Flame retardant finishing refers to a processing technology that adds flame retardants to the surface or inside of materials such as textiles, wood, and plastics through physical or chemical methods to give the materials flame retardant properties. Its main purpose is to reduce the flammability of the material, so that the material is not easily ignited when it comes into contact with a fire source, or it can quickly self-extinguish after ignition, reducing the spread and spread of the flame. The development and application of flame retardant finishing tech1nology not only improves the safety of material use, but also provides important guarantees for fire safety in modern society. The following is a detailed introduction to the flame retardant finishing process:
1#Padding method:
Padding method is a widely used flame retardant finishing process. The basic principle of this process is to immerse the fabric in a solution containing a flame retardant, and then use a roller to press it so that the flame retardant is evenly attached to the fabric. The specific operation process is as follows: First, prepare a flame retardant solution of appropriate concentration according to the type of material and the required flame retardant properties. During the preparation process, factors such as the solubility, stability and compatibility of the flame retardant with other additives need to be considered. For example, for some poorly soluble flame retardants, it may be necessary to add appropriate solvents or dispersants to improve their dispersibility in the solution. Put the fabric to be finished into the flame retardant solution and immerse it for a certain period of time so that the fabric can fully absorb the solution. The length of the immersion time depends on factors such as the thickness of the fabric, the structure of the organization, and the penetration performance of the flame retardant. Generally speaking, thicker fabrics require a longer immersion time to ensure that the flame retardant can fully penetrate into the fabric. After the impregnation is completed, the fabric is pressed by a roller to remove excess solution so that the flame retardant content on the fabric meets the specified requirements (liquid carrying rate). The rolling pressure and rolling ratio are important parameters that affect the padding effect and need to be reasonably adjusted according to the characteristics of the fabric. The padding method has the advantages of simple operation, high production efficiency, and low cost, and is suitable for large-scale industrial production. However, this process also has some shortcomings, such as the poor durability of flame retardants on fabrics, and the flame retardant properties may decrease after repeated washing. In order to improve the durability of flame retardants, some post-treatment methods such as baking and cross-linking can be used to make the flame retardant react chemically with the fabric fibers to form a strong bond.
2#Coating method:
The coating method is to mix the flame retardant with a film-forming agent, a solvent, etc. to form a coating liquid, and then evenly coat the coating liquid on the surface of the material through a coating device to form a coating with flame retardant properties. The advantage of the coating method is that the thickness and performance of the coating can be adjusted as needed to obtain different degrees of flame retardant effects. At the same time, the coating can also give the material other functions, such as waterproof, anti-fouling, wear resistance, etc. In the coating method, the selection of suitable film-forming agents and flame retardants is the key. The film-forming agent should have good film-forming properties, adhesion and flexibility, and be able to form a continuous and uniform coating on the surface of the material. Common film-forming agents include acrylic resin, polyurethane resin, silicone resin, etc. The selection of flame retardants needs to be comprehensively considered according to the type of material and the requirements of use. For example, for some applications with high environmental protection requirements, halogen-free and low-toxic flame retardants should be selected. The operation process of the coating method includes the preparation of the coating liquid, coating construction and drying and curing. When preparing the coating liquid, the film former, flame retardant, solvent and other additives need to be mixed evenly in a certain proportion, and fully stirred and dispersed to ensure the stability and uniformity of the coating liquid. The coating can be applied by scraping, spraying, roller coating and other methods, and the appropriate construction method should be selected according to the shape and size of the material. Drying and curing is the last step of the coating method. By heating or natural drying, the solvent in the coating is evaporated, the film former is cured, and a firm coating is formed. The disadvantage of the coating method is that the coating will affect the feel and air permeability of the material, making the material less comfortable to wear. In addition, the friction resistance and washability of the coating also need to be improved. In order to improve these problems, the performance of the coating can be improved by optimizing the coating formula, improving the coating process and other methods.
3#Impregnation method:
The impregnation method is similar to the padding method. Both methods essentially use flame retardants to improve the flame retardant properties of materials, but they also have their own distinct characteristics and scope of application. The padding method focuses on impregnating the fabric in the flame retardant solution and then rolling it with a roller to achieve the adhesion of the flame retardant on the fabric. It is more suitable for flame retardant finishing of various fabrics. The impregnation method is mainly used to treat some porous materials, such as wood, foam plastics, etc. This process is to completely immerse the material in the flame retardant solution so that the flame retardant penetrates into the material to achieve the purpose of flame retardancy. The advantage of the impregnation method is that the flame retardant can penetrate deeply into the material and the flame retardant effect is long-lasting. During the impregnation process, key factors such as impregnation time, temperature and solution concentration need to be controlled.