Kupanga, kukonza, kugwira ntchito ndi kugwiritsa ntchito zipangizo za TPU

TPU (thermoplastic polyurethane)ndi mtundu wa polyurethane womwe ungapangidwe pulasitiki potenthetsera ndipo ukhoza kusungunuka ndi zosungunulira. Poyerekeza ndi polyurethane yosakaniza ndi mtundu wa casting, polyurethane ya thermoplastic ilibe kapena ili ndi crosslinking yochepa ya mankhwala mu kapangidwe ka mankhwala, ndipo mamolekyu ake ndi olunjika, koma pali kusinthana kwina kwa thupi.
Lingaliro la chomwe chimatchedwa kusinthana kwa thupi, lomwe linayambitsidwa koyamba ndi Schollenberger CS mu 1958, likunena za kukhalapo kwa "malo olumikizirana" osinthika pakati pa unyolo wa mamolekyu a polyurethane wolunjika ukakumana ndi kutentha kapena zosungunulira. Si kwenikweni cholumikizira cha mankhwala. Koma chimagwira ntchito ngati cholumikizira cha mankhwala. Chifukwa cha kulumikizaku kwa thupi, polyurethane imapanga chiphunzitso cha kapangidwe ka mawonekedwe osiyanasiyana, ndipo hydrogen bonding ya polyurethane imalimbitsa mawonekedwe ake ndikupangitsa kuti isavutike ndi chinyezi chambiri.

Kodi gulu la TPU ndi chiyani?

Tsopano popeza tadziwa TPU, kodi magulu ake ndi otani? Malinga ndi miyezo yosiyanasiyana ya magulu, TPU ikhoza kukhala ndi magulu osiyanasiyana.

Mwachitsanzo, malinga ndi kapangidwe ka gawo lofewa, lingagawidwe m'magulu a polyester, polyether ndi butadiene, omwe ali ndi gulu la ester, ether kapena butene motsatana. Malinga ndi kapangidwe ka gawo lolimba, lingagawidwe m'magulu a urethane ndi urethane, omwe amapezeka kuchokera ku diol chain extenders kapena diamine chain extenders motsatana. Gawo lofala limagawidwa m'magulu a polyester ndi polyether.
Malinga ndi kukhalapo kapena kusakhalapo kwa crosslinking, ikhoza kugawidwa m'magulu awiri: thermoplastic yoyera ndi semi-thermoplastic. Yoyamba ndi kapangidwe koyera kopanda ma crosslinking bonds; yomalizayi ili ndi allophanate yochepa ndi ma crosslinking bonds ena. Malinga ndi kugwiritsa ntchito zinthu zomalizidwa, ikhoza kugawidwa m'magulu awiriawiri opangidwa ndi mawonekedwe apadera (zigawo zosiyanasiyana zamakina), mapaipi (zikwama, ma profiles a ndodo), mafilimu (mapepala, mapepala), zomatira, zokutira, ndi ulusi.

Kodi TPU imapangidwa bwanji

Ngakhale pali magulu ambiri a TPU, onse ndi a polyurethane pankhani ya kapangidwe ka mamolekyu. Ndiye zinagwirizana bwanji? Malinga ndi njira zosiyanasiyana zopangira, zimagawidwa makamaka mu bulk polymerization ndi solution polymerization.

Mu polymerization yochuluka, ikhoza kugawidwa m'njira ya pre-polymerization ndi njira imodzi-step kutengera ngati pali pre-reaction: njira ya pre-polymerization ndi kuchita diisocyanate ndi macromolecular diol kwa nthawi inayake, kenako ndikuwonjezera unyolo kuti apange TPU; Ma molecular diol, diisoesters ndi ma chain extenders amasakanikirana nthawi imodzi ndikupanga TPU.
Kupoletsa kwa yankho ndi kusungunula diisocyanate mu solvent kaye, kenako kuwonjezera macromolecular diol kuti igwire ntchito kwa nthawi inayake, kenako ndikuwonjezera unyolo wowonjezera kuti upange TPU.
Mtundu wa gawo lofewa, kulemera kwa mamolekyulu, kuchuluka kwa gawo lolimba kapena gawo lofewa komanso momwe TPU imagwirizanirana zimakhudzira kuchuluka kwa TPU. Kuchuluka kwake kuli pakati pa 1.10 ndi 1.25, komwe sikusiyana kwambiri ndi ma rabara ndi mapulasitiki ena. Pakulimba komweko, kuchuluka kwa polyether TPU ndi kotsika kuposa kwa polyester TPU.

