Vision systems have a role to play in a variety of baking applications.
Though U.S. bakers have been slow to incorporate them,
these systems are becoming more prevalent.
In the past five years, machine vision technologies have begun to play a key role in wholesale baking applications in a variety of ways. Baking industry insiders see an ever-expanding number of uses for the technology in the not-too-distant future.
One reason for the advance is the technology is expanding beyond its traditional use at automotive and other industrial assembly manufacturers. Vision technology now is being used in quality, packaging and appearance control across many other industries, including baking, says Bob Rongo, owner, Decision Technology LLC, Indianapolis.
“There's growth potential in baking because machine vision can be used for overall quality control and for verifying the final product looks right,” Rongo says. “But it also can be used within the baking process itself and for packaging. It can really be customized to fit a number of needs.”
Vision systems also increase operating efficiency on baking lines and can cut labor costs, adds Eric Riggle, vice president, Rademaker USA Inc., Hudson, Ohio.
First, a definition
Think of these systems almost as an inspector or operator on the production or packaging line. As the name implies, vision systems have the capability to see what's happening on the line, albeit in a limited way far removed from how a human relies on vision.
These systems instead use digital cameras, smart cameras and image processing software to carry out their duties. They can be programmed to perform narrowly defined tasks, such as to count objects on a conveyor or to search for defects in product or product packaging.
But machine-vision systems go beyond merely noting defects. Through software tied to other equipment and devices, they can theoretically help make decisions about and act on what they see. If a system is programmed to ensure each loaf of bread is of uniform color, for example, and it “sees” a loaf that is too light or too dark, it relays that information to a robot or an operator further down the line. The operator or robot then knows to remove that loaf from the line.
Though vision systems have been somewhat slow to catch on in American wholesale baking applications, that has been changing as bakers determine how to best incorporate this equipment into their lines, Rongo says. The baking industry in particular lends itself to a number of machine-vision applications, he adds.
The systems can be purchased separately and incorporated into existing production lines or they can come as an overall part of equipment purchased from a vendor. Companies, such as Rongo's, create customized lines, vision included, for specialized applications.
Legs and tails aligned
Four years ago, Rademaker introduced its Croissant Vision System, which ensures moulded croissants are positioned properly for the bending and pinching of croissant legs and tails.
“The holy grail of croissant production is the automatic bending and pinching of the croissant because that's where the labor is,” Riggle says. “For years that's been something equipment makers have been diligently pursuing.”
The making of croissants through the moulding procedure is easy to automate, Riggle says. But if the croissants aren't precisely positioned when entering the automated moulding system, they can't be perfectly bent and pinched by the machine.
To do this shaping by hand, the operator picks up a pre-moulded croissant and bends and pinches it to align its legs and tails properly. When made by machine, the tips aren't always correctly positioned.
With the Rademaker system, upon exiting the baking process, the unformed croissants travel past the vision system, which incorporates high-intensity lamps that cast a shadow on each croissant. The croissant shadow, when captured on camera, tells the system where each croissant is exactly positioned as it travels down the conveyor. The system then sends a signal to equipment downstream, which uses this positioning information to automatically and uniformly line up the unformed croissants. Once lined up properly, the croissants can be mechanically bent and pinched with precision.
All this is quite a feat, as Rademaker's croissant-automation equipment is capable of producing 24,000 croissants per hour.
Bakers have responded to the system as a curiosity, Riggle says. Rademaker has sold systems in France and Belgium, where bakers are interested in baking automation because labor rates are higher than in the United States, he adds.
The croissant vision system is not cheap, Riggle says, though putting a dollar amount on it is hard because these systems are customized to bakers' needs. Because the Rademaker production line that includes the vision system can produce 24,000 croissants per hour, buyers need to compare cost savings with that of maintaining six to 10 operators on the line to manually form croissants.
One other important point making for slow adoption: U.S. consumers aren't as zealously dedicated to their croissants as the French, which means a smaller stateside market for wholesale croissant baking equipment in general.
“In France, the croissant is like what white bread is here,” Riggle says.
Nevertheless, he's confident vision systems have a place in U.S. croissant production. They can cut operating costs and ensure a uniform and accurately folded product. Also, the vision systems will soon make their way into other Rademaker applications, such as aiding the manipulation of pizza dough.
Packaging inspection
At Cognex Corp., Natick, Mass., the vision hardware and software is integrated in one package. Bakers then program the system for their own needs.
“Our systems can be made to display a picture or a message to an operator, but they can also be more complex,” says Lisa Eichler, director of marketing, vision systems. “They can talk to the controller on the line that controls all the equipment or they can talk to a robot to tell it where the bag of chips is that it needs to put in a carton. Or they can talk to a software package that controls many different type of devices.”
The company already routinely provides vision systems for a variety of baking applications. For example, Manner AG, Perg, Austria makes a variety of wafers, biscuits and cookies. The company's large baking oven produces 8,000 tons of flat wafers and biscuits each year.
To ensure the packages of all varieties of its century-old Manner wafers are consistent and undamaged, the company recently implemented a vision sensor called the In-Sight 5400 and combined it with PatMax pattern-matching technology on its packaging line. Both hardware and software is from Cognex. The software and hardware combination allows many different package characteristics to be checked simultaneously and quickly, says Reinhard Gassner, Manner's plant manager. Now, Manner is capable of maintaining packaging speeds of up to 400 packages per minute. The wafer itself is packaged in many different package varieties.
“If the conveyor belt is operating at a speed of 270 packages per minute, then just a few seconds of defective production means several dozen rejected packages,” Gassner says. “This is not just a question of cost; it also has a negative effect on the production flow.”
The vision system is programmed to recognize each package, no matter where it sits on the line and to detect any fault in the packaging itself, Gassner adds. The pattern-matching software pairs the actual packaging the vision system sees against its knowledge of how the package should look. In this way, it recognizes appearance defects. With the system in place, individual packages of wafers flow through the inspection station on the conveyor belt without needing to be fixed in a particular position.
The system can determine whether the packaging is centered correctly and wraps the product properly. It also can determine the presence of the hazelnut picture on the wafer wrapper, for example, thus ensuring wafer packages correspond to the wafer type inside. The system also checks packages for dents and tears.
The system alerts Manner employees to a dented or otherwise unacceptable package. Employees react quickly, because if a package is dented it may become jammed further down the production line, resulting in additional and unnecessary product rejects, Gassner says.
Since implementing the vision system, productivity on the Manner line has increased by 5 percent because interruptions in product flow — to manually check for crushed packages — is kept to a minimum, he adds.
While Decision Technology hasn't seen many orders for vision systems from the baking industry, Rongo has seen growing interest and several inquiries from wholesale bakers. He also has sold vision systems to companies that provide packaging and material handling products to the baking industry.
Decision Technology is a systems integrator. To create a customized vision system, the company purchases cameras, software and other devices, depending on client needs. It then integrates the devices to best carry out the task at hand.
One wholesale baker recently inquired about a high-speed pie-slicing application. At this bakery, pies are automatically sliced, and each slice is then packaged in a plastic container. The vision system for this application would have validated that the package labeling was placed correctly on the container.
In general, many of the ways machine vision is used across industries can be translated to baking applications, Rongo says. In the case of folding machines used to cut large pieces of metal to size, vision systems often monitor the width of the cut. If the width isn't correct, blades automatically adjust for the correct cut.
“In this instance, the cutter is cutting aluminum, but something like that could be used in baking as well,” Rongo says.
Like others in the know, he expects the baking industry will be seeing and hearing more about vision systems and more fruitfully reaping their rewards in the near future.
