleigh, NC.)
wall layers. Instead, the gelatinous layer (G layer) is usually deposited adjacent to the cell lumen (Fig. 2c). The G layer contains little or no lignin and consists mainly of cellulose microfibrils oriented parallel to the fiber axis.
111. CHEMICAL COMPOSITION OF WOOD A. Normal Wood and Reaction Wood
The chemical constituents of wood are well known, and a number of authors have provided an excellent review of this work [4-81. The major cell wall constituents are cellulose, hemicelluloses, and lignin. Other polymeric constituents, present in lesser and often var- ying quantities, are starch, pectin, and ash for the extractive-free wood.
Tables 1 and 2 show comparisons of the chemical composition made by Time11 [9]
for five hardwoods and five softwoods, respectively. Although the cellulose content is more or less the same (43 -t 2%) for both groups, the hardwoods contain less lignin. The lignin content of hardwoods is usually in the range of 18-25%, whereas that of softwoods varies between 25% and 35%. However, tropical hardwoods can exceed the lignin content of many softwoods. The structure of lignin is different between these two groups: softwood lignins are composed mostly of guaiacyl units, whereas hardwood lignins consist of sy- ringyl and guaiacyl moieties [ 101.
The hemicelluloses found in these groups vary both in structure and quality, as shown in Fig. 3. The predominant hardwood hemicellulose is a partly acetylated, glucuronoxylan (O-acetyl-4-O-methylglucuronoxylan), accounting for 20-35%, whereas softwoods con- tain glucuronoarabinoxylan (arabino-4-0-methylglucuronoxylan) in the range of 10%.
Hardwoods contain only a small quantity of glucomannan. In softwoods, however, a partly acetylated galactoglucomannan (0-acetylgalactoglucomannan) makes up as much as 18%.
In addition to these major cell wall components, pectic materials and starch are included in much smaller quantities in both softwoods and hardwoods. Ash usually makes up between 0.1% and 0.5% of wood, but tropical species often exceed this range. Wood
Semua kayu strukturnya selluler dengan dinding sel yang terdiri dari campuran selulosa,
karbohidrat nonselulosa dan lignin, yang tersusun sebagai suatu matrix diperkuat.
Karakteristik Kayu sebagai Material Eco-Friendly
(2)2.Kayu bersifat anisotropis
Kayu menunjukkan sifat
fisik & mekanik yang
berbeda yang berbeda
jika diuji pada tiga sumbu
arah utamanya.
Karakteristik Kayu sebagai Material Eco-Friendly
(2)2.Kayu bersifat anisotropis
Karakteristik Kayu sebagai Material Eco-Friendly
(3)3.Kayu bersifat higroskopis
Kayu dapat kehilangan atau menyerap air sebagai akibat dari
perubahan kelembaban dan suhu atmosfir.
Karakteristik Kayu sebagai Material Eco-Friendly
(4)4.Kayu dapat dibiodegradasi
Kayu dapat dibiodegradasikan oleh serangan organisme jamur/fungi, bakteri, dan serangga tertentu. Sifat ini
merupakan peluang untuk memproduksi bioenergi
Karakteristik Kayu sebagai Material Eco-Friendly
(5)5.Kayu dapat dibakar
Jika kayu digunakan sebagai bahan bangunan ringan, sifat kemudah-
terbakarannya harus diperhitungkan. Sifat ini membuat kayu menjadi salah satu dari sumber bahan bakar utama
Kayu bakar Bencana kebakaran rumah
Karakteristik Kayu sebagai Material Eco-Friendly
(6)6.Kayu sangat lembam terhadap bahan kimia
Kayu sesuai untuk pemanfaatan di industri yang sangat memerlukan ketahanan terhadap bahan kimia dan korosi. Namun demikian jika kayu dikenai keadaan udara (atmosfir), karena pengaruh cuaca akan secara berangsur-angsur terkikis dengan laju pengikisan sekitar 6 – 7 mm per abadnya. Keadaan yang biasanya dapat dengan mudah dicegah
dengan cara pengecatan permukaannya; perlindungan yang juga menambah keunggulan dekoratif dan mengurangi porositas
permukaannya.
