A preform made from two different materials that do not bond together by a bi-injection process, using the same mold, is presented. An outer layer of the preform can be first made, then an inner layer molded through a center hole in a bottom of the outer layer, and the two layers connected. Inner/outer preform materials can be different, such as PET/polyolefin or polyamide, or the same, such as PET/PET. To prevent mutual bonding during molding of the second layer, a non-stick coating may be sprayed onto a surface portion of the first layer prior to molding the second. In embodiments, manufacturing order can be either outer/inner, or inner/outer, and the non-stick coating sprayed on the inside/outside of the layer first molded.