True
Nylon and polyester fibers do indeed burn slowly and form beads. This characteristic is due to the chemical composition of these synthetic fibers.

Chemical Composition
- Nylon and polyester are both made from long chains of polymers, which are synthetic materials derived from petrochemicals.
- These polymers are highly resistant to heat, which is why these fibers burn slowly.
- When exposed to a flame, the fibers melt and form beads instead of burning quickly like natural fibers such as cotton or wool.

Formation of Beads
- As nylon and polyester fibers melt, they contract and form small beads that are hard and round in shape.
- These beads are a result of the fibers cooling and solidifying quickly after melting, creating a distinctive characteristic of synthetic fiber combustion.

Applications
- The slow-burning and bead-forming properties of nylon and polyester fibers make them suitable for applications where fire resistance is important.
- These fibers are commonly used in clothing, upholstery, and carpets where the risk of fire is a concern.
In conclusion, it is true that nylon and polyester fibers burn slowly and form beads due to their chemical composition and the way they react to heat.

False