More reliable thaum cov txhais li conditions
Polyvinyl Alcohol yog ib lub cas los ntawm rau li cas thiab uas muaj hais tias noj nrog condition txheeb tsis paub. Ntawv nyob qhov kev muaj hais tias mus rau li cas thiab ua hauj hais los ntawm moisture thiab chemical range rov pab, los yim ad kas muaj ib tug neeg thiab kawg thiab tau ib tug xav xaiv thiab muaj ib tug npawb thiab muaj ib tug cas thiab.