Frequently Asked Questions

Liquid adhesives & sealants

Even an excellent adhesive will never hold as well as a mechanical system.

False. Structural adhesives achieve shear stress holding capacities exceeding 700 kg/cm²; in very few cases there are mechanical fixings capable of equaling these performances. With structural adhesives you can easily replace nuts, bolts, rivets and welds.

 

Bonds made with adhesives are resistant but fragile if subjected to vibrations and impact stress, in which case the bond breaks suddenly.

It is not true. Adhesives can also be flexible and give rise to joints capable of resisting sudden shocks (such as a hammer blow) and particularly violent and wide-ranging vibrations.

These adhesives absorb forces and maintain the tightness of the joint thanks to their ability to deform and then return to their original dimensions.

 

Liquid adhesives cannot be applied to ceilings or upside down surfaces because they would drip and dirty everything underneath.

It is not true. In this case, specific adhesive products must be used, with very high viscosity that do not leak or drip (thixotropic adhesives).

 

How strong can the adhesive be?

They can have very high strength, to the point of forming structural joints (resistance to shear force ≥ 100 kg/cm²).

 

Two-component adhesives are complex to use: mixing the 2 parts is a long and delicate process

This is not true: cartridge application systems are commercially available which mix the parts of a two-component adhesive in perfect proportions without generating product waste and allowing the adhesive to achieve its best performance.

 

Liquid adhesives are difficult to apply: they make a mess and a large amount of them is wasted.

It’s not true: there are application systems available on the market with dispensers that eliminate or limit application waste to a minimum, allowing the product to be used easily, only where needed and in the correct quantity.

 

Adhesives are not environmentally friendly, they are complicated to use, they give off an unpleasant odor and the solvent is toxic.

It’s not true: there are adhesives produced without solvents or produced using water as a dispersion medium. These have no contraindications and are compatible with the environment, they are ecological adhesives.

 

When using an adhesive you must wait for the glue to dry for hours or days before you can use the glued objects.

That’s not true: there are quick adhesives that allow you to use glued objects a few moments after gluing.

 

You have to hurry with stickers because they dry quickly.

That’s not true: there are adhesives with “open” times and medium/long working times, which allow you to work on the joints calmly before cross-linking begins.

One-sided and Double-sided tapes

How tight can adhesive tapes be?
Very high depending on three factors: chosen adhesive, preparation of the substrate, shape and size of the joining surface.

 

Adhesive tapes are not suitable for making watertight seals, paste sealants must be used.

It’s incorrect. Paste sealants are excellent products but there are watertight tapes for instant sealing that allow the sealed joints to be immediately wettable.

 

Why are die-cut used?

Die-cut of double-sided adhesive  are used because they greatly simplify the creation of assemblies. With the die-cuts, the adhesive is placed only where it is needed, without making any mess, and it is possible to apply adhesive to one part even in the absence of the other: the free side remains protected by the liner and can be used later when the time comes to join.

 

What does VHB mean and what are VHB double-sided tapes?

VHB is an acronym chosen by 3M to identify its range of high-performance double-sided tapes. VHB is the acronym for Very High Bond, literally “very strong bond”.

 

Are adhesive tapes only for temporary fixings?

That’s not true: the right tape, applied correctly and in the context for which it was designed, lasts for many years.

 

Are adhesive tapes ugly and do they ruin the aesthetics of the objects on which they are applied?

Absolutely not: first of all, to obtain a good aesthetic result, the application of adhesive tapes must be carried out with care; Furthermore, there are adhesive tapes whose precise purpose is to beautify, decorate, protect and make surfaces more comfortable to the touch.

 

Does the tape tear easily?

That’s not true: there are reinforced tapes capable of withstanding very high tensile loads.

 

When removed, do adhesive tapes dirty the surface on which they are applied?

This is not true: removable tapes retain the characteristic of being easily detached from surfaces even for a long time after their application.

 

Can a tape be used on an uneven or rough surface?

Certain! The thickness of the adhesive mass and the conformability of the support allow the adhesives to work on irregular (or rough) substrates with excellent results.

 

Why should you use double-sided tape instead of glue?

Because it allows you to immediately move the joined products. Because it allows you to glue a product and join it to another at separate times.

 

Are adhesive tapes resistant to low temperatures?

There are adhesives suitable for low temperatures. Many resist low or very low operating temperatures, some even allow low application temperatures.

 

Are there double-sided adhesives that resist detergents, oils and solvents?

Yes. There are specific adhesives with great resistance to these external agents in various situations of use.

 

Are there adhesive tapes that resist high temperatures?

Yes: there are tapes made with support in heat-resistant materials up to peaks above 350 °C and with silicone adhesive mass capable of guaranteeing adhesion even at continuous temperatures of 200 °C.

 

Do adhesive tapes hold up under water?

Yes: the nature of the adhesive and that of the support establish whether a tape is able to maintain its sealing characteristics unaltered if immersed in water.

 

How can we be sure that the bond will last a long time?

We can carry out aging tests using a climatic chamber which simulates exposure to atmospheric agents for long periods of time in forced conditions.

 

Can double-sided tapes be used to glue very different materials (for example metal and fabric)?

Absolutely yes! Indeed, this is one of the strong points of adhesive tapes, the existence of products with different adhesive on the two faces of the support.

 

Are the adhesive tapes always visible?

There are completely transparent products with which it is possible to carry out invisible gluing or taping.

 

Must great pressure be exerted for adhesion to be effective?

It depends on the type of adhesive, the application and the surface to which it is applied: normally no greater pressure is needed than that which can be exerted with a simple tool such as a roller.

 

Does a mechanical screw-bolt system no longer hold?

No: the mechanical joint works on a small surface (which is that of the external diameter of the head of the bolt, washer, rivet or screw). At that point the seal is strong but at that point the substrate could also give way (for example in the case of plastic or composite materials). The adhesive works on much larger surfaces, distributing the force evenly: the result is greater strength of the joints and less overall fragility of the system. Furthermore, the viscoelastic effect of an acrylic adhesive or foam foam allows it to absorb shocks more effectively.

 

In which sectors can adhesive tapes be used?

In any sector and for many applications.