Splay is a term used with injection molded plastics to refer to off-colored streaking that occurs when moisture is caught in the material feed, or if the material degrades

Chemical decomposition

Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...

during processing. If cold material impacts the surface from filling at a high rate of speed, jetting may appear, which looks very similar to splay.