Tsarin Samar da Takardar PET Mai Gaskiya da Muhimman Abubuwa

Akwai nau'ikan zanen filastik da yawa kuma ana amfani da su sosai. A halin yanzu, manyan nau'ikan sune polyvinyl chloride, polystyrene da polyester (PET)Daga cikinsu, zanen gado na PET suna da kyakkyawan aiki, sun cika buƙatun ma'aunin tsafta na ƙasa don samfuran da aka ƙera da kuma buƙatun kariyar muhalli na duniya, kuma zanen gado ne masu kyau ga muhalli.

Kayan aikin takardar PET

Kamar sauran robobi, aikin zanen gado na PET yana da alaƙa da nauyin kwayoyin halitta, kuma danko na ciki yana ƙayyade nauyin kwayoyin halitta. Girman danko na ciki, mafi kyawun halayen jiki da sinadarai, amma rashin ruwa mai kyau, wanda ke sa ƙirar ta zama da wahala. Ƙananan danko na ciki, mafi ƙarancin halayen jiki da sinadarai da kuma ƙarancin ƙarfin tasirin. Saboda haka, ya kamata a zaɓi danko na ciki na zanen gado mai haske na PET daga 0.8dl/g zuwa 0.9dl/g.

Tsarin samar da PET

Babban kayan aikin samarwa na zanen gado masu haske na PET sune: hasumiyar crystallization, hasumiyar busarwa, extruder, die head, three-roll calender, da winder.

Tsarin samarwa shine: lu'ulu'u na kayan abu → busarwa → plasticization extrusion → extrusion molding → calendering da siffanta → na'urorin naɗewa.

Mataki na farko shine crystallization

Ana dumama yanka PET kuma a haɗa su da lu'ulu'u a cikin hasumiyar lu'ulu'u don daidaita ƙwayoyin, sannan ana ƙara zafin canjin gilashin na yanka don hana mannewa yayin aikin bushewa da toshewar hopper.

Kwaikwayon kristal gabaɗaya mataki ne mai mahimmanci, wanda ke ɗaukar mintuna 30 zuwa mintuna 90 kuma zafin jiki bai wuce 149°C ba.

Mataki na 2: Bushewa

A ƙarƙashin yanayin zafi mai yawa, ruwa zai iya sa PET ta yi ruwa ta lalace, wanda hakan ke haifar da raguwar mannewarta. Sifofinta na zahiri, musamman ƙarfin tasirinsu, za su ragu yayin da nauyin ƙwayoyin halitta ke raguwa. Saboda haka, dole ne a busar da PET kafin a narke fitar da shi don rage yawan danshi, kuma yawan danshinsa ya kamata ya zama ƙasa da 0.005%.

Ana amfani da na'urar busar da danshi wajen busar da shi. Tunda kayan PET suna da hygroscopic, ruwa zai ratsa saman yanka don samar da haɗin kwayoyin halitta, kuma wani ɓangare na ruwan zai kasance a cikin yankin, wanda hakan zai sa busarwa ta yi wahala. Saboda haka, ba za a iya amfani da iska mai zafi ta yau da kullun ba.

Ana buƙatar wurin raɓar iska mai zafi ya kasance ƙasa da -40°C, kuma iskar zafi tana shiga cikin hopper ɗin busarwa ta hanyar madauri mai rufewa don ci gaba da busarwa.

Mataki na uku shine gyaran extrusion

Bayan lu'ulu'u da bushewa, ana canza PET zuwa polymer mai takamaiman wurin narkewa. Zafin ƙera polymer ɗin yana da yawa kuma kewayon sarrafa zafin jiki yana da kunkuntar.

Ana amfani da sukurori mai shinge da aka keɓe ga polyester don raba ƙwayoyin da ba a narke ba da kuma narkewar, wanda ke taimakawa wajen kiyaye tsarin yankewa mai tsawo da kuma ƙara yawan fitar da kayan fitarwa.

Ana amfani da kan lebe mai sassauƙa mai sand ɗin shinge mai laushi. Kan lebe mai kauri ne, kuma hanyar kwarara mai laushi da lebe mara karce ya kamata su sami kyakkyawan ƙarewa a saman. Na'urar dumama kan lebe tana da aikin tacewa da tsaftacewa. Gibin lebe na kan lebe mai laushi ya kamata ya tabbatar da daidaito mai kyau. Gibin lebe mai laushi na kan lebe mai laushi yana shafar karkacewar kauri da kuma lanƙwasa na zanen.

