Lub ntsiab lus cav ntoo, muaj pes tsawg leeg, zog, yam ntxwv thiab kev teeb tsa. Ntoo - yog dab tsi no?

Txiv neej siv ntoo los ntawm lub sij hawm immemorial. Roj, lub tsev ntaub ntawv, rooj tog zaum, seev suab paj nruas - cov khoom ntawm ntoo nrog peb mus ib txhis. Nyob rau hauv tas li ntawd, cov ntoo - ib tug natural daim qhia hnub hli thiab nyob keeb kwm.

Muaj yog ib tug tag nrho ceg ntawm science - dendrochronology, uas cia koj paub lub hnub nyoog ntawm cov khoom, thiab nyob rau hauv uas cheeb tsam tau txiav down ib tsob ntoo, los ntawm uas nws tau ua. Kawm seem ntawm lub xyoo rings, koj yuav kawm txog cov xwm thiab cov cua ntawm ancient sij hawm. Zoo thiab tsis zoo, tus qauv ntawm cov ntoo raws li ib tug lub tsev cov ntaub ntawv uas cov khoom - tag nrho ntawm cov teeb meem tsim nyog xim.

Yuav ua li cas nws ua hauj lwm

Cov khoom thiab cov yam ntxwv ntawm cov ntaub ntawv uas yuav tsis tau to taub tsis tau coj cov qauv thiab cov muaj pes tsawg leeg ntawm lub cav ntoo. Tus heev notion ntawm nyob ntawm uas siv nws. Rau qhov nruab nrab neeg thiab cov builder yog tus tsuas yog daim txiag ntoo nyob rau hauv cov tawv ntoo, uas yuav siv tau nyob rau hauv lub tsev los yog chaw ua hauj lwm. Rau botany qauv ntawm cov ntoo thiab ntoo - qhov no yog tag nrho cov complex, uas muaj xws li tag nrho cov ntsiab ntawm cov keeb kwm mus lub crown.

Crohn siv nyob rau hauv kev lag luam me ntsis, thiab cov ceg yog li feedstock rau fibreboard thiab cov duab los qhia. Lub ntsiab tseem ceeb yog lub pob tw. Nyob rau hauv tus ntoo khaub lig-sectional qauv ntawm lub qhov muag cov ntoo lub cev. Lub uppermost txheej - qhov cortex, tiv thaiv nyob hlwb los ntawm lwm influences. Ntawm cov tawv ntoo thiab tus kav lub cev yog ib tug txheej ntawm nyob hlwb - cadmium. Nyob rau hauv lub plawv los ntawm lub thoob kis cov tub ntxhais. Xoob cov ntaub so ntswg los ntawm uas nws yog ib, kom nws ua unsuitable rau utilitarian hom phiaj.

ntoo tub ntxhais yog muaj li mas tuag hlwb, cob deposits dyeing thiab tanning cov neeg ua hauj. Lub keeb yog surrounded los ntawm cov sapwood - ib feem ntawm tsob ntoo, uas yog lub luag hauj lwm rau nqa dej rau cov nplooj los ntawm cov keeb kwm. Raws li, muaj ib tug ntau ntawm cov dej, nws yog ntau dej kaw ntom nti thiab muaj zog rot. Cov lus hais rau cov ntsiav yog tsis nyob rau hauv tag nrho cov ntoo. Nyob rau hauv ib co ntawm lawv muaj tsis muaj qhov sib txawv ntawm qhov chaw thiab tuaj txog pem ntwg chim. Tej pob zeb no yog hu ua sapwood.

Me qauv ntawm cov ntoo

Siv lub tshuab kuaj kab, peb yuav tau saib tob mus rau hauv lub tsev. Ntoo muaj ib tug tag nrho ntawm tuag tawv hlwb. Hluas vegetative hlwb muaj ib tug plhaub thiab puab ib feem - lub cytoplasm thiab nucleus. Raws li nyias pob tshab daim nyias nyias yog cellulose los yog cellulose. Nrog yauv metamorphosis thiab, nyob ntawm seb yuav ua li cas nws tso cai, yog hloov dua siab tshiab rau hauv cov huab hwm coj los mus rau lub Cortex (probkovanie) los yog cav ntoo (lignification) nroj hlwb thaum lub sij hawm.

