Crocodile paint small class . . . Why is the exterior paint not suitable for winter construction?

In winter low temperature environment, the coating easy to become viscous, slow curing speed, these factors undoubtedly add to the construction of difficulties. In the construction specification of exterior paint, there are clear requirements for the construction temperature, which stipulates that the construction environment temperature shall not be lower than 5 degrees C. Next, let's analyze the reasons for the composition of the material from its properties and membrane-forming

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in order to facilitate everyone to understand, first of all to explain a few technical terms:
construction personnel
what is the table dry time?
alligator paint
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.
construction workers,
is the actual drying time?
alligator paint
the time required to form a solid paint film under the prescribed drying conditions, from the applied liquid paint film of a certain thickness to the solid paint film.
construction workers,
are the main ingredients of putty?
Crocodile paint
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 collosus.
construction workers
synthetic resin emulsion exterior paint is what?
Crocodile paint
with synthetic resin emulsion as the base material, and pigments and a variety of additives (film additives, desiccants) made, after application can form a flat surface of the thin coating of the outer wall coating.
Exterior paint and putty should not be the main reason for winter operation
1, can be dispersed latex powder minimum film temperature is generally between 0 degrees C to 10 degrees C, more common is 5 degrees C, on this basis, latex powder can present a continuous film. Conversely, if it is below this temperature, the film of latex powder is no longer continuous and will break. Therefore, the minimum film-forming temperature is an important indicator that the project can be constructed. Generally speaking, the lower the minimum film temperature, the better the construction.
2, the main problem existing in the emulsion-type exterior wall coating is that a good coating film cannot be formed at too low a temperature. Usually at temperatures above 8 degrees Celsius 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. And the actual drying time, putty in about 18 hours, paint single layer in about 24 hours, dry through need about 2 weeks.
In summary, in winter, even if the choice to work at the highest temperature at noon, although the surface can be dry, but in fact the paint is still in a liquid and semi-solid state, the paint in the afternoon frozen, will eventually cause cracking and powdering phenomenon, the surface will also appear a large area of color change.
, according to the investigation, the external wall paint winter construction work did not take insulation measures of the project, the quality accident rate of more than 50%. Therefore, winter exterior wall engineering construction, we must pay special attention to.
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