Have you ever wondered how exactly tape works?
There are multiple types of adhesives on the market. However, when you think of the word tape, you most likely imagine pressure-sensitive adhesive tape.
What is a pressure-sensitive tape, and how do we use it? Keep reading, and we'll tell you along with its benefits and typical uses.
What is Pressure Sensitive Adhesive Tape?
Pressure-sensitive adhesive tape (PSA) can be a strip of cloth, paper, metal, or plastic so long as the material has permanently tacky adhesive on at least one side. This adhesive must be permanently stuck at room temperature, though not necessarily heat-activated.
Going off the name, PSA is pressure activated and only sticks if you compress it.
Pressure-sensitive adhesive differs from other adhesives because it doesn't require much pressure to adhere, whereas other tapes may need water, solvent, or heat to activate the adhesive. In addition, it shouldn't change phases, a.k.a. shift from a liquid to a solid.
Engineers use pressure-sensitive adhesives daily because of their load-bearing properties, which means that if the bond is strong enough, it can bear significant weight.
In the adhesive world, you may sometimes hear specific terminology:
- Polymer refers to a large molecule with many atoms. The atoms are connected in a chainlike fashion.
- Viscoelasticity refers to when a material is both liquid and solid.
So, in short, pressure-sensitive adhesive tape, also referred to as PSA, self-adhesive, and self-stick adhesive, is a polymer with viscoelasticity. The tape is sticky with a peel that protects the adhesive until you need it to bear weight.
Scientists, engineers, and everyday consumers find uses for PSA tapes daily. As adhesive technology increases and grows, people will find this type of tape even easier to use and less costly than traditional solutions for fastening.
Characteristics of Pressure Sensitive Adhesive Tape
To qualify as pressure-sensitive adhesive tape, a tape must have three qualities.
Adhesion: This refers to the strength of the adhesive, the sticky material to the substrate, or the surface the tape sticks to.
Cohesion: Refers to the strength of the adhesive or the strength of the stickiness.
Tack: Refers to how long the adhesive takes to stick to a given substrate or surface. An extremely tacky tape would stick immediately with little pressure. A less tacky tape would take harder pressure to stick.
Remember, to qualify as a pressure-sensitive adhesive, a tape must require pressure to bond. If it involves anything else like a solvent or heat, then the tape does not qualify as pressure-sensitive adhesive tape.
Why Use Pressure-Sensitive Tape?
Pressure-sensitive tape is quick, efficient tape. It's becoming increasingly popular for a variety of reasons.
Pressure-sensitive tapes are thin and light, making them easy to work with.
Because pressure-sensitive adhesive tape requires no element other than pressure to activate it, it bonds materials quickly. Plus, it can easily bond materials that are dissimilar. You do not have to worry about if the materials are compatible.
Thus, when you use pressure-sensitive adhesive tape, you can assemble a project quickly. You do not have to wait for the heat to activate the adhesion or a solvent to do its job.
Just press on the tape, and you're good to go!
When you use pressure-sensitive adhesive tape, you can reduce the noise caused by vibrations. Instead of rattling like a traditional fastener, the tape will absorb noise.
Pressure-sensitive adhesive reduces the need to refinish a surface and eliminates traditional visible mechanical fasteners. You'll no longer have a screw or fastener sticking up but rather a smooth finish.
PSA tape also creates uniform thickness. It can fill gaps and create a more aesthetically pleasing product.
What is Pressure-Sensitive Adhesive Tape Used For?
Pressure-sensitive adhesive tape can be used for practically anything. In fact, you'll find it all around you if you look closely enough.
Box-sealing or packing tape, masking tape, duct tape, double-sided tape, electrical tape, and even athletic tape, like what you see on hockey sticks and baseball bats, are all variations of PSA tape. It can be used to bond, shield EMI/RFI, manage heat, mask off areas, protect surfaces, dampen vibration, suppress sound, seal, gasket, and numerous other solutions.
PSA tape is much different than heat-activated adhesives, which require heat to make them sticky.
PSA tape doesn't take much pressure to activate. You can find it in all industries and even the healthcare industry with athletic tape and wound-care solutions.
How is PSA Tape Made?
An adhesive transfer occurs when the sticking solution transfers from one substance to another, adhering the two objects together.
In general, different types of adhesive tape are separated by their design and the function they serve.
Think about when you pull away the waxy paper of an envelope, which isn't permanently stuck to the adhesive. The adhesive stays on the original envelope or bag, and when you press down, it transfers adhesion to another material. This is a single-coated adhesion.
This type of tape occurs when you have an adhesion on only one side of a material.
A silicone-coated release liner is employed to keep the adhesive untouched. This part is often referred to as the web or face stock.
Most tapes qualify as single-coated adhesive tapes. Usually, single-coated tape has a backing of 1 to 10 mils thick. The adhesive thickness is anywhere from 2 to 5 mils.
Single-coated tapes are commonly self-wound and have paper or film release liners. Sometimes a single-coated tape, like filament or duct tape, will have woven cloth or glass strands to reinforce it. These tapes are paired with adhesive systems that have a rubber base.
