II. Kodi chikho cha pepala la ayisikilimu chowola n'chiyani?
Zowolamakapu a ayisikilimu pepalaZingathe kuwonongeka. Zimachepetsa mavuto pa chilengedwe. Zingathe kuchepetsa zinyalala za zinthu kudzera mu kuwonongeka kwa tizilombo toyambitsa matenda ndi kubwezeretsanso. Chikho ichi cha pepala ndi chisankho chokhazikika komanso chosamalira chilengedwe. Chimapereka yankho lokhazikika kwambiri kwa makampani ophikira zakudya.
A. Tanthauzo ndi makhalidwe
Makapu a mapepala a ayisikilimu ovunda ndi ziwiya zamapepala zopangidwa ndi zinthu zovunda. Zimawonongeka mwachilengedwe pamalo oyenera. Poyerekeza ndi makapu apulasitiki achikhalidwe, makapu a mapepala ovunda ali ndi makhalidwe awa:
1. Kuteteza chilengedwe. PLA yowonongekamakapu a ayisikilimuamapangidwa kuchokera ku starch ya zomera. Motero, amatha kuwola m'chilengedwe. Izi zitha kuchepetsa kuipitsa chilengedwe. Zili ndi zotsatira zabwino poteteza chilengedwe cha Dziko Lapansi.
2. Yongowonjezedwanso. PLA imapangidwa kuchokera ku zinthu zongowonjezedwanso, monga starch ya zomera. Poyerekeza ndi mapulasitiki a petrochemical, njira yopangira PLA imagwiritsa ntchito mphamvu zochepa komanso mpweya woipa womwe umatuluka m'mlengalenga. Ili ndi kukhazikika bwino.
3. Kuwonekera. Makapu a pepala a PLA ali ndi mawonekedwe owonekera bwino. Izi zitha kuwonetsa bwino mtundu ndi mawonekedwe a ayisikilimu. Zingathandize kuti ogula azisangalala ndi mawonekedwe awo. Kupatula apo, makapu a pepala amatha kusinthidwa kukhala ogwirizana ndi ena. Izi zimapatsa amalonda mwayi wotsatsa malonda.
4. Kukana kutentha. Makapu a pepala a PLA amagwira ntchito bwino. Amatha kupirira chakudya pa kutentha kwina. Chikho ichi cha pepala ndi choyenera kwambiri kusungiramo zakudya zozizira komanso zotentha monga ayisikilimu.
5. Yopepuka komanso yolimba. Makapu a mapepala a PLA ndi opepuka komanso osavuta kunyamula ndikugwiritsa ntchito. Pakadali pano, makapu a mapepala a PLA amapangidwa kudzera mu njira yapadera yopangira makapu a pepala. Izi zimapangitsa kuti kapangidwe kake kakhale kolimba komanso kosasinthasintha kapena kusweka.
6. Chitsimikizo chapadziko lonse lapansi. Makapu a pepala a PLA akutsatira miyezo yoyenera ya chitsimikizo cha chilengedwe padziko lonse lapansi. Mwachitsanzo, muyezo wa ku Europe wa EN13432 wowononga zachilengedwe ndi muyezo wa ku America wa ASTM D6400 wowononga zachilengedwe. Uli ndi chitsimikizo chapamwamba.
B. Njira yowola ya makapu a mapepala owonongeka
Mukataya makapu a ayisikilimu owonongeka a PLA, mfundo zotsatirazi ndi zomwe zimafotokoza mwatsatanetsatane za njira yawo yowonongera:
Zinthu zazikulu zomwe zimapangitsa makapu a mapepala a PLA kuwola m'malo achilengedwe ndi chinyezi ndi kutentha. Pa chinyezi ndi kutentha pang'ono, makapu a pepalawo amayamba kuwola.
Mtundu woyamba ndi hydrolysis.chikho cha pepalaChinyezi chimayamba njira yothira madzi m'thupi motsogozedwa ndi chinyezi. Chinyezi ndi tizilombo toyambitsa matenda zimalowa m'maselo ang'onoang'ono ndi ming'alu mu kapu ya pepala ndikugwirizana ndi mamolekyu a PLA, zomwe zimapangitsa kuti zinthu ziwonongeke.
Mtundu wachiwiri ndi enzyme hydrolysis. Ma enzyme ndi ma catalysts a biochemical omwe amatha kufulumizitsa ma reactions owonongeka. Ma enzyme omwe ali m'chilengedwe amatha kuyambitsa hydrolysis ya makapu a mapepala a PLA. Amaswa ma polima a PLA kukhala mamolekyu ang'onoang'ono. Mamolekyu ang'onoang'ono awa amasungunuka pang'onopang'ono m'chilengedwe ndikuwola kwambiri.
Mtundu wachitatu ndi kuwonongeka kwa tizilombo toyambitsa matenda. Makapu a mapepala a PLA amatha kuwola chifukwa pali tizilombo tambirimbiri tomwe timatha kuwola PLA. Tizilombo toyambitsa matenda timeneti timagwiritsa ntchito PLA ngati mphamvu ndikuiwononga kukhala carbon dioxide, madzi, ndi biomass kudzera mu njira zowola ndi kuwola.
Kuchuluka kwa kuwonongeka kwa makapu a mapepala a PLA kumadalira zinthu zingapo. Monga chinyezi, kutentha, momwe nthaka ilili, komanso kukula ndi makulidwe a makapu a mapepala.
Kawirikawiri, makapu a mapepala a PLA amafunika nthawi yayitali kuti awonongeke kwathunthu. Njira yowononga makapu a mapepala a PLA nthawi zambiri imachitika m'malo opangira manyowa m'mafakitale kapena m'malo achilengedwe oyenera. Pakati pawo, mikhalidwe yabwino kwa chinyezi, kutentha, ndi ntchito ya tizilombo toyambitsa matenda. M'malo otayira zinyalala m'nyumba kapena m'malo osayenera, kuchuluka kwa kuwonongeka kwake kungakhale kocheperako. Chifukwa chake, pogwira makapu a mapepala a PLA, ziyenera kutsimikiziridwa kuti zayikidwa mu dongosolo loyenera lochotsera zinyalala. Izi zingapereke mikhalidwe yabwino yowononga.