Talk about the technology of reflective water-separated building coatings

Building reflection insulation coatings, also known as solar thermal reflection insulation coatings, the coating can reflect and radiate solar irradiated energy.
reflective insulation of hot water architectural coatings, is based on synthetic resin, water as a dispersion medium, pigments (mainly infrared reflective pigments), fillers and additives, by a certain process made of paint.
reflective thermal insulation paint is divided into flat-coated and texture-based,
-quality
than
flat-coated type is difficult to achieve reflective insulation effect

.
general texture paint such as real stone paint (refers to natural colored sand as a filler texture paint) generally without pigments, plus the surface
porous
, it is difficult to achieve the effect of reflective insulation. Some manufacturers have studied the ability to achieve reflective insulation on white sand by coating reflective pigments, but with little effect.
multicolored paint for water-wrapped water mixed with a variety of colors of textured paint, multi-color paint reflective insulation effect mostly need composite coating to achieve, multi-color paint color more, testing when the human error is larger, can not fully reflect the overall reflective insulation effect of the test board. With white sand as the main filler, with a small amount of pigment filler textured sand paint, you can use reflective insulation pigments and cold pigments for color adjustment, relative to real stone paint can get better reflective insulation effect.
According to the different action structure, the new national standard GB/T 25261-2018 "building reflective insulation coating" has clear provisions, building reflective insulation coating products are divided into insulation paint, reflective thermal insulation flat paint, reflective thermal insulation texture coating, will be implemented in 2019-2-1, need to strengthen technical research and the corresponding product realization methods. The existing line label JG/T 235-2014 "Building Reflection Insulation Coatings" only specifies the technical requirements of reflective thermal reflection ratio, near-infrared reflection ratio, hem reflectivity and so on, and the methods and knowledge of the corresponding product implementation are summarized as follows:
1, depending on the length of the wavelength, Sunlight can be divided into ultraviolet (UV), visible and infrared, the three bands of solar energy are
1, UV, accounting for 4% of solar energy
2, visible light, accounting for 43% of solar energy
3, near-infrared, accounting for 53% of solar energy, the main source of heat.
II,
According to the impact on the thermal conduction mechanism, the market reflective insulation coatings can be divided into three categories
1, barrier type - prevent thermal conduction: low thermal conductivity × thickness→ thermal resistance (medium coating)
2, reflective type - high reflectivity less heat absorption: originated from aluminum-based reflective coating
3, radiation type - heat energy in the form of infrared radiation emission: high hemisphere emission rate

III, reflective insulation coating design - raw materials
1, hollow microbeads: A glass microbeads, B ceramic microbeads
2, silica aerogel - super hollow, ultra-light, separated Heat, temperature resistance
3
, far infrared powder
-
FAR infrared strong emission rate
(
high hemisphere emission rate), high price and limited lift, the use of restricted .
4, reflective insulation pigment
A reflective insulation titanium dioxide white powder - based on titanium dioxide through special crystallization, so as to achieve a high infrared reflection performance.
BReflective insulation color pigments
also known as color cold pigments - absorb visible light to obtain color, while having a higher infrared reflectivity;
4, reflective insulation coating formula to achieve
1, the selection of hollow microbeads, the implementation of JG/T 235-2014 standards, its actual coefficient is based on low thermal conductivity, for a certain thickness of the medium coating is more appropriate. For the JG/T 235-2014 standard, the solar reflection ratio is not easy to achieve after product contamination with white paint or light high brightness values, and the color card database analysis is required to see if other colors can meet the standard.
2, the selection of reflective insulation titanium dioxide powder, the implementation of JG/T 235-2014 standards, based on titanium dioxide through special crystallization, so as to achieve a high infrared reflection performance, the current architectural paint is more commonly used, white paint or light color high-brightness value of the product easy to meet the standards, other low- and medium-light colors can meet the standards need to do color card database analysis. Carbon black and iron black absorb all sunlight strongly and cannot be used as color pigments for reflective insulation coatings.