Karakteristik Kayu sebagai Material Eco-Friendly
(7)7.Kayu sangat awet
Di tempat dengan kondisi yang tak sesuai bagi agen perusak, kayu dapat digunakan dengan sangat tahan
A.D. 604
The oldest wooden building in the world (Horyuji, Japan)
The oldest wooden building in Korea (Bongjeongsa)
11 Century
(Prof. Nam-Hun.Kim)
Karakteristik Kayu sebagai Material Eco-Friendly
(8)8.Kayu bersifat isolator
Strukturnya yang berserat dan banyaknya udara yang dapat
diperangkap membuat kayu memiliki sifat isolasi yang baik. Kecuali kayu, bahan bangunan yang digunakan untuk rumah umumnya bukan merupakan isolator yang baik.
Kehilangan panas dibanding kayu :
Batubata 6 kali
Kaca jendela 8 kali Beton dari pasir 15 kali
Baja 390 kali
Aluminium 1700 kali
Concrete Wood
Cold radiant heat Warm radiant heat
Karakteristik Kayu sebagai Material Eco-Friendly
(8)8.Kayu bersifat isolator
(Prof. Nam-Hun.Kim)
Pengenalan jenis kayu
• Indonesia memiliki kurang lebih 4.000 jenis kayu
• Jenis kayu komersial penting sekitar 400 jenis
• Diperlukan teknik pengenalan jenis kayu untuk memberi kepastian dalam perdagangan kayu
• Perlindungan jenis: menghindari ilegal trading, penyelundupan, dll. WOOD IDENTIFICATION KEYS
A collection of labeled wood samples can be invaluable in helping you b ecome familiar with a variety of woods. It may also contain a species
you wish to identify.
I orrectly identifying an unfamiliar
\; wood sample out of thousands of possibilities requires close observation, and a thorough knowledge ofwood and its properties. But as a practical matter, the possible choices are usuallylimited to several familiar species, and a commer- cially available set of labeled wood sam- ples, such as the one shown at right, may include a piece that matches the wood you are attempting to identifr. Most often, however, you will need to record the features of a sample, then use a wood identification key from a book to make sense ofyour results.
An identification key is essentially a master list of woods and their proper- ties that serves as a cross-reference to link the features of a particular sample to a species name. Some keys require that you compare their entries against features that are visible to the naked eye or with a 10x magnifier, while others demand that you note microscopic details. Still other keys are based on the user having wide-ranging sensory infor- mation about the wood, including its colot odor and texture, and the bark and leaf shape of the tree from which it came.
Using a key is like climbing the branches of a tree. You are asked to answer a series of paired statements, choosing the one that best describes the wood in question and proceeding to the next pair indicated. At each statement, the user forks onto a different branch
until reaching a leaf that identifies the sample. The first statement may involve the texture of the wood. If the wood is porous, for example, you are sent to one set of statements; if it is non-porous, you jump to a different set of statements. You continue this way, flipping from page to page in a book, as each answer gradual- lyreduces the choices. Finally, the search is narrowed to a single species.
Avoid keys that try to cover every wood species in the world; they will prove too general. Choose one that describes trees in a specific region, such as North American softwoods or tropical hard- woods. Several classic keys can be found in woodworking boola; check your local library or boolstore. Some public agen-
cies (below) also offer wood identifica- tion services.
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SOURCES FOR WOOD IDEI{TIFICATIOI{
Books
Edlin, Herbert L., What Wood ls That?
A Manual of Wood ldentification.
New York: Viking, 1969.
Hoadley, Bruce, ldentifying Wood.
Nevvton, Connecticut: Tau nton Press, 1990.
Panshin, A.J. and DeZeeuw, Carl,Textbook of Wood Technologr.
New York: McGraw Hill, 1980.
Rendfe, 8.J., World Timbers: Volumes 1-3. London: Ernest Benn, 1970.
Sharp, John 8., Wood ldentification:
A Manual for The Non-Profexional.
