Mene ne bambanci tsakanin PET da PETG?

DABBOBI, wani polycondensate, ana amfani da shi musamman a cikin fina-finan fakitin abinci da zare na yadi, da sauran aikace-aikace. Yanzu ana ƙara amfani da shi azaman kayan marufi, ba kawai a cikin kwalaben soda ba, har ma a cikin gwangwani da faranti masu amorphous na PET (APET), gwangwani da faranti na PET mai launin crystalline (CPET). A cikin shekaru biyar da suka gabata, an yi amfani da PET na injiniya da copolyesters, a matsayin sabbin samfuran polymer, a cikin kayan injiniya da kayan marufi na musamman, bi da bi.
Nasarar PET a cikin marufin soda ya faru ne saboda tauri da bayyananniyar sa, iyawar daidaitawa, ƙimar tattalin arziki mai kyau, da kuma haɓaka fasahar sarrafa kwalba mai sauri. Gwangwanin abin sha na PET suna da sauƙi, ba sa karyewa, ana iya sake amfani da su, kuma suna da iska mai kyau. Kwalbar abin sha ta PET mai lita 2 mai cike tana da sauƙi 24% fiye da kwalbar gilashi iri ɗaya; kwalbar da babu komai tana da nauyin 1/10 na kwalbar gilashin da girmanta iri ɗaya. Wannan yana adana aiki, kuzari, da farashi a duk hanyoyin haɗi daga masana'anta zuwa mai amfani.
Sinadarai da Kadarorinsu

Ana samar da PET don kwalaben abin sha daga terephthalic acid (TPA) wanda aka samu ta hanyar oxidation na p-xylene. Ana tsarkake ko kuma a mayar da martani ga terephthalic acid da methanol don samar da dimethyl terephthalate (DMT), ko kuma a ƙara oxidize shi don samar da tsantsar terephthalic acid (PTA). Wani kayan asali na PET shine ethane, wanda ake canzawa zuwa ethylene glycol (EG) ta hanyar amsawa. PET wani polymer ne mai narkewa wanda aka samar ta hanyar ci gaba da polymerization na DMT (ko PTA) da EG a cikin yanayin narkewa, sannan kuma tsarin polymerization mai ƙarfi don samun manyan lu'ulu'u da nauyin kwayoyin halitta na ƙarshe da ɗanko na ciki. Tsarin yanayin ƙarfi kuma yana sa abun ciki na ethanol na polymer ya yi ƙasa sosai.

Resin PET na kasuwanci gabaɗaya yana narkewa a kusan 480F (), amma wurin narkewar PET mai yawan lu'ulu'u shine kusan 520F ().

PET mai lu'ulu'u mai daidaitawa yana da ƙarfi mai kyau. Tauri da bayyananne, kuma yana jure wa acid mai rauni, tushe da sauran abubuwa masu narkewa da yawa.

Maki na musamman

PET mai girman mannewa na iya samar da launi mai ƙarfi, kore da rawaya mai haske. Ba a buƙatar haɗa polymer mai launi a cikin reactor tare da mummunan tasiri akan halayen jiki, kuma yana inganta daidaiton launi. Akwai resins masu tsabta na viscosities daban-daban na ciki. PET copolymers suna yin lu'ulu'u a hankali, wanda ke ba su damar samar da kwalaben soda masu inganci a cikin yanayi daban-daban na sarrafawa. Hakanan akwai polymer mai ƙarfin mannewa na fitarwa. Wannan kayan ya haɗa fa'idodin ƙarfin narkewa mai kyau da lu'ulu'u mai jinkiri, kuma ana iya sarrafa shi cikin sauƙi akan kayan aikin mannewa na fitarwa mai dacewa. Ana ci gaba da gabatar da nau'ikan polymers masu ƙarfi, masu hana harshen wuta da sauran polymers na musamman don dacewa da sabbin aikace-aikace.

PETGcopolyester wani misali ne na adadi mai yawa na copolyesters. Ba kamar PCTA ba, wanda aka gyara shi da acid, PETG polymer ne da aka gyara da diol wanda aka yi ta hanyar haɗa CHDM diol da TPA (terephthalic acid) da ethylene glycol. Ana iya ƙera ko fitar da PETG copolymers kuma yawanci suna kasancewa marasa tsari, bayyanannu kuma kusan ba su da launi, ko da a cikin manyan sassan giciye.

Yana da ƙarfi sosai, tauri da kuma ƙarfi mai kyau, koda a yanayin zafi mai ƙasa. Haɗin bayyananne, tauri da ƙarfin narkewa yana sa ya zama da amfani ga ƙera allura, ƙera busa da kuma fitar da bayanan martaba, bututu, fina-finai da zanen gado. Ana samun PETG a cikin tsari mara gyara ko tare da ƙarin abubuwa daban-daban, gami da abubuwan saki, manyan batches, da masu gyara tasirin don ƙera allura.

