Brief introduction of prefabricated building adhesive
Because of its fast construction speed, small constraints by climate conditions, labor saving and improving construction quality, prefabricated buildings have been implemented in the 1960s abroad. However, the prefabricated buildings in China have developed rapidly in recent years. Prefabricated building is the assembly and partial pouring of prefabricated parts on the construction site. There will be many joints in this construction method, and special sealant needs to be injected to play a waterproof role. The performance of sealant will directly affect the waterproof effect of the prefabricated building. Once the sealing failure leads to leakage, it will not only affect the appearance and quality of the prefabricated building, but also seriously affect the living and use of users. Moreover, the subsequent maintenance cost may be several times of the initial sealing material and construction cost. Sealant for assembly building joint is a very important waterproof material in every assembly building, which is widely used. Types of assembly sealant
What are the types of sealant used for assembly building joints? What are the characteristics of different types of sealant? I will share with you in this article. According to the different chemical composition, the sealant commonly used in the market can be divided into polyurethane (PU, structural diagram 1), silicone (SR, structural diagram 2), silane modified polyether (MS, structural diagram 3), etc.
▲ Figure 1 typical main chain structure of polyurethane
▲ Fig. 2 main chain structure of silicone adhesive
▲ Figure 3 main chain structure of silane modified polyether
The molecular structure of sealant determines its performance, and the performance of sealant with different structure is very different. We compare and analyze the existing sealant for assembly building, as shown in Table 1:
Purpose and advantages
Next, we will introduce the above three types of sealant for prefabricated buildings and their applications:
PU Sealants
Polyurethane sealant has good mechanical properties, but poor environmental protection, inconvenient construction and poor aging resistance. Polyurethane sealant is used in assembly buildings. After long-term use, there is a risk of cracking and water leakage due to its own aging. Most of it is used in non sunlight rubber joints (sealing of internal joints of buildings).
Silicone sealant
Silicone sealant has excellent aging resistance, but poor surface finishing. Silicone sealant can be used for assembly building joints without finishing, which can give full play to its aging resistance and have a long service life.
Silane modified polyether adhesive
Silane modified polyether adhesive has both the advantages and advantages of silicone sealant and polyurethane sealant, showing high resistance to displacement, good coating, adhesion, environmental friendliness, excellent resistance to pollution, construction and aging. It is very suitable for the joint sealing of prefabricated cement components in assembly building, and is the first choice of assembly building joint sealant.
R939 assembly sealant
R939 is a kind of one component neutral curing silane modified polyether sealant developed by ruilangda company, with displacement capacity of grade 25. The product has good adhesion ability to cement, concrete, stone and other building materials, with low modulus, good flexibility, environmental protection and pollution-free characteristics. It can be widely used in the sealing of joints of exterior walls, balconies and interior of prefabricated buildings And so on.
application area
Assembly building exterior wall, balcony, indoor joint sealing and other fields.
The stone curtain wall is caulked and sealed.
Technical parameters
Advantages
Single component packaging, easy to use, good extrusion performance in the normal construction temperature range; excellent adhesion, excellent bonding performance for concrete, stone, steel and other building materials; excellent aging resistance, not damaged by the impact of sunlight, rain, snow, UV, ozone; excellent high and low temperature resistance, the cured adhesive strip has excellent performance at - 40 ℃ ~ 120 ℃; High displacement capacity: with the expansion and shear deformation of the concrete joint, the colloid itself will not be damaged and maintain good bonding and sealing performance; low modulus: low stress generated during passive deformation to ensure that the concrete surface will not be damaged; high elastic recovery capacity: it can move with the joint repeatedly, with fast response, fast recovery and small permanent deformation. Environmental protection products: ultra-low VOC, non-toxic and tasteless, no pollution and corrosion to the base material; good finishing performance: the surface can be painted, which can better solve the problems of mortar and real stone paint for rubber surface decoration. Curing mechanism
R939 assembly type building sealant is cured by hydrolysis and dealcoholization of silane and moisture in the air and then condensation. It belongs to moisture absorption curing adhesive. Once the gel is unsealed, it absorbs the moisture in the air and solidifies from the surface to the deep layer, becoming an elastomer. The higher the temperature and humidity is, the faster the curing will be; the slower the curing will be in low temperature and low humidity environment. Chemical resistant medium
The products can be resistant to fresh water, sewage, waste water, calcium carbonate solution, detergent, low-grade acid, corrosive solution, mineral oil, vegetable oil, fat, fuel, organic solvent, paint thinner, etc. for a long time. usage method
1. The construction surface must be kept clean, dry and free of dirt; 2. Paste protective tape on both sides of the construction surface, use suitable liner materials in the joint filling, and pay attention to the embedding depth; 3. During the gluing, the construction surface must be coated with silane modified polyether glue matching special primer; 4. Cut the glue nozzle into the required size and shape according to the process requirements; 5. Cut the sealant seal and install the glue nozzle, Put it into the glue gun; 6. Evenly apply the sealant to the joint and finish the surface; 7. After the surface is dry, the product can be finished by traditional methods to remove the excess glue.
matters needing attention
Avoid construction under 5 ℃ and humidity less than 20%
When bonding cement and concrete base materials, the construction can only be carried out after the base materials are completely dry and cured for 7 days, otherwise the bonding performance will be affected; because the paint contains high solvent composition, the surface of the adhesive will become soft, in order to obtain the best appearance and performance, the adhesive will be colored and packaged 24 hours after curing
R939 adopts aluminum film: 600ml / piece, 20 pieces / box storage
The product must be stored in a low temperature (below 27 ℃) dry environment (less than 20% relative humidity), with a shelf life of 6 months.
Henan ruilangda New Material Co., Ltd. is invested and built by Zhengzhou Huayu Technology Co., Ltd. It is a high-tech enterprise specializing in the research, development, production and sales of adhesives.
The company continues to meet the needs of customers with high-quality products, reasonable prices, fast and thoughtful services, and common development with customers!
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