Knoxville: University of Tennessee
Agricultural Extension Service, Forestry and Wildlife Extension, 1990.
Timber Research Development Association, Timbers of the World:
Volumes I and 2. Lancaster;
Construction Press, 1979.
Agencies that offer wood identification services
Center For Wood Anatomy Research U.S. Forest Products Laboratory 1 Gifford Pinchot Drive
Madison, Wisconsi n 53705-2398 International Wood Collectors Societv 2913 Third Street
Trenton, Michigan 48183
34
IDENTIFYINGWOOD
hether you are restoring a piece of furniture made from an unfamil- iar wood or debating the authenticity of a particular board with a local lumber- yard, a knack for identifring a piece of lumber is a usefrrl skill.
Of course, an entire branch of knowl- edge is devoted to wood science and technology. Books have been written about the subject, careers have been founded upon it, and universities offer courses and degrees devoted to it.
Scientists identifr wood by first slicing offa thin sliver of a sample, then mount- ing it on a slide and examining it under a mlcroscope.
The practicing woodworker, however, who is more interested in sawing than in science, can successfully identiff most woods by methodically searching for a few simple clues with the help of inex- pensive equipment. Most of the toolsyou need are illustrated at right. Your inves- tigation should begin with the easily observable properties ofthe sanrple (page 26).Examne and feel the surface; deter- mine whether it is oily or dry, dull or lus- trous. Check its hardness by trying to dent the surface with a fingernail. You
Examining the end grain of a board through an illuminated 1& magnifier enlnrges several features of a wood sample that are helpful in species identification.
may be able to tell with the naked eye whether a hardwood is ring- or diffirse- porous. As shown in the photos on page 33, these two types of hardwood are rel- atively easy to tell apart when viewed with a hand lens. Note whether the texture of the wood is coarse or smooth. Ifthe sam- ple has been recently cut, it may have a recognizable odor. If it has been sufficiently dried, you may be able to calculate its specific gravity.
Aithough these observations can help narrow down the choices, you will still have to view a wood sample under mag- nification in order to hazardaneducat- ed guess as to its species. The illustration on page 31 shows the three ways that a sample can be studied: transversely, radi-
ally or tangentially. Each method expos- es a different view of a sample's anatom- ical structure. The simplest view is the transverse since it involves looking at the end grain of the sample. However, to avoid a blurred view of crushed fibers, you must first shave the surface with a razor blade or a well-sharpened knife.
To get a tangential view of a sample, you will need to make a clean cut along the growth rings of the wood (page 32).
Making a second cut at right angles to the first exposes a radial view.
Once you have observed and record- ed the sample's properties and micro- scopic details, you can compare the results with a printed key of wood species to identifi the wood.
TOOLS F(|R THE WOOD SLEUTH
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Labeled wood samplea
A set of domeatic or tropical wooda with labela indicatin1 the apeciea; can be ueed to help identify and aompare wooda
Hand lens
Used to axamine wood samplea; available in Bx, 1Ox and 12x ma1nification
llluminaied magnifter
For axaminin7 wood aamplea;
featu ree built- i n ill umin ation for aharper viawinq than hand leno. Typically available with up to 2Ox maanification
Poaketkni e Used to prepare the end qrain of wood aamplea for examination
Razor blade
Used to aut off wood alivers for viewinq under a microacope;
einqle-adqed bladea are the aafeat type
30
Pengenalan jenis kayu (2)
• Cara makroskopis non strukturil yang sering disebut juga
sebagai “ciri umum”: warna, kilap, kesan raba, bau dan rasa &
reaksi kimia.
