Zotulutsa pulasitiki ndi zida zapakatikati pamakampani opanga mapulasitiki, omwe amagwiritsidwa ntchito kwambiri popanga zinthu monga mapaipi, mbiri, mafilimu, ndi waya ndi zokutira chingwe. Ntchitoyi ikuphatikizapo masitepe angapo, kuphatikizapo kukonza zinthu, kutentha ndi kusungunula, kupanga pulasitiki ndi kutulutsa, kuumba ndi kuziziritsa, ndi kukonza positi-. Gawo lirilonse limakhudza kwambiri ubwino wa chinthu chomaliza. Nkhaniyi mwadongosolo akufotokoza muyezo ndondomeko otaya ndi mfundo zofunika luso la extruder pulasitiki.
1. Kukonzekera kwa Zopangira Zopangira ndi Kukonzekera Kwambiri
Chinthu choyamba mu ndondomeko pulasitiki extrusion ndi kuwunika ndi pretreatment wa zipangizo. Kutengera zomwe zimafunikira pakupanga, zopangirazo zimatha kukhala utomoni umodzi (monga polyethylene (PE) kapena polypropylene (PP)) kapena kapangidwe kazinthu zingapo (monga zomwe zili ndi calcium carbonate fillers kapena masterbatches). Zopangira ziyenera kukwaniritsa zofunikira izi:
Chiyero: Pewani kuipitsidwa ndi zonyansa (monga tinthu tachitsulo ndi mapepala), zomwe zitha kuwononga zida kapena kuwonongeka kwazinthu.
Kuuma: Zida za Hygroscopic (monga nayiloni PA ndi polycarbonate PC) ziyenera kuumitsidwa mu chowumitsira pa 80-120 digiri kwa maola angapo kuti zisawonongeke ming'oma panthawi ya extrusion.
Mixing Uniformity: Ngati mpangidwewo uli ndi zowonjezera, premix the masterbatch kapena zowonjezera zina mumkodzo wapamwamba-zosakanizirani mwachangu kuti muwonetsetse kubalana kofanana.
II. Kudyetsa ndi Kutumiza Gawo
Zopangira zopangira kale zimalowa mu mbiya ya extruder kudzera pa hopper. Ma extruder amakono nthawi zambiri amakhala ndi chophatikizira chophatikizira kapena chodyetsa chogwedeza kuti awonetsetse kuti chakudya chizikhala chokhazikika komanso chokhazikika. Mfundo zofunika kwambiri panthawiyi ndi izi:
Kufananiza kwa Feed Rate: Izi ziyenera kulumikizidwa ndi liwiro la screw ndi mphamvu yosungunuka kuti tipewe kudzikundikira kwa zinthu kapena kulowa mu mbiya.
Anti-Mapangidwe a Bridging: Khoma lamkati la hopper nthawi zambiri limadulidwa kapena kukhala ndi cholumikizira kuti chisatseke mlatho ndi kutsekeka chifukwa cha kusayenda bwino kwa madzi.
III. Kutentha, Kusungunuka, ndi Plasticization
Zida zikalowa mu mbiya, zimasungunuka pang'onopang'ono ndikupangidwa ndi pulasitiki ndi kuphatikiza kwa wononga kasinthasintha ndi kutentha kwakunja. Njirayi imagawidwa m'magawo atatu ogwira ntchito:
Gawo Lotumiza (Kudyetsa Gawo): Zowononga zimazungulira pa liwiro lotsika, kukankhira zinthu patsogolo. Kutentha kwa mbiya kumakhala kotsika (nthawi zambiri madigiri 80-120) kuteteza kusungunuka msanga.
Chigawo Choponderezedwa (Chigawo Chosungunuka): Kutentha kwa mbiya kumawonjezeka pang'onopang'ono kufika pamwamba pa malo osungunuka a pulasitiki (mwachitsanzo, pafupifupi 160-180 digiri ya PE). Kuzama kwa screw groove kumachepa, kukulitsa mphamvu zometa ubweya ndikusintha tinthu tolimba kukhala viscous kusungunuka.
