Jiangsu Textile Research Institute Inc.

Intrinsically flame-retardant fabrics are favored because of the inherent flame-retardant properties of the fibers themselves. These fabrics are flame-retardant without the need for chemical treatment and retain their flame-retardant properties after repeated washing, wear and use. However, although the flame retardancy of intrinsically flame retardant fabrics mainly comes from the chemical structure of its fibers, there are still many factors that affect its final flame retardant performance.

1. Fiber composition and structure

The molecular structure and crystal structure of fibers have an important influence on their heat resistance and carbonization behavior. Highly crystalline fibers tend to have higher thermal stability and flame retardant properties because the higher the crystallinity, the slower the fiber decomposes at high temperatures and the thicker the char layer formed during combustion, thus providing better flame retardancy. Effect.

2. Textile technology

The textile process has a significant impact on the final performance of intrinsically flame retardant fabrics. The yarn density, organizational structure and finishing process of the fabric will determine the flame retardant and other properties of the flame retardant fabric to a certain extent.

Yarn Density: The higher the yarn density of the fabric, the tighter the flame retardant fabric is, which helps block the spread of flames and heat. However, too high a density may lead to a decrease in the breathability of the fabric, affecting the wearer's comfort. Therefore, there is a need to find a balance between flame retardant performance and comfort when designing.

Fabric structure: The structure of the fabric (such as plain weave, twill, satin weave) will also affect its flame retardant effect. A tight tissue structure usually better prevents the spread of flames, thereby enhancing flame retardancy. For example, plain weave fabric is often used in high-demand protective clothing due to its many yarn interlacing points and tight structure.

Post-finishing process: Although inherently flame-retardant fabrics do not require flame-retardant chemical treatment, other post-finishing processes (such as waterproofing and anti-fouling treatment) may affect the flame-retardant properties of the fabric. For example, some waterproof treatments may cover the surface of the fabric, affecting the breathability and heat resistance of the fabric, thereby indirectly affecting the flame retardant performance.

3. Environmental factors

The performance of intrinsically flame-retardant fabrics will vary under different environmental conditions. Temperature, humidity and chemical environment may all affect the flame retardancy of fabrics.

Temperature: Extremely high temperature environments may accelerate the decomposition and carbonization of materials. Although intrinsically flame-retardant fabrics are designed with use in high-temperature environments in mind, the flame-retardant properties of the fabric may be compromised under high-temperature conditions beyond their tolerance range. has declined.

Humidity: High humidity environments may reduce the flame retardant properties of fabrics, especially if the fabric is highly hygroscopic. The presence of moisture may change the structure and thermal conductivity of the fiber, thereby affecting the flame retardant effect of the fabric.

Chemical environment: Long-term exposure to chemical environments such as acids, alkalis, and grease may weaken the performance of some flame-retardant fibers. For example, a strong acid environment may have a certain corrosive effect on aramid fibers, resulting in a decrease in their strength and flame retardancy.

4. Thickness and weight of fabric

The thickness and weight of fabric are also important factors affecting its flame retardant performance. Generally speaking, thicker fabrics provide better thermal protection, but may also affect other properties.

Thickness: The thickness of the fabric directly affects its flame retardant effect. Thicker fabrics generally insulate heat better and prevent flames from penetrating, providing better protection. However, fabrics that are too thick may reduce flexibility and breathability, affecting the wearer's comfort.

Weight: The weight of a fabric is usually related to its thickness. Heavier fabrics generally mean better thermal protection, but may also increase the burden on the wearer. For protective clothing that works for a long time, the increase in weight may cause fatigue, so the balance between flame retardancy and weight needs to be considered during design.

5. Use and maintenance

Use and maintenance have a significant impact on the long-term performance of intrinsically flame retardant fabrics. Even intrinsically flame-retardant fabrics can result in reduced performance if not properly used and maintained.

Washing frequency and method: The flame retardant properties of intrinsic flame retardant fabrics will not disappear due to washing, but improper washing methods, such as using strong acid and alkali detergents, may destroy the structure of the fiber and indirectly affect its flame retardant properties. Therefore, it is recommended to use neutral detergents and avoid high-temperature drying.

Wear and Aging: Flame retardant fabrics may lose performance due to wear and aging over long periods of use. Wear and tear can cause the fabric structure to thin, affecting its overall protective properties, while aging can cause the fibers to become brittle, affecting its strength and durability.

Ultraviolet exposure: Prolonged exposure to strong ultraviolet rays may cause fiber degradation. In particular, some polymer materials will undergo photodegradation under ultraviolet irradiation, resulting in a decrease in flame retardant properties. Therefore, excessive UV exposure should be avoided in the storage and use environment of fabrics.

6. Combinations and blends

In practical applications, intrinsically flame-retardant fibers are often blended with other fibers to obtain better overall properties. However, this blend may also affect the flame retardancy of the fabric.

Blending ratio: In blended fabrics, the content of intrinsic flame-retardant fibers directly determines the flame-retardant performance of the fabric. Generally speaking, the higher the flame retardant fiber content, the better the flame retardant effect of the fabric. The design needs to ensure that the proportion of flame retardant fibers is sufficient to provide the required protection.

Effect of other fibers: Other non-flame-retardant fibers (such as cotton, polyester, etc.) blended with intrinsic flame-retardant fibers may reduce the overall flame-retardant performance. For example, cotton fibers tend to produce flames when burned, so special attention needs to be paid to choosing the right proportions and combinations when designing blends to balance flame retardancy with other functionalities.