Chemically Bonded Seals

A composite part in rubber molding consists of either an elastomer that is chemically bonded using an adhesive or mechanically locked to a substrate (ferrous and non-ferrous metals, plastics, fabrics) using through holes or undercuts. Sometimes, both methods are employed at the same time, providing a robust chemical and mechanical bond. The strength and the type of bond ultimately depends on the application of the composite part. These types of high-strength applications commonly utilize adhesives that create chemical bonds that are stronger than the elastomer itself. The chemical bond even remains intact when the elastomer itself fails from the stress or forces on it.

In addition to bonding, the adhesives provide environmental resistance from corrosion. At the other end of the spectrum, sometimes all that is required is a light mechanical bond to hold the components together temporarily in position until assembly is completed. Some important factors must be considered to establish an effective chemical bond that adheres the rubber to a substrate. The type of adhesive is specifically chosen and is based on the family of elastomer, curing system, and substrate. Adhesives can be water or solvent based, clear, pigmented, consist of a primer coat and covercoat system, or just a one coat system.

The adhesives can be applied to the necessary component surfaces using various methods. Some of the depositing methods include spraying, brushing, and dipping. Sometimes, the adhesive can be used neat, or are required to be diluted with the appropriate solvent according to the manufacturer’s recommendation and application method.

During the molding and vulcanization process (which requires heat and sustained cavity pressure as a catalyst), chemical reactions are taking place. On a molecular level, cross-linking occurs between the elastomer and adhesive and between the adhesive and substrate. Substrate surface preparation is extremely important for good adhesion. Bonding surfaces need to be clean and free of oils, cutting fluids, rust inhibitors, dirt, oxidation or other contamination. A wide array of surface preparation methods, either mechanical or chemical, can be employed and are specifically chosen based on the substrate material and geometry. Bonding for seals are a mixed choice. In the short term, chemically bonded seals can perform and create a sufficient seal for liquids and many gases. However, in applications for long term use epoxy bonds are permeable to certain gases and moisture and are not used in seals that require high hermetic seal integrity.

Darcoid Nor Cal Seal is into supply of various kinds of seals and sealing solutions, including chemically bonded seals. The types of chemically bonded seals from Darcoid include Rubber-to-Metal Bonded Seals (Parofluor ULTRA FF356-75), Ultra-High Purity (UHP) Bonded Doors, which are used in semiconductor manufacturing operations must be replaced frequently due to particle generation caused by mechanical wear, chemical attack and thermal cycling and UHP Slit Valve Door, which is. an engineered sealing system designed to improve productivity and reduce downtime in critical semiconductor processing applications.

Darcoid is a paramount endeavor that is into delivering a diverse range of machinery accessories like different varieties of polymers, gaskets, adhesives, molded shapes, thermal products, rubber seals, sealing products like Parker seals, O rings, dynamic seals, semiconductor seals, composite seals, rubber gaskets, medical components, sanitary and hygiene seals and a few other such rubber materials is to prevent friction and leakages and also for an ace performance enhancement of your machinery.

At Darcoid Nor-Cal Seal, we take the time to learn about your unique needs, and then use our experience and knowledge to deliver you the best solution