Kodi TPU imakonzedwa bwanji

Utomoni wa TPU umafunika kukonzedwa kuti upange zinthu zomalizidwa, ndipo TPU imakonzedwa makamaka pogwiritsa ntchito njira yosungunula ndi njira yothetsera. Kapangidwe kake ka molekyulu ndi chipika cholimba chomwe chimapezeka pochita diphenylmethane diisocyanate (MDI) kapena toluene diisocyanate (TDI) yokhala ndi unyolo wowonjezera ndi diisocyanate monga diphenylmethane diisocyanate (MDI) kapena toluene diisocyanate (TDI). Mamolekyulu ndi macromolecular polyols amachitapo kanthu kuti apange magawo osinthasintha mosinthana.

Kusungunula ndi njira yomwe imagwiritsidwa ntchito kwambiri mumakampani opanga mapulasitiki: monga kusakaniza, kuyika calender, kutulutsa, kuumba ndi kuumba (kuphatikiza jakisoni, kupondereza, kusamutsa ndi kugawa centrifugation ndi zina zotero. Kukonza yankho ndi kusungunuka kwa ma pellets mu zosungunulira kapena polimeri yolunjika mu zosungunulira Pambuyo popanga yankho, kuphimba, kupota, ndi zina zotero kumachitika.
TPU imapangidwa kukhala chinthu chomaliza, chomwe nthawi zambiri sichifuna vulcanization ndi cross-linking reaction, zomwe zingafupikitse nthawi yopangira, ndipo zinyalala zimatha kubwezeretsedwanso ndikugwiritsidwanso ntchito.

Kuchita kwa TPU

Monga polyurethane yopangidwa ndi chitsulo (madzi) ndi polyurethane yosakaniza (yolimba), TPU ili ndi modulus yapamwamba, mphamvu zambiri, kutalika kwambiri komanso kusinthasintha kwakukulu, kukana kuvala bwino, kukana mafuta, kukana kutentha pang'ono komanso kukana ukalamba. Pakati pawo, mphamvu zambiri zomangika, kutalika kwambiri, komanso kukanikiza kochepa kwa nthawi yayitali zonse ndi zabwino zazikulu za TPU.

1. Mphamvu yokoka kwambiri komanso kutalika kwambiri
TPU ili ndi mphamvu yokoka komanso kutalika kwabwino kwambiri. Kuchokera pa deta yomwe ili pachithunzi pansipa, titha kuwona kuti mphamvu yokoka ndi kutalika kwa polyether TPU ndikwabwino kwambiri kuposa ya polyvinyl chloride pulasitiki ndi rabala.

Kuphatikiza apo, TPU imatha kukwaniritsa zofunikira za makampani azakudya popanda kuwonjezera kapena kuwonjezera zowonjezera zochepa pakukonza, zomwe zimakhala zovuta pazinthu zina monga PVC ndi rabala.

2. Kulimba mtima kumakhudzidwa kwambiri ndi kutentha
Kulimba kwa TPU kumatanthauza kuchuluka kwa kuchira mwachangu ku mawonekedwe ake oyambirira pambuyo poti kupsinjika kwa kusintha kwa zinthu kwatulutsidwa, komwe kumawonetsedwa ndi mphamvu yobwezeretsa, ndiko kuti, chiŵerengero cha ntchito yobwezeretsa kusintha kwa zinthu ku ntchito yofunikira kuti kusintha kusinthe. Ndi ntchito ya dynamic modulus ndi internal friction ya elastomer ndipo imakhudzidwa kwambiri ndi kutentha.

Kutentha kwa springback kumachepa ndi kuchepa kwa kutentha, mpaka kutentha kwina, kusinthasintha kumawonjezekanso mofulumira. Kutentha kumeneku ndi kutentha kwa crystallization kwa gawo lofewa, komwe kumadalira kapangidwe ka macromolecular diol, ndipo polyether TPU ndi yotsika kuposa polyester TPU. Pa kutentha komwe kuli pansi pa kutentha kwa crystallization, elastomer imakhala yolimba kwambiri ndipo imataya kusinthasintha kwake, motero, rebound imafanana ndi rebound kuchokera pamwamba pa chitsulo cholimba.

