Abstract: A toilet assembly comprising: a toilet bowl; a toilet seat; and a hinge pivotally connecting the toilet seat to the toilet bowl, the hinge including a base portion connected to the toilet bowl, the base portion being made of a relatively rigid material; a leaf portion connected to the toilet seat, the leaf portion being made of a relatively rigid material; and a living hinge portion pivotally connecting the base portion to the leaf portion, the living hinge portion being made of a relatively flexible material.

Abstract: The invention provides a method of co-injection molding. The method includes mixing a plastic inner material and an endothermic-blowing agent to form a core mixture. A plastic outer material is injected from a first injection unit into a co-injection manifold to create a flow of outer material therethrough. The core mixture is injected from a second injection unit into the co-injection manifold to create a flow of core mixture therethrough. The flow of the outer material and the flow of the core mixture are then controlled through the co-injection manifold and into a mold cavity. The core mixture expands as heat is provided for the endothermic-blowing agent to absorb.

Abstract: The invention provides a method of co-injection molding. The method includes mixing a plastic inner material and an endothermic-blowing agent to form a core mixture. A plastic outer material is injected from a first injection unit into a co-injection manifold to create a flow of outer material therethrough. The core mixture is injected from a second injection unit into the co-injection manifold to create a flow of core mixture therethrough. The flow of the outer material and the flow of the core mixture are then controlled through the co-injection manifold and into a mold cavity. The core mixture expands as heat is provided for the endothermic-blowing agent to absorb.