To make the realization of various gluing or assembling tasks easier and to guarantee the quality of the finish, there are currently different modern and very efficient tools on the market. Among these tools is the hot melt glue. It is an option to facilitate the maintenance, installation, and especially the assembly of parts or goods to be glued. These types of glues are thermoplastic adhesives, usually in solid form and heated with a heating element such as a glue gun, glue melter, or glue generator.
What is a hot melt adhesive?
Hot melt adhesives, or HMAs, refer to hot melt glues, which are a class of thermoplastic and hot melt adhesive products that can permanently bond two different or identical substrates. Generally sold in flake, granule, and sometimes stick form, hot melt adhesives can be melted with a heating device prior to application to the surfaces to be joined to ensure their effective properties. The rod-shaped models are obtained by molding or extrusion processes and exist in different sizes and shapes (oval and round sections). For the other presentation models, a robust melter with a pump, heated hose, and glue applicator is required. Then, the use of a tool such as a heat gun is necessary to apply it effectively. Regarding the heat gun to be used, it consists of a trigger that pushes the rod through the heating element, which causes the hot melt glue to melt. It is then projected from the gun through a cylindrical duct in the form of a pasty liquid that is then applied to the elements to be glued.
Hot melt adhesives: properties and characteristics
The main property of a hot melt adhesive is the temperature at which it can be applied to the surfaces to be bonded, which is approximately 200 °C. However, as long as it is not heated in a thermal device, this type of adhesive is solid at room temperature and therefore very easy to handle, transport, and store. Due to the instant cooling bonding, a hot melt adhesive allows for a continuous and instant final assembly. It has a very short opening time and thus requires a quick assembly of the surfaces to be bonded. Moreover, the use of this type of glue is without risk because it is a non-toxic product. Besides, it is partially made of thermoplastic resins such as EVA or Ethylene Vinyl Acetate and does not contain any solvent products.
In sum, hot melt adhesive has several interesting properties, such as non-toxic product (solvent-free), fast curing and setting, very short opening time, easy handling when cold, adhesion on various types of substrates, and application temperature between 120 °C and 200 °C. These properties have enabled it to be used in a wide range of industries, such as automotive interiors; bundling and binding; various packaging (especially cardboard boxes); furniture making (surface gluing, edge sealing); baby and adult diaper manufacturing; etc.
The advantages of using hot melt adhesives
Practical and easy to use, hot melt glue is distinguished by its versatility and high performance. It is very popular thanks to its numerous advantages. It is highly sought after by DIY enthusiasts and especially professionals. First of all, this type of glue has the ability to harden almost instantly. Its gluing does not require much drying time. Indeed, its adhesion is very high and the adjustment of the opening time is very fast. As a result, the materials or components assembled in this way have excellent resistance to impact, and chemical attack and are well suited to withstand significant temperature variation. Secondly, its solid presentation facilitates their handling, transport, and storage. In addition, their viscosity is high compared to other types of adhesives, so they are perfectly suitable for many non-porous or porous surfaces, such as metal, glass, rubber, wood, leather, fabric, cardboard, felt, etc. It is easy to use, just apply it to one of the two surfaces and apply a little pressure to install it. As a result, high productivity improves production speed.
How to properly use a hot melt adhesive
The use of hot melt glue is an excellent choice to ensure the quality of the setup without necessarily damaging the goods. Its high adhesion makes it effective and ensures a simple and reliable closure of any type of packaging. So, to properly use hot melt glue, first insert the glue stick into the back of the heating device. Then, connect the hot melt gun to 200 volts of AC power and let the thermal device heat up for 3 to 4 minutes. In the spray mode, lightly squeeze the trigger and the hot glue will be sprayed along the duct of the gun. Finally, immediately apply the melted glue to the surfaces of the components to be attached. Simply join and hold the two components for 10 seconds until the glue hardens.