In recent years, flame retardant technology in textiles has made significant advancements, effectively reducing the frequency of fire incidents in places where flame retardant textiles are used.
It has been proven that the use of materials and products with flame retardant properties can greatly reduce the occurrence of fire accidents, lower personal injuries and fatalities. The application of flame retardant fabrics is one of the most effective fire protection measures.
Flame retardant finishing method for textiles
Flame retardant finishing of textiles refers to the process in which flame retardants are physically (adsorption, deposition, bonding) or chemically (chemical bonding) applied to fabrics. Textiles treated with flame retardants cannot be ignited by an open flame, exhibit reduced flame propagation speed, decreased combustion performance, do not continue to burn after removing the ignition source, have shortened smoldering time or no smoldering, and release lower total heat during the combustion process, forming a thicker char layer.
Based on the method of introducing flame retardants into the fabric, the manufacturing methods of flame retardant textiles can be categorized as follows:
1. Coating method
Flame retardants are added to coating adhesives, which are then applied to fabrics using a scraper or other tools. The flame retardants are bonded to the fabric through the adhesive properties of the resin, achieving flame retardant effects. The choice of coating adhesives is selective, requiring the flame retardants to exhibit excellent flame retardant performance without affecting the basic properties of the coating adhesive.
2. Impregnation method
It refers to the process of immersing the fabric in a solution containing a proportional amount of flame retardant, followed by dehydration and drying at a certain temperature. The advantage of the impregnation method is that it ensures uniform distribution of the flame retardant on the fabric.
3. Pad-dry-cure method
This is the most widely used flame retardant finishing method, with the process flow of padding → low-temperature pre-drying → high-temperature curing → post-processing. Its advantages include simple equipment, convenient operation, low cost, and good effectiveness.
4. Microencapsulation method
The flame retardant is first encapsulated in microcapsules, and then the fabric is immersed in a solution containing the flame retardant microcapsules and reactive resin. Afterward, the fabric is subjected to a curing process, allowing the flame retardant microcapsules to deposit stably between the fabric structures, thereby imparting flame retardant properties. This method is suitable for flame retardants with small molecules or little reactivity with the fabric, and it can provide the fabric with durable flame retardant performance.
5. Fiber post-treatment method
Chemical treatment is applied to the fiber to establish a network of chemical crosslinking or coordination bonds between fibers, or the fibers are subjected to heat treatment to increase their carbon content. This enhances fiber thermal stability, prevents fiber chain breakage, and improves flame retardancy. However, this flame retardant treatment method is only suitable for a few types of flame retardant synthetic fibers, such as polyester fibers and polyacrylonitrile-based carbon fibers.
6. Pad-dry-cure method
The coating method and microencapsulation method are suitable for flame retardant processing of all fabrics, with shorter process flow and lower equipment investment. However, the resulting flame retardant fabrics may vary significantly in flame retardant effectiveness due to different flame retardant processes.
These are the commonly used production methods for flame retardant fabrics in the market.
