Are you fully prepared to choose a rubber gasket?
Although finding the right gasket material is definitely part of the puzzle, there’s also the matter of deciding how you need your gasket seal adhesive to function within your application.
As a custom gasket manufacturer, we’re often working with a range of different adhesives and materials. Today, we’re guiding you through a few of the questions we’d ask about your gasket design.
By the end of this article, you should understand the factors that should go into choosing a rubber gasket seal adhesive.
An adhesive holds a gasket in place, depending on the application (of which there are literally thousands). Yet, not all gasket applications require an adhesive. For instance, some are held on by mechanical fasteners: bolts (classic car engine) or screws (watch).
Now, say you’re choosing a rubber gasket seal adhesive: what questions should you ask before selecting one for your next application? Let’s take a look at some questions that might help you.
Before committing to a seal design, ask an adequate number of questions about your design goals to find the best adhesive fit for your project.
Compared with tape, a seal made with a rubber gasket is more robust simply because the rubber is thicker and more durable so it can absorb more force exerted on it.
How much force? Well, although each application is different, it’s clear that putting 1,000 psi of force on a small surface area is enough to test any adhesive. In any case, the adhesive will likely fail before the rubber gasket itself due to the incredible amount of force.
That brings us to the surface area. If an application has limited space available to apply the adhesive, the importance of the adhesive is magnified (larger surfaces have superior adhesion). For instance, if the surface area is large enough, one converted piece of rubber with suitable adhesive can replace that same rubber with 25 screws.
Some demanding applications use mechanical fasteners and adhesives to increase the bond and prevent failure. For example, bolts may serve as a backup if the adhesive fails. Conversely, an adhesive may do nothing more than hold the gasket in place until a mechanical fastener is added to make a solid seal.
Similar to how available surface area directly affects a bond’s holding power, the environment in which the rubber gasket seal performs is critical. Exposure to high temperatures, pressure, and chemicals must be considered and tested.
Although rubber gaskets have been used in nearly any application imaginable (field testing is the ultimate test), a converter needs to send samples of any solution to a customer for trial. Application methods and conditions do vary, so testing is a must.
Not every type of adhesive is designed to hold for the same amount of time. Even different gasket applications have different requirements, from temporary to permanent and everything in between.
Adhesives are generally classified based on their form: tape, film, paste, liquid and solid. By the nature of the rubber, rubber gasket seals have high initial tack and hold, but not as strong a final hold as acrylic tape.
Hundreds of converters can flatbed die cut various shapes of rubber. The magic happens with the adhesive, but that can’t be determined until the substrates (A.K.A. the surfaces) are considered.
Substrates ultimately determine which adhesives can be used, and the type of adhesives may or may not limit the material you use for the gasket. Some substrates, like metals, are not very picky regarding adhesives. However, low surface energy plastics have limited adhesives and do not behave well with all types of gasketing material.
This blog post mentions “applications” throughout, so why include it now? Because this is the most important question (and we’ve saved the best for last).
Some applications lend themselves best to rubber gaskets because of a converter’s ability to create the right solution. Have you noticed trucks on the highway with no visible bolts on the side? That’s likely an adhesive tape/gasket creating a seal and eliminating the need for bolts or rivets.
Apply 40 pounds of pressure to ¼ inch foam rubber, compressing it to ⅛ inch, and it becomes waterproof. Compress it to 1/16th inch, and it handles pressure at 10,000-foot depths. Compress it to 1/32 inch, and its seal is tight enough for space travel. This is how the compression factor plays a role in gasketing.
Large and thin rectangles of rubber can be complex to handle independently. However, a converter can precisely die cut them and use a backing material to keep their shape until they’re put in place. At that point, a liner is removed, and the other matching part is applied, usually using automation to make it an exact fit.
The importance of automation in gasket-making can’t be overlooked. Many converters can cut flatbed parts that must be applied by hand. The real value comes with engineering that creates a converted, automation-friendly, and ready product.
Designing a gasket is no easy task, and it becomes even more challenging when you begin to consider gasket adhesives.
If you have a gasket design, consider submitting it for evaluation based on how simple it would be to manufacture. As a flexible material converter, we’ve made millions of gaskets and can recommend materials and adhesives to increase manufacturability.
You can also find additional resources and gasketing tips in our Learning Center, or contact us with questions. Hopefully, these questions will help you design the perfect gasket— happy gasketing!
Originally published: November 23, 2021