Which insulation type is not known for high flexibility but provides good thermal resistance?

Cross-linked Polyethylene (often abbreviated as XLPE) is known for its excellent thermal resistance properties, making it suitable for high-temperature applications while being resistant to moisture and chemical damage. This type of insulation is used significantly in wire and cable applications due to its ability to maintain performance under temperature fluctuations, but it is not particularly known for high flexibility.

The process of cross-linking creates a three-dimensional network of polymer chains, which enhances its mechanical and thermal properties, but at the expense of flexibility. Therefore, while it offers robustness and durability, it does not possess the same level of flexibility that other types of insulation, like natural rubber, would provide.

Understanding this distinction can help in selecting the right insulation type for various applications where thermal resistance is critical, but excessive flexibility may not be necessary.