Polyurethane insulation pipe stability and safety Polyurethane insulation pipe with a high-pressure foaming machine in the steel pipe formed in the outer jacket between the one-time injection of rigid polyurethane foam liquid from. That is commonly known as "tube tube foaming process." One of its functions is waterproof, the other is thermal insulation, and the third is to support the heat network. When the medium temperature is: -50 °C -120 °C, use rigid polyurethane foam insulation layer.
Polyurethane insulation pipe consists of core pipe (work pipe) rent-reducing layer, heat insulation layer, reflective layer, fastening steel strip, sliding bracket, air layer, outer protection steel pipe, sprayed polyurethane, and winding glass steel. With the characteristics of high strength, non-destructive and able to withstand a large upper load, in order to achieve long life, the steel casing needs to be treated with anti-corrosion.
The polyurethane insulation pipe has a reasonable structure design, low rolling friction force, and reduced bearing force on the fixed bearing. The mechanical analysis principle is simple, and the stability and safety of the pipe are greatly improved. Solved the problem that every 50-60m of air layer structure exists, a pair of row tide tube must be installed, which greatly reduces the rate of damage to the outer casing and makes the pipeline more beautiful along the line. At the same time, the increased cost of about 50/m due to the setting of the tide tube is reduced.
Some applications of polymer cement waterproof coating misunderstanding polymer cement waterproof coating (JS waterproof coating for short), with its good physical properties, simple construction methods and can be constructed on the wet grass, etc., has been rapidly since the end of the last century to the beginning of this century The development and application of a wide range of applications. However, in recent years, this type of product has caused a great number of quality problems, left a very bad impression for many construction units and management departments, and began to be skeptical. New products are faced with poor quality eliminated products in less than a decade. The embarrassing situation is regrettable. The reason is that apart from the market's intention of sacrificing the quality and supervision of the construction process, the low-price competition manufacturers have not been able to let slips of work and materials, and it is also related to the improper application of this product and many industry insiders' misconceptions about the product.
1. Misunderstanding of latex selection and ingredient ratio Mistakes The basic principle of JS waterproof coating is inorganic cementitious material with cement and quartz sand as the main ingredients. The formed coating film is basically maintained. Based on the high strength and strong water resistance properties of the cementitious material, its flexibility (ie, elongation) is maximized. At the same time, polymer latex also brings a negative effect, namely the decrease of hardness and the weakening of long-term water resistance and old-age performance. The negative effect size is closely related to the type and amount of latex used (ie, the modification ability of latex). There are two main types of latex used in JS coatings on the market: polyacrylate latex and polyethylene-vinyl acetate latex. The former has better modification ability than the latter, and the former with the same performance is also significantly less than the latter, and its negative effect is also significantly less than the latter. However, most people mistakenly believe that JS paint should be used as much as possible. The amount of latex should be greater than the price of the same product.
Therefore, in order to show that the amount of latex used in their products is large, some manufacturers or merchants mix the purchased latex raw materials and then formulate JS coatings. The quality of the products is far from the real JS coatings. What is more, some construction teams are After low-cost contracted waterproof projects, the use of commercially available polyvinyl acetate latex (commonly known as white latex) or polyvinyl alcohol glue (commonly known as 107 glue) after the construction of mixed, the consequences can not be described, seriously damaged JS coatings, Less than 10% of polyacrylic latex is really used, which is the main reason why JS paint slides into the ranks of “bad†products.
2, lack of understanding of the use of classification JS waterproof coating elongation and the amount of latex is directly related to the size, but the size of latex directly affects the long-term water resistance of the coating, in order to resolve this conflict, engineering specifications and product standards The technical treatment is to divide the JS paint into two types. The type I is a large amount of latex, and the elongation requirement is more than 200%. It is used for intermittently immersed engineering parts (such as roof, exterior wall, etc.) to meet Deformation requirements. Type II uses slightly less latex and has an elongation as high as 80% to meet engineering sites (basements, toilets, etc.) that are less deformable but have long-term water resistance requirements. However, in many projects, there is no distinction between the use of the basement and There is a type of roofing. Type I or Type II not only fails to achieve the desired effect, but also has a number of quality risks. It is disappointing.
