Foam is an integral component in the packaging industry. Hot melt adhesives are very effective for bonding all types of foams to packaging materials. Urethane and polyethylene foams are used to increase the protective qualities of packaging. These types of foam can be easily bonded to themselves and other materials such as corrugated cardboard and wood using standard APAO and EVA hot melt adhesives.
Bonding foams to substrates such as metals, resins, and plastics are somewhat more of a challenge. In these cases pressure sensitive hot melts (PSA’s) are generally used because of their ability to form long-lasting bonds. However, PSAs should not be used when the normal temperature is elevated or it the bond is to be put through substantial stress.
Methods of Application
There are many methods for applying hot melt adhesive to attach foam to packaging substrates including:
- Bead extrusion: Although delivering a random pattern of beads to bond the substrates will suffice, it is not the most efficient method.
- Roll, swirl and spray coating: These methods all apply a thin layer of coating to the substrates. The processes also reduce the required temperature of the hot melt. Roll coating is the fastest of the three methods, but it can sometimes be wasteful as it drives large quantities of adhesive into open cell foam, which has no effect on the bonding process.
Let us help you find the hot melt supply unit that best suits your needs. At Sure Tack Systems we have a broad range of applicators to choose from. Contact us today to find out more about our hot melt dispensing systems.