2. Block diagram

The block diagram, or functional diagram, is a fundamental document in the access path, describing all the sequences or stages (reaction, separation, shaping, etc.) that lead from raw materials to the finished product.

It's built around a very simple layout of rectangular blocks and lines. Each block represents a function to be performed, hence the name "functional block" often given to this diagram. The lines, with arrows to indicate the direction of flow, represent input, output and connection material flows.

This document provides a clear overview of the essential stages and parameters of the process, starting with the broad outlines and gradually identifying and defining all the stages (figure 3 then figures