Coating technology: an anti crack and anti pollution construction technology for exterior wall coating

Core tip: the traditional method of building exterior wall decoration is to use veneer brick However, due to various reasons, with the passage of time, the large area of exterior wall brick falls off, threatening the safety of residents; aware of the danger of using wall brick on the exterior wall of high-rise buildings, building coating materials are widely promoted The exterior wall coating has the characteristics of light weight, environmental protection, low carbon, waterproof and excellent stain resistance More and more exterior wall decoration adopts the coating construction process However, in the engineering practice, the coating process also exposes its own shortcomings, such as poor stain resistance, cracking and so on Analysis Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Paint House News: the traditional method of building exterior wall decoration is to use veneer brick However, due to various reasons, with the passage of time, there is a large area of falling off of the exterior wall brick, threatening the safety of residents; aware of the danger of using wall brick on the exterior wall of high-rise buildings, building paint has been widely promoted The exterior wall coating has the characteristics of light weight, environmental protection, low carbon, waterproof and excellent stain resistance More and more exterior wall decoration adopts the coating construction process However, in the engineering practice, the coating process also exposes its own shortcomings, such as poor stain resistance, cracking and so on This paper analyzes the causes of cracking and poor pollution resistance, which are mainly caused by the following aspects: first, the product itself problems: for example, the selection of common external wall putty, poor alkali resistance of primer, poor permeability and sealing, construction of only two common external wall finishes, without flexibility; Second, the product matching combination: for example, the elastic matching system should be considered in the external insulation base, but only the ordinary styrene acrylic exterior wall coating should be selected in practice; the corresponding matching system is not selected in combination with the objective factors such as serious pollution and acid rain in the urban environment; Third, construction process: for example, large-area exterior wall base coating construction, no interlayer expansion joint is set, and due to the unqualified flatness of the base, the putty layer is completely used for leveling and repair, resulting in uneven stress distribution, resulting in local cracks; in addition, if the moisture content of the base exceeds the standard, the construction is maintained, resulting in the falling off of Pan alkali How to solve the problem of cracking and stain resistance has not been well solved in the industry The purpose of this scheme is to overcome the shortcomings of the above existing technology and provide a construction technology of building exterior wall coating with simple process, convenient construction, crack resistance and pollution resistance In order to achieve the above purpose, the following technical scheme is adopted in this scheme: a construction process of anti crack and anti pollution for exterior wall coating of building, including the following steps: 1) construction of plastering layer and external insulation base of exterior wall of building, cutting or reserving expansion joints; 2) acceptance after the completion of step 1; next step after passing; otherwise, return to the previous step; 3) Remove the floating ash and oil stain from the external insulation base, scrape and apply two layers of reinforced external wall putty, and control the thickness of each process putty layer to meet the specified requirements, and then polish it; 4) after removing the floating ash, roll coat the silicon acrylic alkali resistant primer, roll coat evenly, without leakage; close the base while enhancing the adhesion between the coatings; 5) use tools according to the design texture effect requirements The roller coating elastic intermediate paint is applied with corresponding texture effect The roller coating is even, increasing the thickness of the roller coating film and enhancing the crack resistance of the coating; 6) after the elastic intermediate paint is dry, the roller coating water-borne polyurethane finish paint is applied twice, evenly The expansion joint in step 1) is arranged to the wall concrete base The step magic enhanced exterior wall putty adopts polymer modified silicate based flat bottom slurry products, such as Haihong brand putty e1980, e1990 The silica acrylic alkali resistant primer in step 4) is Hai Hong e1090 The elastic intermediate paint in step 5) is Haihong elastic knurling intermediate paint or elastic knurling emulsion paint e8920, e8220 The water-based polyurethane finish in step 6) is Haihong brand water-based polyurethane finish e5830 The scheme includes base treatment, coating product matching selection, color design, grid joint setting and construction control The key technology is the selection of coating products and construction technology The coating includes putty, primer, intermediate coat and waterborne polyurethane finish, The construction process mainly includes: base treatment (including plastering layer construction), the flatness and perpendicularity of plastering mortar for external wall shall meet the requirements of the specification, expansion joints shall be set to the structural layer according to the design and specification requirements, the plastering layer for base layer shall have enough maintenance time, the wall surface shall be free of sand, cracks, looseness and other phenomena, and the moisture content of base layer shall not be greater than 10 %The concrete is directly used as the base course The cleaning of the base course surface is conducive to the adhesion of the coating The cement mortar flow marks, dust, no dirt and alkaline substances are removed The pH value is less than 10 The putty is made of high-tech polymer modified silicate based flat bottom slurry, which has the following advantages: ① high bond strength; ② good cracking resistance; ③ high hardness; ④ good water and alkali resistance; ⑤ good freeze-thaw resistance However, the initial function of putty is to improve the base course and decoration effect, so as to make up for the defects of the base course (such as sand holes, plastering marks, joints and roughness) It is only suitable for local repair or full scraping construction However, in the actual construction, it is overused to correct the flatness and perpendicularity, which should be the standard that the base plastering should meet, so that the putty layer is too thick, leaving the whole coating and even the base with such hidden dangers as poor adhesion and easy cracking Primer, as the "interface layer", is the material directly combining the whole coating and the external insulation system We recommend that the primer type used in the external insulation base is silicon acrylic alkali resistant primer, which is characterized by: ① better adhesion; ② excellent combination of waterproof and air permeability; ③ strong alkali resistance and sealing; ④ non corrosive and harmless The elastic intermediate paint is a thick product, which can be constructed into flat coating, knurling and other different effects according to the decoration effect The main functions are as follows: 1 The feasibility of thickness is ensured; second, excellent elasticity; third, good weathering resistance; 4 The emulsion with good decorative polyurethane surface coating is designed according to the characteristics of China's use of the environment The outstanding features of the product are: 1) good flexibility index; 2 Good stain resistance; 3 Good waterproof; 4 Good weather resistance The film thickness of this scheme is 3-5 times of that of common exterior wall coating In a wide temperature range, the film has the properties of extension and recovery, covering crack (0.2mm < crack < 2.omm), excellent pollution resistance and acid rain resistance Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,