Metal-reinforced gaskets are a staple in the industry. They provide radial strength for both handling and in-application uses. The gaskets are dimensionally stable and very robust.
But some gaskets have screen cores…is this a good thing? In most cases, no. Read on to learn why.
Screen Core Materials
Screen core is one version of a metal center layer sandwiched between two layers of sealing material. It provides a metal core layer for a laminate that offers strength while allowing a place for an adhesive bond to occur. It also provides an additional level of lateral strength as the facing cannot slide laterally on the screen core. While it seems like it might be a good idea, the drawback comes with the issue of sealability. By its nature, screen is a woven material, generally wire, in an over/under overlapping pattern. This is what creates the problem. The over/under configuration provides a leak path for the fluid being sealed. The facing material must conform tightly to the metal or a leak will generate. This is difficult for the facing to do as there is an inherent void to be dealt with. In some cases, this can be addressed by a heavy layer of adhesive, but this is not the best solution since it only puts a band-aid on the problem.
If Not Screen Core, Then What?
A better solution is a solid core laminate using flat metal and a thermally-cured adhesive. This product provides NO leakpath along the core due to the adhesive bond. Another core style is expanded steel. While it is a “porous” core, it also has NO direct leak path through the core by the nature of its design, thus allowing the adhesive to bond the two sides of facing directly through the core.
As with all products that contain a thermally-cured adhesive, you need to pay attention to the operating temperatures of your application and the specification of your chosen material. In fluid sealing applications, temperature capability of solid core materials is often more than sufficient to withstand the conditions of the application.
Find A Solution
As you can see, there are some things to be aware of if you’re thinking about using a screen core as a layer of metal-reinforcement. For fluid sealing applications, there are better choices available, such as solid core laminates or expanded core laminates.
If you aren’t familiar with solid core laminates, talk with your trusted gasket material supplier to learn about your options.
Metal Tech offers solid core products under the SURBOND product group for fluid sealing applications.