Before the advances of science and technology, earthenware pots were patched together using the first glue type substances, made from either animal material or tree sap. Much later in the nineteenth century, basic medical advances meant that rubber-based glues were starting to be applied to fabric substrates to keep dressings in place. With World War II came further significant advances with the troops’ requirement for a durable, waterproof product to use as a sealing tape for ammunition cases, leading to the creation of the first duct tapes as we know them!
In our 21st century society, a world without adhesive tape is impossible to imagine as its usage has spread across every possible market, from the technical automotive, aerospace, military and smartcard applications, to permeating every part of industrial manufacturing, including restoration and remediation. Tapes are used today for increasingly demanding applications, capable of withstanding huge amounts of pressure and stress, thin enough to be used in passport and credit cards without being noticed, and with different technical adhesive technologies used to withstand water, heat, UV, fire and solvents.
And yet, despite the infinite options of pressure-sensitive tapes that are offered, and their widespread usage across industries, user understanding of basic adhesive technology remains limited. This means that taking the time to match the best product for your application is often overlooked in favor of the quick tried and tested options users are comfortable with, despite their choice not always being the best tape solution for the application.
A starting point for making a more educated choice is a better understanding of the terminology used in the pressure-sensitive tape industry, which will further allow users to match the right performance to their application need.
TACK: Many users will revert to a “touch and feel” approach to decide for themselves if the tape is “sticky” enough for them. This performance feature is known as “tack” and is actually the initial “grab” of the pressure sensitive tape, a measure of how quickly a bond can be formed. In some applications, surface protection films protect white goods in transit with the adhesive needing to be low in tack, so you can remove it easily while also allowing it to be repositioned. In other cases, a high tack and stickiness may be desirable for your application for a more long-term application. Potentially, a downside of high tack could be that the material is not so easy to remove and can leave messy adhesive residues. If a product is claimed to have “clean peel” it is an indicator that the product can be used short term and then removed without issues or cleaning, and depending on the application, this can save users much time and effort.
However, this is not the only indicator of the adhesive strength, as most adhesive tapes will increase in bonding power over time, to reach an ultimate bond with the surface they are being applied to. If your ultimate goal is the confidence of long-term bonding to your material, for the lifetime of your application, you will need to consider the ADHESION level which is most often presented as adhesion to steel or peel adhesion data, as the industry benchmark testing criteria. Adhesion is the holding power of the adhesive and its resistance to being forced apart after being applied to a surface.
If, however, your application means that the tape is likely to come under pressure from a different force, then you may want to consider the SHEAR of the adhesive tape. This can be thought of as resistance to being pulled apart in different directions. Products are usually tested in a laboratory, mounted vertically to a material and have a weight attached. The time it takes for the tape to slide off the substrate shows the durability of the bond.
There are many different types of adhesives also, each with their own specific properties and uses which determine if the tape can be used permanently, semi-permanently, or if it is removable. One of the most popular is rubber-based adhesives which will allow higher tack, high bond strength, particularly to plastic surfaces and can be a lower cost economic option for volume use. However, if you are using the tape consistently in an outdoor environment, you may require low or high temperature resistance or UV resistance. If so, you will need to check that the tape is suitable for this application as the adhesive formulation will need to possess these specific characteristics, to allow high quality performance in this area.
When it comes to temperature, remember too that rubber-based adhesives can be susceptible to temperature variations and will give you much better performance if you keep them at room temperature before applying and whilst using, as a cold tape means a cold adhesive which may not function per your expectations. That means your usual habit of storing your tapes overnight in a cold van is not advisable!
The other golden rules of applying your tape, include ensuring that the surfaces you are applying the tape to are clean and dry. Even if your tape is waterproof or moisture proof, applying directly onto a wet surface will not give the tape the opportunity to bond first and you need to ensure the bond is not compromised by dirt or solvents too.
So next time you reach out for your usual tape, just stop for a moment and consider if it really is the best tape for the job or whether with a little research, you could find the tape you have always been waiting for!