PLASTIC IDENTIFICATION FLOW CHART Knowing which type of plastic you're working with is a cornerstone of good plastic welding. Petrochemical Flow Chart The Petrochemicals flowchart traces the main steps between raw materials and feedstocks through to building blocks, derivatives and everyday products. Plastic Packaging , why we need it ? Plastic packaging serves several important functions in our modern lives, which are the primary reasons we rely on it Polymer Formation How polymer forms ?