Robotic writing with cake icing onto cakes

 

Northern Foods' divisional company, Park Cake Bakeries operates a bakery, which is largely dedicated to supplying a wide range of cakes and other products to a single UK food retailer. Many of the cakes are decorated and often this entails written messages iced on the top - a task generally undertaken by skilled staff, trained to maintain a consistent high standard of work.

Please note the two dispense valves applying the scripted icing to the cakes - 2 at a time !!

However, at certain times of the year - Easter and Christmas, for example - there is a significant increase in demand which can result in as much as four times the normal throughput. Training additional staff to cope with the expanded demand while still maintaining the normal high levels of quality can take a significant period of time and so volume planning is critical.

For some time now, the Park Cakes management team has been looking for new ways to manage this problem. Group engineering controller, Terry Simpson wondered whether modern technology could be applied to help with the task and realised that robots might possibly be adaptable for the cake decoration process. The search for a partner in this project, however, turned out to be something of a crusade !

Many companies were approached, but none were able to supply a solution, which met the criteria - none, that is, until he met up with a company called System Devices. "When I first met their engineers it was clear that they had the right attitude and they were people I could do business with," Mr Simpson recalls. "I already had a clear idea of what I wanted to achieve but previously it had been difficult to make other organisations fully understand." The company was duly appointed to develop a prototype cake icing machine.

Tip Seal valve as used for the cake icing applicationSystem Devices are UK agents for Epson robots and the Opto 22 Mistic control system. Initially, the message to be iced on a cake was 'drawn' on a CAD package and its co-ordinates downloaded to the Mistic controller which converted the information into smoothed co-ordinate data for an Epson Scara robot guiding a suitable icing nozzle - this is where IDS got involved.

Both System Devices and Park Cake approached Simon Meredith at Integrated Dispensing Systems to source a suitable dispense valve and nozzle to apply the chocolate icing on the cakes and would do so with a clean cut-off without any stringing. IDS had a ready made solution in their stainless steel 2200-245-Series KISS™ Tip Seal Valve. With its cavity free tip seal nozzle it gave a clean cut-off of the icing bead every time the valve was closed. The valve was mounted on a heater block and the valve supplied with warm icing through a heated hose. The valve is built with two inlet ports enabling the valve to be configured so that the icing could be recirculated through the valve - a very important feature when working difficult materials such as chocolate.

Another view showing tip seal valveThere were teething problems with the early prototype, not in respect of positioning the nozzle, but with controlling rate of flow of the chocolate and icing materials from the nozzle. This was solved by System Devices working on experience gained in other industries, and with the help from IDS and a chocolate technologist who provided input on the appropriate consistency and flow characteristics for this application. Further development ensured that the prototype was able to cope with the varying overall heights and surface levels of the cakes themselves. With these encouraging results, System Devices was invited to build a production version of the prototype, capable of icing two cakes simultaneously.

2 cakes receiving icing roboticallyIn the final version, messages are formed using a CAD package on a PC in a remote control room. This is downloaded via a RS232 to the robot-mounted Mistic controller, which converts the data to machine co-ordinates, as well as controlling the icing nozzles. Cake surface variations are measured in real time by a laser range finding system and these parameters are fed back to the Mistic, which compensates for each individual profile.

Cakes are fed to the robot via a conveyor; as this is loaded by hand and the position of the cakes is critical, a simple optical positioning aid, involving two lasers, was developed by System Devices to ensure consistently accurate presentation. Mr Simpson is enthusiastic about the project. "The quality of decoration has exceeded our expectations and our customer is extremely pleased with the results."

Recent developments have included an expansion that will enable four cakes to be iced at a time, and the provision of other types of decoration.