An article comprising: (a) a carrier having a predetermined shape to guide one or more expansion directions of an injection molded expandable material; (b) the injection molded expandable material on the carrier; wherein the expandable material is formed on the carrier at one or more angles perpendicular to the one or more expansion directions; and wherein the expandable material is capable of being activated to expand under an activation condition to come into contact with, and adhere to one or more walls defining a cavity in order to at least partially fill the cavity.