Putty is a kind of building decoration materials. A layer of white putty on the surface of the blank room just purchased is usually more than 90 in whiteness and more than 330 in fineness. Putty is divided into interior wall and exterior wall. Exterior wall putty should resist the wind and sun, so it has high glue, high strength and slightly low environmental protection index. The comprehensive index of interior wall putty is good, healthy and environmental protection, so the interior wall is not used externally and the exterior wall is not used internally. Usually the putty is gypsum or cement-based, so the surface is rough and easy to bond firmly. However, during construction, it is still necessary to apply a layer of interface agent on the base course to seal the base course, and improve the adhesion of the wall, so that the putty can be better bonded to the base surface.
The amount of HPMC really used depends on the climate environment, temperature difference, the quality of local calcium ash powder, the secret recipe of putty powder and “the quality required by the operator”. Generally speaking, between 4kg and 5kg.
HPMC has the function of lubrication, which can make the putty powder have good workability. Hydroxypropyl methylcellulose does not participate in any compound reaction, but only has the effect of assistance. Putty powder is a kind of compound reaction on the water surface and on the wall,
Some problems:
1. Powder removal of putty
A: This is related to the dosage of lime calcium, and also related to the dosage and quality of cellulose, which is reflected in the water retention rate of the product. The water retention rate is low and the hydration time of lime calcium is not enough.
2. Peeling and rolling of putty powder
A: This is related to the water retention rate. The cellulose viscosity is low, which is easy to occur or the dosage is small.
3. Needle point of putty powder
This is related to cellulose, which has poor film-forming property. At the same time, impurities in cellulose have a slight reaction with ash calcium. If the reaction is intense, the putty powder will show the state of tofu residue. It can’t go to the wall and has no bonding force. In addition, it also occurs in products such as carboxy groups mixed in cellulose.
Post time: Mar-17-2022