Wood ndi katundu wake

Mtengo umakhala ndi ziwiya, tsinde, nthambi ndi masamba. Thunthulo limayimira unyinji wa mtengowo ndipo limapanga 50–90 % ya cubature yake; mitsempha ndi nthambi zimapanga 10–50 % unyinji wa matabwa.

Zigawo zoyambira za mtengo

Pali zigawo zotsatirazi mumtengo: mtima, pith, cambium ndi khungwa. Khungwa ndi mbali yakunja ya mtengo, yomwe ili yosiyana kwambiri ndi mtima. Pakati pa khungwa ndi pith pali mphete yopyapyala, yosaoneka ndi maso ndipo imatchedwa cambium. Maselo a cambium, kupyolera mu magawano, chaka chilichonse amalekanitsa maselo a mtima mkati mwa thunthu la mtengo, ndi maselo a khungwa kunja kwa mtengo. Popeza cambium imatulutsa maselo ambiri amtima kuposa ma bark cell, pali mitima yambiri kuposa khungwa.

Mtima ndi gawo lamtengo wapatali la mtengo; ili pakati pa mtima ndi khungwa. Mtima uli pakati pa mtengo. Amakhala ndi minofu yofewa, ya porous, yomwe ili ndi mphamvu zofooka zamakina. Pakakhala mitima m’magulu, laths kapena matabwa, ndiye kuti zinthuzi zimasweka pakapita nthawi. Chifukwa chake, pazinthu zambiri zofunika kwambiri, kupezeka kwa mtima muzinthu sikuloledwa.

Zodula matabwa zazikulu zitatu

Chithunzi cholondola cha matabwa chikhoza kupezeka pamene chikuwonetsedwa m’magawo atatu: transverse, radial ndi tangential.

Chigawo chodutsa ndi chomwe chimalunjikitsidwa ku nsonga ya mtengo, gawo la radial limadutsa pamtengo, kudutsa pamtima, ndipo tangential ndi yomwe imadutsa pamtengo kunja kwa mtima (mkuyu 1).

Chith. 1. Mitengo itatu yamatabwa: 1 - tangential; 2 - zozungulira; 3 - modutsa.

Zaka, nkhuni zoyambirira ndi mochedwa

Pamtanda wamtengowo, mabwalo amatha kuwoneka, omwe amawonjezeka kuchokera pakati mpaka pamphepete, ndipo amatchedwa mphete zapachaka (zaka). Mphete iliyonse yapachaka imakhala ndi gawo lamkati ndi lakunja. Chosanjikiza chamkati chimatchedwa early wood, ndipo chakunja chimatchedwa late wood. Mitengo yoyambirira imapangidwa mu kasupe, ndipo mochedwa - m’chilimwe. Mitengo yoyambirira imakhala ndi porous, imakhala ndi minyewa yopanda kanthu, madzi amadutsamo ndi zinthu zomwe zimasungunuka, zomwe ndizofunikira pakudya kwa mtengo. Mitengo yochedwa imakhala ndi ma cell okhala ndi makoma okhuthala omwe amanyamula katundu wamakina.

Chith. 2. Kuwala kwapakati pazigawo zopingasa, zozungulira komanso zozungulira: 1 - khungwa; 2 - khalidwe; 3 ​​- zaka; 4 - mtima; 5 ndi 6 — cheza chachikulu chapakati.

Pa gawo la radial, zigawo zapachaka zimawoneka ngati mizere yowongoka, pagawo la tangential - ngati mizere yokhota.

Core Rays

Pa gawo lopingasa, lozungulira komanso lozungulira, pafupi ndi zigawo zapachaka, mutha kuwonanso core ray (mkuyu 2). Pamtanda, ali ndi mawonekedwe amizere yopapatiza, pagawo la tangential - mizere yakuda yokhala ndi malekezero opapatiza. Kuunikira kwapakati kumagwiritsidwa ntchito poyendetsa madzi ndi mpweya kupyola thunthu la mtengo kunjira yodutsa, komanso kusunga zakudya zosungirako. Chiwerengero cha cheza chapakati pamitundu yosiyanasiyana yamitengo ndi chosiyana ndipo chimafika pafupifupi 3000 mpaka 1 cm2 mu pine, ndi 143000 mu spruce. M’mitengo ya coniferous, kuwala kwapakati kumakhala 3 — 10 %, komanso m’mitengo yophukira 9 - 36% ya kuchuluka kwa nkhuni.

Kuwala kwapakati kumakhala ndi ma cell, omwe amakhala ndi mphamvu zochepa zamakina, chifukwa chake amachulukitsa kugawanika kwa matabwa.

Madontho apakati ndi kugawanika kwa mitundu ya matabwa

Mumitundu ina yamatabwa, mwachitsanzo. mawanga oyera kapena ofiirira amatha kuwoneka pamtanda wa alder, birch, yew, chub, ndi hornbeam. Mawangawa amayamba chifukwa cha tizilombo kapena chisanu chowononga cambium, ndipo amatchedwa core spots. Madontho apakati awa amachepetsa mphamvu zamakina za nkhuni. Mitundu yonse yamatabwa itha kugawidwa m’magulu anayi:

1. Zopatulika (oki, mtedza, mthethe woyera, paini, mkungudza, larch, ndi zina zotero);
2. Zamoyo zokhala ndi nkhuni zokhwima (beech, linden, spruce, fir, fir wamba waku Siberian ndi Caucasian fir, etc.);
3. Zamtundu wa core and okhwima heartwood (plain ash, elm, etc.);
4. Zamitundu yambiri (birch, aspen, alder yakuda ndi yoyera, hornbeam, mapulo, chestnut, mapulo, ndi zina zotero).

Core, sapwood ndi matailosi

Mu mitundu ya mitengo yofewa, mbali yapakati yakuda kwambiri imatchedwa core, ndipo yamitundu yopepuka imatchedwa stem. Pankhani ya mitundu ya nkhuni yokhala ndi mtima wokhwima, gawo lapakati la gawoli limadziwika ndi chinyezi chochepa kusiyana ndi gawo lozungulira. Mumtengo womwe ukukula, mtengo wa sapwood umatumiza madzi ndikusonkhanitsa zakudya. Mumitundu ina yamatabwa, matabwa amitundu iwiri amatha kuwoneka pamtanda. Izi siziri kanthu koma chiyambi cha kuvunda kwa nkhuni chifukwa cha bowa wapadera wowononga nkhuni.

Kulimba kwa nkhuni sikusiyana ndi pakatikati, koma kumalimbana ndi kuvunda. Ndi kukula kwa mtengowo, mtengowo umasunthira pang’onopang’ono mumtengowo. Pakusintha kumeneku, m’mitsinje yamitundu yamasamba, ndi m’miyendo ya conifers, masamba apadera otchedwa tiles, amawonekera, ndipo ming’alu ndi ma envulopu a maselo amadzazidwa ndi zida zama cell ndi zotulutsa.

Matayilo amadzaza mtima, zomwe zimapangitsa kuti madzi asalowemo. Choncho, srcica imagwiritsidwa ntchito popanga migolo, matanki amatabwa, ndi zina zotero. Izi zimagwiranso ntchito ku mtengo wa beech, womwe uli ndi tsinde labodza, lopangidwa chifukwa cha mtengowo kugwidwa ndi bowa omwe amawononga nthawi ya kukula kwake.

Kuti mupitilize mutuwo, onani zolemba za chinyezi chamatabwa ndi kuyanika matabwa achilengedwe. Ngati mukukonzekera zolumikizira zatsopano, onani mazenera amatabwa amwambo kapena tumizani pempho la mtengo.