From regulations to sustainability, a number of factors are critical for adhesive selection when producing a high-quality label. The adhesive must withstand a wide range of conditions, including moisture and extreme temperatures, to name a few, in order to satisfy a brand’s requirements.

The newest products hitting the market have been optimized to mitigate risk and cut costs, all while delivering a high-performing label. Selecting the wrong adhesive can be damaging for the converter and the brand alike.

“Ideally labels need to promote the brand, inform customers of health and safety information on the product, and leave the product looking just as good at disposal as it did when the product was first purchased,” says Kim Hensley, senior marketing manager, Mactac North America. “Brand managers and packaging engineers want a label that prints great, is positioned correctly, and has superior, lasting adhesion.

“A recent statistic in a June 2016 consumer insights study by WestRock says roughly 65% of consumers have admitted to trying something new because the package caught their eye,” adds Hensley. “Likewise, according to Business Insider, first impressions take about seven seconds, making subsequent judgments based on quick information. Given facts like these, consider how cold food sales would fare if packages featured labels that were falling off or had fallen off.”

Brand owners are cognizant of this fact, too. Even though adhesives might not be associated with shelf appeal – they play a huge role in a label’s appearance.

According to Andrew Wasserman, managing partner at Cyngient, using the right adhesive can serve as a cost-effective method of optimizing packaging shelf appeal, resulting in more sales and profits. He explains, “When we look at the cost of inks, coatings and adhesives, they make up a small amount of total costs – around 2-3% on average for the total cost of producing a label. Yet purchasing agents continue to drive costs down, which can impact creativity. The brand owners suffer in the end – with fewer options and without innovation. At Cyngient, we change that. We’re excited to partner with label manufactures that want to offer their customers best-in-class brand enhancement technology while improving their bottom line.”

Selecting the wrong adhesive can also lead to a bad consumer experience on the shelf. “If you are looking for a sticker that can easily be removed – say for a price/marking label – but you get the wrong adhesive, it can be stubborn or may not be removed at all, leading to a bad consumer experience,” remarks Lauren Kalb, Avery Dennison R&D director. “If you are looking for a wet-strength adhesive for wine but you buy the wrong one, it could result in your label being ruined in the ice bucket and hurting your brand.”

To select the right adhesive, it is key to understand the application’s surface, conditions and longevity of the applied label. “There are a variety of risks when selecting an adhesive, ranging from complete incompatibility to failure to meet required regulatory compliances to failure to meet performance requirements like tight mandrel resistance or ultra-removability. Plus, there could be edge lifting or adhesive ooze, damaging consumer goods and adhesive transfer to consumer packaging,” states Melissa Harton, marketing manager, North America, Acucote, part of Fedrigoni Self-Adhesives. “In cover-up situations, if the blockout is not opaque enough, you face transparency issues.”

According to Dan Riendeau, strategic business unit manager, packaging, FLEXcon, if labels lift or bubble, or the adhesive oozes during production, print service providers will be frustrated with incorporating that label material into their production line.

“For clear labels, clarity of the adhesive is also a consideration for achieving optimum visual aesthetics,” he adds. “Following production, performance in the intended end-use environment is also essential. For consumer packaging, this includes possibly damp and humid conditions such as the shower and/or temperature extremes like the freezer.”

Hot-melt adhesives are certainly trending in this space. In many cases, they are challenging the commonly-used emulsion-based adhesives.

“Traditionally, cold food labels have included either solvent-based or emulsion-based adhesives. However, due to recent efforts to reduce VOC (Volatile Organic Compound) emissions and improve air quality, solvent-based adhesives are being used less and less,” states Hensley. “This is paving the way for an economical, more environmentally friendly adhesive option – hot melt. Today, hot-melt adhesives are giving the commonly used emulsion-based adhesives a run for their money. In addition to environmental benefits, emulsion-based adhesives are known for advantages such as ease of use, safety and strength. And, while many adhesive suppliers agree that emulsion-based adhesives can be an excellent adhesive option, when it comes to cold or frozen foods and beverages, most will agree that hot melt is the superior choice for quick tack and lasting adhesion.”

