Guangzhou Sen You Yi
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Key technology of producing magnesite fireproof door core
Editors:Sen You Yi  Time:2018-3-1

  Magnesite building fire protection board is mainly used for building ceiling, inner partition wall and other decoration parts with fire prevention requirements. At present, the MAGNESITE Building fireproofing board not only has the light, flexible and reprocessing properties of the wood organic plate, but also has the fireproof and water resistance of the inorganic sheet. At present, many magnesia building fireproofing boards have been used in decoration works in China.

  Over the years, the quality of the product is affected by the problems of moisture absorption and return halogen, warpage, sheet embrittlement and the common surface of the surface of the plate in the production of magnesite building fireproof sheet. Some boards only finish two days after finishing, the surface is very humid, and the three day surface is globule, making it difficult for the project to carry out the two decoration.

  Two measures are taken to solve the problems of moisture absorption and back halting of the fireproofing board of MAGNESITE Building: one is to reduce the free MgCl2 in the product as far as possible, to reduce it to a certain extent, and to lose the moisture absorption capacity of the product, which requires a good maintenance process under the premise of having a good formula. The two is to add high efficient anti tide back halogen admixture in the production process, which can form a thin film of hydrophobic water in the capillary hole wall, pore and cavity wall and the outer surface of products, which prevents the transmission of water in these parts and prevents the process of the product from absorbing tide and returning halogen.

  The main reason for the deformation of magnesite building fire retardant plate is its poor volume stability. Such products are generally large in size and small in thickness, resulting in large deformation values, which affect the quality of engineering construction. The main drawback in engineering is that the joints and the warping and bulging on the large surface occur.  There are many reasons for the deformation of magnesite building fire prevention plates. The most important thing is that the products are not well maintained and hardened during production.

  Magnesite cementation used in the production of magnesite building fireproof sheet is a kind of inorganic cementitious material. One of its characteristics is that it must have appropriate temperature and humidity and a certain hardening time after forming, so that it can be fully chemically reacted to give the products excellent physical, mechanical and durability.

  After molding, the products must be placed in suitable temperature, humidity and adequate maintenance time. On the other hand, the hardening process is not good, the amount of hardened products in the product is insufficient and the free MgO and MgCl2 exist in large quantities. In the process of using the plate, the internal chemical reaction of the plate will start again once the appropriate temperature and humidity are encountered. If the material is not well maintained, the volume stability will be very poor. There will be plenty of free moisture inside. When dry environment is encountered, it will cause shrinkage and internal stress.  These two internal stress destructive forces are very large and often cause engineering quality accidents.

  There are many reasons for the warpage of the fireproofing board of magnesite building, such as the lack of the raw material, the lack of good product formula, the poor selection of the modifier, the unreasonable process parameters and so on. As long as we master the causes of the above plate deformation and take corresponding measures, it is not difficult to overcome the defects of sheet metal warpage.

  The embrittlement of magnesite building fireproof sheet is that the sheet is produced in the short term with good toughness and can be rolled into the whole sheet, but after a long time it becomes very brittle and ninety percent off is broken. If it is fixed on the keel, in the hanging place, a hole will be broken with a sharp instrument, and the cross section of the sheet can not see the similar situation. There are two main reasons for the embrittlement defects: first, the high alkali fiber cloth is used in the plate production, that is, the clay crucible cloth. The reinforced material is quickly corroded in the alkaline environment of the magnesite cementing material and gradually loses strength, so the trace of the fireproofing board fiber of the MAGNESITE Building can not be seen in the plate section. The two reason is the embrittlement of magnesite building fire protection board due to improper formulation of plate production. The toughness of magnesite cementing material is incomparable with other materials in the category of inorganic cementitious materials, and toughness will obviously increase when toughening measures are adopted.