• Cara makroskopis strukturil: lingkaran tumbuh, kayu gubal
dan teras, jari-jari kayu, pori, parenkim & saluran damar atau
getah
Pengenalan jenis kayu (3)
Pengenalan secara mikroskopis dilakukan bila cara makroskopis masih meragukan. Ciri mikroskopis: pori kayu, ukuran pori, susunan dan bentuk pori, saluran interseluler, serat (pada kayu keras) atau trakeid (pada kayu lunak), jari-jari kayu, parenkim & tilosis
Pita tangensial Diagonal Dendritik
Susunan Pori Kayu
Struktur anatomi kayu menyerupai seperti “finger- print” dalam pengenalan jenis kayu
Sifat-Sifat Dasar Kayu
• Sifat fisika
• Sifat kimia
• Sifat mekanik
Sifat Fisik: Kadar Air Kayu
• Air merupakan penyusun alami dari semua bagian pohon hidup.
• Pohon yang baru ditebang memiliki kadar air yang tinggi antara 40 – 200%
• Kayu dalam penggunaan kadar airnya menyesuaikan dengan lingkungan sekitarnya berkisar antara 12-16%.
• Kadar air kayu adalah jumlah air pada sepotong kayu yang
dinyatakan sebagai persentase terhadap berat kayu pada kondisi tanpa air (kering tanur/BKT).
Sifat Fisik: Berat Jenis Kayu
• Perbandingan dari kerapatan suatu bahan terhadap
kerapatan bahan standard yang ditentukan pada suhu tertentu.
• Air pada kerapatannya yang tertinggi (4oC; 39.2oF)
merupakan bahan standard yang universal untuk penen tuan BJ semua bahan --->
kerapatannya = 1 g/cm3; 1000 kg/m3; 62,4 pon/kaki3
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UNDERSTANDING WOOD
Specific grnvity is a better irdicator of n wood's weight thart size. With a speciJic gravity of 0.90, a piece of cborry weiglrs the sanrc tts a trtttclt lnrger block of white pine, wlrcse speciJic grovity is only 0.35.
TYPES ()F GRAIN
Featured tn lumber wiLh even wood ftbere thaL are parallel Lo the verLtcal axta of the trunk; makea for eLronq wood, but hae ltttle or no fi4ure
Found tn lumber where the ftbera devi' aLe from the verLtcal axie of the Lrunk;
not ao atronq ae etraiqhL-qratned wood, but producee an attracttve fiqure
treea with twtEt ed trunka; common in 1coLch pine and aweet cheetnuL
Interlocked grain
Found tn lumber from treeE with oppoein7 internal LwtaLe;
eomeLimee found in elm and very common in tropical epeciee Froduced by wood ftbere Lhat undulate tn ehort, even wavee: yielde fiddleback ftqure
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Kayu dengan Berat Jenis Yang Berbeda
• Mekanika kayu berhubungan dengan sifat yang
membicarakan aksi gaya-gaya luar pada kayu dan reaksinya
• Ada 3 macam gaya primer yang dapat beraksi pada kayu : 1. Gaya dapat berupa aksi penekanan/compression bila
gaya-gaya tersebut memperkecil
dimensi/mengurangi volume bendanya; disebut
“stress tekan/compressive stress”
2. Jika gayanya cenderung menambah
dimensi/volumenya maka gaya yang terjadi adalah tarikan/tensile; disebut “stress tensile/stres tarik”
3. Gaya dengan arah berlawanan yang memberikan aksi memisahkan benda kayu menjadi 2 bagian; disebut “
“stress geser/shear stress”
Sifat Mekanika kayu
Gaya tarik (Tensile)
Gaya tekan (Compressive) Gaya geser (Shearing)
Reaksi pada kayu àKekuatan tekan
(Compresive strength)
àKekuatan tarik (Tensile strength) àKekuatan geser
(Shear strength)
Pemanfaatan Kayu Untuk Tujuan
Struktural Bangunan
Sifat Kimia: Komposisi Organik Kayu
Penyusun elemen dalam kayu berkombinasi menjadi sejumlah polimer organik, yaitu selulosa, hemiselulosa dan lignin. Sifat ini penting untuk pemanfaatan kayu untuk produk kertas, bioenergi, produk kimia, dsb.