The adhesives space has not been immune to the continuing supply chain challenges, either. Ross Hodnett, product manager, durables, FLEXcon, comments that it is more important than ever for converters to identify suitable backup or alternative materials.

In the durables landscape, adhesive performance is under immense scrutiny. These adhesives must withstand the harshest conditions. For example, insufficient wet-out over rough or textured surfaces will cause poor adhesion, and chemical and solvent exposures can dissolve or react with the adhesive and create failures.

“Oily surfaces need specific adhesives that can absorb the oil and still create a good bond,” notes Hodnett. “Low surface energy plastics simply do not allow for strong adhesive bond unless very high-performance options are used. At the end of the day, use of the wrong adhesive for the surface requirements of the end-use label or the anticipated environmental conditions will result in labels that don’t adhere properly. Furthermore, should warning labels fall off and injuries occur, potential legal liability will be a real threat for the equipment manufacturer.”

Sustainable solutions that stick

The label and package printing industry is continuing to take strides to leave a better carbon footprint, and adhesives manufacturers are no different. Despite the current supply chain challenges that may have temporarily put sustainability on the backburner, suppliers are continuing to innovate in this space.

Numerous suppliers are seeing an increased desire for Association of Plastic Recyclers (APR)-approved products, and product approvals from organizations like the APR remain a high priority. Acucote’s Harton notes, too, that understanding the recycling identification code and the package’s end-of-life destination helps raw material suppliers design sustainable labeling solutions.

“APR permutations are also evolving, which allows labelstock manufacturers to submit new product combinations and expand their portfolio,” explains Acucote’s Harton. “Compostability is another significant player, as customers desire this type of adhesive. To date, we are encouraging vendors, as they make component improvements or develop new adhesives, to keep compostability in mind. An alternative is biodegradable adhesives, too. Acucote’s CP1 provides customers a biodegradable solution.”

Avery Dennison is targeting renewable resources and recycling capabilities with its newest adhesives. Throughout all of Avery Dennison’s regions, the company is directly introducing renewable content into some of its emulsion and hot-melt adhesive products, advancing more sustainable solutions without adding cost or sacrificing performance.

To meet its 2025 Sustainability goals that 70% of chemicals the company buys conform to, or enable end products to conform to, its environmental and social guiding principles, Avery Dennison is in the process of removing banned chemicals of concern as listed in the company’s restricted substances list.

“Our direct use of renewable content, as well as our adoption of a biomass balanced approach, is industry-leading innovation that is advancing a circular economy and fulfilling our goal of ensuring that 100% of our standard label products will contain recycled or renewable content,” says Avery Dennison’s Kalb. “Too much recyclable PET plastic ends up in the waste stream because of contamination from conventional labels, which don’t separate cleanly during the recycling process. Our CleanFlake label materials feature a breakthrough adhesive that allows the label and package to neatly part ways during the recycling process, improving yields of recycled PET plastic.”

Understanding the anticipated life cycle of the container and the label at the development stage is critical to maximizing the chance containers will be recycled rather than wind up in the landfill, adds FLEXcon’s Riendeau. “The APR has published guidelines to help printers and brands design labels and choose label materials that will help ensure container recyclability and minimize the chance of contamination of the recycle stream.”

Looking ahead, the newest adhesive innovations have the potential to pave the way for the future of labeling. “New UV hot-melt coating technologies are allowing pressure sensitive film manufacturers to coat adhesive without the need for water or solvent carriers, thus reducing both the solvent and water waste in the adhesive coating process and the energy used to ship the materials,” says FLEXcon’s Hodnett.

Regulations and requirements 

When dealing with regulations, which are ever-changing, adhesives must meet the requirement(s) provided by the customer. Since North American regulations change frequently, it is important for suppliers’ technical teams to stay up-to-date on all the latest global requirements.

