Kutsegula kwa molecular sieve 5A ndi pafupifupi 5 angstroms, yotchedwanso calcium molecular sieve.Itha kugwiritsidwa ntchito m'mafakitale opangira mpweya ndi ma hydrogen.
Mfundo yogwirira ntchito ya sieve ya mamolekyu imagwirizana kwambiri ndi kukula kwa pore kwa ma molekyulu a molekyulu, wAtha kutsatsa ma molekyulu a mpweya omwe ma molekyulu awo amakhala ochepa kuposa kukula kwake.Kukula kwa kukula kwa pore, kumapangitsanso mphamvu ya adsorption.Kukula kwa pore kumakhala kosiyana, ndipo zinthu zomwe zimasefedwa ndikulekanitsidwa ndizosiyana.Pogwiritsidwa ntchito ngati desiccant, sieve ya molekyulu imatha kuyamwa mpaka 22% ya kulemera kwake mu chinyezi.