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Hot Melt Adhesive

Hot Melts have a relatively brief history in comparison to other adhesives, such as animal glue and hide glue, with their commercial use limited to the past 50-60 years. Hot Melt adhesives are polymer based and are 100% solids, containing no solvents or water.  Hot melt adhesives are thermoplastic, which means they are solid at room temperature but liquefy upon heating and solidify again upon cooling.

The lack of water and solvents allow hot melts to attain peak bonding strength very quickly (as soon as they cool). Hot melt adhesives are normally applied at a temperature of about 350 degrees Fahrenheit.  Hot melt adhesives create mechanical bonds, which means that the polymetric components in the hot melt wet out and penetrate the bonding surface prior to solidifying as they cool down again.  When adhering to thermoplastic surfaces (plastics, polyolefin laminates, and some coatings), bonding is similar to welding due to the high temperature of the hot melt adhesive during application.

Hot melt adhesives are used in a wide variety of industries, such as construction and electronics industries.  Metals, plastics and paper are just some of the materials to which hot melt adhesives provide excellent adhesion.  Hot melt adhesives are also used in some book binding processes, while others use natural eco-adhesives such as our animal glue.

Hot melt adhesives come in pellets, pillows, and glue sticks.  The proper form depends on the application, size of the operation, and function of the hot melt adhesive in product production.

PUR glues are one type of hot melt adhesive, but they work differently than traditional hot melts.  Click here to visit our PUR Glue Adhesive Product page for more information.

While L.D. Davis does not manufacture hot melt adhesives, we distribute hot melts from reputable adhesive companies.  We also distribute fugitive glue and PUR glue in addition to manufacturing our own line of animal glue and liquid adhesives, both eco-adhesives.

Physical Properties of Hot Melt Adhesive

  • Polymer – Polymers used for most hot melts utilized in the bindery are ethylene vinyl acetate (EVA) and styrene block copolymer (SBC, for pressure sensitive hot melts). The polymer component of a hot melt determines its strength, toughness and flexibility.
  • Tackifying resin – Tackifying resin controls the adhesion and hot tack properties of hot melts. They can be synthetic hydrocarbons or natural pine rosin or rosin derivatives.
  • Wax – Waxes are selected for controlling the open time and set speed of the hot melt.
  • Antioxidant – Antioxidants are added to improve the pot life (prevent charring and other oxidation reactions).
  • Plasticizers and/or diluents are sometimes also added to improve the flow characteristics and modify the viscosity and open time of the hot melt.

The Major Advantages of Hot Melt Adhesive

  • Aggressive Bonds
  • Reduced Char
  • Low/No Odor
  • No Stringing / Tailing
  • Increased Mileage – Reduced Viscosity Gain
  • Light in color
  • Clean Machining