A plastic process flow diagram maps out the journey plastic takes on its way to being recycled. It depicts the progression of the plastic from scrap materials to a usable product.

A plastic process flow diagram is a chart using simple pictures and descriptions to show the process for recycling scrap plastics. The chart begins with the scrap plastics being sorted, then ground into small particles that are washed and ground into even smaller particles. The particles are then extruded into pellets or new products.

Extrusion is the last step in the plastics recycling process. The plastic flakes go through a series of mechanisms known as the hopper, barrel, cylinder,and screw that heat and melt the plastic and move it forward through the machine. Once the plastic is melted, the screw continues to push it though a die which shapes the plastic. It then moves through a cooling device and becomes a usable product.

A plastic process flow diagram shows the recycling of only certain plastic products such as post-consumer plastic, or plastic products used to full service capabilities once before being recovered. It also shows plastic scrap, or the recycled polymers remaining from plastic production, and mechanical plastic processing which includes melting or shredding of plastic waste.