Plua plav-dawb chalk yog ib qho kev txhim kho ntawm cov chalk tsis tu ncua, tsim los tshem tawm cov hmoov av chalk hauv chav kawm. Nws tsuas yog ntxiv cov roj lossis polyols ua cov khoom sib txuas rau cov chalk zoo tib yam, thiab tom qab ntawd ntxiv cov khoom ntim nrog lub ntiajteb txawj nqus loj dua, xws li av nplaum, marl, cement, thiab lwm yam, uas tuaj yeem ua rau muaj qhov tshwj xeeb thiab qhov ntim ntawm cov hmoov av chalk, thiab nws tsis yog. yooj yim rau Scattered, tab sis nyob rau hauv kev siv tswv yim, nws txo cov nyhuv ntawm chalk plua plav paug tsis pom tseeb heev.
1. Ntxiv cov khoom siv tshuaj lom neeg rau hauv cov khoom tseem ceeb, ua kom lub ntiajteb txawj nqus, sau chalk rau ntawm lub blackboard, tsis muaj plua plav ya tshwm sim, huv si thiab huv si, thiab zam kev ua haujlwm kab mob los ntawm chalk ua npuas ncauj nkag mus rau hauv lub cev los ntawm kev ua pa.
2. Ntxiv ib qho me me ntawm lubricating agent thiab binder, cov chalk tsis lo rau tes thiab khaub ncaws, thiab tsis muaj cov cim dawb ntawm tus xib fwb ntawm tus ntiv tes tom qab kev kawm, yog li koj tsis tas yuav ntxuav koj txhais tes.
3. Ntxiv ib qho me me ntawm cov dej noo- cov ntaub ntawv pov thawj, thiab nws yuav tsis deteriorate thaum khaws cia ntev. Ordinary chalk yog yooj yim heev rau nqus dej noo thaum khaws cia rau lub sijhawm ntev, qhov hardness txo, thiab kev sau ntawv yooj yim tawg.
4. Cov ntawv dub siv hauv tsev kawm ntawv suav nrog cov cement board, wood board thiab frosted glass board. Vim tias qhov sib txawv ntawm qhov sib txawv ntawm qhov saum npoo ntawm cov ntawv dub, qhov degree ntawm softness thiab hardness ntawm chalk kuj txawv. Lub cim tshiab ntawm hmoov av-dawb chalk tuaj yeem hloov nws qhov tawv tawv ntawm qhov xav tau, thiab nws yuav tsis plam lossis tawg yooj yim thaum siv rau ntawm ntau yam ntaub ntawv blackboards, thiab nws ua tau zoo, ua haujlwm tau zoo-txuag thiab muaj tes zoo kev xav.
5. Plua plav-dawb chalk yog ib qho khoom siv siab tshiab- thev naus laus zis tsim tau zoo ntxiv rau cov khoom siv tshuaj pleev ib ce rau kev tsim khoom. Ib puag ncig tus phooj ywg, tsis yog - lom thiab plua plav- dawb, nws yog ib qho khoom siv qhia ntawv zoo tshaj plaws rau kev qhia niaj hnub.
