If in DIY, the undisputed king is the drill… in crafts, the undisputed queen is the hot melt glue applicator gun.
Some of the many aspects that make it ideal for home use and crafts are:
- Strong hold and bonding power.
- Suitable for joining virtually any type of material.
- Instant bond.
- Super cheap tool. For 5 or 6€ you can find one like the one that appears in the video.
If you follow us and have seen several of our videos and articles, you may have noticed that we use this tool in practically all our crafts.
For this reason, we wanted to dedicate this article to talking to you about the technical aspects and the multiple applications of hot melt adhesives, as well as showing you the simple handling of the applicator gun for this type of adhesive.
Video on the use of hot melt adhesives
Having made this brief introduction, we will start by showing you a video in which we talk about it and do a resistance test of a joint made with hot melt adhesives.
Technical characteristics of hot melt adhesives
Hot-melt adhesives, also called hot glue, thermo-glue, thermoplastic adhesive, or HotMelt, are made up of thermoplastic materials that are 100% solid at room temperature which, when melted, gradually melt from temperatures of 70ºC, becoming a ready-to-use pasty fluid. to apply on the objects to join.
Its main advantage is the fast and solid union it performs. However, if the materials to be joined are going to be subjected to high temperatures, the adhesive melts again, since it is a thermoplastic material, and therefore the materials become unstuck.
When it cools down, it does not undergo changes in its chemical structure, which is why it makes high cohesion, resistance and elasticity joints.
It joins practically any type of material, such as metals, plastics, wood, ceramics, glass, cardboard, packaging, binding, etc, etc.
In addition to surface adhesion, hot melt adhesives can be used to fill holes, due to their high viscosity.
Joints must be made quickly before the adhesive cools and hardens. It must be applied correctly with the applicator gun since, once cooled, it cannot be easily separated. However, it is always possible to melt and separate the glue with a heat gun or a clothes iron.
The setting time and obtaining its maximum resistance is equivalent to the cooling time, which occurs in a few seconds.
To obtain optimal results, the surfaces to be bonded must be completely clean of dust, grease, oil, etc…
Hot melt adhesive applicators
The applicator par excellence for this type of adhesive is the hot melt adhesive gun. Although it is true that there are some variants of different sizes and qualities.
The gun, which is electric, uses a continuous-duty heating element to melt the plastic glue, which is introduced at the rear in the form of a bar. The latter can be pushed through the gun by a trigger or directly by hand.
The melted glue that comes out of the heated nozzle is initially hot enough to burn and blister the skin.
The applicators that can be purchased for home use and for crafts are quite cheap, being able to find them from around €6.
The use of large guns is recommended, since they are more comfortable and easier to use.
As in DIY, the undisputed king is the drillthe queen of crafts is the hot melt glue gun.
Technical aspects of hot melt adhesives
The bars of this type of adhesive are composed of solid materials based on thermoplastic polymers that melt with heat. They also do not contain water or solvents.
The most used material, mainly due to its economic nature, is Ethylene Vinyl Acetate (EVA).
However, they are also manufactured with other types of materials, such as Polyurethane, Polypropylene, and Polyamide.
This type of adhesive works without losing any of its properties in ambient temperatures between -30ºC and 80ºC. So hot melt adhesives can be used practically anywhere on the planet and at any time of the year, and their results remain optimal.
Bond Strength Test
The application temperature ranges from 120ºC to 215ºC, depending on the application for which it is intended. However, almost all of them are normally applied at 195ºC.
The time during which the adhesive can be handled without losing any adhesion, due to its cooling, ranges from 1 second to 60 seconds, depending on the components that make up the adhesive.
This handling time is also known as “open time”.
These adhesive sticks are manufactured in various diameters depending on the type of hot melt gun, which will vary if it is for industrial or home use.
In the latter case, the most used diameter is 11 millimeters, and the length of the bars are available in various sizes, from about 10 centimeters onwards, with the most common length being 20 cm.
However, for domestic use there are other smaller pistols that use 7mm diameter bars. But being smaller, they are more uncomfortable to handle.
There are also dual-use adhesive sticks, since they melt at low temperatures, although they can also be used at high temperatures without degrading.
For industrial use there are endless possibilities both in terms of the characteristics of the adhesive itself, depending on the applications to which they are going to be used; as the existing diameters, the most common being 12mm, 15mm and 45mm.
For its part, regarding the adhesive for domestic and DIY use, there is much less variety in the types of adhesive, but there is plenty to choose from in relation to colors. There are from the translucent multipurpose, to black, through various colors such as red, green, blue, etc., also including glitter, such as those that appear in the video.
Hot melt glue guns exist in low and high temperature versions. The former heat up to 120°C, and are suitable when high temperatures are not necessary, for example, to place ribbons on clothing, do children’s crafts, etc.
For their part, high-temperature guns heat up to around 195°C and provide a stronger adhesion.
Finally, indicate that there are dual guns, which have a switch for both uses, high and low temperatures. Logically, these are more expensive than normal applicator guns.
Advantages of hot melt adhesives:
- It does not dry out or age.
- The paste is strong and effective in seconds.
- Quick application, which saves costs, time and work.
- Contains no toxic or volatile substances.
- It has multiple applications, both at home and in industry:
– Bonding of carpets, tiles, parquet, doors, furniture.
– Sealing joints, in sinks, bathrooms, sinks.
– Repair of ceramic, plastic or metal objects.
– Repair of toys, shoes, armchairs, etc.
Safety when using hot melt adhesives:
Despite the completely innocuous appearance of the hot melt adhesive applicator gun, there are a few minimum safety measures to keep in mind when using this tool:
– It is an electric tool so, since there is a risk of electric shock, we must proceed with the same precaution as with any other electric tool.
– We should never push the adhesive bar with any element and, above all, insert a screwdriver inside the gun, since we would run the risk of electric shock.
– Always handle the tool carefully so as not to burn yourself as it reaches very high temperatures.
Be very careful not to put the adhesive that comes out of the gun in contact with the skin since it comes out very hot and there would be a risk of burns.
– Do not touch the metal nozzle of the gun, since it also reaches high temperatures.
– Keep in mind that the gun takes a while to cool down. Unplug it and let it cool down in a place where there is no risk of fire, nor is it within the reach of people and, above all, children.
– And, as we always advise at BricoBlog, use common sense. This way you will avoid many accidents.
Buy these products
If you want you can buy directly at amazon, from here, the applicator gun or a pack of thermo-adhesive bars or both products. You just have to click on the text or image.
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