UPM Raflatac has gone to great lengths to ensure that its products can satisfy a wide range of food labeling requirements. “UPM Raflatac is proud to say we are the first self-adhesive laminate supplier to have all their factories in the US certified according to the ISO 22000:2018 Food Safety Management System standard,” notes Bruce Ruppert, product development manager, UPM Raflatac, Americas. “One aspect of that standard is that our product development teams ensure that the adhesive being developed and recommended for specific end uses meet the regulatory requirements for those applications. We consider these compliances to be as critical to the quality of the label as the label adhering to the package during development of adhesive and laminates.”

“By following these regulations we have to make sure our labels are meeting customers trends and shelf appeal expectations but also formulating using substances in our food contact products that are GRAS (generally recognized as safe) or meet established safety limits and requirements,” adds Avery Dennison’s Kalb.

Label converters should ask numerous questions when getting into the food labeling space. How will a food be packaged, and where will it be stored? What container type will be used? Will the label need to withstand harsh conditions such as pasteurization, refrigerator, freezer, or ice chest? Is direct or indirect food contact a possibility?

“Food labeling is one of the most challenging segments in consumer packaging,” says FLEXcon’s Riendeau. “Understanding the requirements of each application is key. These are variables that converters and label suppliers need to understand when providing recommendations to brands and end users to ensure regulatory compliance and application success.”

While perusing the shelves in the grocery store, one might often wonder how these cold or frozen products got from their original location to the store – all while maintaining freshness. The packaging plays a monumental role in that endeavor. Adhering to any number of mandates helps ensure freshness, which is important for the health of brands and consumers.

“In today’s cold food industry, refrigerated and frozen food manufacturers are faced with an increasing number of challenges, from making sure products are easy to ship and transport to meeting necessary compliance regulations and more,” comments Mactac’s Hensley. “And, while product packaging and labeling might not seem important in the overall equation, these two finishing components are vital to ensuring products make it through the cold food chain successfully. In order to keep the products fresh and protected, there are many factors manufacturers need to consider such as storage, shelf life, varying environments and temperatures, the possibility of food-package interactions, costs and branding. And although cold food labeling comprises just one small piece of the entire packaging process, should the label fail, the resulting implications can be enormous.”

“If we are told that the label will be applied to HDPE films for frozen food, we would recommend our All Temp RP48 adhesive if minimal condensation is present or our RH03 adhesive if the substrate has significant condensation,” explains UPM Raflatac’s Ruppert. “A standard general-purpose adhesive would typically fail in this type of application.”

Food labeling, in particular, has a multitude of adherences. “Typically, in food labeling we are asked for indirect food contact 175.105 or direct food contact 21 CFR 175.125 Paragraph B,” states Acucote’s Harton. “We do receive inquiries for other regulatory compliances, and these are addressed on a project basis. Our DFC, direct food contact adhesive, is both 21 CFR 175.125 Paragraph B, FDA 175.105 and acid free.”

According to Kyle Strenski, business director, UPM Raflatac, Americas, the considerations for food are quite extensive. Other packaging considerations for adhesive-use include glass, PET, PP, HDPE, flexible films, paper, and metal.

“Let’s not forget about the process the food goes through that can impact the adhesive requirements,” remarks Strenski. “HPP, flash freeze, heat, spraying with liquids, shipping in containers and more are all relevant. These different conditions and requirements could mean the adhesive has to be indirect food contact-approved, different application temperature ranges, high coat weight, ultra-clear, non-water whitening, and the list goes on.”

In addition to food labeling, there are many segments that require durable labels. UL is the most significant agency for the successful application of these products. In fact, UL 969 recognition is a prerequisite for many printed label parts in the durable labeling space. Plus, BS 5609 recognition for drum labeling is another important classification for durable labeling. It applies specifically to applications for GHS compliant labels on petrochemical drums and hazardous material containers.

