The manufacturing process for tapes is complex as one must ensure that the right materials are combined to ensure optimal adhesion of the tape to the desired surface (substrate). There is a science behind tape adhesion. This science is composed of five factors: the adhesive, the pressure, the substrate, the time and the environment. Here we discuss the adhesive and the four main types of tape adhesives.
What Is an Adhesive?
An adhesive is a material that joins two objects together by the contact of their surfaces (substrates). During the bonding process, the adhesive surface of the tape and the surface molecules of the object fuse together to form a strong chemical bond.
When designing an adhesive, engineers consider three important elements: adhesion, cohesion and tack.
- Adhesion: adhesion is the ability of the adhesive to adhere to another surface. It is the most important element in selecting the right adhesive for an application.
- Cohesion: cohesion refers to the internal strength of the adhesive. It is expressed as the shear strength or retention strength after bonding. A high degree of cohesion means resistance to high temperatures, low tack and higher retention power.
- Tack: tack is the property of a pressure-sensitive adhesive to adhere almost instantly to a surface. It, therefore, determines the ability of the adhesive to quickly permeate the surface with which it comes into contact.
It is important to note that the strength of the adhesive is closely related to the substrate material. This means that one adhesive may be suitable for one application but not another. Since each application has its own requirements for adhesion, cohesion and tack, it is recommended that you work closely with a tape converter to make the right adhesive choice for your application.
What Types of Adhesives Are Used to Make Tapes?
Pressure-sensitive adhesives, AKA tape, are simply adhesives that stick when you apply pressure. Generally, when you’re dealing with tape, there are two separate layers. The first layer is the backing material, which can be made of paper, cloth, plastic, or other synthetic material. The second layer is the adhesive material. There are three types of tape adhesives. Choosing the right one for your application depends on many factors. Here’s a breakdown of the main categories and the pros and cons of each. A custom adhesive tape manufacturer can help you understand which type of tape fits your needs.
Acrylic Based Adhesives
Acrylic adhesives are typically synthetically made, which makes them very versatile. They can usually withstand high temperatures, humidity, chemicals, UV, light, and oxidation, depending on how they are developed. These types of tape adhesives are customizable to your application. They age well and are transparent. Acrylic based adhesives can have a longer dwell time, which is the time the full bonding capability is reached. Acrylic adhesives can be used in many places. Common uses include packaging that will come under a wide range of temperatures, such as refrigerated boxes, or packages that may need to be stored for a long time.
Rubber Based Adhesives
Natural rubber-based adhesives have a higher bond strength and greater shear strength than acrylic-based adhesives. However, they are limited in their application as they do not work well in high-temperature environments nor do they offer good resistance to UV. Natural rubber-based adhesives are generally inexpensive but have many environmental vulnerabilities.
If you have ever used duct tape, you have used natural rubber tape. Low-temperature masking tapes and surface protective tapes also fall into the category of natural rubber-based adhesive tapes.
Synthetic Rubber (Butyl) Adhesives
Butyl tape is a type of adhesive that works in cold and moist environments. It is a synthetic rubber material that isn’t as sensitive to extreme temperatures. Butyl tape creates an airtight seal on many different surfaces, including glass, wood, aluminum, and many other construction materials. Unlike natural rubber, butyl tape works in cooler temperatures. It can be manipulated to fit many different shapes and is extremely sticky. Construction workers use it for roofing repairs and to fix leaking pipes. It can be used in marine applications, sealing port holes and deck fittings.
Silicone Based Adhesives
A silicone pressure sensitive adhesive tape works in many applications where a rubber or acrylic tape might not. Like acrylic adhesives, silicone adhesives are created in a lab. The base is sand. The process to create the adhesive can get expensive, but silicone adhesives can handle the hottest and coldest temperatures.
Silicone adhesives are a premium, high-performance type of adhesive that can bind silicone to silicone. They are used in many medical applications, where the adhesive will need to be removed from the skin, such as bandages or surgical tape. Silicone adhesives are also used in marine applications, where the seal needs to be waterproof and won’t crack over time. Silicone adhesives are used in the construction industry where the materials may be exposed to extreme weather, high temperatures, or strong winds.
Choosing the Right Tape for the Application
Tapes are very customizable. Generally speaking, when choosing bonding materials, you want to choose kind to kind. This can significantly help you make the right decision. The nice thing about tapes is that you create different types of bonds using both sides of the tapes. If you are bonding dissimilar materials, use a double-sided tape that bonds appropriately to each element.
As an experienced custom adhesive tape manufacturer, MPI Matco has helped many Canadian industries find the right bonding solution for their specific application. Tell us about your challenges that call for a unique adhesive solution and we’ll help you find a solution.