What process is used to increase burnback resistance in foam?

The process used to increase burnback resistance in foam involves adding air to the foam solution. Incorporating air into the foam creates a more stable and resilient bubble structure, which enhances the foam's effectiveness at smothering flames and preventing reignition. The air helps in expanding the foam, thereby increasing its volume and reducing the likelihood of burnback. A well-formed foam blanket not only covers the burning material but also isolates it from oxygen, which is crucial in fire suppression. This method improves the overall performance of the foam in terms of both suppression and burnback resistance, making it a key factor in firefighting effectiveness.

Other processes listed, such as adding more water or using a higher concentrate, do not directly contribute to increasing burnback resistance in the same way that incorporating air does. While mechanical agitation is important for creating foam, it alone does not ensure improved burnback resistance without the inclusion of air.