Correcting package weights puts giveaway on ice

Meeting minimum weight and net contents requirements without producing significant amounts of waste is a delicate balance for manufacturers and their packaging operations. The cost of overfills and gratuitous product giveaway add up quickly. At the same time, businesses must always be mindful of legal requirements and fair trade regulations that protect consumers against negligent underfills.

At Oregon Freeze Dry (OFD), the world's largest custom processor of freeze-dried products, statistical process control (SPC) is key to maintaining consistent weights within its packaging operation and achieving higher profitability.

With a menu of more than 500 items, the Food Div. at OFD has evolved into a distinctly segmented business. In addition to providing private-label manufacturing, the company features a fullline of ingredients used by some of America's largest food companies. It's also a major supplier of field rations to the U.S. military and markets its own line of backpacking foods under the Mountain House® brand. The company has more than 20 million kg of drying capacity at its three facilities, representing about 70 percent of North America's total freeze-drying capacity.

The packaging department consists of two horizontal form/fill/seal lines, a vertical f/f/s line, two vibratory gravimetric feeder systems and a cup line. OFD packaging options include film bags, foil pouches, cans, paper and barrier cups, either in bulk or single-serving sizes.

Transforming waste into savings

Weight compliance affects OFD on a multitude of fronts; the most obvious of which centers around material waste. Every fraction of product saved is money in the bank. However, underfills can be just as wasteful, when the cost of reworking the product, refilling operations, time and labor are factored in. Improper verification of net weight can also take its toll on customer satisfaction and repeat business.

Because the instructions for rehydrating the freeze-dried product is based on net contents, if the customer adds too much or too little water, then product quality, nutritional value, texture and/or flavor may be compromised.

To address these critical weight and filling issues, OFD has standardized on the Synergy 2000™ SPC application from Zontec Inc. (www.zontec-spc.com). A real-time system, the software handles data collection, process monitoring and corrective action on the food-packaging lines and in the quality-assurance lab to maintain weight records for incoming raw materials from suppliers. The software is also used for analysis and reporting by the SPC administrator and packaging engineers.

Once the product is freeze-dried, it moves to the packaging lines, where feeder buckets and weighcells fill the amount of product to correspond with the label weight on the package. Packaging operators take samples off the line for their SPC weight checks at predetermined intervals. Typically this is every hour, but sometimes it is more often, depending on specific product requirements. The software contains a built-in connectivity interface with Trooper and Explorer scales from Ohaus Corp. (www.ohaus.com) and only requires that the operators press the “Print” key to send the calculated net weight into the system. Data is automatically saved when entered to guard against accidental data loss.

Real-time process feedback

Tim Stutzman, OFD's manufacturing systems analyst, has configured the Synergy 2000 program so that the operators monitor the process using a combination spreadsheet display, along with the corresponding control chart for net weights. “It's a very proactive system,” says Stutzman, “because it helps identify problems on the spot.” Data points on the control chart are color-coded in green, yellow or red to indicate whether the samples are within control limits, trending away from the target weight or out of control. “If out-of-control conditions occur, the operator can immediately adjust the machine to bring the weight back within acceptable limits,” he explains.

“It's an extremely useful function, and it has saved us a lot of money preventing potential rework. As you can imagine, rework can become a major expense, since it involves doing your work twice.”

Not only is the software having a financial impact on the business, OFD has also observed a higher level of ownership for the work performed by operators and greater pride in their output. “This tool has instilled in them a better sense of control. They see the big picture of the process, are able to hone in on a cause when things go wrong, and assume direct responsibility for taking the proper corrective action,” Stutzman says

The overall success of the SPC implementation hinges on the rigorous training program all operators participate in. First, there are three sessions on SPC concepts for a total of four hours in the classroom. They then receive an additional hour of training on Synergy 2000.

According to Stutzman, “What's so fascinating is seeing them make an instant connection between the SPC basics and the software. They know immediately what the software is telling them. It's a very user-friendly piece of technology. Within minutes, they feel comfortable using it.”

Data flexibility

On the analytical and reporting side of the process, OFD can quickly query the data and view the results in spreadsheet, chart, customizable report or e-mailable formats. The flexibility in working with the data comes in handy during on-site customer audits, when lot traceability needs to be conducted or for continuous-improvement efforts.

For example, packaging engineers study the historical data using histograms and work with capability studies to determine if specification limits can be tightened. If so, they adjust the process targets, refining the process over time.

Software helps customers

The software also helps OFD customers with their commercialization process by rolling out new products faster, with minimal packaging issues. “When these opportunities present themselves,” Stutzman says, “engineers perform tests on the packaging lines, import the data into Synergy 2000, generate a selection of charts and analyze the results. The charts are an excellent means of communicating our process capability to the customer.”

OFD's partnership with software developer, Zontec, is proving to be a worthwhile investment. “Of all the SPC systems available, Zontec best fits our application” concludes a pleased Stutzman. “We know our weights are consistent. We know we're saving money. We know we're reducing rework. We know we're not giving away as much product. We know we're not taking on new items that we don't have a process for. It keeps us focused on what's important.”