M'zaka zaposachedwapa, zinthu zopangidwa ndi polyurethane zakhala zikutchuka kwambiri, monga mapanelo osungira zinthu zozizira opangidwa ndi Harbin Dong'an Building Sheets ku China, omwe amapangidwa ndi zinthu zopangidwa ndi polyurethane.
Kawirikawiri, polyurethane imatha kugawidwa m'magulu awiri: thermosetting ndi thermoplastic, ndipo ingapangidwe kukhala mapulasitiki a polyurethane (makamaka mapulasitiki a thovu), ulusi wa polyurethane (spandex), ndi polyurethane elastomers. Zipangizo zambiri za polyurethane zimatchedwa thermosetting, monga ma thovu ofewa, olimba komanso osasunthika pang'ono.
Kubwezeretsanso zinthu pogwiritsa ntchito polyurethane nthawi zambiri kumagwiritsa ntchito njira zobwezeretsanso zinthu, chifukwa njira imeneyi ndi yothandiza komanso yotsika mtengo. Makamaka, ingagawidwe m'njira zitatu zobwezeretsanso zinthu:
Njira iyi ndi njira yogwiritsidwa ntchito kwambiri pobwezeretsanso zinthu. Thovu lofewa la polyurethane limaphwanyidwa m'zidutswa zingapo za masentimita ndi chopukusira, ndipo guluu wa polyurethane wochita kupopera umapopera mu chosakanizira. Guluu womwe umagwiritsidwa ntchito nthawi zambiri umakhala wophatikiza thovu la polyurethane kapena NCO terminated prepolymer yochokera ku polyphenyl polymethylene polyisocyanate (PAPI). Mukagwiritsa ntchito zomatira zochokera ku PAPI polumikiza ndi kupanga, kusakaniza nthunzi kumathanso kuyambitsidwa. Mu ndondomeko yogwirizanitsa zinyalala za polyurethane, onjezani 90% zinyalala za polyurethane ndi 10% zomatira, sakanizani mofanana, kapena onjezani utoto wina, kenako kanikizani chisakanizocho.
Ukadaulo wopanga ma bonding sikuti umangokhala ndi kusinthasintha kwakukulu, komanso umasiyana kwambiri ndi momwe makina amagwirira ntchito pa chinthu chomaliza. Njira yopambana kwambiri yobwezeretsanso zinthu za polyurethane ndikupanga thovu lobwezerezedwanso la polyurethane pogwiritsa ntchito thovu lofewa la thovu, lomwe limagwiritsidwa ntchito makamaka ngati kapeti kumbuyo, mphasa yamasewera, zipangizo zotetezera mawu ndi zinthu zina. Tinthu ta thovu lofewa ndi zomatira zimatha kupangidwa kukhala zinthu monga ma pads apansi pa galimoto pa kutentha ndi kupanikizika kwina; Pogwiritsa ntchito kupanikizika ndi kutentha kwakukulu, zinthu zolimba monga ma pompu housing zimatha kupangidwa.
Thovu lolimba la polyurethane ndi reaction injection molding (RIM) polyurethane elastomer lingathenso kubwezeretsedwanso m'njira yomweyi. Kusakaniza tinthu ta zinyalala ndi isocyanate prepolymers kuti tipange ma hot press, monga kupanga ma bracket a mapaipi a makina otenthetsera mapaipi. | 2、Kupaka kotentha kwambiri Thovu lofewa la polyurethane lopangidwa ndi thermosetting ndi zinthu za RIM polyurethane zimakhala ndi mphamvu zina zofewetsa kutentha komanso pulasitiki pa kutentha kwa 100-200 ℃. Pa kutentha kwakukulu ndi kupanikizika, zinyalala za polyurethane zimatha kulumikizidwa popanda kugwiritsa ntchito zomatira. Kuti zinthu zobwezerezedwanso zikhale zofanana, nthawi zambiri zimakhala zofunikira kuphwanya zinyalalazo kenako kuzitentha ndikuzikanikiza kuti zikhale mawonekedwe ake.
Mikhalidwe ya kapangidwe kake imadalira mtundu wa zinyalala za polyurethane ndi chinthu chobwezerezedwanso. Mwachitsanzo, zinyalala zofewa za polyurethane zimatha kukanizidwa kutentha kwa mphindi zingapo pa mphamvu ya 1-30MPa ndi kutentha kwa 100-220 ° C kuti zipange zoziziritsa kukhosi, zoteteza matope, ndi zina.
