Jul 23, 2024 - 3-5 minutes
What You Need to Know About Waterborne Acrylic Linerless Label Adhesives
Find out why you should consider waterborne acrylic pressure sensitive adhesives (PSAs) for linerless label manufacturing, how to implement them in your production and ways the right supplier can make it easy to accomplish.
If you’re manufacturing linerless labels, you likely have been utilizing hot melt pressure sensitive adhesives (PSAs) as your linerless label adhesive technology. However, you may not know that waterborne acrylic PSAs also can be used for linerless label applications, too. Learn why this technology may be a good fit for your linerless label manufacturing needs, how to implement them and how the right supplier can help.
Why Waterborne Acrylic PSAs are Compatible for Linerless Labels
Based on an acrylic polymer structure, waterborne acrylic PSAs remain tacky when dried and form a quick bond to substrates including paper, corrugate, plastic, metal, glass and textile substrates when pressure is applied. Common applications that utilize linerless labels with waterborne acrylic PSA technology include:
- Logistics packaging
- Cold temperature and freezer-grade packaging
All-Temperature Performance
Waterborne acrylic PSAs provide stable adhesion across temperatures, including hot, humid conditions or freezer-grade levels down to 0°F (-17°C). This is due to their:
- Chemical structure: Waterborne acrylic PSAs are made of polymers with high thermal stability, making them more resistant to heat-related degradation. This helps a linerless label adhesive maintain adhesion in hot climates.
- Flexibility: The acrylic-based formulation can include specific monomers or additives to enhance flexibility for either high or low temperatures. The flexible strength helps waterborne acrylic PSAs protect against contraction or expansion for consistent adhesion.
If you are looking for a linerless label adhesive that can endure shipping in tropical or humid climates, a waterborne acrylic PSA may provide higher performance over a hot melt PSA. This is because a hot melt PSA’s thermoplastic component can soften or melt at elevated temperatures and lose adhesion; as a result, the linerless label could slide off the end-use application if it’s under extreme heat or humidity conditions. Further, a hot melt PSA’s thermoplastic property may contract at low temperatures when used on a linerless label for freezer-grade packaging, leading to reduced surface adhesion. Therefore, you may want to consider a waterborne acrylic PSA technology instead as it will not lose adhesion in low temperatures.
Compatibility With Silicone Release Coatings
Without a release liner, it’s critical for linerless label adhesives to offer compatibility with the silicone release coating so that the label can still come off the roll cleanly. Waterborne acrylic PSAs can be helpful in addressing this because they offer:
- Controlled tack: A waterborne acrylic PSA formulated with a controlled tack allows it to provide the necessary adhesion strength to stay in place on a roll while still releasing cleanly from the silicone release coating without leaving residue behind. This also helps ensure that a printed design on the label is clear and not impacted by any adhesive residue.
- Low surface energy interaction: Silicone release coatings may have low surface energy (LSE), which can cause challenges with proper adhesion. However, waterborne acrylic PSA coat weights can be designed to accommodate LSE silicone release coatings, helping to ensure consistent adhesion that is still capable of releasing off the roll.
It's also important to test the end-use performance of your chosen silicone release coating with a waterborne acrylic PSA. A supplier with expertise on linerless label construction and testing capabilities can help you save valuable time and resources, as they can determine how these label layers work together effectively while also reducing complexities in your supply chain to manufacture linerless labels.
Consider using UV silicone release coatings with a waterborne acrylic PSA. UV silicone release coatings are formulated for use on flexographic equipment with paper, film and foil substrates. Printed with wax-free aqueous, solvent, or UV inks, this topcoat is intended for use as a basecoat for a release coating in linerless labels, helping to remove the label from a roll seamlessly with no residue left behind.
Processing Efficiencies
As a solvent-free technology, waterborne acrylic PSAs help you increase your processing speeds by:
Reducing production steps: Without the need to burn off solvents, you do not have to utilize a thermal oxidizer or specialized storage and ventilation that may require additional processing steps.
- Facilitating easy application and clean up: Waterborne acrylic PSAs can be easily wiped off if there are any spills or excess adhesive during the application process. This helps reduce downtime and enables a neat application.
- Increasing cost efficiencies: It's also important to note that waterborne acrylic PSAs are more cost effective compared to microspheres. Rather than purchasing microspheres as an additive for removability to a linerless label adhesive formulation, a PSA that is 100% acrylic will provide both the adhesive strength and tack levels needed for clean removability, helping you save on costs and simplify logistics.
How to Implement Linerless Labels Into Your Production
It is worth considering ways you can implement linerless labels into your manufacturing, especially if you already have the coating equipment for both hot melt PSAs and waterborne acrylic PSAs. With the adhesive equipment in place, you should then focus on your capabilities for the silicone release coating:
- If you currently purchase silicone and place it on facestock, you simply need to adapt your production steps for linerless label manufacturing. You already have the equipment and materials.
- If you currently purchase pre-siliconized release liner, you simply need to purchase pre-siliconized paper that will be the facestock instead of the liner. Your adhesive will go on the other side of the pre-siliconized paper for linerless labels rather than a separate facestock with linered labels.
Either way, you'll take the same next steps to manufacture linerless labels. You can read about those next steps here.
How Bostik Can Help With Your Waterborne Acrylic PSAs For Linerless Labels
With the market’s most complete and integrated PSA portfolio, Bostik has the knowledge and support capabilities that allow you to rely on us as your one-stop-shop supplier for your linerless label construction needs. Designed to help you address end-use applications with high and low temperatures, Bostik manufactures waterborne acrylic PSAs for linerless label adhesives that allow you to form quick, strong bonds with equipment you already own. Additionally, we can also provide silicone release coatings with our PureRad™ solutions to help your linerless label layers work together effectively.
When you work with Bostik, you’ll receive:
- Customized Solutions: Whether you are new to manufacturing linerless labels or looking for new innovative methods, Bostik can help you eliminate the release liner with both waterborne acrylic or hot melt PSA formulations depending on your specific application needs.
- Technical Support: Our team of experts will assist you throughout the entire process in determining whether waterborne acrylic PSAs are right for your linerless label needs. We’ll help you understand how the formulation will work with other label layers to meet your specifications, customizing formulations to meet application and printer requirements. This involves testing samples and providing recommendations according to what is suitable with your equipment.
- Troubleshooting: We’ll support you through any processing setbacks with suggestions on what may be causing issues and how to improve efficiencies. We’ll also work with you on how to optimize your lines to reduce issue likelihood going forward.
Are you interested in learning how waterborne acrylic PSAs can play a role in your linerless label manufacturing? Contact a Bostik expert to learn how we can make it easy to incorporate this PSA technology into your processes.
Other Relevant Content:
3 Reasons You Need the Right Waterborne Acrylic PSAs for Labels
How to Choose the Right Linerless Label Adhesive
How to Incorporate Linerless Labels Into Your Production Lines