Why is the exterior paint not suitable for winter construction?

China Paint Online News Information

Exterior paint construction specifications for the construction temperature made requirements, the construction environment temperature must not be lower than 5 degrees C, Henan Songyuan as a professional paint enterprises for the vast number of consumers to answer winter construction precautions, according to the characteristics of the composition of the material and film-forming machinery to analyze its causes.1, on the paint and putty several words explained:
1, table dry time: under the prescribed drying conditions, a certain thickness of wet paint film, the surface from liquid to solid but still liquid under the time required.
2, the actual drying time: under the prescribed drying conditions, from the application of a certain thickness of liquid paint film to the formation of solid paint film required time.
3, putty main components: cement, gray calcium powder, quartz powder, heavy calcium, glue powder, HPMC (hydroxypropyl, methyl cellulose), anti-crack fiber, wherein the powder is mainly ethylene acetate plus other copolymers and other protective collusion.
4, synthetic resin emulsion outer wall coating is a synthetic resin emulsion as the base material, with pigments, body pigments and a variety of additives (film aids, desiccants) preparation, after application can form a surface flat thin coating of the outer wall coating.2, external wall coatings and putty can not winter main reasons
1, can be dispersed latex powder minimum film temperature is generally between 0 degrees C to 10 degrees C, but more common is 5 degrees C, at this temperature, latex powder presents a continuous film, on the other way, below this temperature, latex powder film is no longer continuous, there is a fracture situation. Therefore, the minimum film temperature is an indicator of the constructionable temperature of the project. Generally speaking, the lower the minimum film temperature, the better the construction. A large amount of water in the putty swells after being frozen, causing internal stress aggregation and eventually causing the putty to crack.
2, the main problem existing in the current emulsion-type exterior wall coating is that it can not form a good coating film at too low temperature, usually must be more than 8 degrees C construction to ensure quality, so winter is not suitable for application.
3, the test temperature requires putty table drying time of 5 hours, and paint table drying time of 2 hours or less. The actual drying time putty is about 18 hours, the coating single layer is about 24 hours, and the dryness is about 2 weeks. Synthesis of the above points, even if the winter construction choice at noon temperature slightly higher when the operation, although can reach the surface dry, but the internal liquid and semi-solid state, the paint after noon internal freezing will also cause cracking and powdering phenomenon, the surface will also appear a large area of color change.
, according to the investigation, the outer wall paint winter construction work did not take insulation measures of the project, the quality accident rate of more than 50%. Therefore, the winter exterior wall decoration project construction in winter must pay attention to.
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