Gawo la Metering (Homogenization Section): Kutentha kumasungidwa kosalekeza (pang'ono pamwamba pa malo osungunuka), ndipo screw imagwira ntchito mofulumira kwambiri kuti iwonetsetse kusungunuka kwachitsulo chosungunuka ndi mawonekedwe a yunifolomu.
Zofunikira zaukadaulo: Kutentha kwa mbiya, kuthamanga kwa screw (nthawi zambiri 50-300 rpm), ndi kusungunuka kwamphamvu (5-20 MPa) ziyenera kusinthidwa malinga ndi momwe zinthu zilili. Mwachitsanzo, kukonza kwa PVC kumafuna kutentha kochepa (madigiri 150-180) kuti apewe kuwonongeka kwamafuta.
IV. Extrusion ndi Kufa Kupanga
Kusungunula kopangidwa ndi pulasitiki kumatulutsidwa kudzera mu mutu kuti apange mtanda wofunidwa-wofanana ndi machubu ozungulira kapena ma profailo amakona anayi). Die design imakhudza kwambiri mtundu wazinthu ndipo iyenera kukwaniritsa izi:
Flow channel balance: Imawonetsetsa kupanikizika kofanana mbali zonse kudutsa kusungunula kuti kupewe kukhutitsidwa kwapadera kapena kupanikizika kwambiri.
Kuwongolera kutentha: Kutentha kwakufa kumakhala kotsika pang'ono kuposa kutentha kwa migolo kuti kulipirire kutayika kwa kutentha ndi kusunga madzi.
V. Kuziziritsa ndi Kujambula
The otentha extruded kusungunula ayenera mofulumira utakhazikika ndi kupangidwa. Njira zodziwika bwino ndi izi:
Kuziziritsa madzi: Izi zimatheka pomizidwa mu thanki yamadzi kapena makina opopera (monga mizere yopangira mapaipi). Kutentha kwa madzi ozizira kuyenera kusinthidwa kutengera zinthuzo (nthawi zambiri 15-40 digiri).
Kuziziritsa mpweya: Koyenera mafilimu owonda kwambiri kapena zinthu zoonda-zotchingidwa ndi mipanda, pogwiritsa ntchito feni kapena zoziziritsa kukhosi kuti muchepetse kutentha.
Pakadali pano, makina ojambulira amakoka mankhwalawa mwachangu kuti atsimikizire kukhazikika kwazithunzi. The chiŵerengero cha kujambula liwiro ndi extrusion liwiro (kujambula chiŵerengero) zimatsimikizira kachulukidwe mankhwala ndi katundu thupi.
VI. Kudula ndi Kutumiza{1}}Kukonza
Pambuyo pozizira, mankhwalawa amadulidwa mzigawo (monga machubu a mamita 6) kapena kudulidwa mumipukutu (mwachitsanzo, mafilimu, mawaya, ndi zingwe) pogwiritsa ntchito chodulira pa intaneti. Zogulitsa zina zimafunikira kukonzedwanso, monga:
Chithandizo chapamwamba: Chithandizo chamoto kapena mankhwala a corona kuti apititse patsogolo kusindikiza;
Kuyang'anira Ubwino: Kuyang'anira makulidwe a khoma pogwiritsa ntchito choyezera makulidwe a infrared kapena kuyang'ana zowoneka bwino pazowonongeka.
Njira yowonjezeretsa pulasitiki imaphatikiza ukadaulo wosiyanasiyana (sayansi yazinthu za polima, uinjiniya wamakina, ndi thermodynamics). Kupititsa patsogolo magawo pagawo lililonse (mwachitsanzo, mbiri ya kutentha ndi masinthidwe a screw) kumatha kupititsa patsogolo luso la kupanga komanso mtundu wazinthu. Chifukwa cha kupita patsogolo kwaukadaulo wopangira zida zamakono, zida zamakono zopangira zida zamakono zaphatikiza{4}}zowunika nthawi yeniyeni ndi mayankho odziwikiratu, kupititsa patsogolo makampani opanga mapulasitiki kukhala olondola{5}}ndi njira zowondera zachilengedwe.
