Nauyin itace

Nauyin itacen ya dogara da yawansa da kuma yawan danshin da ke cikinsa. Akwai ƙayyadaddun nauyin al'amarin itace da kuma nauyin nauyin itace. Ƙayyadadden nauyin itace ba ya dogara da nau'in itace; yana bayyana nauyin kayan katako na katako a cikin juzu'in naúrar ba tare da danshi da iska ba kuma shine 1,5. A cikin aikace-aikacen, ana amfani da nau'in nau'in nau'in nau'in nau'in itace, wato, nauyin 1 cm³ itace taro bayyana a cikin grams. An yi la'akari da nauyin itace da kayan fasaha ta hanyar nauyin girma. Tare da karuwar zafi, nauyin nauyin katako yana ƙaruwa. Mafi girma da yawa na itace, da mafi m da kasa porous shi ne.

Danshi itace

Ruwan da ke cikin bishiyar ya kasu kashi;

1. capillary (free) - cika kogon sha'awa
2. Hygroscopic - located a cikin cell bango
3. Chemical - yana shiga cikin sinadarai na abubuwan da suke yin itace.

Adadin ruwa a cikin itace, wanda aka bayyana a cikin nauyin kashi, ana kiransa danshi abun ciki na itace. Akwai cikakke i dangi zafi.

Idan harafin A yana nuni da nauyin itace a asalin asalinsa, ana nuna nauyin busasshiyar itace da harafin A.₁, dangi zafi a cikin kashi B, cikakken zafi a cikin kashi B₁, to ana iya ƙayyade yanayin zafi bisa ga dabara:

An ƙaddara cikakken zafi bisa ga dabara:

Ƙayyade abun ciki na danshi na itace yana yin haka ta hanya mai zuwa. Ana yanke prism daga tsakiyar allo kuma a auna shi akan ma'auni tare da daidaito na 0,01 - kuma zai zama girman A, to, wannan priism, wanda nauyinsa bai kamata ya zama ƙasa da 20 g ba, an bushe shi a zazzabi na 105. ⁰ har sai ya kai madaidaicin nauyi A_1. An yi la'akari da nauyin nauyi na yau da kullum idan bambanci tsakanin ma'auni biyu a jere bai fi 0,3% na busassun nauyi ba. Musanya cikin tsarin girman A da A sama₁, samu ta ma'auni, mun ƙayyade dangi ko cikakken zafi na itace.

Idan, alal misali, ainihin nauyin priism da aka yanke daga tsakiyar allon shine 240 g, kuma nauyin busassun itace ya kasance 160 g, to, cikakken zafi na samfurin da aka gwada zai zama:

Ana ƙididdige zafi da aka samu ta wannan hanyar azaman zafi na dukan itace.
Lokacin bushewar itace, ana fara zubar da ruwa kyauta. Lokacin da duk ruwan kyauta ya ƙafe ana kiransa iyakar hygroscopic ko madaidaicin fiber. A wannan lokacin bushewa, girman itacen da ake bushewa ba ya canzawa. Yanayin zafi wanda yayi daidai da iyakar hygroscopic don nau'ikan itace daban-daban (a cikin%) shine kamar haka:

• Pine gama gari 29
• Weymouth Pine 25
• Spruce 29
• Larci 30
• Jela 30
• Bukva 31
• Lafi 29
• Jason 23
• Kiji 25

Itace tare da ƙãra zafi shine kyakkyawan jagorar zafi, ya fi muni aiki akan dashinas, yana da kyau a gluing, zanen, varnishing da polishing; a saman itacen fentin rigar, fenti da varnish da sauri sun tarwatse. Itace mai ɗanɗano yana haifar da ƙusoshi da kusoshi zuwa tsatsa. Girman kayan aikin kafinta, waɗanda aka yi da ɗanyen itace (ƙofofi, tagogi, benaye na katako, parquet, da sauransu), suna rage girman su yayin bushewa, sakamakon fashewar ya bayyana, taurin haɗin da ke tsakanin abubuwan shine. rasa. Don haka, ingancin itace wajen yin gini, darewarsa da juriya daga rubewa ana saninsa da farko ta yanayin zafi, sannan kuma ta hanyar nau'insa da yanayin amfaninsa. A ƙarƙashin yanayin al'ada na amfani, busassun itace na iya yin hidima a cikin gine-gine na shekaru da yawa.

A lokacin bushewa, itacen yana canza ti a tsayin daka da 0,10%, a cikin radial shugabanci da 3 - 6%, kuma a cikin tangential shugabanci da 6 - 12%. Wannan yana canza nauyi. Auna yana farawa lokacin da zafi ya kai matakin jikewa na zaruruwa (23 - 31%). Abubuwan da ke tattare da itacen suna raguwa ba daidai ba yayin aikin bushewa, don haka nauyin itacen ya bambanta ta hanyoyi daban-daban.

Itace tare da babban yawa (oak) yayi nauyi fiye da itace tare da ƙananan ƙananan (linden). Game da nau'in nau'in coniferous, adadin ma'auni kuma ya dogara ne akan sa hannu na katako na marigayi. Tare da karuwa a cikin adadin marigayi itace, nauyin nauyi yana ƙaruwa a cikin Pine. Wannan shi ne saboda gaskiyar cewa marigayi itacen nau'in conifer yayi nauyi sosai lokacin bushewa fiye da itacen farko. An ba da bayanai game da girman nauyin itacen nau'in coniferous a cikin tebur 1. 

An ba da adadin nauyin nau'ikan itace daban-daban a cikin tebur 2.

Canjin da ba daidai ba a cikin ma'auni a cikin tsarin ma'auni saboda bushewa, da kuma aiwatar da tsarin bushewa mara kyau, yana haifar da bayyanar damuwa na ciki da na waje a cikin itace, wanda ke haifar da yanayi, da bayyanar waje da kuma wani lokacin ciki. fasa.

Tangentially yanke allunan sun fi wanki fiye da radially yanke, kuma kusa da su kusa da gefen, mafi girma da iska (Fig. 3).

Ana haifar da tsagewar waje ta rashin daidaituwar bushewa na waje da na ciki na itace. Saboda babban bambanci tsakanin zafi na waje da na ciki yadudduka na itace, damuwa damuwa yana bayyana a samansa, wanda ya haifar da bayyanar tsagewar waje. Don kauce wa bayyanar cututtuka na waje, tsarin bushewa ya kamata a yi a hankali a hankali. A lokaci guda kuma, za a yi sauye-sauyen girma a hankali kuma a ko'ina, don haka dakarun da ke haifar da yadawa za su kasance ƙananan, ta yadda ba za a sami tsagewar waje ba.

Sl. 3 Yanayin allo

An san cewa itacen yana bushewa da sauri daga gaba, don haka ana fesa gaban alluna, katako da katakon katako a baya fiye da sauran sassan alluna da katako. Kumburin itace shine tsarin baya na bushewa da nauyi. Ya ƙunshi gaskiyar cewa busasshen itace yana iya ɗaukar danshi da haɓaka girmansa. Ana amfani da dukiyar itace don kumbura don jiƙa busassun ganga, bututun katako, tankuna, da sauransu, sakamakon haka suna kumbura.