Putty powder is a kind of building decoration material, the main components are talcum powder and glue. The white layer on the surface of the blank room just purchased is putty. Usually the whiteness of the putty is above 90° and the fineness is above 330°.
Putty is a kind of base material used for wall repair, which lays a good foundation for the next step of decoration (painting and wallpaper). Putty is divided into two kinds: putty inside wall and putty on exterior wall. External wall putty can resist wind and sun, so it has good gelation, high strength and low environmental index. The comprehensive index of putty in the inner wall is good, and it is hygienic and environmentally friendly. Therefore, the inner wall is not for external use and the outer wall is not for internal use. Putties are usually based on gypsum or cement, so rough surfaces are easier to bond firmly. However, during construction, it is still necessary to brush a layer of interface agent on the base to seal the base and improve the adhesion of the wall, so that the putty can be better bonded to the base.
Many putty powder users have to admit that the depowdering of putty powder is a very serious problem. It will cause the latex paint to fall off, as well as the bulging and cracking of the putty layer, which will cause cracks in the latex paint finish.
De-powdering and whitening of putty powder are currently the most common problems after putty construction. To understand the reasons for putty powder de-powdering, we must first understand the basic raw material components and curing principles of putty powder, and then combine the wall surface during putty construction Dryness, water absorption, temperature, weather dryness, etc.
8 main reasons for putty powder falling off.
reason one
The bonding strength of the putty is not enough to cause powder removal, and the manufacturer blindly reduces the cost. The bonding strength of the rubber powder is poor, and the amount of addition is small, especially for the interior wall putty. And the quality of glue has a lot to do with the amount added.
Reason two
Unreasonable design formula, material selection and structural problems are very important in putty formula. For example, hydroxypropyl methylcellulose (HPMC) is used as a non-waterproof putty for the inner wall. Although HPMC is very expensive, it does not work for fillers such as double fly powder, talcum powder, wollastonite powder, etc. If only HPMC is used, it will cause delamination. However, CMC and CMS with low prices do not remove powder, but CMC and CMS cannot be used as waterproof putty, nor can they be used as exterior wall putty, because CMC and CMS react with gray calcium powder and white cement, which will cause delamination. There are also polyacrylamides added to lime calcium powder and white cement as waterproof coatings, which will also cause chemical reactions to cause powder removal.
Reason Three
Uneven mixing is the main reason for the powder removal of the putty on the interior and exterior walls. Some manufacturers in the country produce putty powder with simple and varied equipment. They are not special mixing equipment, and the uneven mixing causes the powder removal of the putty.
Reason four
The error in the production process causes the putty to be powdered. If the mixer does not have the function of cleaning and there are more residues, the CMC in the ordinary putty will react with the ash calcium powder in the waterproof putty. The CMC and CMS in the inner wall putty and the outer wall The white cement of the putty reacts to cause de-powdering. Some companies’ special equipment is equipped with a cleaning port, which can clean the residue in the machine, not only to ensure the quality of the putty, but also to use one machine for multiple purposes, and buy one equipment to produce a variety of putty.
Reason Five
The difference in the quality of fillers is also likely to cause de-powdering. A large number of fillers are used in the interior and exterior wall putty, but the content of Ca2CO3 in heavy calcium powder and talc powder in various places is different, and the difference in pH will also cause de-powdering of putty, such as those in Chongqing and Chengdu. The same rubber powder is used for the interior wall putty powder, but the talcum powder and heavy calcium powder are different. In Chongqing, it does not remove powder, but in Chengdu, it does not remove powder.
reason six
The reason of the weather is also a reason for the powder removal of the putty on the inner and outer walls. For example, the putty on the inner and outer walls has a dry climate and good ventilation in some arid areas in the north. There is rainy weather, long-term humidity, the putty film-forming property is not good, and it will also lose powder, so some areas are suitable for waterproof putty with calcium powder.
reason seven
Inorganic binders such as gray calcium powder and white cement are impure and contain a large amount of double fly powder. The so-called multi-functional gray calcium powder and multi-functional white cement on the market are impure, because a large amount of these impure inorganic binders are used, and the waterproof putty of the inner and outer walls will definitely be powder-free and not waterproof.
reason eight
In summer, the water retention of putty on exterior walls is not enough, especially in places with high temperature and ventilation such as high-rise doorways and windows. If the initial setting time of ash calcium powder and cement is not enough, it will lose water, and if it is not maintained well, it will also be seriously powdered.
Post time: Jun-02-2023