Jenis Selulosa Hemiselulosa Lignin
(% berat kering)
Kayukeras (hardwood) 40 – 44 15 – 35 18 – 25
Kayulunak (softwood) 40 – 44 20 – 32 25 – 35
Serat Akasia Serat pada kertas Produk kertas
Pengolahan Hasil Hutan
Tomy listyanto
Suatu usaha merubah kayu bulat (log) menjadi papan/balok kayu persegi pada sisi-sisinya dan pemotongan untuk mendapatkan dimensi panjang sebagai bahan baku untuk pengolahan lebih lanjut.
(Haygreen & Bowyer, 1996)
Pengolahan Primer Kayu Solid
Penggergajian Kayu
Perbedaan Sortimen Kayu Gergajian
Flatsawn
Quatersawn
Pengolahan Primer Kayu Solid
Penggunaan Kayu Solid – Kayu Komposit
Kayu gergajian solid
Kayu laminasi Laminasi dengan
perekatan
Dimensi lebar
Dimensi panjang Partikel kayu Finir kayu
Kayu lapis (Plywood) Papan partikel (Particleboard)
Pengolahan Finir Kayu & Kayu Lapis
Pengolahan Primer Komposit Kayu
FROM LOG TO VENE,ER
1'\ nce its bark is stripped away, a log
\J .un be cut into veneer in one oi three rvays: saw cutting, rotary cutting or flat slicing. Saw cutting, which goes back to the early 19th Centi"rry, employs huge circular saws to rip strips of veneer from logs. Although not as efficient as other techniques, saw cutting is still used to produce some crotch veneers from irregularly grained or dense woods such as ebony.
Rotary cutting and flat slicing can produce veneers as thin as 7s to l,/r zo inch and as long as I B feet. In rotary cutting, a log mounted in a huge lathe rotates against a presslu€ bar while a razor-sharp knife oeels off a continuous sheet of veneeithe length of the log. Fir plp,vood, as well as some decorative veneers such as bird's-eye maple, are normally rotary cut. Half-round, rift and back cutting are variations that produce veneer from half-loss rather than whole ones.
In flat slicing, a half-log is held onto a frame that swings r-rp and down against a stationary horizontai knife; a slice of veneer is removed with every down- stroke. FIat slicing produces crown-cut veneers. A type of flat slicing known as quarter-clrt slicing is used on woods that display a striking figure when quarter- sawn, as in sapeie, white oak or lacewood.
Flat-sliced sheets of verteer move nlortg tt conveyor for drying tud
storage hr n vetreer .fnctory.
VENEER-CUTTING METH(lDS
Rotary autting Used Lo cut con' etruction plywood and eome decora' tive veneera guch ao btrd'o-eye maple
Half-round autting A method used for burla and aome decorattve apectea
Eack cutting A rotary cutting method that. yielde buLL and croLch veneer9
Flat eliaing Uaed to make crown- cut veneer?; pro' ducea veneera wiLh repeatinq figure thaL facrltLaf,ea book' matching and oLher decorative effects
Quarber-aui aliaing Uaed to cut decora- f,tve veneerg, auch ae ribbon, atripe and flake, that are obtarned from quar' Lereawn loqe
Ri{t cutting Yielde veneer wtth the raye at rou7hly 45" to the eurface;
uoed primarily on whiLe oak
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• Perumahan dan konstruksi serta industri membutuhkan produk panel yang berdimensi lebar sehingga mendorong berkembangnya teknologi komposit kayu (kayu lapis, papan partikel, papan serat dsb).
• Finir: lembaran papan tipis dengan tebal seragam, yang diperoleh melalui : pengupasan, pengirisan, dan penggergajian
Kayu lapis merupakan komposit kayu yang dibuat dengan menggabungkan beberapa lembar finir kayu yang umumnya berjumlah ganjil yang disusun bersilangan dengan menggunakan perekat.
Penggunaan Kayu Lapis
Pengolahan Primer Komposit Kayu
Pengolahan Papan Partikel
Pengolahan Primer Komposit Kayu
Pengolahan Papan Partikel
• Papan partikel adalah produk panil yang dihasilkan dengan memampatkan partikel-partikel kayu dan sekaligus mengikatnya dengan suatu perekat (Haygreen dan Bowyer, 1996).