Njira iyi yagwiritsidwa ntchito bwino pobwezeretsanso zida zamagalimoto zamtundu wa RIM polyurethane. Mwachitsanzo, mapanelo a zitseko zamagalimoto ndi mapanelo a zida zitha kupangidwa ndi ufa wa polyurethane wa RIM wa pafupifupi 6% ndi fiberglass wa 15%. | 3、Amagwiritsidwa ntchito ngati chodzaza Thovu lofewa la polyurethane lingasandulike kukhala tinthu tating'onoting'ono pogwiritsa ntchito njira yophwanyira kapena kupukutira kutentha kochepa, ndipo kufalikira kwa tinthu totere kumawonjezedwa ku polyols popanga thovu la polyurethane kapena zinthu zina, zomwe sizimangobwezeretsa zinyalala za polyurethane, komanso zimachepetsa mtengo wa mankhwalawo. Kuchuluka kwa ufa wosweka mu thovu la polyurethane lopangidwa ndi MDI lozizira lokhazikika ndi 15% yokha, ndipo 25% ya ufa wosweka ukhoza kuwonjezeredwa mu thovu lotentha lopangidwa ndi TDI.
Njira imodzi ndi kuwonjezera zinyalala za thovu zomwe zadulidwa kale mu polyol yofewa ya thovu ya polyether, kenako nkuzinyowetsa mu mphero yoyenera kuti apange chisakanizo cha "polyol yobwezeretsedwanso" chokhala ndi tinthu tating'onoting'ono topangira thovu lofewa.
Zinyalala za RIM polyurethane zimatha kuphwanyidwa kukhala ufa, kusakaniza ndi zinthu zopangira, kenako n’kupanga RIM elastomers. Zinyalala za polyurethane rigid thovu ndi polyisocyanurate (PIR) thovu zitaphwanyidwa, zingagwiritsidwenso ntchito kuwonjezera 5% ya zinthu zobwezerezedwanso mu kuphatikiza kuti zipange thovu lolimba. |
M'zaka zaposachedwapa, njira yatsopano yobwezeretsa mankhwala yatulukira
Gulu la University of Illinois lotsogozedwa ndi Pulofesa Steven Zimmerman lapanga njira yowola zinyalala za polyurethane ndikuzisandutsa zinthu zina zothandiza.
Wophunzira maphunziro apamwamba Ephraim Morado akuyembekeza kugwiritsanso ntchito ma polima pogwiritsa ntchito njira zamankhwala kuti athetse vuto la zinyalala za polyurethane. Komabe, polyurethane ili ndi kukhazikika kwakukulu ndipo imapangidwa kuchokera ku zigawo ziwiri zomwe zimakhala zovuta kuwola: isocyanates ndi polyols.
Ma polyol ndiye chinsinsi cha vutoli, chifukwa amachotsedwa mu mafuta ndipo sawonongeka mosavuta. Pofuna kupewa vutoli, gulu lofufuza linagwiritsa ntchito acetal yomwe imasungunuka mosavuta komanso yosungunuka m'madzi. Zinthu zomwe zimawonongeka zomwe zimapangidwa ndi ma polima osungunuka ndi trichloroacetic acid ndi dichloromethane kutentha kwa chipinda zitha kugwiritsidwa ntchito popanga zinthu zatsopano. Monga umboni wa lingaliro, Morado imatha kusintha ma elastomer omwe amagwiritsidwa ntchito kwambiri popaka ndi magalimoto kukhala zomatira.
Komabe, vuto lalikulu la njira yatsopano yobwezeretsanso zinthu ndi mtengo wake komanso poizoni wa zinthu zopangira zomwe zimagwiritsidwa ntchito pochita izi. Chifukwa chake, ofufuza akuyesera kupeza njira yabwino komanso yotsika mtengo yokwaniritsira njira yomweyi pogwiritsa ntchito zosungunulira zofewa monga viniga kuti ziwonongeke.
M'tsogolomu, nyumba ya Harbin Dong'anpepalas kampaniKomanso tidzatsatira kwambiri luso la makampaniwa ndikupitiriza kuyika ndalama mu ukadaulo ndi ukadaulo woteteza chilengedwe, kupitiliza kupanga zatsopano kuti mapanelo a polyurethane a Dong'an akhale abwino komanso athanzi. Tikukhulupiriranso kuti padzakhala ukadaulo watsopano woteteza chilengedwe womwe udzabadwa mtsogolo.
Nthawi yotumizira: Novembala-09-2023