An array of resilient floor tiles is assembled into a continuous sheet after being laid down. An array of included, sacrificial resistive wires is buried along the edges of the tiles and is controllably heated in order to cause welding of the edges of tiles across the paths of the wires to neighboring tiles. Subsequently the wires may be used to give the array integral tensile strength. The welded array is provided with greater strength for resisting use, expansive and contractile forces caused by environmental heat and cold and also long-term tile contraction owing to loss of plasticizer as may be seen with PVC-based tiles.

An array of resilient floor tiles is assembled into a continuous sheet after being laid down. An array of included, sacrificial resistive wires is buried along the edges of the tiles and is controllably heated in order to cause welding of the edges of tiles across the paths of the wires to neighboring tiles. Subsequently the wires may be used to give the array integral tensile strength. The welded array is provided with greater strength for resisting use, expansive and contractile forces caused by environmental heat and cold and also long-term tile contraction owing to loss of plasticizer as may be seen with PVC-based tiles.

A composite molded article in which another material is integrated on a face having grooves in a grooved resin molded article having grooves in which end parts of a fibrous inorganic filler protrude and are exposed from lateral faces of the grooves on a surface side in at least the insides of the grooves. Exposure of the end parts of the fibrous inorganic filler and formation of the grooves may be accomplished by laser irradiation, and the depth of the grooves may be at least 200 m. Another molded article comprising the other material is arranged surrounding the fibrous inorganic filler in the insides of the grooves.

Methods for fastening two fiber composite parts to each other with a fastener that includes electroactive polymer material. The parts have an opening within an inner circumferential surface. Fibers protrude from the inner circumferential surface into the opening and interlock with chains of micrograins of the electroactive polymer material. The fastener may switch between an activated state and a deactivated state and in the deactivated state, the fastener engages the exposed fibers.