Consumers clamor for easy-open packages in research report after research report—many times appearing as the No.1 complaint when it is not a feature of the packaging. Yet, in today’s safety-conscious environment, the need to assure customers that your product is safe to consume or use is ever present.

Adhesives expert Pierce Covert, president of Glue Machinery Corp., shares advice about balancing secure package sealing and tamper-evident/theft-prevention packaging with easy-open convenience.

How can brand owners and suppliers work together to develop a package that is easy for consumers to open while maintaining the seal integrity needed to protect the product from tampering/pilfering during distribution?

Covert: First and foremost, brand owners must clearly explain to marketing and design companies: exactly what their package needs to look like; the functional integrity of the package; all details of the product it is going to hold; how long it’s going to carry (the product); and the shelf life of the product. The converters provide the actual materials that come together to create the package, so it’s important to consider the content of the materials to be used.

When the converters create the package—when it’s actually being made into a box with scores and folds—they need to know exactly how that runs through automated machinery. Often these factors aren’t taken into account. For example, boxes are over glued or under glued, or the opening characteristics that the end user experiences are not exactly what the brand owner had in mind.

In the production of cases and case sealing, you typically would want to apply a certain adhesive bead profile—multiple bead profiles onto the minor flaps or major flaps, compress them properly and allow for relatively easy opening with noticeable fiber tear to the package. Generally, companies do not want to ship boxes and cases that end users must open with a knife, which can result in damage to the cartons or the products inside the case. Most people who stock shelves want to be able to easily get into a case—usually pop it open and not put a whole lot of effort into doing that.

This also applies to smaller cartons. You’ll often find that cartons that are difficult to open must be pried open and this destroys aesthetics of the carton. Also, when carton flaps are torn they can be difficult to reclose for future use.

Also, when something is extremely difficult to open due to the incorrect glue quantity or placement, it can be discouraging for the consumer.

The goal is to apply the correct adhesive in the correct quantity, and compress it between two flaps of material to allow the flaps to be opened with ease, yet showing some destructive qualities between the two substrates.

So you'd need to make sure you’re sealing the package so it would be easy on the target audience to open. You mentioned an older audience or children perhaps.

Covert: All users should have the same positive experience with opening a package and consideration should be given to whether this is a single- or multi-use package? Is the package used like a cereal box, where you want to open and reclose it, and use it four or five times? If you have to completely shred the lid of that box to get into the package, it affects the multi-use functionality of the package—and the aesthetics of the package are compromised.

In terms of working together, brand owners and converters need to figure out what they want their box to look like. They need to get with the box manufacturers to actually create a box that will fold and, of course, come together as needed.

Adhesive suppliers need to provide the correct adhesive to bond, but another important factor is the equipment that’s used to apply (the adhesive) and compress it. It's a combination of efforts between the brand owners, converters, box manufacturers, adhesive suppliers, adhesive machinery suppliers and equipment used to do the actual packaging.

What information do adhesive machinery suppliers need from brand owners or converters—to offer good advice?

Covert: We need to know what the substrates are. We need to know what the speed of operation on the packaging line. We need to know what the overlaps of the flaps are like. We need to know, when the flaps are compressed, if there is any deflection of the minor flaps between the major flaps. We need to know the compression used to close the flaps. We need to know the weight inside the box. We need to know what kind of temperatures that package might experience. We need to know if there’s elevated temperature of the product when it’s put into the package.

You had mentioned something about semi-destructive characteristics of the adhesive bond. This is tamper-evident packaging. Is that a consideration in food packaging safety?

Covert: Yes. When you look to purchase a product, you want it to be evident that the package has been opened. A package that has been properly glued and opened will show clear signs of fiber tear between the flaps. Once opened, it’s difficult to reseal and difficult to conceal that it was opened at one point. Tamper evidence is very important.

Are there any adhesive considerations that play into preventing contamination?

Covert: Box design and proper adhesive sealing are extremely important.

For all packages you want to minimize any chance of dust, dirt or critters entering the package. Proper adhesive pattern placement can effectively seal a box and should be considered in all applications to include RSC (regular slotted container) and FOL (full overlap) cases.

Some cartons are called “sift proof,” and are designed to keep something like rice or sugar from leaking out of a box. We run a series of patterns between minor and major flaps that completely seal/caulk in the product.