Adhesives and tapes are 2 alternatives to traditional material joining methods like welding or screwing. Find out why bonding is a versatile joining solution as well as some best practices for implementation.
The easiest materials to bond are those with very high surface energy, i.e. metals.
Materials with very low surface energy are the most difficult to bond, as they prevent the glue from spreading well.
These are mainly:
Between the two categories, we find most of the high surface energy plastics, which are commonly bonded in the industry (PVC, ABS, polyester, nylon, polyimide, PMMA, etc.).
Discover a summary table of surface energies by material below:
Thanks to the progress made by adhesive manufacturers in recent decades, it is now possible to bond almost any material, whether flexible or rigid, with low or high surface energy.
Like adhesive tape assemblies, adhesive bonding has the advantage of being discrete, which allows for virtually invisible assemblies.
Adhesive bonding has the added advantage of allowing for extremely strong structural connections. The adhesives used are generally epoxy, acrylic, or urethane based.
For example: LED signage panels, although they must withstand external stresses (wind, cold, heat, etc.), can be assembled by bonding.
The use of adhesives has evolved considerably in recent years. Bonding has become an automatable process compatible with industrial robotics.
The most important step in the application of any adhesive is to clean the surfaces to eliminate any contaminants. The products to use vary greatly depending on the materials to be cleaned. It is therefore imperative to use compatible products.
In general, a cleaning includes:
Air bubbles are the sworn enemy of bonding, because their presence reduces the cohesion of the adhesive joint.
Moreover, in the case of assemblies designed to withstand high temperatures, the heating process can cause air bubbles to rise and burst on the surface.
The presence of air bubbles is therefore synonymous with a weakening of the glued joints.
Adhesives are very complex chemical products whose properties vary according to various factors.
It is therefore imperative to respect the bonding constraints, which include:
In the case of structural applications, when the bonding must guarantee a very high shear strength (7 to 40 MPa) additional steps are necessary to optimise the bonding.
Here are some examples:
The strength of a bonded assembly is based on 3 properties: the adhesive strength, the cohesive strength, and the tack.
The cohesion of the adhesive is determined by its chemical composition and depends on the nature of the adhesive.
Membership characterizes the fact that the adhesive adheres to a surface, so it is a parameter that depends as much on the nature of the materials, the adhesive, and the surface properties.
Tack is a 3rd force, which depends on the pressure applied and the contact time. The higher the tack, the faster the adhesive "reacts".
Although there is no such thing as a miracle glue, bonding can be used to assemble all types of materials, for structural or non-structural applications. Because we master both materials, adhesives and application processes, do not hesitate to ask ADDEV Materials for advice.
Our teams will answer you as soon as possible
English (UK) 
Français 
Polski 
Nederlands (België) 
Deutsch 
Magyar 
Română 
Čeština 