To ensure the best bonding results, a compatible hot melt adhesive is essential for each glue gun and application. Hot melts vary in width and length and are generally in the form of waxes, resins and a variation of thermoplastic polymers. The chemical composition of hot melts varies, because they may produce soft or hard glue product. They are manufactured in different colors to match specific job applications. Typically, hot melts are waterproof and able to withstand chemical treatments, but they are not suitable in high temperature applications.
Glue Gun Operation
During the process, the hot melt sticks are pushed through the back cavity of the device either manually or by pulling a trigger, depending on the model of the gun. Once activated, the glue is pushed to a check valve, which is a spring loaded with balls that are located directly behind the nozzle. The valves are designed to stop the flow of the glue and to prevent spills. Various glue gun models are equipped with a viewing window which allows the user to determine if an efficient amount of adhesive is in the chamber.
Generally, melting takes between two and five minutes, but the process may be shorter depending on whether the gun has been preheated or is already in use. In standard glue guns, the temperature of the hot melts is controlled by thermistors, thermally sensitive resistors that limit the heat current during the melting process. Since they regulate heat, glue gun resistors allow operators to handle the device without getting burned.
Glue is dispensed from a conical nozzle, which is typically metal and may become extremely hot. Various manufacturers fabricate glue guns that feature nozzles with a protective rubber encasing, to prevent burns. The glue can be dispensed in thin strips, and once expelled from the gun, glue generally takes only a few minutes to dry and harden.
Additional Information & Considerations
Experts and manufacturers advise some guidelines to ensure an effective process:
Heat proof counters or trays are essential during the glue gun operation, as hot melt adhesives may drip if too much force is applied to the glue.
Temperature is a major factor in the post glue gun application process. Glue that is exposed to too much light or heat will melt, whereas glue that is exposed to cold temperatures will become brittle.
Selecting the right type of gun model is essential for every application: Low temperature guns melt glue at 250 degrees and are suitable for delicate materials. High temperature guns can reach 400 degrees and are only compatible for more durable or “hard” materials. Manufacturers produce dual temperature models for multiple projects.