• Papan partikel merupakan salah satu produk papan tiruan yang memanfaatkan limbah kayu, potongan-potongan kecil kayu (ketaman, serutan, partikel, serpihan) kemudian dicampur perekat hingga merata, selanjutnya dilakukan pengempaan pendahuluan dan pengempaan panas.
Mebel
Mebel : perabot yg diperlukan, berguna, atau disukai, spt barang atau benda yg dapat dipindah-pindah, digunakan untuk melengkapi rumah, kantor, dsb.
Pengolahan Sekunder Kayu
Pengolahan Mebel : mengolah kayu gergajian kering dengan memotong menjadi komponen-komponen mebel, kemudian komponen tersebut diratakan dan dihaluskan untuk dirakit menjadi mebel dengan pengerjaan akhir berupa finishing.
Pulp & Kertas
Pulp: Bahan berserat yang dihasilkan dari pengolahan bahan berselulose (tanaman berkayu dll.) menjadi komponen-komponennya, baik secara mekanis, kimia, atau kombinasi dari ke duanya (kimia dan
mekanis/semikimia) dan merupakan bahan baku pembuatan lembaran pulp, kertas, dan papan serat, rayon serta produk turunan (sintetis) lainnya.
Kertas merupakan lembaran homogen dari serat selulose yang
dikempa/felted, direkat/ digabungkan menjadi satu oleh ikatan yang saling menjalin/interweaving dan oleh penggu-naan zat pengikat/perekat, serta dibuat dalam berbagai type.
Kertas dapat dimanfaatkan untuk berbagai tujuan yang begitu banyak, seperti penulisan, pencetakan, pembungkus, pakaian, industri,
kebersihan/kesehatan/sanitary dsbnya.
Pengolahan Sekunder Kayu (2)
Proses Pembuatan Kertas
Pembuatan kertas :
1. Reduksi kayu menjadi serat (pulping) 2. Pembuatan suspensi serat dalam air 3. Penghalusan atau penggilingan serat
4. Pencampuran bahan aditif (pengisi, warna, perekat dll.) 5. Pembuatan kasuran serat
6. Penghilangan air
7. Pengeringan lembaran 8. Perlakuan permukaan
Pengolahan Sekunder Kayu (2)
Proses Pembuatan Pulp & Kertas
Pengolahan Sekunder Kayu (2)
Produk Kertas
Energy from Tree or Forest
Prof. Nam Hum Kim
Hasil Hutan Non Kayu
Kelompok Tumbuhan Monokotil : Bambu, rotan, kelapa, nipah, sawit, sagu.
Kelompok Ekstraktif : minyak atsiri, minyak lemak, getah resin, getah
karet, perekat alam, zat penyamak, zat pewarna, tbh-obat/alkoloid.
Kelompok Produk Hasil Budidaya : ulat sutra, lak, madu,walet, dan
jamur.
Produk HHNK
Kelompok Ektraktif:
Minyak Atsiri - Minyak Kayu Putih
ASAL :
DARI DAUN
ALAM/TANAMAN KAYU PUTIH
DISTILASI HASIL :
RENDEMEN 0,5 – 1,4%
POTENSI :
HUTAN ALAM
(LEBIH 90%) : KURANG 2,5 TON/HA HUTAN TANAMAN :
DI JAWA : 2,5 - 4,0 TON/HA
Produk HHNK
Kelompok Ektraktif:
Getah Resin – Gondorukem & Terpentin
ASAL :
DARI GETAH SADAPAN POHON PINUS ALAM/TANAMAN
DISTILASI HASIL :
GONDORUKEM – RESIDU DARI PENGOLAHAN GETAH PINUS (60 – 70%)
TERPENTIN – PRODUK DESTILAT DARI PENGOLAHAN GETAH PINUS (9 - 14%)
KEGUNAAN :
GONDORUKEM: BATIK, KERTAS, SABUN, VERNIS TERPENTIN: PELARUT ORGANIK, PELARUT CAT, BAHAN KAMFER DSB
Produk HHNK
TERIMA KASIH