Lub hlwb tsim tsis tu ncua lignin. Nws yog vim li cas rau lignification. Qhia los ntawm ob hom ntxhov hlwb - prozenhimnye thiab parenchymal. Tus thawj hom yog tej ntoo, nyob ntawm seb tus yug - los ntawm 85% mus rau 99%. Nyob rau hauv lem, lawv muab faib nyob rau hauv lawv cov kev khiav dej num. Conductive hlwb yog lub luag hauj lwm rau cov me nyuam ntawm cov as-ham thiab dej los ntawm cov keeb kwm mus rau lub nplooj, neeg kho tshuab - rau lub dag lub zog thiab stability ntawm tsob ntoo. Parenchymal hlwb ua cov kev ua ntawm lub pantry rau cov nroj tsuag. Lawv noog cov as-ham (rog, starches) thiab muab rau lawv raws li uas yuav tsum tau thaum lub sij hawm nyuaj lub sij hawm.

softwood

Nyob ntawm seb lub hom ntawm cov ntoo thiab lawv cov qauv sib txawv. Hom ntoo yog muab faib mus rau hauv coniferous thiab deciduous. Tus qauv ntawm conifers yog ntau yooj yim. Ua li lub ib thooj ntawm traheidnye hlwb. Qhov tshwj xeeb nta ntawm softwood muaj xws li cov kev lub hlwb uas tsim lub cob. Ntau hom tej zaum yuav yog across tawg khiav ri niab thiab united nyob rau hauv cob ducts.

Hardwood

Ntau txoj ntoo ntawm deciduous breeds thiab lawv cov qauv. Ntoo yog muaj li ntawm vascular thiab parenchymal hlwb libriform fibers. Txij li thaum deciduous ntoo poob lawv cov nplooj nyob rau hauv lub caij nplooj zeeg, lub caij ntuj no, lawv yuav tsum tau ib tug loj mov ntawm cov zaub mov. Li no, cov neeg coob coob ntawm cov parenchymal hlwb lub luag hauj lwm rau tsub zuj zuj ntawm muab kev pab cuam, dua li nyob rau hauv softwood. Qhov no yuav ua pom los ntawm ib tug qhia cov tub ntxhais.

zog

Ib tug xov tooj ntawm cov yam ntxwv zog muaj ib tug ntoo. Nta ntawm cov qauv rau qhov ua rau. Durability nyob rau hauv cov ntoo yog heev siab heev, thiab cov kev tsim kho cov ntaub ntawv rau qhov ntsuas no nws occupies ib nrab txoj hauj lwm. Tab sis muab qhov me me kev faib ua feem ntawm nws yog piv rau hauv no hwm rau cov hlau. Cov tsis muaj zog point ntawm tus ntoo yog hais tias nws yog - anisotropic khoom. Lub peev xwm ntawm kuj rau kev puas tsuaj nyob rau hauv cov kev coj ntawm kev quab yuam txheeb ze mus rau lub fiber tshiab. Qhov zoo tshaj plaws kev ntsuas ntawm lub dag lub zog pom thaum raug rau cov khoom raws grain.

Tus nruj ntawm cov ntoo yog me me, yog vim li cas rau qhov no - cov qauv. Ntoo - ib tug ntxeem tau, saj zawg zog cov ntaub ntawv uas. Kab teeb tau los lawv zoo lawm tom qab ib tug luv luv load. Tab sis lub residual deformation vim ntev raug nyob twj ywm mus tas li. Ntoo beam yuav tsis tau rov qab lawv cov zoo tom qab ntev siv.

