Fabrication

nedc-fabrication

O-ring being bonded in fixture

One of the most important characteristics of an effective sealing system, whether it be an O-ring, a glued seal, or RTV bond is a skilled fabricator.

The first effective solution that NEDC’s Fabrication Department provides is a vulcanized O-ring. This is a process where the cord stock is cut to the required developed length and then placed into a fixture where it is bonded and then cured with heat and pressure. The material itself must be part of the bond in order to get the best and most consistent seal.

NEDC molds O-rings to different specifications such as MIL-DTL-83528F, it also uses the same material in liquid form to ensure the bond as just as strong as the material or stronger. This can only be guaranteed with a true vulcanized bond. NEDC genuinely vulcanizes all of its fluorosilicone and silicone O-rings. With some O-rings, there may be a need to ‘cold bond’ the O-ring, this is essentially gluing the O-ring without heat nor pressure.

Another benefit of vulcanizing materials to bond them together with incredible strength is the ability to make large gaskets. NEDC can manufacture parts that may use vulcanized bonds such as ladder gaskets, window gaskets, and large enclosure gaskets.

Another solution NEDC’s fabricators provide is gaskets that have mesh around its borders or within its borders. NEDC is able to provide not only solid rubber gaskets, but also sponge rubber gaskets with mesh around the borders. An important component to this is ensuring that the mesh sticks permanently. It’s not uncommon for a gasket to use RTV (Room Temperature Vulcanization) to essentially be ‘glued’ together. A good example of this would be a sponge die-cut gasket, with mesh ‘glued’ within the perimeter. There may also be an application that requires an adhesive to be applied after the converting because of a special assembly. These assemblies may require special designs and might need to be hand fabricated.

Some applications require that the gasket be tested before it is sent to the customer. These tests could be as simple as a pull tests or become as complicated as immersion testing. The immersion testing is essentially immersing the assembly in whatever fluid it is being tested in accordance with (IAW) and measuring the result.

Other applications require specific adhesives and specific substrates. NEDC uses many methods to fabricate metal (not limited to) parts to gaskets, including acrylic, silicone & rubber adhesives, such as adhesives provided by 3M Company. Some assemblies require precision as close as 5mil, these assemblies normally require fixtures to ensure that the gasket is exactly where it is supposed to be on the discussed application.

Stamping is another service that NEDC’s Fabrication Department is able to provide. NEDC’s fabricators provide solutions that use inks such as AA56032C, formerly MIL-I-43553. Stamping can range from very simple to very complicated depending on the application. Sometimes instead of an ink, a simple sticker is required, although the sticker placement may have a tolerance on the position as well.

Whatever the application, NEDC provides skilled fabricators to assemble all of the gaskets, O-rings, and insulators it manufactures to package into one convenient sealing solution.