What fastening solutions for are best for plastic? Double-sided adhesive tapes
In our blog we have highlighted how there are some factors to consider before proceeding to glue plastic surfaces with professional adhesives. It is essential, first of all, to be aware of the type of plastic which you are working on, keeping in mind that different polymers have different peculiarities, thus the professional adhesive products one might need can change according to their different characteristics, with the aim of obtaining the best fastening performance for plastic. This is not all, it is also necessary to properly treat the surfaces, preparing them to receive the adhesive itself: cleaning, abrasion, activation, primer application, and so on, according to the specific needs.
Other factors should be kept in mind, too. How strong should the adhesive be, what will be the breaking load used as a reference be? Are the surfaces to be glued large or small? Is there a need to minimize the thickness of the juncture, or are there perhaps 1 or 2 millimetres (0.03 – 0.07 in) of extra space available? Each of these considerations can lead to the use of different adhesives. For instance, structural adhesives, designed for very high breaking loads, resealable fastening methods, and double-sided adhesive tapes. In this user guide to choosing the best plastics fastening solution, the focus will be on the latter: first, a description of thin double-sided adhesive tapes, and then acrylic foam tapes.
The advantages of using adhesive products to glue plastic
Before outlining how to choose the best fastening solutions for plastics in the context of tape, it is best to highlight the advantages of using adhesives over the mechanical fastening solutions. They have several disadvantages: first of all, their visibility, therefore they often compromise the design of products. With adhesives, however, it is possible to have invisible fastening solutions, which do not adversely affect the final aesthetics of the product. Adhesives also guarantee a high level of lightness, reduction of processing needed (thus also reducing time, noise, and vibration) because of high adhesion force, without the need to drill anything at all. So, let’s have a look at what the characteristics of adhesive tapes for the fastening of plastic are, focusing first on thin adhesive tapes first, and then on foam tapes.
What are the fastening solutions for plastic? Thin adhesive tapes
Thin adhesive tapes can be the most suitable fastening solution for plastics when dealing with large plastic surfaces, with low tensile stress required, and the need to keep thickness particularly low. There are two types of thin tapes to glue plastic, namely:
· Supported double-sided adhesive tapes: these are high-performance double-sided adhesive tapes which feature a liner and support with both adhesive sides. They represent the ideal solution when a perfectly smooth surface has to be glued, while their rigidity – a consequence of the support being present – makes them less suitable for gluing surfaces that are not perfectly smooth. An example is 3M™ GPT-020 supported double-sided adhesive tape in sheet form, resistant to high temperatures and with a high initial adhesiveness.
· Transfer adhesive tapes: Transfer adhesive tapes have no support. Once separated from the liner, they are, in fact, made of pure adhesive, so they have lower rigidity; they are, thus, perfect for surfaces that are not perfectly smooth and for fastening foamed plastics, for instance. An example is 3M™ 950double-sided transfer tape.
The best solutions for fastening plastics: acrylic foam tapes
Classic double-sided tapes are not the only option. The most innovative fastening solutions for plastics include acrylic foam tapes, which are double-sided adhesive tapes with a conformable foam core on both sides. Acrylic foam tapes are used, in particular, to fasten the latest generation of plastics, or polymers that are used as alternatives to metals because of their performance. Hence, the need to rely on more powerful adhesives than “normal” thin double-sided adhesive tapes. The disadvantage is that it has a greater thickness: in the case of 3M™ VHB™ LSE-110WF, for example, the thickness is 1.1 mm (0.04 in). Thanks to these special foam double-sided adhesives it is possible to fasten plastic materials in different contexts: for instance, in the production of sports goods, during the creation of signs, in the automotive industry, the manufacturing of household appliances, and so on. All this without having to drill, grind, weld, and carry out any finishing operations.