3. Kuuma kwake ndi Shore A60 ~ D80
Kuuma ndi chizindikiro cha mphamvu ya chinthucho yolimbana ndi kusintha kwa zinthu, kuvulala, ndi kukwawa.
Kuuma kwa TPU kungasinthidwe mwa kusintha chiŵerengero cha zigawo zofewa ndi zolimba za unyolo. Chifukwa chake, TPU ili ndi kuuma kwakukulu. Kuuma kwake kumayambira ku Shore A60 mpaka D80, kufalikira kuuma kwa rabara ndi pulasitiki, ndipo kuli ndi kuuma kwakukulu mu kuuma konse. Kutanuka kwakukulu.
Ndi kusintha kwa kuuma, makhalidwe ena a TPU amasintha. Mwachitsanzo, ngati kuuma kwa TPU kwawonjezeka, padzakhala kusintha kwa magwiridwe antchito monga kuwonjezeka kwa mphamvu yogwira ntchito komanso kufooka, kuwonjezeka kwa kulimba komanso kupsinjika (kulemera), kuchepa kwa kutalika, kuchuluka kwa mphamvu ndi kutentha komwe kumachitika, komanso kuwonjezeka kwa kukana kwa chilengedwe.

Gawo logwiritsira ntchito la TPU

TPU idagulitsidwa bwino koyamba ndi American Goodrich Chemical Company (yomwe tsopano ndi Lubrizol) mu 1958, ndipo kuyambira pamenepo yafufuzidwa ndikukulitsidwa padziko lonse lapansi. Pakadali pano, opanga zinthu zopangira TPU makamaka ndi BASF, Covestro, Lubrizol, Huntsman, Wanhua Chemical, Shanghai Hengan, Ruihua, Asahikawa Chemical ndi zina zotero.
Monga elastomer yokhala ndi magwiridwe antchito abwino kwambiri, TPU ili ndi zinthu zambiri zoyambira ndipo imagwiritsidwa ntchito kwambiri pazinthu zofunika tsiku ndi tsiku, zinthu zamasewera, zoseweretsa, zinthu zokongoletsera ndi zina. Nazi zitsanzo zingapo.
1. Zida za nsapato
TPU imagwiritsidwa ntchito popanga nsapato makamaka chifukwa cha kusinthasintha kwake komanso kukana kuvala. Zovala za nsapato zokhala ndi TPU ndizabwino kwambiri povala bwino kuposa nsapato wamba, kotero zimagwiritsidwa ntchito kwambiri popanga nsapato zapamwamba, makamaka nsapato zina zamasewera ndi nsapato wamba.


2. payipi
Popeza payipi ya TPU ndi yofewa, yolimba bwino, yolimba komanso yolimba kutentha kwambiri, payipi ya TPU imagwiritsidwa ntchito kwambiri ku China ponyamula ndege, matanki, magalimoto, njinga zamoto, zida zamakina ndi payipi ina ya zida zamakina.



3. Chingwe
TPU imapereka mphamvu yolimbana ndi kung'ambika, kukana kugunda ndi kupindika, ndipo kukana kutentha kwambiri ndi kochepa ndiye chinsinsi cha magwiridwe antchito a chingwe. Chifukwa chake, pamsika waku China, TPU ya zingwe zapamwamba, monga zingwe zowongolera ndi zingwe zamagetsi, imagwiritsidwa ntchito kuteteza zipangizo zokutira za zingwe zokhala ndi mapangidwe ovuta, ndipo ntchito zake zikuchulukirachulukira.



4. Zida zamankhwala
TPU ndi njira yotetezeka, yokhazikika, komanso yapamwamba kwambiri m'malo mwa PVC. Siidzakhala ndi mankhwala owopsa monga phthalate, ndipo idzasamutsidwa kupita ku magazi kapena zakumwa zina m'ma catheter azachipatala kapena matumba azachipatala kuti ibweretse zotsatirapo zoyipa. TPU yamtundu wa extrusion ndi mtundu wa jakisoni ingagwiritsidwe ntchito mosavuta ndikusintha pang'ono zida zomwe zilipo za PVC.