Thaum cov ntawv thermal muab tso rau hauv ib puag ncig saum toj 70 degree, thermal txheej pib hloov xim. Yog vim li cas rau nws discoloration kuj pib los ntawm nws muaj pes tsawg leeg.
Muaj ob lub ntsiab thermal Cheebtsam hauv thermal ntawv txheej: ib qho yog leuco dye lossis leuco dye; lwm tus yog xim tsim. Hom ntawv thermal no tseem hu ua ob-cov khoom siv tshuaj thermal recording paper.
Feem ntau siv los ua leuco dyes yog: siv lead ua violet lactone (CVL) ntawm trityl phthalide system, fluoran system, tsis muaj xim benzoylmethylene xiav (BLMB) lossis spiropyran system.
Feem ntau siv dispersants yog: polyvinyl cawv L-3266, polyvinyl cawv GL-05, polyvinyl cawv KL-03 (tsim los ntawm Nyiv Synthetic Chemical).
Feem ntau siv cov tsho tiv no sab saum toj thiab hauv qab lub tsho tiv no yog: gohsefimer Z-200, polyvinyl cawv T-350, polyvinyl cawv N-300.
Feem ntau siv los ua cov tshuaj tsim cov xim yog: para-hydroxybenzoic acid thiab nws cov esters (PHBB, PHB), salicylic acid, 2, 4-dihydroxybenzoic acid los yog aromatic sulfones thiab lwm yam tshuaj.
Thaum cov ntawv thermal yog rhuab, leuco dye thiab cov neeg tsim tawm teb cov tshuaj lom neeg los tsim cov xim, yog li thaum cov ntawv thermal siv tau txais cov cim ntawm lub tshuab fax lossis luam tawm ncaj qha nrog lub tshuab luam ntawv thermal, cov duab thiab cov ntawv raug tso tawm. Txij li thaum muaj ntau ntau yam ntawm leuco dyes, cov xim ntawm cov ntawv sau qhia txawv, xws li xiav, ntshav, dub thiab lwm yam.