3. The relationship between the coating thickness and the number of construction passes Even the waterproof coating must have a certain coating thickness as a quality guarantee. In the Technical Specifications for Roof Engineering and Technical Specifications for Underground Engineering, the basic thickness of JS coating The requirement is 1.5 ~ 2.0mm. In the actual project design and construction monitoring often only pay attention to the number of construction times but ignore the final thickness of the coating checks, often see some design drawings only indicate "with JS waterproof coating a few coats of cloth" It does not specify thickness requirements. Site management also only cares about painting several times. For some lack of integrity of the construction team drill hole, add water to dilute the paint, the design requirements painted one or two times also get the praise of on-site management personnel, in the low-cost contract to the project can also make a lot of profit , The product with excellent performance can't stand such damage.
4. Ignoring the importance of on-site mixing to the film performance JS coating is a two-component product. It is actually the last process of product production—mixing and phase separation. It is left to the on-site construction team to complete. It is not known that the phase separation of two-component products is critical to the formation of coating performance. In addition, the two-component JS coating is not as easy as the two-component liquid-liquid two-component products. The manufacturer's product manuals have explained the correct method of on-site mixing, but many of the construction team mixing process is perfunctory, and some even do not have a dedicated stirrer, on-site to find a stick to manually stir and stir. A very small number of people know the judgment and mastery of the “phase end pointâ€, and the performance of the final molded film is greatly compromised because of incomplete mixing and phase separation.
5, the misunderstanding of the tensile strength JS coating product standards in the film tensile strength requirements are respectively I type ≥ 1.2MPa, II type ≥ 1.8MPa, many people mistakenly believe that the higher the tensile strength, the better, In fact, JS coating tensile properties test method, there is a standard curing 7 days after the heat curing process of 50 °C 24h, many coating products in the heat curing process at 50 °C due to plasticizer volatile migration and stretching The rapid increase in strength indicates that the performance of heat aging of these products during exposure is very rapid and their service life is not long. Therefore, products with abnormally high tensile strength should be vigilant. If necessary, heat aging retention test can be done. Rather than unilaterally thinking that the higher the tensile strength, the better.
6. Feel free to set the position of the foundation in some of the details of the joints of the project in order to avoid the concentration of the tire base layer to extend the dispersion stress and reduce the cracking of the coating. Therefore, the position of the tire base directly affects the use effect. It should be that the closer the tread base is to the base layer, the more it can achieve the effect of decentralized stress. Actually, many projects randomly set the position of the tire base uninterested to set it in the middle of the coating. In some projects, the foundation is laid on the surface of the coating. I once found this phenomenon at a construction site and asked why the construction personnel exposed the foundation to the surface. The co-workers answered: “The money that the contractor will use to settle the child’s foundation†is ridiculous.
7, one-sided understanding "can be in the wet base construction."
JS waterproof coating is characterized by being able to construct on moist base layer compared to other waterproof coatings. There is a problem of moisture level. It does not mean that any wet climatic conditions or very high basic moisture content can be applied because JS coating latex Is cured by volatilization, too high base layer moisture content and too humid climate conditions on the latex curing film is unfavorable, will reduce the coating film elongation. At the same time, the cement in JS coating is cured by hydration. The base layer and weather conditions that are too dry are not good for cement curing. Therefore, during the hot dry season, some water should be sprayed on the base layer before construction. In fact, JS coatings still have some requirements for the temperature and humidity range of the construction. Generally, the humidity is between 5°C and 35°C, and the humidity is between 50% and 70%. It is suitable for construction regardless of temperature and humidity conditions, although it can also form films. However, the performance of coating film is far away.
8. Misunderstandings of the water mix can be added Most manufacturers in their product descriptions indicate that during the first pass of the brushing process, water can be added to dilute the paint to improve the penetration of the substrate and increase the adhesion to the substrate. Therefore, many people misunderstood that JS coating is free to add water, which is very harmful. The two components in JS coating—the ratio of polymer to cement (polymer to cement ratio) and the ratio of water to cement (water and cement The ratio is determined by the manufacturer through multiple tests. Any change in one of the components is more significant than the effect on the performance of the coating. The phenomenon of increasing the amount of powder and then adding water to adjust the consistency is common in practical projects. In fact, many projects are using the name of JS coatings to steal materials. If so, the future of JS coatings will continue.
