In addition to the persons and property exempt from ad valorem taxation as prescribed in Section 40-9-1, the following properties shall also be exempt from ad valorem taxation:
All products or materials, including natural and man-made fibers and cloth, when stored by a textile manufacturer or processor for the purpose of using such products or materials in such a way that they become a part of the finished product of such plant.
Ala. Code § 40-9-4 (1975)