Hardness ntawm lub tsev ntaub ntawv yog txiav txim los ntawm dab tsi lub load tsim nyog rau nias lub steel pob nrog ib tug me me. Rau lub zog ntoo nws yog tsuas 1000 N. Nyob rau hauv cov ntaub ntawv no, tsis tshua muaj hardness - nws yog ib tug ntawm lub ntsiab zoo ntawm cov khoom. Ntoo yog ib qho yooj yim ua, nws yog nrees nyob rau ntawm tes, screws, self-tapping screws.

Ntoo dej cov ntsiab lus yog txiav txim los ntawm cov kev cov ntsiab lus ntawm dej nyob rau hauv lub pores. Nyob rau hauv cia li ib tug felled tsob ntoo, nws nce mus txog 100%. Nyob ntawm seb lub hom phiaj ntawm kom qhuav ntsuab zoov yog raug mus ua cov tsis los ntawm 40 mus rau 15%.

meej mom

Ntoo muaj ib tug uas tsis muaj thermal conductivity nqi. Nws yuav advantageously siv raws li ib tug insulating cov ntaub ntawv uas. Yooj Yim ntawm kev ua rau nws tau siv ib tug ntau ntawm cov seev. Nws yog tsis yooj yim sua xav txog tej yam tej band tsis muaj seev suab paj nruas ua los ntawm cov ntoo. Stunning nkauj laus ncas - qhov tshwm sim ntawm tej thaj chaw ntawm cov ntoo, raws li lub peev xwm los resonance. Ntoo yog yooj yim bent, qhib ib tug zoo xaiv rau qhov siv thiab ua ntau yam nkhaus lug. Tsis tas li ntawd ntoo cov khoom muaj zoo suab-absorbing cov yam ntxwv. Zoo nkauj nto opens pem qhov chaw rau lub tswv yim thaum muaj chaw seem tsim.

shortcomings

Lub peev xwm coj ib tug load ntawm ntoo khoom nyob rau hauv cov kev coj ntawm kev quab yuam daim ntawv thov. Qhov no yog vim lub anisotropic qauv ntawm cov ntoo. Nyob rau hauv tas li ntawd, lub zog zog nyob ntawm seb tseem nyob rau qhov sib thooj rau qhov chaw ntawm lub pob tw, humidity, muaj cov pob caus ntawd thiab tej kab nrib pleb. Qhov no ua rau siv ib tug ntau lub sij hawm nyob rau hauv cov kev xaiv ntawm haum cov ntaub ntawv uas rau cov hauj lwm.

Raws li cov organic khoom, ntoo yog lam tau lam ua rau kab, pwm, fungi. Rau ntev-kawg nkaus lag luam yuav tsum tau nqa tawm ib tug kim tshuaj kho mob. Nws yuav tsum tau muab sau tseg tias cov ntoo qauv tsis pre-kev kho mob - ib qho yooj yim prey rau hluav taws.

ntoo ua

Nyob rau hauv kev, muaj peb hom ntoo ua:

• Cov feem ntau - txhua yam txujci. Ntoo sawing, planing, phua.
• Nyob rau hauv tshuaj-mechanical kev kho mob ntawm cov khoom yog raug ib nrab kev npaj. Ntoo chips, shavings tov nrog ib tug phau ntawv thiab rhuab. Ib tug tshuaj polymerization cov tshuaj tiv thaiv thiab lub qhov zis ua ntaub ntawv xws li plywood, chipboard, fiberboard.
• Thaum cov tshuaj kho mob mus rau lub ntoo acids, alkalis, ntsev, yog raug rau cov cua kub. Nws yuav hu ua los ntawm tej kev kho mob cov khoom hluav ncaig, rosin cov pos hniav, tannins, cellulose.

Tsob ntoo laus txiv neej nyob rau hauv lub pua pua lab ntawm xyoo. Tag nrho cov puas tau muaj ib tug kev vam meej raws li nyob rau kev siv ntawm cov ntoo. Phau ntawv, rooj tog zaum, seev suab paj nruas - tag nrho cov no yog tau ua tsaug rau no cov cim ntuj khoom.