The advanges of HPMC & MHEC in dry mix mortar products
November 22nd 20241. Winter construction conditions and requirements
For putty powder construction, the qualified base has five basic characteristics: firm, flat, dry, neutral and clean. For the construction conditions of putty powder, the construction ambient temperature must be controlled above 5 ℃ and the ambient humidity must be controlled within 85%, otherwise the construction is not allowed.
2. Construction conditions and requirements of putty powder
For the construction of putty powder for internal and external walls, some projects still need to be constructed when the temperature is lower than 5 ℃ after entering winter due to the construction period requirements. In order to improve the construction quality, the following matters should be paid attention to during construction:
(1) Inspection and treatment of base course
Base course treatment is the basis of coating engineering. The content of base course treatment includes: removing dust, oil stain and loose matter on the surface of base course; Reduce or eliminate surface defects; Make the physical or chemical properties of the base surface.
(2) Putty construction
For the construction of coating system, ensure the drying of the substrate and the surface temperature of the wall before construction in winter. When the temperature is lower than 5 degrees in the daytime, try to construct on the wall with direct sunlight, and the low temperature at night should be higher than 0 degrees Celsius, otherwise construction cannot be carried out, so as to avoid the putty layer being frozen.
(3) Polish the putty and judge the drying condition
The putty can be polished only after it is completely dry, so that the putty can be polished without sticking sandpaper and the control of surface flatness after it is completely dry. If the putty is not dry or frozen, the putty will stick to sandpaper during polishing, and the surface is not easy to polish.
(4) Coating construction
Coating construction: before coating, it is necessary to confirm that the substrate is completely dry, and the construction temperature of water-based coating should be controlled above 5 ℃. During the drying and film-forming process, when the temperature is lower than zero, the lotion will be frozen and lose its bonding and film-forming function, so as to ensure that the minimum temperature during the film-forming drying process cannot be lower than 0 ℃.
(5) Storage of paint
In winter, the paint stored on site should be placed indoors by classification and stacking, and ensure that the indoor temperature is above 0 ℃. When the temperature is lower than 0 ℃, heating or electric heating should be used to keep the indoor temperature. Open fire indoor temperature is strictly prohibited. The paint that is not used up in the construction should be placed indoors, and the frozen products will not be used.
(6) Paint film maintenance and finished product protection
The drying time of the paint film on the surface of the object takes 7 days at the standard temperature of 25 ℃. In view of the generally low ambient temperature of coating construction in winter, the drying and reaching time of the paint film should be relatively extended. During this period, the pollution and bump on the surface of the paint film should be reduced as much as possible to avoid the overall effect of repair caused by pollution and bump. For construction in winter, corresponding protective measures shall be taken according to the construction conditions on site to avoid freezing of the coating film. To ensure the smooth progress of project coating quality and construction progress.
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