The flammability and fire-resistance properties of viscose spandex fabric differ from cotton in the following ways:
Flammability:
- Viscose, being a regenerated cellulosic fiber, is generally more flammable than cotton.
- The chemical structure of viscose makes it more susceptible to ignition and rapid burning compared to natural cotton fibers.
- When exposed to an open flame, viscose-based fabrics tend to ignite more easily and can continue to burn with a higher intensity.
Fire Resistance:
- Cotton, on the other hand, is considered more inherently fire-resistant than viscose.
- The natural cellulosic structure of cotton fibers provides a higher level of thermal stability and resistance to ignition.
- Cotton-based fabrics tend to have a slower rate of flame propagation and are less likely to sustain a fire once the ignition source is removed.
Char Formation:
- When exposed to high temperatures or flames, viscose-based fabrics tend to produce a more brittle and friable char.
- This char can easily break apart, potentially exposing the underlying fabric layers and leading to further combustion.
- Cotton, in comparison, typically forms a more cohesive and stable char that can better protect the underlying fabric structure.
Melting Behavior:
- Viscose spandex fabric , due to the presence of synthetic spandex fibers, can exhibit a melting behavior when exposed to high heat or flames.
- The melting of the spandex component can lead to the formation of molten/dripping material, which can pose an additional safety risk.
- Cotton, being a natural fiber, does not exhibit the same melting behavior, and it tends to char and disintegrate rather than melt.
Flammability Testing and Regulations:
- The flammability and fire-resistance of textiles, including viscose spandex and cotton, are typically assessed through standardized testing methods and regulations.
- These standards, such as the ASTM D6413 (Standard Test Method for Flame Resistance of Textiles) or the Flammability of Clothing Textiles regulation, may impose different performance requirements for viscose-based and cotton-based fabrics.
It's important to note that the specific flammability and fire-resistance properties of a fabric can also be influenced by factors such as fabric construction, finishes, and any added fire-retardant treatments. Careful selection and testing of materials are crucial for applications where fire safety is a critical consideration.
