Njira Yopangira Pulasitiki ya Polystyrene ndi Kugwiritsa Ntchito Kwake Popaka Chakudya
Polystyrene pulasitiki, yomwe imadziwika bwino kuti polystyrene mu Chingerezi, ndi mtundu wa pulasitiki wosiyanasiyana womwe umagwiritsidwa ntchito kwambiri m'magawo osiyanasiyana amafakitale, kuphatikizapo ma CD a chakudya. Nkhaniyi ifotokoza za njira yopangira polystyrene ndi momwe imagwiritsidwira ntchito mwatsatanetsatane pakuyika chakudya.
Mbiri Yachidule ndi Kapangidwe ka Mankhwala a Polystyrene
Polystyrene idapangidwa koyamba ndi Edward Simon mu 1839. Komabe, mpaka m'ma 1930, polystyrene idapangidwa kukhala chinthu chogulitsidwa ndi kampani yaku Germany IG Farben. Polystyrene ndi polima wonunkhira wopangidwa kuchokera ku monomer styrene, yomwe ndi vinylbenzene compound. Kapangidwe kake ka mankhwala kamakhala ndi mayunitsi obwerezabwereza a styrene monomer:
\[ [-CH_2-CH(C_6H_5)-]_n \]
Kumene \(C_6H_5\) kuli mphete ya phenyl yomwe imapatsa polystyrene mawonekedwe ake apadera monga kuuma ndi kulimba.
Njira Yopangira Polystyrene
1. Kupanga kwa Styrene Monomer:
Njira yopangira polystyrene imayamba ndi kupanga styrene monomer. Styrene imapangidwa kudzera mu dehydrogenation ya ethylbenzene, yomwe imatenga magawo angapo:
– Alkylation ya benzene: Benzene imakumana ndi ethylene kuti ipange ethylbenzene pamaso pa asidi.
– Kuchotsa hydrogen mu ethylbenzene: Kenako, ethylbenzene imatenthedwa pa kutentha kwakukulu (pafupifupi 600-650°C) ndi iron oxide catalyst kuti ipange styrene ndi hydrogen.
2. Kupopera kwa Styrene:
Styrene yomwe imachokera imapangidwa kuti ipange polystyrene. Njira zingapo zopopera zingagwiritsidwe ntchito, kuphatikizapo mass, suspension, ndi emulsion polymerization. Komabe, yodziwika kwambiri ndi suspension polymerization, yomwe imaphatikizapo masitepe otsatirawa:
– Kuyambitsa: Kuyambitsa ma polymer kumayamba ndi kuyambitsa ma free radical omwe amachititsa kuti styrene ipange ma free radical.
- Kufalikira: Ma free radicals ochokera ku ma monomers adzakopa ma monomers ena, ndikupanga maunyolo atali a polima.
– Kutha: Njirayi imapitilira mpaka polima itafika kutalika kwa molekyulu komwe mukufuna ndipo zomwe zimachitika zimatha.
3. Kutulutsa ndi Kupanga:
Pambuyo pa ndondomeko ya polymerization, polystyrene yomwe imachokera imakhala ngati ma pellets kapena ma granules. Kenako ma granules a polystyrene amaumitsidwa ndikusungunuka pogwiritsa ntchito makina otulutsira. Njira yotulutsira iyi imalola kuti zinthuzo zipangidwe m'mawonekedwe osiyanasiyana momwe zimafunikira, monga mapepala oti azipaka chakudya.
Kugwiritsa Ntchito Polystyrene Mu Mapaketi a Chakudya
Polystyrene ili ndi mitundu yosiyanasiyana kutengera kapangidwe kake ndi mawonekedwe ake, kuphatikizapo:
– General Purpose Polystyrene (GPPS): Ili ndi mphamvu zowonekera bwino komanso zofooka, zomwe nthawi zambiri zimagwiritsidwa ntchito popanga zinthu zotayidwa monga masipuni apulasitiki, mafoloko, ndi mbale.
– Polystyrene Yogwira Mtima Kwambiri (HIPS): Yopangidwa ndi mphira wa butadiene, imakhala ndi mphamvu zambiri ndipo imagwiritsidwa ntchito popangira zinthu zomwe zimafuna kulimba kwambiri.
– Expanded Polystyrene Foam (EPS): Zipangizozi zili ndi mphamvu zabwino zotetezera kutentha ndipo ndi zopepuka, zomwe zimagwiritsidwa ntchito popanga zotengera chakudya monga styrofoam.
