Countermeasures for the development of technical requirements for wooden fire doors, price of Class B wooden thermal insulation fire doors

The allowable deviations for the warpage of door frames and door leaves in the "Permissible Deviations for the Production of Wooden Fire-Proof Doors" are and respectively, while the allowable deviations for the flatness of the contact surface between the frame and the door in the "Permissible Deviations for the Installation of Wooden Fire-Proof Doors" are. If the warpage deviations of the door frame and the door leaf are respectively, the flatness deviation of the contact surface between the frame and the leaf after installation is greater than 1, which does not meet the requirements of the standard. Class B Wooden Insulated Fireproof Doors There may be gaps between them. During the fire door test, the furnace was under positive pressure. If there is a gap in a wooden fire door from the fire-facing surface to the back-fire surface, high-temperature gas or flames will quickly pass along the gap, and the wood around the gap will be carbonized and burned, and the gap will expand, eventually causing flames or flames to appear quickly on the back-fire surface of the fire door. The cotton pad is ignited, or the temperature of a single point on the unfired surface reaches ℃ plus room temperature. Therefore, the protection treatment of gaps has an important impact on the fire resistance performance of fire doors. Japan requires that high-temperature glue must be applied between the frame materials of wooden fireproof door leaves and between the frame material and the filling material. Inflatable fireproof sealing strips must be used between the frame material and the wrapping strips, and between the door leaves and the door frame. When domestic enterprises perform product type certification, they usually apply high-temperature glue between the door leaf frame materials, between the frame material and the filling material, and between the frame material and the wrapping strips. They also apply fire retardant paint or use intumescent fire retardant materials between the door leaves and the door frame. sealing strip. However, since applying high-temperature glue or using intumescent fireproof sealing strips has a great impact on production efficiency and increases production costs, some companies omit this process during actual production.
Product structure
Different from ordinary plywood doors, wooden fire door door leaf frame materials must be connected by tenon. However, the use of tenon structure requires many processing steps, difficult assembly, and high wood consumption per unit product. Therefore, some companies use the round bar tenon or saddle-stitch connection method of ordinary plywood doors in actual production.
The thermal insulation materials used inside wooden fire doors are usually high-density aluminum silicate fiber or rock wool fiber products, which have poor rigidity and strength and require the use of high-temperature adhesives and wire mesh for fixation. Applying high-temperature glue and fixing wire mesh have a great impact on production efficiency. Some companies omit this process in actual production.
Wooden fire doors are divided into eight types (from easy to difficult). When sampling for type identification, the most difficult specifications of each fire resistance grade (Class A, Class B, Class C) applied for by the enterprise are randomly selected. Individual individuals are selected. The company obtained a less difficult type of type certification, but expanded the production scope at will.
For glass-mounted fire doors, when the glass area exceeds a certain range, the temperature and heat radiation of the glass backside should be measured during the type inspection. Strength. Some companies use smaller area of glass during type certification, and do not need to test the temperature and thermal radiation intensity of the glass backside. During actual production, the glass is set according to the user's needs. Price of Class B Wooden Insulated Fire Doors
Fire Doors Accessories
Fire hinges, fire locks, door closers, sequencers, intumescent fire seals between door frames and door leaves and between double door leaves are important components of fire doors. The above accessories must also be It is a qualified product certified by the assessment center. In actual projects, considering factors such as decorative effect and cost, ordinary hinges, locks, and door closers are used at will, or door closers, sequencers, and inflatable fireproof seals are not used. phenomenon, especially the less use of sequencers, has seriously affected the fireproof and smoke isolation function of fire doors.
The consistency of type certification inspection technical documents and the actual condition of the test piece
According to the "Type Approval of Fire Protection Products According to the provisions of the "Implementation Rules for Fire Door Products", enterprises should provide the quality inspection center with structural diagrams (including door elevations, cross-sections, node diagrams) and material lists of wooden fire door products of each specification and fire resistance level inspected. etc. However, the quality inspection center cannot verify some technical details, such as whether the wood has been flame-retardant, the content of flame retardant, whether it is painted with transparent fire-retardant paint, the tree species and material of the door frame material, whether high-temperature glue is used, etc. These Some companies do not indicate or reduce the level of factors that have an important impact on the fire resistance limit of fire doors.
In actual production, some companies reduce the content of flame retardants in wood, or do not perform flame retardant treatment on wood at all. For some Enterprise surveys show that a common practice in production is to immerse the door leaf frame and door frame in a flame retardant solution for a few minutes after assembling them. Under normal temperatures and pressures, the flame retardant solution can only penetrate most of the doors within an hour. Within the range of the wood surface[], it has no obvious effect on improving the fire resistance limit of wood.
The burning carbonization speed and flame retardant treatment performance of wood of different tree species vary greatly. Some companies use Meranti during type certification testing. Wood of other tree species, but wood of any tree species can be used in production.
The filling material of fire doors generally uses aluminum silicate fiber or rock wool. The working temperature of aluminum silicate fiber is above ℃, and the working temperature of rock wool The temperature is lower than ℃. The fire resistance of aluminum silicate fiber is obviously better than that of rock wool, but the price is higher. Some companies use aluminum silicate fiber as the filling material of door leaves during type certification testing, but use rock wool as the filling material during production. Filling materials.
Factory certification and product review
The technical strength of my country’s wooden fire door manufacturers varies greatly. Only a few companies have relatively advanced and complete production technology equipment and corresponding technical capabilities. Most of them have relatively advanced and complete production technology equipment and corresponding technical capabilities. Some enterprises can meet the basic production conditions, but the production equipment is relatively outdated, and some enterprises have poor production equipment and technical capabilities.
Due to the differences in economic and social levels in various places, there is a very large gap in the equipment and production technology level of companies that have obtained production and sales licenses for wooden fire doors. The lower the level of equipment and production technology, the lower the cost of the product, but it is in a favorable position in market competition.
In addition, the sample base for type certification testing is not less than Tang, and in some places the sample base is even reduced. The type certification test pieces of some companies are specially made test pieces and cannot reflect the actual production status of the product.
Market Access
Although the production and sales licenses for fire door products are uniformly issued by the assessment center, most areas have set restrictions on the entry of products from other provinces and cities. In order to enter foreign markets, some larger companies have no choice but to set up local branches. At present, wooden fire door products are basically produced locally and sold locally. This kind of local protectionism has affected the technological progress of wooden fire doors, protected backwardness, and resulted in no significant progress in the overall technical level of the industry.
The unstandardized market environment has caused counterfeit and shoddy products to flood the market, seriously damaging the legitimate rights and interests of legal production companies and restricting the normal development of fire door production companies.
Most of the domestic fire door manufacturers are small and medium-sized enterprises with large numbers and small scales. They often adopt separate and decentralized operations, with low corporate visibility and high operating costs. There is no professional market for fire protection products. The use and design departments have little room for product selection, and it is difficult to communicate information between supply and demand. Price of Class B wooden thermal insulation fire doors
If you have any questions about fire doors, we will try our best to answer them for you. For more details, please visit the official website of Shenzhen Tongxiao Industrial Co., Ltd. or consult the relevant staff