Process emptying - What is it?

A downstream stop forces the upstream process to stop, as the flow can not continue, therefore the idea of WIP (work in process) comes in to play. That amount varies by the machines in place. Some parts like heat treatment, foil welding, conditioned air packing, gluing, etc., need to run empty to avoid waste products or equipment damage. 

Any products that can't leave are either not adequately sealed, protected, pressurized, etc. In a typical setup, all these products are either manually removed or automatically discarded into a waste bin, losing efficiency and costing money.                                                                                                      

These types of processes need a controlled stop so they can empty the products that are already in process before shutting down or going into hibernating mode.

Depending on the machine that needs to run empty, various types of solutions can help. The main goal is to have enough accumulation time/length to take in a the work in process (WIP) that much exit the machine. Accumulation systems designed for this are thus adapted to the amount to be emptied and the number of times such a process stop is expected. 

It is also essential to consider the achievable speed difference between the up and downstream process as such a speed difference is needed to empty the accumulator during the running process to be ready for the next controlled stops. 

This way, an accumulator can help prevent product loss and increase efficiency.