In the putty powder, play the thickening, water conservation and construction of the three roles. Water retention: make the putty powder dry slowly some auxiliary gray calcium at first reaction under the action of water. Construction: cellulose has lubrication effect, can make putty powder have good construction. HPMC does not participate in any chemical reaction and only plays an auxiliary role.
Putty powder with water, on the wall, is a chemical reaction, because of the generation of new substances. The main component of ash calcium powder is: Ca (OH2, CaO and a at first small amount of CaCO3 mixture. CaO + H2O=Ca (OH2-Ca (OH2 + CO2= =CaCO3 + H2O ash calcium produces calcium carbonate under the action of CO2 in water and air. While HPMC only holds water, auxiliary ash calcium better reaction, it itself does not participate in any reaction.
The powder loss of putty powder mainly has a lot to do with the quality of gray calcium. And has not too much to do with HPMC. The low calcium content of gray calcium and the CaO and Ca in gray calcium (OH2 ratio is not appropriate, will cause powder loss. If it has something to do with HPMC, then if HPMC is poor in water retention, it will also cause powder loss.