If your project requires joining two pieces of plastic and need a stronger connection than you'd get with glue you can weld two pieces of plastic together by using a rotary tool to spin a plastic rod.
Weststone Brand Clear Acrylic Solid Rods 4"(100mm) x 2mm Used for bracing, cabling, piping, wiring, or conduit. Ideal for scratch model building applications Check our store for more colors, BLACK, ...