EZ release glue is a spot-gluing application that holds pages or products in place until the consumer separates them with a light pull. When used effectively, EZ release glues can add a dynamic element to your products. For example, they allow you to attach small samples or fold-out panels that can be easily opened.
There are two basic varieties of EZ release glues: cold-applied and hot melt. Over the past few years, we've noticed an industry-wide migration away from the use of cold applications. While hot melt glue does offer certain advantages over its cold-applied cousin, there are still occasions in which cold-applied glue is the best adhesive choice. Understanding the pros and cons of both applications can help commercial printers make the right gluing choice for their project. Rickard Bindery is here with an overview of the advantages and potential challenges inherent in each type of EZ release glue.
Cold-applied Glue
Cold EZ release glues come in wax and latex-based varieties, both of which consist of the same basic properties.
Advantages:
Cold glues can be applied very thinly, making them ideal for product inserts and other applications where excess bulk can become an issue for machine feeding and downstream processes. Cold glues also do not discolor papers. This is particularly important for health care products and inserts where “discoloration”, no matter how slight, sends the wrong message.
Potential Challenges: Cold EZ release glues take a little longer to set (3 to 4 minutes) and tend to spread when the opposing sheet is tightly squeezed. Both wax- and latex-based cold glues continue to cure after they appear to be dry, sometimes for up to two weeks after application. Though wax-based glues are lighter and leave little residue, they may have trouble holding thick stocks. Latex EZ release formulas are also light and low in residue, but they contain ammonia, which can react adversely to aqueous coatings. Finally, the performance of cold glues can be greatly affected by external humidity and temperature conditions.
Hot Melt
Advantages: Hot melt EZ release glues are heavy, making them ideal for thick stocks. Hot glues cure very quickly and will typically be set when the piece leaves the machine. This makes hot glues perfect for direct mail pieces, as the bond will remain strong over time and the bulk of hot glue will not affect the flow of the product through the mail stream. Hot glues can also easily be used with aqueous coatings.
Potential Challenges: As oil-based products, hot glues can have adverse reactions with some coatings and inks, causing the glue area to become slightly yellow regardless of the ink coloring.
Materials tip
Most glue - hot, cold or otherwise - has difficulty bonding to varnish, though some manufacturers are developing hot melts that can work with certain varnish-covered products. If planning a varnish-coated piece, check with Rickard Bindery to determine the appropriate glue for your product.
The Rickard Advantage
Unsure of the right EZ release gluing option for your project? Ask the experts at Rickard Bindery to provide seasoned advice and plenty of choices. We offer a wide range of large- and small-format folding, stitching, gluing, attaching and sealing services to finish your projects with style. Contact us today to let us help you with your next project.
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