Problems needing attention in the production of chicken coop insulation board-development and hidden worries-Jinan Mingjue Jiatu magnesite technology network.

Inorganic glass fiber reinforced plastic thermal insulation chicken coop is a new building material product in rural poultry breeding industry in recent years. The product is made of flame retardant EPS as sandwich insulation material, magnesite cement as base material, and necessary inorganic fillers and modified materials. This product makes full use of the advantages of magnesite cement, such as high strength, easy combination with organic matter, heat insulation and sound insulation, and is prefabricated in the factory and constructed on site. It is an organic combination of traditional magnesite products and new thermal insulation materials, and an ideal substitute for traditional chicken coops. As early as 2004, inorganic glass fiber reinforced plastic thermal insulation chicken coops began to be widely promoted in Langfang, Cangzhou and other places in Hebei Province, and are now being rapidly promoted and applied in China. Because of the low bulk density of foam board and the light weight of inorganic FRP insulation board, it also brings problems to the long-distance sales of products: the long-distance transportation cost is high, that is, the products have a certain "sales radius" Therefore, the project is more suitable for local production and has achieved "localization". At present, a large number of insulation board manufacturers have emerged in Henan, Inner Mongolia, Liaoning, Shandong and other places. Through long-term investigation and tracking, it is found that many manufacturers adopt extensive production methods and don't talk about scientific proportion at all. The product quality is uneven and the prospect is worrying. Here, combined with the current production status of some manufacturers, the author tells you some problems that are often encountered in production and should be paid enough attention to, hoping to attract enough attention to avoid the project falling into the vicious circle of "magnesite strange circle" again. First, the quality of raw materials must be strictly controlled. At present, most producers do not have an objective and correct understanding of the quality of raw materials they use, and believe the so-called paper test report provided by some manufacturers! Good raw materials are the premise of producing qualified products. If this level is not handled well, it will be very difficult to make qualified products! Among them, the important concepts such as the active content of magnesium oxide, the salt content of magnesium chloride and the alkali content of glass fiber cloth must be clear, and the basic detection methods should also be mastered. At present, in Wen 'an and other places in Hebei Province, due to fierce market competition, peers are pushing down prices, which leads to a considerable number of manufacturers cutting corners and even purchasing bitter clay powder as cementing material, brine waste liquid discharged from saltworks as blending agent, and high-alkali cloth pulled out of casserole as reinforcing material. The protective layer of the produced insulation board is less than 2mm! It is absolutely unacceptable to focus only on immediate interests and turn a deaf ear to the internal quality of products! Second, the proportion of raw materials should be adjusted in time. Now many manufacturers are extensive production, and they don't pay attention to any proportion at all. Simply mix magnesium oxide with salt water, make a suitable slurry (add salt water when it is thick, and add powder when it is thin), and then spread cloth on the surface of foam board to make insulation board. This method can not guarantee the quality of products, and the production cost is relatively high (high molar ratio). Good technology must be based on the maximization of product cost performance, that is, making the best products at the lowest cost! Usually, we don't recommend this kind of "thin material making". We should choose some suitable inorganic or organic fillers according to local conditions, which can not only reduce the cost, but also improve the product performance to some extent. Because magnesium oxide is easy to react with water vapor in the air, resulting in reduced activity, and the temperature and humidity conditions in the production environment are also changing, and the formula in the production process is not static, so the Baume degree of brine and the ratio of various raw materials should be adjusted according to the actual situation. Many manufacturers prescribe a prescription all the year round, which is unscientific and undesirable. Three: Modification is very important. Magnesite cement is a ternary reaction system, namely MgO, MgCl 2 and H 2 O, and the main products are Mg(OH) 2, 5 mg (OH) 2 MgCl2 8H2O (5.1.8 phase). The crystal morphology is needle-like structure, which is formed by overlapping each other. This structure is not compact and stable enough, so the modification of magnesite products can not be ignored. By adding magnesite modifier, the curing time and exothermic rate of the slurry can be effectively controlled, the crystal structure can be optimized, and the chemical stability can be improved, thus fundamentally