Conveyor systems and robotic palletizers do the heavy lifting in dairy plants
What is the future of automation in dairies? Dairy Foods posed this question to the equipment suppliers and asked how dairy plant managers can use conveyors and palletizers most effectively.
Robotics are becoming more commonplace in dairies (and other food processing facilities), said an official with a trade association, which is leading equipment suppliers to write sanitary standards that address the cleanability of the machines. Well-designed equipment can contribute to food safety.
Eric Schweitzer, the director of standards and certification at 3-A Sanitary Standards Inc., McLean, Va., said 3-A SSI is developing a new individual equipment standard with hygienic design criteria. This is necessary for ensuring that robot-based automatic systems (RBAS) are designed for cleanability and inspectability, and that RBAS are not a source of food contamination, he said. A final draft document is near completion.
As plant managers and safety officers know, robotic equipment has the obvious benefit of eliminating injuries to dairy plant employees.
“Dairy items tend to be heavy, which can lead to injuries if case packing and palletizing are done manually,” said Barry Rinaldi, director of business development for Schneider Packaging Equipment, Brewerton, N.Y.
Letting machines do low-value but important work, like lifting and stacking, allows dairies to deploy workers to higher-value tasks requiring more skills.
Newer versions of conveyors and palletizers are equipped with fast or automated abilities to orient and pack or reject product. In addition, the equipment is easy to operate, safer and a more reliable choice than building a pallet by hand, Rinaldi said.
Keeping packages free from contamination as they move through fillers to case-packing stations is an obvious concern in dairies. That means cleaning the conveyors and their belts. Rinaldi offered this advice to plant managers:
“Use stainless steel construction conveyors with sealed stainless steel bearings suitable for high-pressure washdown, and an open construction design for easy washdown access and inspection. You should also include an auto-wash system built into the conveyor body to apply washing foam and rinse water programmed for a preset timing cycle.”
3-A SSI has standards for pneumatic and mechanical conveyors that address the design and materials of construction for both product and nonproduct contact surfaces. Schweitzer noted that there are many important elements of these standards and none should take precedence over another. But he cited an example regarding the design criteria for belts: “Metal belts having a product contact surface(s) shall be endless. Nonmetal belts having a product contact surface shall be made of or covered with a food-grade rubber or rubber-like or plastic material. Belts made of an absorbent core material shall have edges sealed with the same material that is used for product contact surfaces. Nonmetal belts shall be endless. To facilitate cleaning, the construction shall be such that belts, guides, guards, rollers and all other parts be easily removable for cleaning and inspection.”
Fred Beer, the president of the Deam Division of Westfalia Technologies, based in York, Pa., recommended selecting chain types that are easy to remove for weekly high-pressure washdown, and “opt for conveyor designs with a removable wear strip without the need for special tools.”
Beer also recommended that dairy plant managers use direct shaft-mounted gear motor drives with variable frequency drive control to eliminate drive chains, sprockets, chain guards and similar parts.
“Use gear motors capable of full washdown – preferably of stainless steel construction,” he said.
Suppliers with experience in the dairy industry have designed their equipment to meet the unique conditions found in dairy plants. For example, Rinaldi said Schneider has design platforms and equipment specifically engineered with features and components designed for washdown environments. These include slug tubing at all points for maximum sterility from microorganisms. The open and accessible construction design allows for total access to every aspect of the machine. Aside from cleanability aspects, design improvements have led to a 30% reduction in the total number of parts on some units. That means less mechanical failure and fewer parts to replace.
More effective palletizer use
At the palletizing station, robotic palletizers give the most flexibility for quick changeovers, Rinaldi said. A simple push of a button readies the palletizer to pack different case sizes.
Robotic equipment also allows palletizing to be centralized, combining multiple production lines into one palletizing cell, Rinaldi noted. In addition, centralized robotic palletizing equipment has the ability to keep product types separate so that more than one product can be palletized in the same cell at the same time while keeping the unit loads separate.
Aside from building pallets, plant managers need to keep an eye on plastic use at the palletizing station. Beer said some dairies are “excessive” in their use of stretch wrap on palletized dairy stacks.
“When necessary, programming the wrapper for selective tier wrapping can reduce the amount of plastic wrap used, as well as resulting waste when removed at the destination,” Beer said.
The need for manufacturing efficiencies and the lack of qualified labor are some reasons that dairies are installing robotic equipment. That is unlikely to change, especially in the warehouse.
“Automation will progress to the point where fully automated storage/retrieval and order pick systems are the norm,” Beer said.
“Today, systems are available to store/retrieve and automatically release full pallet loads, full stacks and even single dairy cases. Warehouse Execution Systems capable of handling all operations in a dairy warehouse/cooler will continue to expand, thereby helping reduce order processing time, improve order accuracy and reduce waste. Robotic palletizing systems with the capability of building loads with mixed SKU cases will eliminate many of the case/stack conveyors and most of the manual labor in the load-out process. AGVs [automated guided vehicles] will be used to load/unload trucks,” Beer said.
To acquire any 3-A Sanitary Standard or Accepted Practice, see the association’s page on Techstreet at www.techstreet.com/3a/
The Dairy Foods Buyers Guide includes suppliers of conveyors and palletizers. See buyersguide.dairyfoods.com/buyersguide.