Fire retardant treatment of wood fire door

Wood fire door fire retardant quality to the fireresistance wood fire doors, fire doors and many production enterprises will be set up for the special process of the process control in the process of production, but due to the lack of mature technology for the flame retardant process, resulting in the various manufacturers of different flame retardant technology, flame retardant technology is not reasonable and not to ensure the quality of the flame retardant, leading to severe fire door fire resistance reduced, causing potential risks to the safety of people's lives and property. The company as our province's first wooden fire door production enterprises in the production process of more than 10 years, and gradually find out a relatively mature technology of flame retardant, are summarized as follows, with brother manufacturers technical discussion, and ask professionals to give criticism.

The common flame retardant methods for wood are: spraying, soaking, cooking, vacuum and vacuum pressure. Spraying and soaking are generally applied to wood surface which is no longer planed, and the thin plate is less than 10mm, which is not suitable for the production of wooden fire doors. Although the effect of the vacuum and vacuum pressure method is very good, but because of its expensive equipment, it has not been used in the production enterprises of the fire door in our province. At present, most of the fire door enterprises in our province use the cooking method to carry out the flame retardant treatment. In the author's opinion, the following points should be paid attention to in the use of cooking method for flame retardant treatment.

1, the fire-retardant wood is also dry and wet

The moisture content of fire-retardant wood is an important factor affecting the quality of wood flame retardancy. As dry wood enters the flame-retardant pool, it is easier to absorb flame retardant liquids, while the amount of wood absorbed by flame retardant wood directly affects the flame retardant quality of wood, and its absorption is directly proportional to the oxygen index and the flame retardant depth of fire-retardant wood. The more fire-retardant liquid is absorbed by wood, the better the flame retardancy of wood, the higher the oxygen index and the deeper the depth of the flame retardant. However, many enterprises believe that wood is also soaked in flame retardant when it is flame-retardant. In fact, wood moisture content is not much related to high point and low point. The wood for fire retardant is generally not dried, and some enterprises even fire the wet square wood just sawed. It is not known that the moisture content of wood will affect the quality of flame retardancy, and the flame retardancy of fire-retardant wood is unstable. According to the test, under the same flame-retardant condition, the wood with a moisture content of less than 15% can raise 5 oxygen index above that of the wood whose moisture content is higher than 40%, and the flame retardant depth is increased by more than 3mm.

2, water and wood after the first flame retardant

In the process of flame retardancy, most manufacturers adopt the order of loading wood, adding flame retardants, adding water and starting fire retardant. General wood is the beginning of the largest amount of water, the process is often caused by the concentration of wood began to absorb flame retardant liquid is extremely low, so in the process of wood fire retardant, also need a wood make the absorption of flame retardant liquid concentration from low concentration to normal concentrations of excessive process, directly affect the wood dry salt the absorption amount and absorption rate, and then the flame retardant effect. With the addition of flame retardant, water, wood and flame, the wood initially absorbs the standard concentration of the flame-retardant liquid, thereby avoiding the process of absorbing wood from the low concentration to the normal concentration, and improving the flame retardant quality. If the enterprise has the conditions, the flame retardant can first be prepared into a prescribed concentration of flame retardants and then added to the flame retardant pool, and the quality of the flame retardant will be better.

3, flame-retardant to reduce the evaporation rate of flame retardants

In our normal flame-retardant process, the process of heating and cooking is usually open, resulting in the evaporation of flame retardants. Too often, a flame retardant process needs continuous adding water to the flame-retardant tank. The flame-retardant liquid absorbed from wood can be dissolved from high concentration to low concentration, then absorbed to high concentration, and then dissolved to low concentration, thus reducing the dry salt content absorbed by wood. But if used with flame retardant, the flame retardant can avoid adding water in the process, second can ensure that the flame retardant pool fire retardant liquid concentration is not fluctuated, but also can save energy third. If the water is not avoided, a good flame retardant should be added to ensure the constant concentration of the flame retardants in the flame retardant pool.

4. Discharging at normal temperature

Many fire door manufacturers often use time as the standard of flame retardancy in the process of wood flame retardancy, and achieve the required time according to the operation rules. So in the process of operation due to the too hot for the labor protection of workers, more importantly, in the process of wood by hot cool, inside the wood cell due to thermal expansion and contraction produce certain negative pressure, flame retardant wood further absorption of flame retardant liquid under the action of negative pressure, so as to improve the quality of fire retardant treatment.

In general, technical conditions in the same fixture, using this technology can significantly improve the quality of flame retardant, flame retardant depth of wood can be improved from 6-8mm to more than 10mm, the oxygen index of samples from the wood surface at 6mm increased from 30 to more than 40, the processing technology can meet the requirements of the wooden fire door.