improving the weather resistance of the product and prolonging the service life. The GX-ⅲ series magnesium modifiers produced by our company are complete in variety and stable in performance, and can be selected and used according to actual needs. For details, please refer to the article "Detailed explanation of performance of GX-Ⅲ series magnesia modifier", which will not be repeated here. At present, some insulation board manufacturers use simple chemical materials for modification, such as ferrous sulfate heptahydrate, alum, trisodium phosphate, oxalic acid, urea-formaldehyde resin, ferric chloride and sodium hexametaphosphate. These small chemical materials have a certain modification effect, and the principle of modification is mainly "plugging". Due to the high content of impurities and impurity ions in industrial chemical raw materials, such as SO 4 2-, Na+, K+, etc. The modification effect is often not thorough enough, and the introduced impurity ions increase the probability of product moisture absorption and halogen return. This backward modification technology should be eliminated. Four: Process issues can not be ignored. The process in the production process is divided into three parts: batching process, molding process and maintenance process. There are many details in the production process, many of which are directly related to the quality of products. The process details are easily overlooked by most manufacturers at present. For example, in the batching process, raw materials are added in sequence, which requires stirring time. What to add first, then what to add, and how long to stir have their own internal reasons. How much bottom material is laid in the molding process, where the glass fiber cloth is laid, and so on. These are all certain. Here I mainly emphasize maintenance technology. The third part mentioned that the solidification of magnesite cement is a ternary system reaction process, in which water is needed, and the reaction is accompanied by a long and massive exothermic process. This reaction takes some time to complete, and the length of time is related to the temperature of the reaction environment. Therefore, a curing environment with heat preservation and moisture preservation is needed to ensure the sufficient degree of curing reaction. The solidification of magnesite cement releases high heat, which is about 1000~ 1350J/gMgO. The heat release rate is very fast, and the highest central temperature of the reaction system can reach 150℃! The hydration heat of ordinary portland cement is only 300~400J/g, which shows that the hydration heat of magnesite cement is 3~4 times that of ordinary cement. From the above data, it can be seen that the exothermic process of magnesite cement curing must be strictly controlled, especially in high temperature production in summer. In order to save production space, some manufacturers usually finish a board, and then use this board as an operating platform to make 4~6 more sheets on it. As we all know, the thermal conductivity of foam materials is very poor, and the curing of magnesite cement is a rapid and highly exothermic process, so the foam board is often burned out due to excessive heat release in production, that is, the phenomenon of "burning board" and "hollowing out" appears. Friends who use anhydrous magnesium chloride should pay more attention! Some manufacturers directly produce in the open air, and the products after demoulding are directly exposed to the sun in the open air, which leads to water shortage and the reaction is interrupted. The manufactured products are low in strength, fragile, and generally have the phenomena of back-halogen, frosting and surface cracking. These practices are all wrong. Therefore, there must be a maintenance environment that can keep warm and moisturize in production! As can be seen from the above, in order to produce fully qualified products, there are four elements to be mastered: quality control of raw materials is the premise, dynamic ratio adjustment is the key, modification technology is the core, and production technology cannot be ignored! At present, extensive production of most manufacturers is difficult to ensure product quality. After a long period of investigation and interview, it was found that more than half of the products on the market failed the halogen return test. Under the combined and alternating action of water and carbon dioxide in the atmosphere, the surface of the product will be powdered, exposed and cracked after 2~3 years, and its performance will gradually lose, not to mention the minimum service life promised by the manufacturer 15 years! Inorganic FRP products have a very confusing temporary illusion: no matter how they are produced, the products have good strength and toughness. Producers often only pay attention to these physical properties of products, thinking that production is successful and there are no technical problems. In fact, they ignored the fact that inorganic FRP materials belong to chemical building materials, and the chemical stability inside the products is the most critical quality factor! I would like to remind friends who are ready to get on the horse to pay enough attention to avoid blind investment and harm others! For details, please visit "Jinan MG Jiatu Magnesite Technology Network"