Polyester materials, methods for making polyesters materials, and uses of the polyester materials in binder materials and articles of manufacture are disclosed. In one embodiment, a process is provided for preparing a polyester solution, including mixing monomers of at least one organic acid containing at least three carboxylic groups and at least one multi-hydroxyl alcohol containing at least three hydroxyl groups to form a reaction mixture, heating the reaction mixture to a first temperature, polymerizing the monomers at the first temperature until reaching an acid value from about 200 to about 400 mg KOH/g, adjusting the temperature to a second temperature less than the first temperature, and forming the polyester solution. The polyester materials may be mixed with cross-linking materials to form binder materials. The binder material may then be used to form articles of manufacture.