vulkanoituun
Vulkanoituun is the past passive participle of the Finnish verb "vulkanoida," which means to vulcanize. Vulcanization is a chemical process that converts natural rubber and polymers into more durable materials by adding sulfur or other equivalent curatives or accelerators. This process involves heating the material, often with the addition of sulfur, which forms cross-links between polymer chains. These cross-links prevent the chains from sliding past each other when stressed, making the material more elastic, resilient, and resistant to heat and abrasion.
Therefore, "vulkanoituun" describes something that has undergone this vulcanization process. For example, "vulkanoituun kumia" translates to