Kunezinhlobo eziningi zamashidi epulasitiki anezinhlobonhlobo zokusetshenziswa. Njengamanje, izinhlobo eziyinhloko ziyi-polyvinyl chloride, i-polystyrene ne-polyester (PET). Ishidi le-PET lisebenza kahle futhi lihlangabezana nezidingo zenkomba yenhlanzeko kazwelonke yemikhiqizo ebunjiwe kanye nezidingo zomhlaba jikelele zokuvikelwa kwemvelo. Zingaphansi kwetafula lokuvikelwa kwemvelo. Njengamanje, ukupakishwa kudinga ukuhlangabezana nokuvikelwa kwemvelo kanye nezidingo zokugaywa kabusha, ngakho isidingo samashidi e-PET siya ngokuya sikhuphuka. Lesi sihloko sixoxa kakhulu ngenqubo yokukhiqiza kanye nezinkinga ezivamile zamashidi e-PET.
Ubuchwepheshe bokukhiqiza amashidi e-PET:
(1) Iphepha le-PET
Njengamanye amapulasitiki, izakhiwo ze-PET sheet zihlobene eduze nesisindo samangqamuzana. Isisindo samangqamuzana sinqunywa yi-viscosity yangaphakathi. Ukuphakama kwe-viscosity yangaphakathi, kuba ngcono izici zomzimba namakhemikhali, kodwa uketshezi olubi kanye nobunzima bokwakha. Ukuncipha kwe-viscosity ye-intrinsic, kuba kubi kakhulu izakhiwo zomzimba kanye namakhemikhali namandla omthelela. Ngakho-ke, i-viscosity yangaphakathi yeshidi le-PET kufanele ibe ngu-0.8dl/g-0.9dl/g.
(2) Ukugeleza kwenqubo yokukhiqiza
Okuyinhlokoimishini yokukhiqiza yamashidi e-PETkufaka phakathi imibhoshongo ecwebezelayo, imibhoshongo yokomisa, ama-extruder, ama-die heads, ama-calender ama-roll amathathu namakhoyili. Inqubo yokukhiqiza yile: impahla eluhlaza crystallization-drying-extrusion plasticization-extrusion molding-calendering and shape-winding products.
1. I-Crystallization. Izingcezu ze-PET ziyashiswa futhi zifakwe ngamakristalu embhoshongweni we-crystallization ukuze ziqondanise ama-molecule, bese zikhuphula izinga lokushisa lengilazi lezingcezu ukuvimbela ukunamathela nokuvinjelwa kwe-hopper phakathi nenqubo yokomisa. I-Crystallization ngokuvamile iyisinyathelo esibalulekile. I-Crystallization ithatha imizuzu engama-30-90 futhi izinga lokushisa lingaphansi kuka-149°C.
2.Yomisa. Emazingeni okushisa aphezulu, amanzi azokhipha i-hydrolyze futhi ehlise i-PET, okuholela ekunciphiseni ukunamathela kwayo okuphawulekayo, futhi izakhiwo zayo ezingokomzimba, ikakhulukazi amandla omthelela, zizokwehla njengoba isisindo samangqamuzana sincipha. Ngakho-ke, ngaphambi kokuncibilika nokukhipha, i-PET kufanele yomiswe ukuze kuncishiswe umswakama, okufanele ube ngaphansi kuka-0.005%. I-Dehumidification dryer isetshenziselwa ukomisa. Ngenxa ye-hygroscopicity yezinto ze-PET, lapho amanzi engena ekujuleni kwendawo yocezu, izibopho zamangqamuzana zizokwakhiwa, futhi enye ingxenye yamanzi izongena ijule phakathi nocezu, okwenza ukomisa kube nzima. Ngakho-ke, umoya oshisayo ojwayelekile awukwazi ukusetshenziswa. Indawo yamazolo yomoya oshisayo iyadingeka ukuba ibe ngaphansi kuka -40C, futhi umoya oshisayo ungena endaweni yokomisa ngesekhethi evaliwe ukuze yomiswe ngokuqhubekayo.
3. Khama. Ngemuva kokucwenga kanye nokomisa, i-PET iguqulwa ibe i-polymer enephuzu lokuncibilika elisobala. Izinga lokushisa lokubumba i-polymer liphezulu futhi ububanzi bokulawula izinga lokushisa buncane. Isikulufu se-polyester-specific barrier screw sisetshenziswa ukuhlukanisa izinhlayiya ezingancibilikisiwe kusukela ekuncibilikeni, okusiza ukugcina inqubo ende yokugunda futhi andise okukhiphayo kwe-extruder. I-Adpts flexible lip die with streamlined throttle rod. Ikhanda lesikhunta licijile. Abagijimi abalula kanye nezindebe zokufa ezingaklwebheki zibonisa ukuthi ukuqeda kufanele kube kuhle. I-heater yesikhunta inemisebenzi yokukhipha amanzi kanye nokuhlanza.
4.Ukupholisa nokubumba. Ngemva kokuncibilika kuphuma ekhanda, ingena ngokuqondile kukhalenda ye-three-roll for calendering kanye nokupholisa. Ibanga eliphakathi kwekhalenda lamarola amathathu nekhanda lomshini ngokuvamile ligcinwa ku-8cm, ngoba uma ibanga likhulu kakhulu, ibhodi lizocwila kalula futhi lishwabene, okuholela ekuqedeni kahle. Ngaphezu kwalokho, ngenxa yebanga elide, ukuchithwa kokushisa nokupholisa kuhamba kancane, futhi i-crystal iphenduka ibe mhlophe, engafaneleki ukugoqa. Iyunithi ye-calendering yamarola amathathu iqukethe amarola aphezulu, aphakathi nendawo naphansi. I-shaft ye-roller ephakathi ilungisiwe. Phakathi nenqubo yokupholisa kanye ne-calendering, izinga lokushisa elingaphezulu kwe-roller lingu-40°c-50c. I-shaft yama-roller angaphezulu naphansi angahamba aye phezulu naphansi.
Isikhathi sokuthumela: Sep-28-2023
