An old industry saying cautions, “Secondary packaging is the last thing on your mind but the first thing your customers see.” Even if product isn’t packaged to be retail ready such as for a shelf display, this statement rings true because secondary packaging plays a key role in making sure the primary package — or what the consumers see — is intact. For this reason, it can’t be overlooked or given less thought than other steps in the manufacturing process.

While there are a variety of materials such as plastic crates, trays and flowwrap used for secondary packaging, common methods include the use of paperboard cartons and cardboard boxes. Bags and pouches as the primary package for snacks and baked foods require additional structure — bag-in-box — if not to create an organized shelf display then to provide safety in transit.

The functions

There are essentially two types of bag-in-box configurations, said Bill Kehrli, vice-president of sales and marketing, Cavanna Packaging Group. Oftentimes, single-serve snacks, crackers, cookies, cake mixes and cereal cannot stand alone on shelves and are placed in cartons, which become the display packaging. Multi-count packages for snacks such as chip varieties are another way these cartons are used.

Some pouches and bags are shelf ready, and though they might be the type of packaging consumers want, these pliable materials can’t defend the bakery product during distribution. They require a corrugated case, which is filled with multiple bags and pouches depending on the size.

“For frozen bagels, for example, a manufacturer will use a bag-in-box format where the primary package would be the bag and secondary would be the case,” Mr. Kehrli said.

In the latter bag-in-box format, the case provides stacking support for palletizing.

“Corrugated is a top choice for its strength and recyclability,” noted Bryan Sinicrope, vice-president of sales and marketing, A-B-C Packaging Machine Corp. “There are many options from full regular slotted container cases to trays to wraparound cases. Another consideration is sealing style, whether adhesive or tape.”

Even though cartons containing bags have a rigid structure, they’re packed in a corrugated case in most situations to provide additional stability and eliminate extra movement during transport.

“The individual case provides the majority of the protection,” said Craig Walker, marketing director and portfolio manager for cartoning, R.A. Jones.

Many cartons are made from paperboard. This generally less-expensive option can be recycled; however, Jerry Buckley, south central regional sales manager, BluePrint Automation, Inc. (BPA), is seeing an increase in the use of thinner E-Flute and F-Flute corrugated board. This material allows the regular display characteristics for a carton bag-in-box and eliminates the need for a shipping case, resulting in a smaller contribution to the carbon footprint.

Mr. Kehrli predicted e-commerce will affect how consumers perceive packaging and how companies make secondary packaging choices due to the decrease in cartons for sustainability purposes.

“Back in the day, when people first started using cartons, it was to provide strength so the product wouldn’t be damaged,” he said. “But since then, we’ve optimized everything. Pouches have skyrocketed. If you eliminate the carton, primary package can go straight into a case.”

The challenges

While sustainability concerns remain with secondary packaging, there are additional obstacles to overcome. One of the biggest complications with bag-in-box is the secondary packaging’s correlation with the primary packaging, specifically with retail-ready cartons, as retailers dictate their guidelines.

“As shelf space is increasingly limited to the manufacturers, their carton sizes are required to stay at a minimum to fit in their allotted space,” Mr. Buckley said. “Therefore, the product fit in the cartons is often very tight, so placement in the proper pack patterns has to be very accurate. Bag fills also have higher volumes in each bag these days, making product and bag film control loading into the cartons very critical.”

For baked snacks, most of BPA’s cartoning equipment uses vision-guided robotic loading, a flexible option for carton pack patterns. Products ride on conveyors throughout the system, and the machine picks up and loads one or two products at a time — in a variety of orientations — tightly into the cartons or cases, allowing for a jam-free process. The system also includes product inspection to eliminate bags that will have a packing issue.

Fitting bags into a box and leaving just the right amount of space with the interface can be challenging.

“In some cases, the product transfers need to be customized to synchronize, orient and collate the product correctly before entering the secondary packaging equipment,” Mr. Walker explained.

R.A. Jones’ bag-in-box applications have features that focus on bag control and carton opening to help customers run at higher speeds and efficiencies.

To mitigate spacing issues with bulk delivery goods such as bagels and bread, Wexxar Bel has a BEL 450 machine with a vacuum that opens a liner or poly bag up when the case is formed. Not only does this allow the bag to be formed to the inside of the box, but it also is done without an operator needing to touch the inside of the bag, which reduces the risk of product contamination and increases efficiency.

With one of the biggest goals of secondary packaging being to protect the bag inside, another obstacle is damaged boxes, which in turn can damage the primary packaging.

“We build in features to compensate for issues that commonly occur on the packaging line: out-of-spec or warped corrugated cases and package variation,” Mr. Sinicrope said.

A-B-C Packaging Machine Corp.’s case erectors include top load magazines to fix warped and band-marked cases as well as a squaring device that can align boxes — even those that were damaged during production. Palletizers also may incorporate a feature that squares a load of boxes to verify a tight fit and maximum stability during shipping.

Retail-ready bags and pouches are typically required to stand up on store shelves. If stood up in cases during distribution, these packages can sag, ruining the product and creating spacing issues. Now, packaging systems allow them to be laid flat in the cases without hurting product and can be easily lifted when going onto a shelf, Mr. Buckley said.

Although improvement solutions are always unfolding, secondary packaging technology has come a long way.

The solutions

Advances in automation have kept up with the bag-in-box format, even as it evolves with consumer preference and retailer demands.

“Flexibility of the equipment and good product control allow for future packaging material, future products and future pack pattern changes,” Mr. Buckley said. “As the demands of larger chain stores and club stores often dictate smaller product runs by the manufacturers, this means more line changeovers throughout the day. One of the key features of modern secondary packaging automation is also the ability to allow for quick and easy size-changeovers of the packaging machinery.”

Mike Parkinson, product manager, IPAK product line, Wexxar Bel, also has noticed the improvement of flexibility and reliability for secondary packaging through servo technology. This is especially important for adjusting case sizes for overall efficiency.

The ability to alter a format using the same machine can save time and money.

“The biggest changes in secondary packaging equipment include more sanitary design, product and package type flexibility, quicker and more repeatable changeovers, and improvement in machine efficiencies or overall equipment effectiveness,” Mr. Walker said.

R.A. Jones’ Criterion Cartoners technology adapts to a wide range of carton sizes, in addition to product formats and speed capabilities — low, intermittent, medium and high. Mr. Walker said it is also easy to operate.

Mr. Sinicrope acknowledged advancements in secondary packaging, such as new control technology that allows companies to receive complete reports for production management, and features for greater flexibility and faster changeovers. He also noted that robotic packing and palletizing systems have paved the way for better and faster bag-in-box automation. A-B-C Packaging Machine Corp. incorporates these methods in its complete line, which includes case erectors, robot packers, case sealers and palletizers.

While flexibility and efficiency have improved the process for bag-in-box, the initial goals for secondary packaging must be top of mind when baking and snack companies decide what equipment will work best to drive a reliable operation. These secondary packaging goals — to provide shelf presentation and in-transit protection — ensure the product inside is intact and ready for consumers.