The present invention provides a core for receiving a wound product wherein the core is made of a waste sludge produced in a papermaking process. The process for making the core includes the steps of mixing the sludge with a binder material, which may be either a wet strength or a dry strength agent, and then compressing the mixture into a core through a process such as extrusion or molding. Optionally, the sludge may be dried prior to mixing with the binder material.