February 5, 2016
by Charlotte Atchley
Consistent quality products — that’s what every baker and snack producer hopes to deliver to their customers day in and day out. This requires quality checks to ensure that each batch of buns, bread or cookies is good enough for the end consumer. While this can be done by an operator inspecting random samples coming off the line, that method can only go so far. Vision systems make up the difference.
“Operators can’t look at every product on the line,” said Andrew McGhie, business manager, North America, EyePro System. “They look at most of them but not all nor the bottom of product, so a lot of the inspection systems now look at the top and bottom of products. One-hundred percent of the product is being inspected top and bottom, so that’s a big advantage to the baker, knowing that everything going out of their facility has been inspected.”
Vision and X-ray systems keep an eye on consistency as well as catch products contaminated with foreign materials. These systems offer bakers a wealth of information they can use not only to detain products that don’t conform to the standard but also improve the process and keep rejects to a minimum.
“Vision systems enable quality control,” said Bert Vanmiddelem, area sales manager, Pattyn Bakery Division. “They allow the baker to eliminate any non-conforming product before it goes in the package; therefore, the end customer receives only good product.”
Inspecting with vision
The cameras on a vision system can measure practically anything. “Vision systems out there can get as finite as you want to,” said Terry Bartsch, vice-president, sales, Shaffer, a Bundy Baking Solution. They can measure dimensions such as length, width, diameter and slope; they can even measure color and temperature and can be integrated with other equipment to take in even more data. X-ray units can look for foreign materials before and after a product is packaged.
“Things such as X-ray, multiple cameras including color and other types of vision imaging allow better inspection of products,” said Joel Wiskochil, Northeast regional sales manager, BluePrint Automation. “Vision systems are now used to detect defective product based on size, shape and even color such as burnt or broken cookies.”
EyePro System uses two different kinds of cameras to generate different sorts of data for its customers: a 2D color camera and a 3D camera. The color camera measures length, width, diameter and color and, based on predetermined parameters of what makes a quality product, rejects those that are out of spec. By measuring color, bakers can tell if a bun is too light or dark and even catch colors that aren’t supposed to be there, possibly signifying some plastic that may have gotten into the food.
Beyond dimensions and color, these 2D cameras can also check for sesame seed count and distribution and other defects on the product surface such as blisters, grease and even flour on the heel of a bun or loaf. “You can set up parameters that say a small amount of flour is OK but a large amount isn’t,” Mr. McGhie said.
Three-dimensional cameras scan the products with a laser to create a 3D image. They can measure slope and height and surface features such as scoring and imprints.
Pattyn Bakery Division’s 3D Laser Vision system works by analyzing product volume rather than product contrast. Some cameras count a product based on the shadow it creates against the conveyor belt, but this method can mistakenly count anything else that creates contrast with the belt: crumbs, smudges, flour.
“Our 3D laser vision system is based on capturing volume,” Mr. Vanmiddelem said. “When a product passes our counting laser, the camera registers the deformation of the laser beam and creates a 3D image of the product.” If this image and volume matches what’s typical for that formulation, then the system considers it a match, and it is counted. Influences in product variation, belt pollution and the environment are minimized.
While vision systems can detect irregularities on the surface, X-ray cameras go beneath by examining density. They can also look through packaging so products can be inspected at the last possible stage in production.
“Whether occurring in packaged, unpackaged or in bulk foods, physical contaminants can be identified and removed before reaching the retail supply chain, helping manufacturers to avoid costly recalls and damage to brand reputation,” said Kyle Thomas, Strategic Business Unit manager, Eagle Product Inspection. For food safety inspections, X-rays can look through packaging, even metalized film or foil pans, to check for foreign materials.
While X-rays have an obvious application in food safety, they can also be used for quality assurance. “Eagle inspection systems are also capable of performing multiple quality checks such as mass measurement and component counts as well as capturing important data through our TraceServer software program that makes product traceability effortless,” he said.
With so much information at their disposal, it’s important that bakers strategize to get the most out of their vision systems.
While vision systems can measure a plethora of aspects of a certain product, bakers should only focus on a few. “Just because you can measure something doesn’t mean you should,” Mr. McGhie cautioned. Companies should focus on the attributes that are important to the end customer. If customers value even distribution of toppings, they need to measure topping distribution. If they are concerned about product color, then focus on color.”
Senior operators and the quality assurance team can help determine what should be measured and appropriate targets for each measurement. These targets should be set based on what the production process can actually accomplish as well as customer demands. “You need to set to the processing parameters, not necessarily the customer specifications,” Mr. McGhie continued. “Those two need to be aligned, but you need to set your processing parameters based on what’s acceptable.”
It is also beneficial to designate one person in the company to be in charge of the equipment, to take ownership of it. This person should be able to answer questions regarding measurements and waste reports and handle any necessary troubleshooting on the system. Without someone in the company who really understands an inspection system’s capabilities and workings, its potential contribution will never be reached, and the company runs the risk of not seeing a full ROI.
Then there’s the data; all that information can be very helpful when used correctly. Real-time reporting on waste can help make production adjustments on the spot, and trend graphs can help manage customer relations.
All of these measurements and data capabilities can be overwhelming. It’s critical, however, that manufacturers use that data to their advantage. It can give bakers insight into how their process is working and changes that need to be made to minimize the amount of rejections.
Before a system is installed, operators need to enter the parameters of what makes a quality product — dimensions, product color, toppings, etc. — are entered into the system. Based on these specifications, the computers measure the product and then decide whether to accept or reject it. By seeing exactly why product is being rejected and how far off from the parameters it is, bakers can understand what production steps need extra attention and adjustment.
“Bakers can get a lot of feedback from the vision system, and they can use it to learn more about their production process,” Mr. Vanmiddelem said. This data comes through in real time allowing operators to adjust production immediately, thus reducing waste.
This feedback loop can even be completely automated. If buns are getting too dark, the system can alert the oven, which can automatically adjust to correct bun color before rejects even start. This upstream flow of information is where the true power of inspection systems comes into play. “The key is the information you’re getting and responding to the information,” Mr. McGhie said.
For this information to truly be valuable, however, those parameters must be strategically set. What constitutes a good product in terms of size and color should be regularly achievable by the production process. “It’s important to set your tolerances meaningfully and based on process capabilities, otherwise your waste levels could be adversely affected,” Mr. McGhie continued. When a product is outside of those specific ranges, it means something to the operators, and they will address the problem. If those targets are set arbitrarily, companies run the risk of operators ignoring the data and sometimes even turning the system off.
Historical trend graphs can also help when customers have issues with the product. By having objective data to show customers that product is indeed within specifications, bakers can improve customer relations and maybe even open up conversations about whether parameters need to be changed and what their production process is capable of.
When bakers take full advantage of vision and X-ray inspection systems, they can not only ensure every item meets their quality and food safety standards, but they can also improve their production process and minimize waste.