Vice President of Operations
Thompson Scale Company
A look inside the operation
After apples are sorted and sized they are automatically weighed and delivered to a chute one apple at a time until the target weight is met. The multiple chutes have individual target weights, allowing some operators to package three pound bags while other operators fill the five pound bags. When the bags are filled, they pass through a closure machine that attaches a plastic tab and label to each bag. All bags are then placed on a common take-away conveyor, delivering the bagged product downstream to manual loading stations.
Cartons are then placed on pallets and transported to cold storage within the packing shed—remaining there until they are loaded onto trucks for distribution to Umlor Orchards’ customers.
Special attention is given to moisture content within the apples throughout the process to ensure minimal moisture loss by the time it reaches the grocers’ produce department. Though a bag of apples may initially weigh five pounds when packaged; underestimating the role that time and temperature play during the process may lead to a loss of moisture, presenting the potential for under weight bags on the retailer’s shelf. Moisture loss also greatly affects the appearance, texture and taste of the apples.
It’s all about the customer
The existing process allows for a production rate and daily output that meets their current customers’ needs. Furthermore this layout and process gives Umlor Orchards the flexibility to pack out a variety of bag sizes separately or together to meet current demand. As part of this existing process, production personnel spot-check bag weights to verify bags are within acceptable limits. This method relies on the operator to check on a regular basis and respond to any under-weight issues that may arise.
New customers coming to Umlor Orchards find the filling and handling process and methods very attractive, because of the flexibility to run a variety of packages to meet their needs. However, some of these new customers demand a more reliable method of bag weight verification, asking for 100 percent inspection.
Adding total weight inspection presents a very serious problem since a single operator cannot possibly keep up with the current production rates and manually verifying each bag.
This presented Umlor Orchards with a real process logistic problem. How do you maintain your current packing methods, use the same equipment and, at the same time, meet your customers’ requirement for 100 percent weight inspection?
Adding several additional people to manually check every bag crowds the production line, bottlenecks throughput and adds a tremendous amount of overhead to operating expenses.
Weighing the possible options
You could use an in-motion checkweigher, as they are designed to weigh each package to a specific target weight and set of reject limits. This solution would make more financial sense, as well as lower long-term operating expenses. It would also meet the 100 percent inspection stipulation, but it would also mean changing the whole way Umlor Orchards packaged their product. No longer could both three and five pound bags get packed at the same time. This would throw the advantage of Umlor’s line flexibility out the window.
A new dedicated production line would work, but it would be very expensive and a huge undertaking. And the long timeframe of doing such a project would be an inconvenience to customers.
Call in the pros
For fear of not meeting the established customers’ needs, as well as the possibility of losing newer and future customers, Umlor Orchards began asking the advice of vendors and colleagues to find a solution that would answers all their production needs.
After some weeks of searching for an answer Omlor Orchards contacted Exchange Team Advantage (ETA), based in Ludington, Mich., and talked to Doug Sarto and Matt Gill. It became clear to them early on that Vince Umlor, owner of Umlor Orchards, had a good vision for what the company wanted to accomplish, but he just needed help getting there. Vince told them, “I need to make sure it can run three-pound and five-pound bags simultaneously—without any kind of hesitation. I need to be clear about this point. If it can’t do that, then this will not work for us.”
After listing all of Omlor Orchards problems, Doug and Matt surveyed the company’s production line. And since they were independent sales representatives for several packaging related companies, including an in-motion checkweigher company, they were confident a solution was just around the corner.
Doug and Matt spoke with the sales engineering team at Thompson Scale Company (Thompson Scale), a Houston, Texas based manufacturer of in-motion checkweighers. They explained their customer’s problem and asked for a unique solution. Details on production, types of bags, weight ranges, and production rates, etc., were discussed. Thompson Scale was soon fully involved in creating solutions for the verification problems Omlor Orchards was facing, and to bring a successful process to fruition.
