The main polymers used in hot melts are ethylene vinyl acetate (EVA), polyolefins, polyamides and polyesters, styrene block copolymers, polyethylene and ethylene methyl acrylate (EMA) or ethylene n-butyl acrylate (ENBA).
Hot meltadhesive is a thermoplastic adhesive, also known as hot glue. Hot melt tapes have a significantly higher adhesion compared to acrylic tape. They have superior holding power (referred to as shear value) and superior tensile strength, with fast adhesion.
A hot melt tape is ideal for applications involving machine-applied tapes, overfilled cartons or boards with a high degree of recycled content. They work well in temperatures ranging from 45°F to 120°F. Melt viscosity and crystallization rate (and corresponding open time) can be tailored for the application. The melting point of hot melt adhesives must be above the minimum temperature that the application will see in service.
Theoretically, any thermoplastic can be a hot melt adhesive, but the ten or more preferred materials are typically solids up to 79.4°C or more, then melt sharply to give a low viscosity fluid that is easily applied and capable of wetting the substrate to be bonded, followed by a rapid setting to the cool down. Variables such as inconsistent film thickness, thin adhesive coating, and poor release coating can hinder tape performance. The key difference between hot melt tape and acrylic tape is that hot melt is made from thermoplastic polymers, while acrylic tape is made from acrylic resins. The main advantages of using acrylic tape include its superior durability and longevity on polar surfaces, resistance to extreme temperatures, UV light, oxidation and chemicals, color stability and aging resistance, high level of cohesion, etc.
proportional to the molecular weight of the base polymer; a value high indicates the ease of application of the adhesive, but shows poor mechanical properties. Shurtape HP 132 and HP 232 are specially formulated with a resin and synthetic rubber hot melt adhesive that provides an instant, permanent bond in sub-zero temperatures to keep packages sealed and secured. Modified rosins and modified terpenes, which have a molecular weight to softening point ratio of less than about 10, when used as tackifiers alone or in combination in a hot melt provide adhesives that can be applied at low temperature and exhibit high resistance to heat and good cold resistance. As with other adhesives, there are many different types of hot melt base polymers and hot melt formulations available, each with advantages and disadvantages.
Additional tape features to look for include good adhesion for initial grip to the corrugated surface, a strong film backing for less stretch and tear, and good adhesion to the backing for those applications requiring shingles, or stacking multiple strips of tape to create the seal. PPM is well aware of the advantages and disadvantages of both tapes, offering a wide variety of different tapes, both with hot melt adhesive and acrylic, ideal for different types of applications. The term hot melt refers to hot melt adhesive, which is a form of thermoplastic adhesive commonly sold as solid cylindrical rods having various diameters.