The Chocolate-Covered Donuts

They forgot that melted chocolate is sticky...

A large baking company produced a line of small donuts, many of which were covered with powdered sugar or with chocolate. The donuts were usually packaged eight in a box. The packaging operation was accomplished by placing the donuts on a long conveyor belt, there being eight lines of donuts moving along the belt. A separate, narrow conveyor was located immediately adjacent to each side of the donut conveyor, the narrow conveyors carrying the retail boxes. At the first packaging station were seated two persons, one on either side of the conveyor. Each person would reach over to the large conveyor, grasp two donuts, and place them in a box as it moved in front of the person. That box was conveyed to the second station, where two other persons repeated the process, so there were now four donuts in each box. This operation was repeated twice more until each box on each side of the conveyor held eight donuts. After leaving the final filling station, each box was closed by a person standing at the end of each narrow belt. In other words, nine persons were required to fill and closed each box of eight donuts. (This figure does not allow for relief workers.)

To reduce the intensity of labor in packaging the donuts, the baker initiated a project which was intended to place the donuts in bags. The baker had a production line which produced potato chips, and, on that line, product was conveyed to an overhead hopper and dropped into a scale. When the weight of the chips on the scale reached a predetermined set point, the scale feed was stopped momentarily, and the chips were dropped down into a bag that was fed from a stack and held open by a stream of carbon dioxide. Once the chips were in the bag, the bag was closed, sealed, and conveyed on for loading into shipping boxes. One person was assigned to load bags into the system as needed, clear jams, and generally monitor the operation. The baker believed that the chip-weighing process could be adapted to weigh donuts, in which case, eight labor positions could be eliminated. Accordingly, a system was designed, equipment was ordered, and the project was turned over to the project manager for construction and start-up.

The project manger asked if there were any concern about the donuts sticking together either in the overhead feed hopper or in the scale. After about three months of testing by the equipment manufacturer, including adding parafin wax to the chocolate, it was concluded that there was no practical way to prevent chocolate-covered donuts from sticking together, and the project was cancelled.

(stock image)