The Comprehensive Guide to: Hot Melt Adhesives (HMAs)

At FineCal, we’re responsible for providing our customers with a range of adhesive products perfect for their sector and requirements. We also think it’s our duty to ensure that our customers understand the differences between the products we sell, and which ones are best for their needs. It’s for that reason we provide as much information about each type of product as possible. This week, we’re exploring Hot Melt Adhesives. What Makes Hot Melt Adhesive Different from other glues? Hot Melt Adhesives (also known as Hot Melt Glue or HMAs') are notably different from other common adhesive products. Firstly, the natural form of the adhesive is solid and plastic-like in appearance. In order for the adhesive properties to activate, the hot melt adhesives require heating, which due to its thermoplastic properties causes the substance to become mouldable and pliable. Reversible Bonds Once it cools down after application, the hot melt adhesive solidifies again, drawing the two surfaces closer together and causing the adhesion to set in. However, when re-heated to the correct temperature the bonds caused by cooling can be reversed – unlike many other types of glue that form irreversible bonds with the materials they are applied to. Although this makes hot melt adhesives more diverse and flexible, this feature can also serve as a hindrance should you apply the adhesive to a substrate that undergoes high temperatures. For this reason, materials that are exposed to high temperatures should employ a more irreversible, heat proof adhesive. Coverage in all Nooks and Crannies Once melted, the liquid form of the hot melt adhesive flows into and allows easy application to spaces other glue products cannot reach as well, especially when combined with the appropriate hot glue applicators (guns) and nozzles. Many glue guns are designed specifically to distribute glue into incredibly small, uneven or complex spaces. This ensures all nooks and crannies are reachable by the glue, in turn allowing for stronger bonds and more percentage coverage between surfaces. High Productivity Due to the molten state of the adhesive, and the fact it can flow effortlessly into the space where it’s applied, hot melt glues are especially fast to work with, and ensure high productivity. Less time is needed to achieve complete coverage, and the glue guns that accompany the adhesive also enhance swift application. It’s for this reason and all-round ease of production that many manufacturers employ this style of glue. What Form Do Hot Melt Adhesives Take? To the untrained eye, a pre-melted hot melt adhesive looks like a thin or chunky plastic cylinder. Thinner cylinders allow for quicker heating and are often utilised for craft and home use. Larger diameters (termed slugs) are more frequently used for industrial purposes. Once inserted into a glue gun, the adhesive is warmed up causing it to transform into a hot molten glue that can be applied to your chosen surface with ease. The pre-melted forms come in a variety of sizes to cater for different guns, purposes and surface types. What Materials Are Hot Melt Adhesives Best Used For? The great thing about hot melt adhesives is that there is a huge a variety of compounds available, meaning that there are specific glues designed for use on different materials, including: Rubber Plastic Glass Brass Wood MDF Plywood Cardboard The large range of materials that can be used with hot melt adhesives make it the perfect glue to use across several industries such as: Arts & crafts Packaging Manufacturing Engineering Electronics And in sectors such as: Aerospace Construction Sign & Display Woodwork Automotive Equipment you need for Hot Melt Glues Unlike other adhesive products, the hand-held equipment that accompanies hot melt glues is of equal importance to the adhesive itself. Without the glue gun there is no way of heating the adhesive to the correct temperature for application or applying it accurately and precisely to surfaces. Hot Melt Adhesive Guns Hot melt glue guns are designed to heat the solid glue sticks and allow users to apply the glue exactly where it is needed. There are many types of glue guns available to use, depending on the size of glue stick, the surface you’re applying adhesive to and the heat required to melt the particular compound. Many brands develop their own equipment to especially for specific glue products or for a particular task. How To Use Hot Melt Adhesives Depending on the type of glue and type of gun, using hot melt adhesives can vary slightly. However, generally speaking, the glue stick is inserted into the back of the gun. Once the gun has warmed up, the glue starts to melt. The stick of glue is then driven through the heated gun manually by squeezing the trigger on the gun or simply by pushing the stick further into the gun with your thumb. It’s easy then for the user to control & release the flow of molten glue onto the substrate. Hot Melt Adhesives At FineCal At FineCal, we devote ourselves to understanding what products your business needs. Our extensive range of adhesives, adhesive tapes and packaging materials is designed to cater for engineering, manufacturing and home use. Our team of highly trained experts are always on hand to answer any questions you might have about any of our products or applications. Get in touch with one of our friendly representatives today and discover how we can help.

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