Electrical tape, masking tape, carton sealing tape, and pretty much all medical tapes qualify as single-coated tape.
The transfer tape will transfer adhesion to two different surfaces. It brings the adhesive material to one surface and leaves the other vacant. This is similar to a clean line of glue that you would place on a surface.
Transfer tape is tricky to use and requires a little bit of practice and skill.
The tape itself is a mass of adhesive film with two release coats. In other words, it's sticky on both sides. This design allows for it to cling to odd surfaces.
To function at its highest potential, the tape should have an adhesive that is more difficult to remove on one side. This allows the transfer tape to unwind appropriately.
When you think of double-coated tape, think of double-sided tape. Basically, this is PSA with adhesive on both sides of the tape. You can use it for plastic films, tissue, any nonwoven, and many other materials. Also, you can find double-coated PSA being used as either laminate or carpet tape.
To create double-sided tape, a company will coat two sides of a carrier material with adhesive. They then wind it up with a release liner to prevent the tape from sticking to itself. Often, companies paint the liner with a silicone release agent.
A self-wound tape is a type of tape coated on one side with a pressure-sensitive adhesive and the other side with a release coating. The self-wound tape has no release liner coated with silicone on it. Duct tape, masking tape, and carton sealing tape all qualify as self-wound tape.
What Kind Of Adhesives are Used for PSA Tapes?
Adhesive companies primarily use three types of adhesives to create PSA tape.
Rubber is the least expensive PSA with the fastest sticking ability. Rubber adhesives have natural or synthetic rubbers in them. Companies will formulate those adhesives with resins, oils, and antioxidants.
Rubber adhesives work best indoors with less stress than an outdoor environment puts on them. They stick to low-surface energy materials. Many engineers formulate them with the idea of removing them quickly.
You can find rubber adhesive on masking tape, carton sealing tape, duct tape, and filament tape. Rubber does not feel tacky by nature, so engineers add resins to create the tacky adhesive needed.
Natural rubber has a higher molecular weight than synthetic rubber. It sticks well to LSE surfaces. Plus, you can remove it cleanly, but it does not do well in the heat and has a short lifespan.
Synthetic rubber is another title for what engineers call "hot melt" adhesives. It is a thermoplastic with a lighter weight and shorter polymer chain than natural rubber. The engineers customize the synthetic rubber, and as a result, it sticks better to surfaces.
Acrylic adhesives hold up better over time. They also tend to resist wear and tear by solvents and the environment. Plus, they can tolerate higher temperatures than rubber adhesives and develop a stronger bond.
People tend to use acrylic both indoors and outdoors. It has a longer duration than other adhesives.
Acrylic adhesives are tacky by nature, but engineers endeavor to make them tackier. As for polymers, the ones used for acrylic adhesives are flexible. Developers can adjust them during manufacturing to make the adhesive perform better.
Solvent acrylic comes from grains dissolved in a solvent. This adhesive does not adhere well to low surface energy plastics. They do stick better, though, than rubber.
Emulsion acrylic comes from spherical particles surrounded by surfactants in a water carrier. Emulsion acrylics cost less and are better for the environment than solvent acrylic adhesives. Their water-based properties make them less moisture resistant, so most people prefer a solvent acrylic.
Neither rubber nor acrylic creates the bond with silicone like how silicone adhesive does.
Silicone adhesives are priced at a higher cost than other adhesives. They can tolerate very high temperatures and thus handle extreme environments better than other adhesives.
Many people think silicone adhesives have a low sticking power because they don't bond well initially. In reality, it takes time before silicone adhesives can fully bond to a surface.
People typically use tape with silicone adhesive for applications in extremely elevated temperatures and caustic environments. You can find silicone adhesives in Teflon tapes, printed circuit board film masking tapes, and silicone release liner splicing tapes.
Which Type of PSA Tape Should I Use?
When you're selecting the best type of PSA tape for your particular job, consider the following criteria:
What surface are you sticking the adhesive to?
What are the conditions that you'll expose the tape to? Will the environment be hot and humid? How windy will it be?
Why are you using this adhesive? What materials does it hold together, and what do you want it to do?
How do you plan on applying your PSA?
Are you using the PSA as a permanent or temporary solution?
Make your final decision based on the answers to these questions. Find an adhesive tape that functions wherever and however you want it to.
Using Die Cut PSA
As stated earlier, activating a pressure sensitive adhesive only requires the light pressure of your fingertips. You don't need heat, water, or a solvent.
Because pressure-sensitive tape can be sticky and difficult to handle, your best bet for a tricky or particular job is a die-cut PSA. When you have the PSA die-cut for the corners and shape you need, you'll use the right amount of adhesive every time.
Without a die-cut PSA, you'll either have to cut your adhesive to the desired dimensions and hope you get it right, or you end up with scraps of leftover adhesive and a gummy surface.
Strouse can laminate PSA to any material you need to die cut.
A Low-Pressure, Sticky Solution
Now that you understand the ins and outs of pressure-sensitive adhesive tape, you can purchase your best tape for the job you have at hand.
For all your adhesive solutions, contact us. We'd love to help.