Packaging is massively changing due to increased shipping and changes in the way people eat or use products. This can create more demands on manufacturers to be sustainable, cost effective and timely with delivering the supplies needed. While heat seal technology can greatly help with these needs, it’s important to know how the performance of a heat seal could impact your product.
How is a Heat Seal Different From a Cold Seal?
Heat seal bonding properties can differentiate from cold seal bonding in numerous ways. Both are used in food packaging, but they can provide a range of outcomes depending on how they’re used.
Cold seal adhesives are known for self-sealing bonding. They are often used in packaging for candy, chocolate, ice cream and cereal. Cold seal adhesives can also be utilized for fill and seal packaging, bandages in medical packaging, as well as mono-web and laminate materials. While cold adhesives can provide fast processing times like a heat seal, they are sensitive to air contact. They can also lack chemical resistance to certain materials, which could create processing requirements by the FDA. While cold seals are excellent for certain applications, these packaging formats may be more successful with other sealing technologies.
Heat seal adhesives involve a multi-layered film that has an outer coating to prevent melting. The central layer can be made with polypropylene and an interior sealant layer. In order to create a successful heat seal, it must be held in place with pressure during the cooling process. That’s when the bond will develop as it solidifies. Heat seals are mainly used for package sealing necessities with pouch, bag, tray and bowl food packaging. Heat seal adhesives are considered to be a smart economical choice over cold seal films, as it does not require specific processes or materials.
What are some attributes of a heat seal?
- Durability: Unlike tapes, a heat seal can withstand temperature, humidity changes, and rough handling.
- Substrate versatility: Heat seals have a strong bonding force with moisture resistance, and can hold physical and chemical bonding between corrugated paper and linerboard. Corrugated paper has notorious bonding challenges, however its recyclability keeps it in high demand. By using a heat seal with corrugated paper, you can easily address these demands.
- Enhanced design flexibility: A heat seal can melt glue on key parts of various shapes, such as the inner flap of carton. This allows the manufacturer more opportunities to develop complex packaging as well as more space for graphic design elements.
- Low costs: Heat seals aresuitable for mass production with low energy consumption. It does not require extra usage of partitions like other options might need.
How a Heat Seal Can Improve Your Product
The main requirements for a successful heat seal are heat, dwelling and pressure. If manufacturers meet these necessities correctly, they will receive a finished product that includes the following characteristics:
- Functionality: Heat seal films offer wide range of performance opportunities that can be optimized to meet the specific needs of each product.
- Recyclability: Heat seals can save manufacturers from extra challenges as they work to meet increasing demand for sustainable packaging such as recyclable tray structures, which often requires a change in lidding films and sealants, too.
- Temperature resistance: Heat seal bonding has the ability able to withstand low temperatures of -40°F (-40°C). It can also handle up to two years in storage with no certain requirements, providing loading flexibility options.
- Anti-theft performance: Heat seals provide increased anti-theft and anti-tampering properties due to their strong bonds. Any attempt to open the product will tear the material because the adhesive infiltrates into the corrugation. Tamper-evident packaging is a growing trend with the rise of ecommerce, and heat seals help address the needs of manufacturers.
- Attractive appearance: Companies consider the ability to convey the branding on packaging just as important as the materials used. Heat seals have the ability to avoid hindering the product appearance and allow for bigger display space, whereas other options could obstruct important images or text on the packaging, interfering with important details for the consumer.
Bostik’s Heat Seal Solutions
Along with considering key performance criteria of heat seal bonding for your packaging, Bostik offers a range of technologies that can help efficiently seal your products:
Bostik Vitels®: These heat seal resins are excellent to adhering to PET, which is in high demand due to its recyclability. Vitels® can offer high clarity and strong adhesion to polar materials. They eliminate the need for a PE or EVA lamination of PET trays, and is compatible with films such as PET, vinyls, foils, PE/PP, PLA and paper. Bostik Vitels® can also be utilized in processes including gravure, slot die, cast film, co-extrusion coating or blown film. It provides solutions for packaging of food that’s oily or high-acidity, a strong seal bond through contamination, low activation temperature and non-blocking, while still being easily peelable for consumers.
Other Heat Seal Solutions Offered by Bostik
Common Heat Seal Coating Technology: This heat seal can be useful if you’re looking for low temperature films that include water-based or solvent-based coatings. These coatings often consist of polyvinylidene chloride, acrylic or ethylene acrylic acid, and require priming to properly prepare the base film.
Alternative Heat Seal Coating Technology: In order to address the challenges with time and production costs caused by priming, Bostik developed a smart low temperature heat seal coating that does not require any priming. It can adhere to a number of commonly used substrates including BOPP, BOPET, PLA and cellulose. Adhesion is achieved by certain resins, which offer the ability to bond to low surface energy substrates without any need for priming.
Addressing packaging challenges for food is easy when you use the right adhesive. Bostik can provide solutions that meet these criteria requirements, enabling you to improve your manufacturing processes, enhance your packaging’s performance and please consumers. Contact a Bostik representative today to learn about our solutions for food packaging.
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