“Our R&D team performs the testing required to meet the UL 969 standard for any new product FLEXcon produces so that we can offer a pre-qualified product to the market,” says Hodnett. “Additionally, the team helps with testing to add new recognitions for existing products, which is an ongoing pursuit as print technologies continue to change.”       

Product innovation

Acucote, part of Fedrigoni Self-Adhesives, has engineered its newest products to meet demand for acrylic adhesives, with new offerings for both cold temperature and removable applications. The company’s OL2 adhesive is ISO 10993 endorsed and deemed safe in medical device applications with direct contact to skin surfaces. This acrylic was re-engineered and no longer contains endocrine disruptors, as did its predecessor.

“Another advancement was changing our permanent freezer grade from a rubber-based to acrylic. By moving to Arctic, our new acrylic, Acucote improved coater efficiencies and improved productivity,” says Harton. “GR7 is another success story. GR7 is a special performance removable, and its technical advancement is its performance functionality. It provides a low temperature removability and services applications that previously could not be achieved with our portfolio.”

In North America, Avery Dennison has its Adhesive Center of Excellence in Mill Hall, PA, which is dedicated to creating products that are more sustainable and offer new functionality.

Most recently, Avery Dennison unveiled its new hot-melt adhesives, C4500 and C4510. Compared to the previous generation of hot melts, these launches are friendlier to the environment and maintain minimal adhesive bleed, the company says.

“To help meet our 2030 Renewable Content Sustainability goals, these adhesives have been developed with renewable agricultural resources – C4510 contains 40% renewable content and C4500 contains 45% renewable content and is a USDA Certified Biobased Product,” says Kalb. “They also help converters improve press efficiency.”

Cyngient offers a comprehensive portfolio of adhesive products, including HYPERcolor, part of Cyngient’s HYPERcure line of structural adhesives. HYPERcolor, touted as a new method of brand enhancement, is a pigmented cold foil adhesive that is a low-cost alternative to hot stamping that also expands the gamut of cold foil colors.

“HYPERcolor offers true innovation,” says Wasserman. “It creates an expanded gamut of cold foil colors – utilizing just silver foil and a single print station – which brings down the total of overall costs when compared to pigmented foils. HYPERcolor also provides shrink sleeve converters with an eco-friendly solution that is Nestlé-compliant and adheres to California Proposition 65, all while providing a lower migration option to standard adhesives.

FLEXcon has debuted several new adhesives in its portfolio of flame-retardant products. FLEXcon L-59FR Series has been developed  specifically for the transportation industry, as it meets federal motor vehicle safety standards (FMVSS 302), complies with certain federal aviation flammability requirements under FAR 25.853, and is now commercially available for specific applications in the automotive and aerospace industries.   

CHILL AT by Mactac is an all-temperature label material specially formulated for demanding cold temperature applications – and works well at room temperature, too. CHILL AT labels have a versatile temperature range of -65 to 150 degrees Fahrenheit (-54C to 65C) and an application temperature of -10 degrees (-23C). This makes them ideal for refrigerated and frozen food labeling, as they were designed to stick quickly and stay in place, especially when temperatures go below 40 degrees Fahrenheit. 

“We also offer polypropylene labelstocks that meet the highest recyclability standards in PET bottle labeling,” says Hensley. “Our polypropylene labelstocks with PUREfloat adhesive are recognized by the APR and meet critical guidance recognition.”

UPM Raflatac has designed its newest products with an eye on sustainability. UPM Raflatac’s RW85C adhesive was specifically designed to meet APR requirements when paired with polypropylene facestock. UPM Raflatac is committed to providing brand owners products that make packaged material more sustainable, comments Ruppert.

“We provide products in our SmartCircle (using and enabling recycled material) and SmartChoice (using renewable sources for labels) lines,” he explains. “Our RW85C wash off adhesive for PET containers is another example of enabling recycling.”