Polyurethane insulation pipe consists of core pipe (work pipe) rent-reducing layer, heat insulation layer, reflective layer, fastening steel strip, sliding bracket, air layer, outer protection steel pipe, sprayed polyurethane, and winding glass steel. With the characteristics of high strength, non-destructive and able to withstand a large upper load, in order to achieve long life, the steel casing needs to be treated with anti-corrosion.
The polyurethane insulation pipe has a reasonable structure design, low rolling friction force, and reduced bearing force on the fixed bearing. The mechanical analysis principle is simple, and the stability and safety of the pipe are greatly improved. Solved the problem that every 50-60m of air layer structure exists, a pair of row tide tube must be installed, which greatly reduces the rate of damage to the outer casing and makes the pipeline more beautiful along the line. At the same time, the increased cost of about 50/m due to the setting of the tide tube is reduced.
Some applications of polymer cement waterproof coating misunderstanding polymer cement waterproof coating (JS waterproof coating for short), with its good physical properties, simple construction methods and can be constructed on the wet grass, etc., has been rapidly since the end of the last century to the beginning of this century The development and application of a wide range of applications. However, in recent years, this type of product has caused a great number of quality problems, left a very bad impression for many construction units and management departments, and began to be skeptical. New products are faced with poor quality eliminated products in less than a decade. The embarrassing situation is regrettable. The reason is that apart from the market's intention of sacrificing the quality and supervision of the construction process, the low-price competition manufacturers have not been able to let slips of work and materials, and it is also related to the improper application of this product and many industry insiders' misconceptions about the product.
1. Misunderstanding of latex selection and ingredient ratio Mistakes The basic principle of JS waterproof coating is inorganic cementitious material with cement and quartz sand as the main ingredients. The formed coating film is basically maintained. Based on the high strength and strong water resistance properties of the cementitious material, its flexibility (ie, elongation) is maximized. At the same time, polymer latex also brings a negative effect, namely the decrease of hardness and the weakening of long-term water resistance and old-age performance. The negative effect size is closely related to the type and amount of latex used (ie, the modification ability of latex). There are two main types of latex used in JS coatings on the market: polyacrylate latex and polyethylene-vinyl acetate latex. The former has better modification ability than the latter, and the former with the same performance is also significantly less than the latter, and its negative effect is also significantly less than the latter. However, most people mistakenly believe that JS paint should be used as much as possible. The amount of latex should be greater than the price of the same product.
Therefore, in order to show that the amount of latex used in their products is large, some manufacturers or merchants mix the purchased latex raw materials and then formulate JS coatings. The quality of the products is far from the real JS coatings. What is more, some construction teams are After low-cost contracted waterproof projects, the use of commercially available polyvinyl acetate latex (commonly known as white latex) or polyvinyl alcohol glue (commonly known as 107 glue) after the construction of mixed, the consequences can not be described, seriously damaged JS coatings, Less than 10% of polyacrylic latex is really used, which is the main reason why JS paint slides into the ranks of “bad†products.
2, lack of understanding of the use of classification JS waterproof coating elongation and the amount of latex is directly related to the size, but the size of latex directly affects the long-term water resistance of the coating, in order to resolve this conflict, engineering specifications and product standards The technical treatment is to divide the JS paint into two types. The type I is a large amount of latex, and the elongation requirement is more than 200%. It is used for intermittently immersed engineering parts (such as roof, exterior wall, etc.) to meet Deformation requirements. Type II uses slightly less latex and has an elongation as high as 80% to meet engineering sites (basements, toilets, etc.) that are less deformable but have long-term water resistance requirements. However, in many projects, there is no distinction between the use of the basement and There is a type of roofing. Type I or Type II not only fails to achieve the desired effect, but also has a number of quality risks. It is disappointing.