Ya kamata a busar da PETG a zafin digiri 120-160 na F na kimanin awanni 4-6 kafin a yi ƙera ko a fitar da shi. A duka hanyoyin guda biyu, zafin narkewar ya kama daga 420F zuwa 510F. Lokacin riƙe kayan aiki a yanayin zafi mafi girma ya kamata ya zama ɗan gajeren lokaci don hana lalacewa mai yawa. Ya kamata a yi ƙera allurar a kan injin ƙera allura, wanda ke buƙatar kowace allura ta kasance tsakanin kashi 50% zuwa 80% na ƙarfinta.

Ana iya fitar da PETG daga waje a kuma yi masa fenti a yanayin zafi tsakanin 400-450F don yin kwalaben haske don shamfu, sabulun wanke-wanke na ruwa, kayayyakin tsafta, man ma'adinai, da marufi na abinci. Wannan kayan ya cika ƙa'idodin FDA don hulɗa da abinci.

Fitar da sinadarin na iya samar da nau'ikan bayanai iri-iri, da kuma bututun marufi, fina-finai, da takardu, gami da marufin na'urorin likitanci. Ana iya tsaftace PETG da PCTA da ethylene oxide da kuma hasken Y.

Idan aka yi amfani da shi don yin allurar ƙera, yawanci ana sarrafa PETG a zafin narkewa na 450-510F, tare da zafin mold na kimanin 70-130F. Aikace-aikacen da ake amfani da su a yanzu sun haɗa da murfin kayan aiki, garkuwar injina, kwantena na kwalliya, alamun na'urar liba, abubuwan nuni da kayan wasan yara.

Ana amfani da PET galibi a cikin marufi na soda da abubuwan sha masu laushi. PET tana da kusan kashi 100% na kasuwar kwantena masu lita 2 waɗanda ba za a iya sake amfani da su ba, kuma an san kwalaben PET masu lita 1.5, lita 1, lita 0.5 da ƙananan su sosai.

Ana amfani da PET a cikin abinci, barasa, da sabulun wanki. Ana sa ran buƙatar PET za ta ci gaba da ƙaruwa don abubuwan sha marasa iskar gas da kuma marufi na kayayyakin masana'antu. Abincin da aka shirya sun haɗa da mustard, kayayyakin roba, man gyada, kayan ƙanshi, man girki, hadaddiyar giya da ruwan 'ya'yan itace mai ƙarfi. Sabbin launuka, musamman launukan Weber, sun shahara a cikin marufi na magunguna, bitamin da sabulun wanki.

Ɗaya daga cikin sabbin aikace-aikacen da suka fi saurin girma ga kwantena na PET shine marufi na abinci ko abin sha, wanda ke buƙatar cikawa a yanayin zafi mai yawa. Dole ne a sanya abinci da yawa, musamman 'ya'yan itatuwa ko abinci ko abin sha masu yawan 'ya'yan itace, a cikin akwati a 180F ko sama da haka. Wannan yana ba da pasteurization (warkarwa) na samfurin da akwati a lokacin cikawa. Kwantena masu dacewa da al'ada, kamar jakunkunan soda da abin sha masu laushi, suna raguwa da lalacewa lokacin da aka sanya su a yanayin zafi sama da 160F, wanda ya faru ne saboda wani ɗan sassauta damuwa. Ana samar da yawan damuwa yayin ƙera bututun. An haɓaka fasaha don inganta juriyar zafi yayin sarrafawa, wanda galibi ake kira fasahar "saitin zafi". Dangane da takamaiman fasahar sarrafawa, akwai cikakkun bayanai game da fasahar sarrafawa da yawa, waɗanda suka mallaki sosai, bisa ga waɗanne kwantena za a iya samar da su don cikewa a 190-195F. Kayayyakin da ke buƙatar marufi tare da wannan halayyar sun haɗa da ruwan 'ya'yan itace tsarkakakke. Abubuwan sha masu yawan ruwan 'ya'yan itace, shayi, wasu abubuwan sha masu isotonic da wasanni, kayan ƙanshi, ruwan 'ya'yan itace mai ƙarfi da wasu ruwan ma'adinai.

Ana amfani da sauran amfani na ƙarshe na PET sosai a cikin murfin extrusion da fim da takarda na extrusion. Ana amfani da PET a matsayin kayan shafa extrusion don marufi na allon takarda mai iya yin tanda. Bugu da ƙari, ana iya amfani da PET mai lu'ulu'u (CPET) a matsayin kayan asali don yin tiren tanda.

Fim ɗin PET yawanci ana amfani da shi ta hanyar biaxial kuma ana amfani da shi azaman X-ray da sauran fina-finan daukar hoto, marufi na nama da cuku, tef ɗin maganadisu, rufin lantarki, faranti na bugawa da jakunkunan marufi na kwalba. Haka kuma ana amfani da PET azaman kayan tef na masana'antu. An fara amfani da fim ɗin PET da takarda mara lu'ulu'u, mara tsari, don ƙirƙirar kwantena, tire, samfuran kumfa da kofunan abin sha.

Takaitawa: PETG sigar PET ce da aka inganta, tare da bayyananniyar hanya, ƙarfin aiki mai yawa, juriyar tasiri mafi kyau, kuma ba shakka farashi mai girma.