Adhesives at Work: Innovative Label Adhesives Meet Today's Packaging Demands
Hot-melt adhesives and solvent-free acrylic adhesives offer solutions for food and beverage product labeling.
Food and beverage packaging has come a long way since the prehistoric days of using natural materials like leaves and gourds for containers. Today’s food and beverage industry demands packaging that’s far more sanitary, innovative and eye-catching than what nature can provide.
Two popular packaging trends include the use of squeezable containers and labels that can withstand high-pressure processing (HPP) to create standout packaging. Although these packaging trends satisfy market demands, they pose some challenges when it comes to applying labels to the packaging.
Trends and Label Adhesive Demands
Traditionally, food packaging and beverage labeling have relied on paper labels. However, as the need to influence consumer purchasing decisions has increased, so has the importance of eye-catching packaging. With just seconds to grab the attention of a consumer, food and beverage manufacturers have developed innovative ways to package their products and make them stand out on store shelves.
Squeezable and odd-shaped containers make up a large part of food and beverage packaging. They are often used for products like ketchup, honey, chocolate syrup, ready-to-drink sports drinks, vitamin waters, juice and more. While this type of packaging is certainly unique and eye-catching, it poses some challenges for labeling.
Being able to account for the unique shape of a container and its squeezability can greatly impact the labeling chosen for these products. Labels on these containers need to resist edge lifting, film creasing and the adhesive pulling off. In addition, the label needs to be able to conform to these odd shapes and show no signs of creasing, even when continually compressed.
Squeezable or odd-shaped packaging isn’t the only trend in the food and beverage industry today. With the growing popularity of processed foods comes the challenge of making sure bacteria does not grow. Most processed foods are heat-treated to kill bacteria. While heat-treating makes the foods safe to consume, the process can destroy the product’s quality. High-pressure processing (HPP) is used now to provide an alternative means of killing bacteria that can cause spoilage or foodborne disease without the loss of nutrients.
HPP pasteurizes foods and beverages by uniformly applying extreme hydrostatic pressure around and throughout a food product, deactivating the cellular activities of foodborne pathogens and other spoilage organisms. HPP is applied when labeled products are in their preparation stages. The packaged product is submerged in cold water (approximately 35°F) in a pressure vessel. The pressure inside the vessel is raised to an extreme level, usually about 75,000 psi, for three to five minutes. Next, the product leaves the pressure vessel dripping wet and moves on to the drying cycle of the process.
Pressure-processed foods typically feature better nutrient retention, texture and color when compared to heat-processed foods. Although HPP is effective in killing bacteria while retaining the quality of the food, it can be a challenge to label the product properly. Food packaging that endures HPP requires a label adhesive that can withstand high pressure (as well as wash and drying cycles) while maintaining a desired look.
The market trends of squeezable packaging and HPP each present a unique set of challenges when it comes to label adhesives. The adhesive and labeling industry has worked hard to develop and provide innovative solutions that not only stand up to these challenges, but help enhance the aesthetic appeal of the product packaging.
Label Adhesive Technologies
Changing food and beverage packaging demands require label adhesives that have excellent tack and provide an appealing look on store shelves. For squeezable food and beverage packaging surfaces, the label adhesive solution is a solvent-free acrylic adhesive on a squeezable polypropylene film. And for labels that can withstand HPP, hot-melt adhesives are a viable option. Each of these adhesives has its own set of properties and advantages for these packaging demands.
Squeezable polypropylene films answer the growing need for label conformity in unique food and beverage packaging. This type of film is designed to have the resilience and conformability of polyethylene-type label films, but with the added advantages associated with polypropylene. Squeezable polypropylene films with solvent-free acrylic adhesives provide excellent tack and ultimate adhesion for a variety of low-energy surfaces, including PET, HDPE, LDPE, PP, and others.
Not only will this type of film adhere nicely to packaging, film labels also are more durable and moisture resistant, and can give a “label-less” look vs. paper labels, making them appear more vibrant on store shelves. Film labels enhance the aesthetic of the packaging by providing bolder-looking graphic designs. In addition, solvent-free acrylic adhesives offer features like extended open time, excellent clarity, non-water whitening and high service range.
While polypropylene films with solvent-free acrylic adhesive conform to unique shapes of food and beverage packaging, processed foods that undergo HPP require label adhesives that solve a different kind of problem. Hot-melt adhesives allow for labels that can withstand intense high-pressure processing cycles. Rubber-based hot-melt adhesives have excellent tack and ultimate adhesion to a variety of surfaces, and hold up to high-pressure processing cycles. They’re designed to go on and stay when applied to food and beverage packaging.
Since the packages are immersed in water during the process, labels need to be water resistant; hot-melt adhesives provide this feature. In addition, hot melts can withstand dampness and maintain both adhesive integrity and aesthetic appeal throughout high-pressure processing. In addition, hot melts can be formulated to be nearly invisible on packaging, adding further to their aesthetic appeal.
Choosing the Right Adhesive
As the food and beverage industry’s packaging requirements evolve, it’s important to consider the performance of the adhesive on the label of the product. Innovative packaging and processes demand label adhesives that can withstand packaging processes, influence how the consumer interacts with the product, and provide excellent tack to ensure that the label stays in place throughout the life of the product.