Lokacin da ake fitar da shi zuwa zanen gado, yanayin zafin da ya dace da yankin gaba na jiki, yankin tsakiya na jiki, yankin baya na jiki, mai canza allo, da kuma ma'aunin zafi shine 240°C-260°C, 265°C-275°C, 260°C-265°C, 260°C-265°C, da 255°C-265°C, bi da bi.

Mataki na 4: Sanyaya kuma saita

Bayan narkewar ta fito daga cikin injin, sai ta shiga cikin injin calender mai birgima uku kai tsaye don yin calender da sanyaya. Nisa tsakanin calender mai birgima uku da injin calender gabaɗaya ana ajiye shi a kusan santimita 8. Idan nisan ya yi yawa, zanen yana da sauƙin yin lanƙwasa da lanƙwasa, wanda ke haifar da rashin kyawun kammala zanen. Bugu da ƙari, saboda babban nisa, watsawar zafi da sanyaya suna da jinkiri sosai, wanda ke haifar da lu'ulu'u da fari, wanda ba ya da amfani ga calendering.

Kalanda mai birgima uku ya ƙunshi birgima uku: na sama, na tsakiya da na ƙasa. An gyara ginshiƙin naɗaɗɗen tsakiya. A lokacin sanyaya da kuma yin kaɗawa, zafin saman naɗaɗɗen shine 40°C-50°C, kuma ginshiƙin naɗaɗɗen sama da na ƙasa na iya motsawa sama da ƙasa. Ana daidaita gibin naɗaɗɗen ta hanyar motsa ginshiƙin sama da ƙasa. Yanayin zafin naɗaɗɗen sama da na ƙasa shine 30°C-60°C da 52°C-68°C bi da bi. Ya kamata birgima uku su tabbatar da daidaitawar sauri, kuma gudun ya kamata ya kasance sama da saurin fitarwa. Manufar ita ce a rage faɗaɗa kayan lokacin da ya bar mayafin da kuma rage damuwa ta ciki na takardar, ta yadda wrinkles za su ɓace.

PET za ta yi lu'ulu'u a cikin kewayon 100°C-250°C, kuma mafi saurin lu'ulu'u shine 140°C-180°C, don haka ana iya kammala lu'ulu'u cikin 'yan daƙiƙa kaɗan. PET tana buƙatar wucewa ta wannan yankin zafin lu'ulu'u cikin sauri kuma dole ne a sarrafa zafin na'urorin guda uku sosai.

Mataki na biyar shine ja da lanƙwasa

Takardar tana ratsa ta cikin na'urar calender kuma tana shiga na'urar jan hankali ta cikin na'urar jan hankali. Na'urar jan hankali ta ƙunshi na'urar jan roba mai aiki da na'urar jan roba mai aiki. Matsin iska yana matse na'urorin jan hankali guda biyu sosai don hana na'urar jan hankali ta lanƙwasa ta cikin na'urar jan hankali lokacin da takardar ta ratsa na'urorin jan hankali guda biyu kuma aka ja ta zuwa na'urar jan hankali.

Tsarin samar da takardar PET

(1) Babban sharuɗɗan samar da zanen gado masu haske na PET shine lokacin bushewa da kuma kula da wurin raɓar iska mai zafi. Tasirin bushewa kai tsaye yana ƙayyade halayen jiki da na inji da kuma samar da zanen.
A lokacin busarwa, ya kamata a kula da yanayin zafin busarwa da lokacinsa. Ya kamata zafin busarwa da lokacin bai yi yawa ko ƙasa ba. Idan ba za a iya rage wurin raɓa ba, ya kamata a duba yanayin sieve ɗin kwayoyin halitta. Sieve ɗin kwayoyin halitta da ya tsufa ba zai iya sha danshi a cikin iska ba, kuma ba za a iya cimma manufar busarwa da yankewa ba. A wannan lokacin, ya kamata a maye gurbin sieve ɗin kwayoyin halitta.

(2) Idan zafin narkewar ya wuce 280°C, Takardar bayanan PET zai canza launi ko ya ruɓe. Saboda haka, ya kamata a sarrafa zafin narkewar ƙasa da 280°C.

(3) Gibin da ke tsakanin leben manne na kan manne yana ƙayyade daidaiton da kauri na takardar. Zafin manne na manne guda uku yana taka muhimmiyar rawa a cikin bayyanawa da kuma kammala saman takardar. Narkewar PET yana buƙatar guje wa yankin zafin jiki mafi sauri na manne kuma nan take ya faɗi daga zafin narkewa zuwa ƙasa da zafin manne. Saboda haka, nisan da ke tsakanin kan manne da manne na calender yana da matuƙar muhimmanci.