Hot melt adhesive dots make for one of the most useful adhesive products on the market. Glue dots—often also called glue “spots”—are small, round dabs of pressure-sensitive hot melt that are applied to a coated surface so they can be easily removed and applied to a variety of substrates. With an instant bond, glue dots eliminate dangerous odors, the mess associated with liquid hot melt adhesives, and residue left behind from film, tape, and webbing.
However, they still maintain the same flexibility of hot melt with applications ranging from production lines to mailing materials. At Hotmelt, we carry several brands of glue dots with varying levels of stickiness so you can always find what you need for your project. These are the six biggest mistakes to avoid when using your glue dots from Hotmelt to ensure you get the application you expect.
1. Adhering Dirty Surfaces
To get the best bond possible, your substrates must be cleaned of any moisture, oil, dust, or other particles. Make sure everything to which you’re attaching your dots is clean and dry.
2. Using the Wrong Size Dot
It might seem like the size of your glue dot is simply a matter of preference, but it takes more consideration than that. Your choice should depend on the size of the surface area you’re bonding. There is a correlation between the amount of surface contact and the strength of the bond. Therefore, the choice between using a ¾” dot or a ½” dot should depend on more than just your opinion. In addition to ensuring your bond is strong, choosing the right-sized hot melt adhesive dots ensures you’ll be able to appropriately space them so that your budget is spent in the most efficient way.
3. Applying Dots in Harsh Environments
Extreme heat, freezing cold, and wetness all put a lot of stress on adhesives. Glue dots are especially susceptible to failure in these harsh environments since they’re applied in a hardened state instead of having a chance to bond after application through processes like heating and drying. If the substances you’re bonding will be exposed to a harsh environment or the failure of your application will be catastrophic, you may want to consider a more secure hot melt solution.
4. Keeping Your Glue Dots on the Shelf Too Long
Hot melt adhesive dots don’t break down over time. However, since they’re already in their final, sticky state instead of a container or a hardened pre-melted form, they can more easily be contaminated with moisture and dust. To ensure a lasting bond, we recommend replacing unused glue dots after 18 months and always keeping them in the cleanest, driest place possible.
5. Choosing the Wrong Profile
“Profile” is the vertical thickness of your glue dot. A lower profile will be thinner or flatter, while a higher profile will have more depth. Low profile dots work great for very smooth, flat substrates that already fit snugly together before any adhesive is applied. Thicker, higher profile dots are great for surfaces that are concave, which have curves, or that are otherwise irregularly shaped.
6. Going with the Wrong TackTack, which is a way to describe just how sticky something is, is vital to get right when it comes to hot melt adhesive dots. Tack measurements start at low, where the adhesive is considered removable. Tacks levels increase until they get to super high tack, where the bond is considered permanent. Lower tack adhesives like Glue Dots’ Low Tack, Low Profile Adhesive Dots provide the removable bond that you might want on something like credit card mailers, while Infinity Bond Permanent Super High Tack, Low Profile Glue Spots provide a permanent bond for things like electronics and appliance assembly.
Choosing the right track is vital to ensure you get the right level of adhesion based on the purpose of your application. Only you will know which hot melt adhesive dots are the best for your application, but, hopefully, we’ve helped you learn how to use them to ensure the bond you expect. Contact the Hotmelt team to assist you in determining the best product for your needs and for tips on making glue dots work for you.