Hot melt adhesive or commonly referred as hot glue, is a thermoplastic adhesive that is supplied in cylindrical sticks of different diameters, that is designed to be melted by a glue gun. This glue gun makes use of continuous heat in order to melt the glue stick, which can be pushed by a mechanical trigger of by the user. The melted glue becomes tacky and becomes solid in a few seconds. Hot melt adhesives are widely used in industries today as it offers several advantages than those solvent-based adhesives. Volatile or organic compounds are less use and the curing step is eliminated. With hot melt adhesives, you can surely dispose it without special precautions and you are assured that it has long shelf life. Hot melt adhesives differs greatly from other glues and adhesives as the hot glue sticks while in the molten state and then becomes solid when cooled. These materials however are not ideal adhesives, that’s why waxes, tackifiers and stabilizers are mixed to tune it for a certain application.
Hot melt glue has different forms such as sticks, chips, pellets, blocks, beads and pillows. It can be applied through hand or operated glue guns, skillets, pots, wheel coaters, foot-pedal controlled dispensers and other specialized equipment. Nordson Glue System has different hot melt adhesive equipments necessary for bonding or filling gaps in order to create or fix something. Glue guns has low and high-temperature versions. High-temperature guns run at 190 degree Celsius and can produce a stronger bond, while low-temperature operates at 120 degree Celsius and are suited well in situations where high temperature cannot be used such as in lace or cloth. You can find dual guns with both low and high-temperature in Nordson Adhesive Equipment, which can aid you in putting things together. If you will assemble or fix something, using a dual gun will be an advantage. In addition to putting things together, hot-melt glue is used to fill gaps. These bonds must be made in a fast manner before the glue hardens. Usually, the glue gun must apply the glue accurately because it cannot be easily spread.
Another innovation in glue gun technology gives the user the ability to spray a certain area thorough a semi-pressure hot melt adhesive. With the use of compress air, the adhesive is used at a controlled rate.
- Affixing parts in electronic devices
- Assembly and repair of models
- Parts assembly in manufacturing
- Coating label stock material for self-adhesive labels
- Home crafts
- Disposable diaper construction
- Closing corrugated boxes and cartons.
Hot Melt Adhesive Pros:
- Easy dispensing and simple to operate
- Fast setting/bonding action
- Little amount of solvent in the adhesive
- Low cost high volume systems
- Pilferage resistant
- Reduced waste
- Superior seal quality
- Tamper evident packaging
- Wide formulation latitude
Hot Melt Adhesives Cons:
- Susceptible to creep under load
- Heat required to melt adhesive is not recommended for delicate applications
- Limited adhesion strength
- Potential to have poor wetting properties
- Some hot melt adhesives are vulnerable to solvent attack