Coating knowledge: eight Application Mistakes of polyurethane waterproof coating

Core tip: polyurethane waterproof coating (JS polymer waterproof coating for short) has been rapidly developed and widely applied from the end of last century to the beginning of this century due to its good physical properties, simple construction method and construction on wet base However, in recent years, this kind of product has appeared a great potential quality hazard, which left a very bad impression on many construction units and management departments and began to hold a skeptical attitude Less than ten years after the new product came out, it has been faced with the awkward situation of being accompanied by the inferior eliminated products, which is regrettable The reason is that in addition to the low price competition in the market, the manufacturer intentionally sacrifices the quality and does not supervise the construction process Let go of work and materials Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Home of coatings: polyurethane waterproof coating (JS polymer waterproof coating for short), with its good physical properties, simple construction method and construction on wet base, has been rapidly developed and widely applied from the end of last century to the beginning of this century However, in recent years, this kind of product has appeared a great potential quality hazard, which left a very bad impression on many construction units and management departments and began to hold a skeptical attitude Less than ten years after the new product came out, it has been faced with the awkward situation of being accompanied by the inferior eliminated products, which is regrettable The reason is that in addition to the low price competition in the market, the manufacturer intentionally sacrifices the quality and does not supervise the construction process In addition to the excessive use of work and materials, it is also related to the improper application of this product and many people in the industry have misunderstandings about this product 1 The basic principle of JS waterproof coating is to modify inorganic cementitious materials with cement and quartz sand as the main components by synthetic polymer latex The film formed by JS waterproof coating keeps the characteristics of high strength and strong water resistance of cement cementitious materials and improves its flexibility (i.e elongation) as much as possible At the same time, the polymer latex also brings about negative effects, that is, the decrease of hardness and the decrease of long-term water resistance and aging resistance The size of the negative effects is closely related to the type and dosage of the latex used (that is, the modification ability of the latex) At present, there are two main types of latex used in JS coating on the market: polyacrylate latex and polyethylene vinyl acetate latex The modification ability of the former is better than that of the latter, and the amount of the former to achieve the same performance is significantly less than the latter, and its negative effect is also significantly less than the latter However, most people mistakenly think that JS coating should be based on the greater the amount of latex, the better When choosing products from different manufacturers, the same price should be taken as the criterion to compare which factory has the larger amount of latex Therefore, in order to show the large amount of latex, some manufacturers or businesses mix the purchased latex raw materials with water to prepare JS coating The product quality is far from the real JS coating What's more, some construction teams use the commercially available polyvinyl acetate latex (commonly known as white latex) or polyvinyl alcohol glue after contracting the waterproof project at a low price (commonly known as 107 glue) mixed construction, its consequences can not be described, seriously damaged the reputation of JS coating At present, less than 10% of JS coatings used in construction projects actually use polyacrylic latex, which is the main reason why JS coatings have slipped into the ranks of "inferior" products 2 Insufficient understanding of classification and use The elongation of JS waterproof coating is directly related to the amount of latex, but the amount of latex directly affects the long-term water resistance of the coating In order to solve this contradiction, the technical treatment of engineering specifications and product standards is to divide JS coating into two types, type I is the large amount of latex, and the elongation is required to reach more than 200%, which is used for engineering parts with intermittent immersion (such as To meet the requirements of large deformation Type II is the engineering part (basement, toilet and bath room, etc.) with a small amount of latex and a elongation of only 80% to meet the requirements of long-term water resistance, but it is not used separately in many projects From basement to roof, one type is used Type I or type II not only fails to achieve the expected effect, but also has many potential quality problems, which is disappointing 3 The relationship between the coating thickness and the construction times no matter how good the waterproof coating is, it must have a certain coating thickness as the quality assurance In the roof engineering technical specifications and underground engineering waterproof technical specifications, the basic thickness of JS coating is required to be 1.5-2.0mm However, in the actual engineering design and construction monitoring, we often only pay attention to the construction times but ignore the final thickness of the coating We often see that some design drawings only indicate "several coats of JS waterproof coating" but not the thickness requirements The site management only cares about painting several times To some lack of integrity of the construction team to drill a hole, the coating water diluted, than the design requirements for one or two times more than the approval of the site management personnel, after contracting to the project at a low price can earn a lot of profits, no matter how excellent the performance of the product can not withstand such damage 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,