100% In-line Seal Inspection of Retort Pouches for Wet Pet Food

Special Dog Company, one of the top pet food producers in Brazil, innovates with in-line inspection of its retortable pouches.

Wet pet food manufacturing is a complex process, and it takes careful attention to consistently guarantee a top quality, healthy and tasty product. Sealing of the filled package is the culmination of all processing steps and protects the food’s quality once shipped from the plant. Incompletely sealed packages, and packages with product spillover outside of the seal, both negatively impact the packaging processes. Exposed product results in contaminating machines, lost production, and extra labor in the form of cleaning and manual sorting of bad packages. If these badly sealed packages escape the production site, the impact can be even greater, with potential risk for expensive product returns, recalls, and brand damage. That’s why Special Dog Company invested in a 100% in-line seal inspection to guard the quality of the seals.

Brazil’s Special Dog Company is one of the largest petfood manufacturers in South America, serving 11 countries.Brazil’s Special Dog Company is one of the largest petfood manufacturers in South America, serving 11 countries.Established in 2001, Special Dog Company is today one of the four biggest pet food producers in Brazil, selling in that market plus 11 other countries. In 2019, the company deployed an ultra-modern wet pet food factory to increase the product portfolio to keep growing in the market.

“The sealing of flexible packages is a critical phase in the packaging process,” says Octávio Soberón, Manager of Wet Pet Food Division. “Even with top quality packaging machinery, bad seals could occur from time to time.” Defective seals are often caused by wrinkles, folds, or product in the sealing area, and lead to open or leaking packages.

Wet pet food is especially prone to sealing concerns because the recipes frequently use glutinous sauces or gels. These easily can stick in or around the pack’s sealing area during the filling process.

Bad seals don’t just affect traditional packaging equipment. They are a major concern during the sterilization process, as when the pet food is heated, it might leak and pollute the autoclave. The disruption to production and man-hours for autoclave cleaning has a domino effect in cost. Worse, if compromised packages are not detected they can lead to reduced shelf life and liability for health risks.

“Packaging is also responsible for making sure the product gets from the factory, through transport and distribution, and on to retail and the home without any loss to the integrity of the product,” says Soberón. At the latter end it may also be responsible for providing barriers to oxidation and moisture migration which can affect palatability and the nutritional composition of the product.”

100% Seal InspectionThe sealing bars of the rotary packaging machine are equipped with SealScope™ sensors that detect product in seal, wrinkles and folds that cause leaking packages.The sealing bars of the rotary packaging machine are equipped with SealScope™ sensors that detect product in seal, wrinkles and folds that cause leaking packages.
Delivering quality products is one of Special Dog Company’s corporate values. This requires investment in top equipment, well-trained people and refined quality procedures. Special Dog Company is certified with many international quality standards and this vision of quality has also resulted in multiple awards as Best Workplace in Latin America, in 2019. Maintaining quality at the highest level also needs continuous improvement in quality procedures and equipment.

For the packaging of the wet pet food, Special Dog Company deployed a Toyo Jidoki rotary pouch packaging machine. To inspect the sealing of the retort pouches, the company extensively researched the market and finally opted for SealScope™, an in-line seal inspection system from Engilico.

SealScope offers a unique approach for in-line seal inspection, according to the company. Vibration sensors are retrofitted on the sealing jaws of the dual-lane rotating packaging machine, at two stations in the carrousel.

During the closing of the sealing jaws, the vibration response is measured and compared to a reference model of correctly sealed packages. When the deviation is higher than a user-defined limit—whether the cause is from product in the seal, wrinkles, or folds in the seals—the package is rejected. This automated inspection leads to immediate benefits. Every single package is inspected, so manual inspection can be reduced or drastically reduced. By rejecting the defective packages, the outgoing quality is instantly increasing.

“The non-destructive seal testing made directly on the sealing bars greatly improved our effective line efficiency from previous manual inspection methods,” says Soberón. Special Dog Company still maintains a random sampling for physical inspection process, as it is needed to comply to their internal statistical quality control standards, but with a much lower number of samples than before. These random samples undergo destructive burst testing amongst other human inspections, requiring 5 to 6 mins/package.

“The main benefit of SealScope in-line seal inspection is to have a good night of dreams, instead of dealing with quality nightmares,” Sobéron says. “Special Dog Company is delivering a 100% inspected product, which means satisfied consumers.”

Leaking packages need to be avoided to prevent outgoing product quality issues and the soiling of packaging machinery.Leaking packages need to be avoided to prevent outgoing product quality issues and the soiling of packaging machinery.Optimizing the packaging process
As SealScope inspects every product, it also serves a continuous monitoring system, not only for the sealing process but indirectly for the complete packaging line. When the repeatability of sealing process varies, this indicates systematic errors in the packaging process.

The system generates user-defined warnings, so the operator can take preventive corrective actions, for instance cleaning of the sealing station or replacement of the Teflon protection foils. As such SealScope helps to avoid further process drift and to keep the machine in optimal shape.

The system also enables operators to optimize the productivity of the packaging process. Often packaging machines run either too slow (to get acceptable quality) or too fast (with an adverse effect on quality). Using SealScope, one can determine the optimal machine speed where production output and package quality are maximized.

With the ever-increasing demand for high-quality wet pet food, Special Dog Company plans to further extend their production capacity. “For the installation of the new line, Engilico’s SealScope system is going to be there, for sure,” Soberón says.

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