Spray guns painting Easter eggs
Red, green, blue or stripes: Dürr helps the Easter Bunny breathe a sigh of relief
Is it really the Easter Bunny who paints all those brightly colored eggs, holding a paintbrush in his tiny paw? It’s hard to imagine, given the number of Easter eggs and the attention to detail required to produce homogeneous colored surfaces and exact colored stripes. The only reliable way of doing this is with high-precision spray guns, known for their high quality standards. For Hühnerhof Wiesengrund, a leading European supplier of boiled, colored hen’s eggs, Dürr partnered with integrator Eugen Fuchsberger GmbH & Co. KG to develop a solution that will have the Easter Bunny breathing a sigh of relief.
Hühnerhof Wiesengrund dyes millions of eggs each week, and its busiest time is Easter. However large quantities are also produced at other times of year since dyed eggs are such a popular choice for snacks or light meals. Supermarkets and discounters offer them ready-packaged, or they can be purchased loose in bakeries, butcher shops, and at farmers’ markets.
Large dyeing plants use two different methods to add color to white eggs. Mottled effects are produced using a roll dyeing method, while spray dyeing achieves extremely uniform, higher-quality surfaces. “When it comes to colored eggs, you really eat with your eyes, even though the color doesn’t actually influence the taste. That’s why a flawless appearance is an important selling point. The quality standard by which the consumer measures all painted surfaces is set by the automotive industry, with its shiny high-gloss coatings. The same goes for dyed eggs,” explains Martin Wüst, Technical Director at Hühnerhof Wiesengrund. The company dye shop has around 100 spray guns, which lose alignment and therefore need to be manually readjusted. The egg’s white shell can show through if too little lacquer is applied, while too much lacquer can produce ugly streaks. Hühnerhof Wiesengrund therefore engaged integrator Eugen Fuchsberger GmbH & Co. KG to find a better solution in partnership with Dürr.
We’re very happy with the homogeneous color, level of shine, and color intensity we get with the EcoGun.
Martin Wüst, Technical Director at Hühnerhof Wiesengrund
For the spray dyeing method, the eggs sit upright on small spindles. They are automatically passed in front of a rig with 30 spray guns, turned, and at the same time sprayed with a lacquer based on natural resin, alcohol, and food dyes using air atomization. The stroke frequency required for this is very high. With the guns used previously, the exposed needles clogged easily. “We looked at the situation on the ground with Fuchsberger, went through possible modifications in theory, and reviewed the most promising idea in a real-life setting,” says Sascha Zolldann, Area Sales Manager at Dürr, in describing the approach. The very first test in the dye shop showed that the automatic → EcoGun AS Auto Mini FS can reliably handle the short cycle without losing alignment or dripping thanks to its fast switching pulse. The result was confirmed after a station in the plant was equipped with a total of twelve Dürr spray guns.
The existing plant’s connections are designed for the spray guns originally used, which differ from those of the EcoGun AS Auto Mini. The technical challenge for the integrator was to adapt the connections for circulating the material, the atomizing air, and the pilot air to the new conditions, and to do so within just a few hours so that the plant could be up and running again as quickly as possible. “The spray guns have a several features that make them easy to integrate. This includes the through bore, which enables the EcoGun AS Auto Mini to be attached from the right or left as well as from above or below. Swivel elements also make the air connection very flexible. Regardless of the direction the hose is coming from, the gun can be swiveled so that connection is guaranteed. Another plus point is that the connection materials are included with the spray guns as standard, something that is not customary on the market,” explains Claus Buschmann, Managing Director of Eugen Fuchsberger.
Hen’s eggs have a very small surface area, but the demands involved in coating them are still high. “Colored eggs are presented to customers in butcher shops or bakeries on well-lit counters, and they form an opinion about the quality from the outer appearance. We’re very happy with the homogeneous color, level of shine, and color intensity we get with the EcoGun,” says Martin Wüst. The EcoGun AS Auto Mini has been specially developed to achieve as good a spray pattern on small areas as the big painting robots do on car bodies. Apart from plain colored eggs, the spray gun can also produce special effects like stripes in all the colors of the rainbow. With its flat round spray pattern, the spray gun applies with a high degree of precision. As a result, the color transitions look as sharp as if the egg had been stenciled. Something the Easter Bunny would need a delicate touch and even more patience for!