Tape Adhesive Chemistries
The adhesive chemistry used to manufacture tapes plays a significant role in defining the tape's end-use. The three types of adhesives used for tapes are acrylic, rubber, and silicone. Each type of adhesive has benefits and drawbacks, so matching the adhesive to the application is critical. Below is an overview of the benefits and drawbacks of each tape adhesive chemistry.
Which Tape Adhesive Chemistry is Right For You?
Adhesives
Acrylic adhesives are known for their durability. Because of their formulation, they withstand environmental elements such as sun, extreme temperatures, and chemical exposure better than rubber-based adhesives. Generally speaking, they’re also capable of achieving higher bond strength than other adhesive chemistries. That said, there are plenty of low tack acrylic adhesive tapes for applications that require removability.
Acrylic adhesives gain strength over time, which can be a benefit or a drawback depending on the application. In terms of percent of total bond strength, it is not uncommon for acrylic adhesives to start below 50% at the time of application and then build to 100% over the course of 24-72 hours. This may not be ideal for an application that requires an high initial tack. In terms of cost, acrylic adhesives are generally more expensive than rubber adhesives.
Benefits
Capable of very high bond strengths.
Very durable. Good for outdoor applications.
Drawbacks
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Some formulations have low initial tack.
Generally more expensive than rubber adhesives.
Adhesives
Rubber adhesives are best known and used for their quick stick properties because they have a high initial tack. Unlike acrylic adhesives, rubber adhesives do not build strength over time after the bond is made. What you see is what you get in terms of the tack. Rubber adhesives are also, generally speaking, the least expensive of the 3 tape adhesive chemistries.
The downside to rubber adhesives is that they are not very durable in comparison to acrylic and silicone adhesives. They typically have a shorter lifespan than other adhesives, and their lifespan is made even shorter if they are exposed to elements such as extended heat, humidity, or UV. This limits their usage to mostly indoor applications since they do not hold up well to outdoor elements. They are also not well-suited for applications where chemical exposure is expected.
Benefits
Good initial tack for immediate bond.
Generally the least expensive adhesive.
Drawbacks
Not resilient to heat, humidity, or UV.
Shorter bond life than other adhesives.
Adhesives
Silicone adhesives are primarily used for two main reasons. First, they are the only adhesive chemistry that will sufficiently bond to silicone-based substrates and other low surface energy materials. If you are bonding a silicone substrate, it is almost always best to use a silicone adhesive. Second, they carry the highest temperature ratings of any of the tape adhesive chemistries, and they are extremely resistant to chemicals. This makes them an ideal choice for demanding applications that will see harsh environments.
The main downside to silicone adhesives is their cost. They are the most expensive of the 3 tape adhesive chemistries. They also have a short shelf-life, and like acrylic adhesives, they do not have the high initial tack of rubber adhesives. Because of these downsides, silicone adhesives are best suited for very difficult bonding challenges that rubber and acrylic adhesives cannot handle.
Benefits
Extremely resistant to heat and chemicals.
Will stick to silicone materials.
Drawbacks
Generally more expensive than other adhesives.
Relatively short shelf-life.
