Diaphragm Design Manual - Simrit

Web Area, Working Areas, Working Zone – See Convolution Width.Materials RelatedAbrasion – Is the wearing away of a material surface through friction. Particles becomedetached through a combined cutting, shearing and tearing action.Adhesion – In rubber parlance, it refers to the strength of the bond between a cured rubbersurface and a corresponding non-rubber surface, i.e. metal, or fabric.Aging – A progressive change in the chemical and physical properties of rubber, especiallyvulcanized rubber, usually marked by deterioration. Aging may be retarded by the use ofantioxidants.Antioxidant – A substance, which inhibits or retards oxidation and certain other kinds of aging.Antioxidants can cause staining or discoloration of the rubber compound when the rubber isexposed to light.Bloom – The coating or efflorescence of sulfur, wax or other ingredients of vulcanized rubber,which may gradually appear on the surface of some rubber articles. Bloom depends on thesolubility of the substance in the rubber.Bonding Agents – Substances or mixtures of substances that are used for attaching rubber tometal, fabrics or other substrates.Checking – The development of minute surface fissures as a result of exposing rubber articlesto sunlight, generally accelerated by bending or stretching.Chemical Resistance – The resistance offered by elastomer products to physical or chemicalreactions as a result of contact with or immersion in, various solvents, acids, alkalies, salts, etc.Coated Fabric – A diaphragm construction that uses previously rubberized fabric. The fabric istypically coated on both sides. These coatings can be of differing thicknesses and made up ofdifferent rubbers or compounds.Compound – In rubber manufacturing, it is the composition or formula of stock, the ingredientsof which, however, may not all be chemically combined and is therefore more of a physicalmixture.Compression Set – see Permanent Set.Coefficient of Expansion – The coefficient of linear expansion is the ratio of the change inlength per degree to the length at 0°Celsius. The coefficient of surface expansion is two timesthe linear coefficient. The coefficient of volume expansion (for solids) is three times the linearcoefficient.Disperse – To cause particles or molecules of matter to separate and become uniformlyscattered throughout a medium. In a rubber compound, the particles of compounding ingredientsare dispersed in the rubber. In latex, rubber globules are dispersed in an aqueous medium.Double Coat – Refers to a diaphragm that has a rubber coating on both sides of the reinforcingfabric. Can be a molded double coat or a coated fabric.© Copyright FNGP 200951