Njira yoyeretsera minofu ya nsungwi yopanda chlorine ya ECF

Tili ndi mbiri yakale yopangira mapepala a nsungwi ku China. Kapangidwe ka ulusi wa nsungwi ndi kapangidwe ka mankhwala ndi kapadera. Kutalika kwa ulusi wapakati ndikutalika, ndipo kapangidwe ka khoma la ulusi ndi kapadera. Mphamvu yakukula kwa mphamvu panthawi yopangira pulping ndi yabwino, zomwe zimapangitsa kuti pulp yophwanyika ikhale ndi mawonekedwe abwino komanso kuwala kokwanira. Kuchuluka kwa lignin mu zinthu zopangira nsungwi (pafupifupi 23%-32%) ndi kwakukulu, zomwe zimatsimikizira kuchuluka kwa alkali ndi sulfidation panthawi yopangira ndi kuphika (mlingo wa sulfidation nthawi zambiri ndi 20%-25%), womwe uli pafupi ndi matabwa a coniferous. Kuchuluka kwa hemicellulose ndi silicon mu zinthu zopangira kumabweretsanso zovuta zina pakugwira ntchito kwabwinobwino kwa makina ochapira pulp ndi zida zakuda zotulutsa madzi ndi kudzaza. Ngakhale zili choncho, zinthu zopangira nsungwi zikadali zinthu zabwino zopangira mapepala.

Njira yoyeretsera madzi ya zomera zazikulu ndi zapakatikati zoyeretsera madzi za nsungwi imagwiritsa ntchito njira yoyeretsera madzi ya TCF kapena ECF. Kawirikawiri, kuphatikiza ndi kuyeretsa kwakuya ndi kuyeretsa kwa mpweya wa pulping, ukadaulo wa TCF kapena ECF umagwiritsidwa ntchito. Kutengera kuchuluka kwa magawo oyeretsera madzi, madzi a nsungwi amatha kuyeretsa madzi mpaka 88%-90%.

Ma tissue athu a nsungwi opakidwa utoto onse amapakidwa utoto ndi ECF (yopanda chlorine), yomwe imataya utoto pang'ono pa tissue ya nsungwi komanso kukhuthala kwa tissue, nthawi zambiri imafika pa 800ml/g. Ma tissue a nsungwi opakidwa utoto a ECF ali ndi khalidwe labwino la tissue, amagwiritsa ntchito mankhwala ochepa, komanso ali ndi mphamvu zambiri zoyeretsera utoto. Nthawi yomweyo, makina a zida ndi okhwima ndipo magwiridwe antchito ndi okhazikika.

Njira zoyeretsera bleach ya ECF elemental chlorine yopanda chlorine ya nsungwi ndi izi: choyamba, mpweya (02) umalowetsedwa mu nsanja ya oxidation kuti ukhale woyeretsa, kenako D0 bleaching-washing-Eop extraction-washing-washing-D1 bleaching-washing zimachitika motsatizana pambuyo potsuka. Mankhwala akuluakulu oyeretsera bleach ndi CI02 (chlorine dioxide), NaOH (sodium hydroxide), H202 (hydrogen peroxide), ndi zina zotero. Pomaliza, bleached pulp imapangidwa ndi pressure dehydration. Kuyera kwa bleached pulp ya nsungwi kumatha kufika pa 80%.