3. The relationship between the coating thickness and the number of construction passes Even the waterproof coating must have a certain coating thickness as a quality guarantee. In the Technical Specifications for Roof Engineering and Technical Specifications for Underground Engineering, the basic thickness of JS coating The requirement is 1.5 ~ 2.0mm. In the actual project design and construction monitoring often only pay attention to the number of construction times but ignore the final thickness of the coating checks, often see some design drawings only indicate "with JS waterproof coating a few coats of cloth" It does not specify thickness requirements. Site management also only cares about painting several times. For some lack of integrity of the construction team drill hole, add water to dilute the paint, the design requirements painted one or two times also get the praise of on-site management personnel, in the low-cost contract to the project can also make a lot of profit , The product with excellent performance can't stand such damage.
4. Ignoring the importance of on-site mixing to the film performance JS coating is a two-component product. It is actually the last process of product production—mixing and phase separation. It is left to the on-site construction team to complete. It is not known that the phase separation of two-component products is critical to the formation of coating performance. In addition, the two-component JS coating is not as easy as the two-component liquid-liquid two-component products. The manufacturer's product manuals have explained the correct method of on-site mixing, but many of the construction team mixing process is perfunctory, and some even do not have a dedicated stirrer, on-site to find a stick to manually stir and stir. A very small number of people know the judgment and mastery of the “phase end pointâ€, and the performance of the final molded film is greatly compromised because of incomplete mixing and phase separation.
5, the misunderstanding of the tensile strength JS coating product standards in the film tensile strength requirements are respectively I type ≥ 1.2MPa, II type ≥ 1.8MPa, many people mistakenly believe that the higher the tensile strength, the better, In fact, JS coating tensile properties test method, there is a standard curing 7 days after the heat curing process of 50 °C 24h, many coating products in the heat curing process at 50 °C due to plasticizer volatile migration and stretching The rapid increase in strength indicates that the performance of heat aging of these products during exposure is very rapid and their service life is not long. Therefore, products with abnormally high tensile strength should be vigilant. If necessary, heat aging retention test can be done. Rather than unilaterally thinking that the higher the tensile strength, the better.
6. Feel free to set the position of the foundation in some of the details of the joints of the project in order to avoid the concentration of the tire base layer to extend the dispersion stress and reduce the cracking of the coating. Therefore, the position of the tire base directly affects the use effect. It should be that the closer the tread base is to the base layer, the more it can achieve the effect of decentralized stress. Actually, many projects randomly set the position of the tire base uninterested to set it in the middle of the coating. In some projects, the foundation is laid on the surface of the coating. I once found this phenomenon at a construction site and asked why the construction personnel exposed the foundation to the surface. The co-workers answered: “The money that the contractor will use to settle the child’s foundation†is ridiculous.
7, one-sided understanding "can be in the wet base construction."
JS waterproof coating is characterized by being able to construct on moist base layer compared to other waterproof coatings. There is a problem of moisture level. It does not mean that any wet climatic conditions or very high basic moisture content can be applied because JS coating latex Is cured by volatilization, too high base layer moisture content and too humid climate conditions on the latex curing film is unfavorable, will reduce the coating film elongation. At the same time, the cement in JS coating is cured by hydration. The base layer and weather conditions that are too dry are not good for cement curing. Therefore, during the hot dry season, some water should be sprayed on the base layer before construction. In fact, JS coatings still have some requirements for the temperature and humidity range of the construction. Generally, the humidity is between 5°C and 35°C, and the humidity is between 50% and 70%. It is suitable for construction regardless of temperature and humidity conditions, although it can also form films. However, the performance of coating film is far away.
8. Misunderstandings of the water mix can be added Most manufacturers in their product descriptions indicate that during the first pass of the brushing process, water can be added to dilute the paint to improve the penetration of the substrate and increase the adhesion to the substrate. Therefore, many people misunderstood that JS coating is free to add water, which is very harmful. The two components in JS coating—the ratio of polymer to cement (polymer to cement ratio) and the ratio of water to cement (water and cement The ratio is determined by the manufacturer through multiple tests. Any change in one of the components is more significant than the effect on the performance of the coating. The phenomenon of increasing the amount of powder and then adding water to adjust the consistency is common in practical projects. In fact, many projects are using the name of JS coatings to steal materials. If so, the future of JS coatings will continue.
Metal Wire,Fence,Wire Mesh Co., Ltd. , http://www.nsmeshmetals.com