Ice packs, raws li cov cuab yeej tswj qhov kub thiab txias, yog siv dav hauv kev kho mob, kev thauj khoom noj, thiab kev ua si sab nraum zoov. Lawv lub luag haujlwm tseem ceeb yog tswj qhov kub ntawm cov khoom lossis ib puag ncig los ntawm kev nqus cua sov lossis tso tawm cov txheej txheem ntawm cov khoom hloov pauv (PCMs). Kab lus no yuav piav qhia txog lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm cov pob khov nab kuab los ntawm cov txheej txheem ntawm lub cev, cov khoom siv, thiab kev siv tswv yim.
Thaum tshav kub kub absorption thiab tso tawm mechanisms ntawm theem hloov cov ntaub ntawv
Lub hauv paus ntsiab lus ua haujlwm tseem ceeb ntawm cov pob khov nab kuab yog ua raws li lub cev lub zog ntawm cov khoom hloov pauv theem. Thaum lub ambient kub siab tshaj qhov melting point ntawm cov khoom ntim cov dej khov, cov ntaub ntawv no (xws li gels, inorganic ntsev tov, los yog cov polymers tshwj xeeb) yuav hloov los ntawm ib tug khoom mus rau lub xeev ua kua, los yog los ntawm ib tug txiav txim qauv mus rau lub xeev tsis zoo. Cov txheej txheem no hu ua endothermic theem hloov. Thaum lub sij hawm hloov cov txheej txheem, cov khoom absorbs ib tug loj npaum li cas ntawm tshav kub, tiam sis qhov kub thiab txias tseem nyob tas li, yog li zoo txo qhov kub ntawm ib puag ncig ib puag ncig. Piv txwv li, cov khoom siv bio-gel ice packs tuaj yeem nqus cov cua kub tsis tu ncua thaum yaj, tswj qhov kub tsis tshua muaj rau ob peb teev.
Hloov pauv, thaum qhov kub ntawm qhov ntsuas kub qis dua qhov chaw khov ntawm cov khoom siv, cov khoom hloov theem yuav tso tawm cov cua sov thiab rov ua dua - solidify. Cov txheej txheem no hu ua exothermic theem hloov. Qee lub hnab ntim dej khov siv tau rov siv dua los ntawm kev rov ua kom khov thiab thawing. Lawv cov ntaub ntawv sab hauv khaws cia txias zog thaum khov thiab tso tawm los ntawm kev hloov pauv hloov thaum xav tau.
Cov khoom siv dav dav thiab cov qauv tsim ntawm Ice Packs
Cov ntaub ntawv ntim cov khoom ntim dej khov feem ntau muaj qhov tshwj xeeb kub muaj peev xwm thiab qis theem hloov kub kom ntseeg tau tias muaj kev tswj xyuas qhov kub thiab txias. Nov yog qee yam khoom siv thiab lawv cov haujlwm:
1. Dej-raws li gel: muaj dej, thickeners (xws li carboxymethyl cellulose), thiab preservatives, nrog rau theem hloov kub ze li ntawm 0 degree, haum rau kev kho mob txias compresses los yog luv luv -lub sij hawm txias.
2. Inorganic ntsev tov (xws li ammonium nitrate): Tsim kom muaj qhov kub thiab txias los ntawm endothermic dissolution, feem ntau siv nyob rau hauv cov khoom siv dej khov pov tseg, tab sis tej zaum yuav ua rau kub hloov pauv vim supercooling.
3. Polymer composite cov ntaub ntawv: Qee qhov siab - cov pob khov khov kawg siv cov polymers tshwj xeeb kom ua tiav qhov kub thiab txias los ntawm kev tswj cov theem hloov, tsim nyog rau kev thauj cov cuab yeej precision.
Tsis tas li ntawd, txheej txheej txheej ntawm cov dej khov nab kuab feem ntau yog ua los ntawm cov dej tsis muaj dej thiab cua sov-cov ntaub ntawv hloov pauv tau yooj yim (xws li PVC lossis TPU), tiv thaiv cov kua dej tawm thiab ua kom cov cua sov nkag mus rau sab nraud, yog li ua kom lub zog txias.
Kev ua tau zoo
Hauv kev kho mob, cov dej khov ntim cov ntaub so ntswg txo qis thiab txo qhov mob los ntawm qhov chaw txias. Hauv kev xa khoom txias, lawv tau siv ua ke nrog cov tub yees kom tswj tau qhov qis - qhov kub thiab txias hauv cov thawv. Nws yog ib qho tsim nyog sau cia tias qhov ua tau zoo ntawm cov pob khov nab kuab cuam tshuam los ntawm qhov kub thiab txias, kev siv cov khoom siv, thiab kev rwb thaiv tsev. Piv txwv li, nyob rau hauv qhov kub ntawm - qhov kub thiab txias, lub sij hawm hloov lub sij hawm ntawm cov ntim dej khov yog luv luv, thaum ob npaug - txheej ntim ntim tuaj yeem txhim kho lawv cov rwb thaiv tsev.
Ice packs ua tiav qhov ntsuas kub los ntawm kev nqus cua sov thiab tso tawm lub voj voog ntawm cov ntaub ntawv hloov pauv, lub hauv paus ntsiab lus uas ua ke nrog cov thermodynamics thiab cov ntaub ntawv tshawb fawb. Nrog rau kev txhim kho thev naus laus zis, kev siv cov ntaub ntawv hloov pauv tshiab yuav ua kom zoo dua cov pob khov nab kuab thiab nthuav lawv cov ntawv thov hauv cov haujlwm tshiab xws li aerospace thiab cov khoom siv hluav taws xob txias. Kev nkag siab txog lawv txoj haujlwm ua haujlwm pab siv cov pob khov nab kuab zoo dua thiab ua tau raws li kev tswj xyuas qhov kub thiab txias ntawm cov xwm txheej sib txawv.