Kupaka Chakudya cha Polystyrene
Polystyrene imagwiritsidwa ntchito kwambiri mumakampani opanga ma CD pazifukwa zingapo zazikulu, kuphatikizapo kulemera kwake kopepuka, mtengo wotsika, komanso kusinthasintha. Nazi njira zina zomwe polystyrene imagwiritsidwira ntchito pokonza chakudya:
1. Zidebe za Chakudya Chachangu:
Chimodzi mwa zinthu zomwe zimagwiritsidwa ntchito kwambiri ndi monga ziwiya za Styrofoam pa chakudya chofulumira. Ziwiya zimenezi zili ndi mphamvu zabwino zotetezera kutentha, zomwe zimapangitsa kuti chakudya chikhale chotentha kapena chozizira kwa nthawi yayitali.
2. Makapu ndi Mbale za Pulasitiki:
Makapu, mbale, ndi ziwiya zodulira (masupuni, mafoloko) nthawi zambiri zimapangidwa kuchokera ku polystyrene kapena HIPS wamba chifukwa cha kuwonekera bwino kwake komanso kukana kugwedezeka.
3. Mapaketi a Nyama ndi Nsomba:
Nyama ndi nsomba zimapakidwa pogwiritsa ntchito mathireyi a polystyrene okhala ndi filimu ya pulasitiki. Mathireyi amenewa amathandiza kusunga chinyezi ndikuwonjezera mawonekedwe a chinthucho.
4. Maphukusi a Dzira:
Mapaketi a mazira a polystyrene thovu amagwiritsidwa ntchito chifukwa cha mphamvu zake zogwira kugunda kwa mtima, zomwe zimateteza kwambiri mazira kuti asasweke panthawi yogawa.
5. Thireyi ya Chakudya ndi Chakumwa:
Mathireyi a polystyrene nthawi zambiri amagwiritsidwa ntchito popereka chakudya ndi zakumwa m'malo monga m'ma canteens, m'malesitilanti, komanso m'mabokosi a chakudya cha ndege.
Nkhawa Zachilengedwe ndi Ntchito Zobwezeretsanso Zinthu
Ngakhale kuti pali ubwino wambiri, kugwiritsa ntchito polystyrene m'maphukusi azakudya kumabweretsanso nkhawa pa chilengedwe. Polystyrene ndi chinthu chosawonongeka, chomwe chimayambitsa vuto la zinyalala za pulasitiki zomwe zimavutitsa chilengedwe.
1. Kuchepetsa ndi Kusintha:
Maboma ambiri ndi mabungwe oteteza chilengedwe akulimbikitsa kuchepetsa kugwiritsa ntchito zinthu zopangidwa ndi polystyrene zomwe zimagwiritsidwa ntchito kamodzi kokha ndikuzisintha ndi zinthu zosawononga chilengedwe monga bioplastics kapena makatoni.
2. Kubwezeretsanso:
Kuphatikiza apo, kubwezeretsanso polystyrene ndi gawo lofunika kwambiri pochepetsa mphamvu yake. Njira yobwezeretsanso imaphatikizapo kusonkhanitsa, kusanja, kuyeretsa, ndikukonzanso polystyrene kukhala zinthu zatsopano.
3. Zatsopano pa Ukadaulo:
Zinthu zatsopano zosiyanasiyana zikupangidwanso kuti polystyrene ikhale yosawononga chilengedwe, kuphatikizapo ukadaulo womwe umalola polystyrene kuwola mwachangu kapena kugwiritsa ntchito zinthu zopangira kuchokera kuzinthu zongowonjezedwanso.
Mapeto
Polystyrene ndi chinthu chofunikira kwambiri mumakampani opanga zakudya chifukwa cha kusinthasintha kwake, kupepuka, komanso kugwiritsa ntchito bwino ndalama. Njira yake yopangira imakhudza magawo angapo, kuyambira kupanga ma monomers a styrene mpaka polymerization ndi kupanga zinthu zomalizidwa zomwe zasinthidwa. Ngakhale kuti ili ndi ubwino wambiri, ndikofunikira kuyang'anira polystyrene mwanzeru kuti muchepetse zotsatira zake zoyipa pa chilengedwe ndikuthandizira ntchito zobwezeretsanso zinthu mokhazikika.
Kugwiritsa ntchito mwanzeru, kutsatiridwa ndi kuyesetsa kwatsopano kuchepetsa kuwonongeka kwa chilengedwe, ndiye chinsinsi cha kugwiritsa ntchito polystyrene mtsogolo.