Custom Check weigher Solution
Thompson Scale offered a small package in-motion checkweigher with an in-feed acceleration conveyor, scale conveyor and drop-nose style reject conveyor, all on a common frame.
Standard checkweigher controls were provided with a bit of custom programming added. And a special routine was devised to simultaneously monitor two different recipes within the checkweigher controls, allowing the checkweigher to weigh and compare each bag weight to the two different recipes in real-time.
“Knowing that every single bag is weighed is not only ‘peace of mind,’ it is priceless,” said Vince.
The checkweigher’s HMI provided information on both recipes being run and their respective target weights. Data output via a built-in Ethernet TCP/IP within the checkweigher controls allows Omlor Orchards’ customers to collect every bag weight for proof of compliance with their customers’ 100 percent inspection requirement.
The operators can see in real-time the production totals, such as the number of low rejects, good weights and high rejects. Viewing the color-coded display screen is easy and can be seen from up to 30 feet away.
The custom checkweigher solution definately checked off all the goals to success for the apple orchard. It addressed production rate throughput, accuracy requirments (+/-2 to 3 grams), and it’s mechanically very durable.
Vince Umlor summed it up best, talking with ETAs Doug Sarto, he said, “We can now tell our customers that every bag is weighed and meets their customer specs.”
Finding the drop-nose reject option
Now that a solution is available to monitor 100 percent of production, the packing shed needed to figure out how to manage off-weight bags that crossed the scale.
Rejection of off-weight bags presents its own set of challenges. Running at high production rates, with bags traveling down fast-moving conveyors, means there’s very little time to weigh, and typically less time to reject an off-weight package.
Running at a production rate of 60 bags per minute equates to one bag per second. At this speed, using a traditional pusher or sweep-arm style reject-device would be difficult or impossible. It would require moving the bag to a reject-chute or slide–sending the bag off to the side of the scale. The arm or sweep would then need to retract back into position before the next bag got to the reject station. That’s only a half second to move the off-weight bag, and half second for the arm or reject-device to retract back into position for the next bag.
The results of pushing a five pound bag at 90 degrees to the flow of the conveyor is–well... a bag full of bruised and battered product. That’s only good for apple sauce! It was obvious that the sweep-arm and/or reject-device was not the solution for this application.
The eventual solution would have to gently remove the off-weight bags. But there was another problem to consider; one that invariably happens in these types of packaging operations. It’s an occasional missed closure on a bag. The open bag–when it happens–travels down the conveyor line scattering loose product that can be difficult to remove from the line with a pusher or diverter reject device.
The answer to both these problems is the drop-nose reject option, which gives a quick and gentle solution to remove off-weight or open bags to a bin or chute located below the production line.
Because the bags are moving in the same direction as the flow, there’s no imparted force trying to change the inertia of the bag—meaning a gentler rejection method and far less damaged product. The undamaged rejects are then reworked into new bags to complete the process.
The golden apple
The checkweigher solution was spot-on, solving every problem that was discussed with ETA and Thompson Scale. Umlor Orchards is now able to maintain their current line configurations with flexibility for packing whatever is in demand at the moment, all while meeting their new retail customers’ expectations on 100 percent inspection.
The folks from ETA assisted with the mechanical and electrical installation, which took just a few hours to complete. Calibration, setup and commissioning were straight forward, and the operators were trained and able to change from one set of recipes to another within a few minutes.
Data from the checkweigher presents a complete picture of bag weights, weight variances and number of rejects. This information is then mined and used to make improvements up-stream at the bagging stations, and down-stream when deciding production capacities for new pending orders. Problem solved!
Thompson Scale Company has been manufacturing of checkweighing systems, packaging machinery controls and custom production scales for over 30 years. Their products include in-motion checkweighers, universal filler controllers, universal remote digital displays, inline rejector conveyors, and filling machinery upgrades. For more information about Thompson Scale, or to inquire about custom solutions for your company, call them at their Houston, Texas office at Phone: (713) 932-9071; or Email them at: firstname.lastname@example.org; visit the Website at www.thompsonscale.com.