Two key processes to use when creating EMI Shielding Gaskets are splicing and molding. To create these gaskets, it’s crucial to be familiar with both of these manufacturing techniques. Gaskets come in several types of materials and in numerous shapes and sizes, so knowing how to splice or mold the material at hand will go a long way when you’re working with EMI shielding gaskets.
Typically, EMI Gasketing is created using a base material of silicone or fluorosilicone. Then, conductive fillers made of materials such as silver, silver-plated aluminum, nickel-plated graphite and more are added. There are several types of these conductive elastomers available, but it’s important to know which will suit your project best before choosing a filler to use.
Splicing – When to Use It
The splicing process begins when conductive elastomer gaskets are created in long strips that need to be manipulated in order to form a proper O-ring. To create that O-ring, the elastomer gaskets are cut to the desired length and then fused together with a strong, proprietary adhesive glue at the ends. This process of cutting and fusing elastomer gaskets is called splicing.
Each unique project calls for either splicing or molding, both of which have their own advantages and disadvantages to consider.
Splicing is a very time-efficient process. Bulk material can be manipulated easily when creating gaskets, allowing for a quick project turnaround.
Hundreds of extrusion profiles to use make it easy to splice for any size. Should that size change, and the dynamic nature of the splicing process also allows for further splicing to be performed, accommodating changes without significant lead time or cost.
Splicing is also a tactic that can be used with hollow cross-section profiles, creating parts that can accommodate low compression force enclosures.
While splicing is an efficient solution for crafting EMI shielding gaskets, there are disadvantages when choosing this route, particularly when being compared to its alternative: molding.
When the splicing process takes place and elastomer gaskets are fused into their O-ring shape, some have found that these O-rings do not retain their shape as well as if they were to have been molded. Part of this might be due to the lack of complexity that the splicing process is able to achieve due to its loop-like way of operating.
The molded O-rings can be crafted to fit near any desired shape or size. The splicing process is also known for its low tolerance range. Typically, splicing will not hold to tight tolerances. Of course, the splicing process also has tight regulations for how small gaskets should be when spliced.
Vulcanizing is a commonly-known bonding technique used for splicing where heat, pressure and a splice are used to fuse the ends of a gasket together. At KRA Fab, our expert manufacturers perform vulcanizations daily. This process is a dependable, cost-efficient way to join profiles of countless types of materials in a variety of different shapes and sizes.
Typically, this tactic is used when there is a space for the free-flowing passage of air to the gasket. All things considered, the vulcanizing technique should be used for low-volume applications as opposed to high-volume production rates.
Spliced vs. Vulcanized O-Rings
Spliced and vulcanized O-rings have different purposes that should be taken into consideration well before the gasket manufacturing process. First, ask yourself whether or not the project at hand is a dynamic application or not. If there are moving parts near the O-ring, a vulcanized O-ring likely isn’t the best fit. If the application is not dynamic, a vulcanizing ring might be a good solution. The vulcanized O-ring is suitable for a wide range of industries and applications, so long as there is a lid that needs to be sealed.