3M Tapes Defined—What You Need to Know
What makes up a piece of tape? Most people don’t ever need to think about it. However, when it comes to industrial tape selections and applications, it’s vital.
Take a look at a strip of common Scotch brand tape—an example of a pressure-sensitive tape. Press a piece of the tape onto a surface—let’s say a desk. It stays in place with just a bit of light pressure. The adhesive on the tape is adhering to a carrier—in this instance made of plastic (substrate #1) and also to the desk (substrate #2).
This is a simple demonstration of what is meant by a pressure-sensitive tape. It gets a bit more complicated from here as we examine two widely-used, versatile tapes—foam tape and transfer tape.
Foam tape - uses foam as the carrier; the foam can be coated with adhesive on one side or both sides; foam tape always has a release liner.
Let’s take a closer look at double-sided adhesive foam tape. One side of the foam has a release liner and the other side winds around onto the same release liner to make unwinding and applying manageable. Foam tape can be used to bridge a gap between two matched machine parts or around pipe joints to prevent gas, fluid, air or sound from escaping.
Transfer tape - has no carrier, therefore nothing holds the tape together except for the pressure-sensitive adhesive. Transfer tapes are good for applications needing flexibility, conformability and stretch, such as when bonding to irregular surfaces. An example of use would be to join two items back-to-back, for instance vinyl lettering used in signage.
Stick to It
Is the surface rough, smooth, porous, coated, uncoated or flexible? Does the carrier need to be strong (duct tape), conductive (foil tape), stretchable (packaging tape), removable (medical tape), etc.? Will the bond be permanent or non-permanent?
An example of an easily removable, non-permanent tape would be the kind used on a person’s skin to attach a tube or patch. 3M makes several gentle-to-the-skin medical tapes including 3M Transpore™ White Surgical Tape.
Substrates and Surface Energy
The strength of an adhesion is determined by the surface energy of the material or substrate. The higher the surface energy, the stronger the bond. The lower the surface energy, the weaker the bond.
On high-energy surfaces, a tape can flow or "wet out” assuring a stronger bond. Imagine peaks and valleys and the ability for the adhesive to easily nudge its way into all of the crevices.
Examples of high energy surfaces include aluminum, steel and glass. On low-energy surfaces, such as some plastics, adhesives tend to resist flowing resulting in poor surface contact and adhesion. Surface energy, however can be altered using an adhesion promotor or by abrading.
In summary, both adhesives and substrates have surface energy. For a tape to wet out to a substrate quickly, the surface energy of the adhesive must be lower than the surface energy of the substrate.
Solid surface has low surface energy; adhesive liquid will bead up on the surface.
Solid surface has high surface energy; adhesive liquid will spread or “wet out” on the surface.
What kind of environment and exposure will your tapes encounter?
- High temperatures
- Solvents or chemicals
- UV light
You’ve probably seen tapes degrade due to age; however, it also happens because of exposure to extreme conditions, for instance high heat. 3M has designed hundreds of different kinds of tapes to suit most any environment. An example of high temperature tape is 3M’s Low-Static Non-Silicone Polyimide Film Tape 7419 used to create a solder mask on a printed circuit board.
Types of Adhesives
The types of adhesives applied to tapes differ and offer various levels of capabilities.
- Acrylic - fair initial adhesion, high shear strength and durable; high heat, chemical and water resistance; commonly has lower vibration and impact resistance than epoxies.
- Epoxy - very strong adhesion; bonds most substrates; one-part or two-part chemistry; widest range of temperature resistance.
- Rubber - high initial adhesion; moderate heat resistance; good shear and solvent resistance.
Want to further expand your adhesives knowledge? View Hisco’s adhesives tooltorial and discover more about their individual properties and applications.
Roll Tape Please
Hisco + 3M + Precision Converting
Converting tape and flexible materials is a world unto itself. Hisco has an entire division dedicated to customizing and converting tapes and flexible materials including die-cutting, laminating, slitting and assembly, and CNC prototyping.
As a 3M Preferred Converter, Hisco has instant access to any 3M tape. Add the fact that Precision Converting has one of the best reputations in the precision converting industry, plus Hisco’s extensive tape and storage resources, and you have everything needed for customizing under one roof.
From the first cut to last—you’ll have an edge on the competition including use of Precision Converting’s highly-specialized liquid nitrogen cutting process for eliminating premature curing on sensitive materials.
Like to know more details about Precision Converting’s expansive capabilities? Take a look.
Choosing a Tape and the Forces at Work
Adhesives play a crucial role in the creation of most tapes. By understanding their nature, strengths and weaknesses you can more clearly determine your tape needs.
How much stress will the tape encounter?
Shear - measured in hours or minutes to failure. Shear determines how long an adhesive can withstand pressure dragging it along the bonding surface before separating.
Tensile - measured in pounds of force per square inch. Tensile is the force required to pull two laminated surfaces directly apart. Unlike other seperation tests, the entire adhesive layer is tested at once.
Peel - measured in ounces of force per inch of width. Peel strength tells how much pressure is required to peel the adhesive away from the adherend at either a 90 or 180 degree angle from the surface.
Post It® notes
- What exactly is the physical or chemical process that makes adhesive tape sticky?
The answer has been discussed for hundreds of years. In this Scientific America article, three different sources attempt to answer the question, including 3M.
- How is 3M tape used on aircraft?
3M's 398FR tape (FAR 25 certified, Boeing and Airbus certified) is used to splice insulation panels in the holds of aircraft. The aerospace industry regularly depends on 3M industrial tapes for high-performance applications.
- Who invented masking tape?
Richard Drew—an engineer for the Minnesota Mining and Manufacturing Company (now known as 3M)—invented masking tape to solve the problem of paint bleeding through the gauze used in the tape. Masking tape is also the first use of paper as a pressure-sensitive adhesive backing. Drew also invented the clear cellulose tape called Scotch Brand Cellulose.
- Should I use duct tape to seal ducts?
No, duct tape is not for sealing ducts. Ducts should be sealed with very special tapes that will resist moisture, mold and heat and that are extremely durable, such as 3M™ Foil Tape 3340.
- What are the origins of the duct tape name?
It’s believed that the tape originally got its name during WWII, when it was invented. The tape was made of cloth duck fabric and a rubber adhesive. At some point it became known as duct tape. Another guess is that it got its name because it could float like a duck in water.
- Where can I see 3M VHB tapes at work?
3M VHB tape bonds 145-pound panels to the Walt Disney Concert Hall building in Los Angeles, CA.
- Can a carrier also be a substrate?
Yes, it can. If you were to press a piece of common Scotch tape to a desk—the desk would be one substrate while the carrier, in this instance, would also be a substrate (i.e. substrate 2). Adhesives attach to the surfaces of two substrates and they can be very different.
- What's the difference between a double-sided and a double-coated tape?
They're the same thing.