Lamitex® laminated plastics are used in numerous applications where they are either submersed or are in constant contact with corrosive chemicals. The degree of chemical resistance of the laminate will depend on the nature and concentration of the chemical agent along with temperature and duration of exposure. The ease of fabrication, light-weight, and resistance to friction, light, and heat are other major advantages for Lamitex composites in these applications.
As opposed to metals; the deterioration of thermoset laminates is attributed to the dissolution of the resin by the newly introduced chemical and/or damage to the material reinforcement. The base fabric of which the thermoset laminate is composed of is considered the ‘reinforcement’. The type of reinforcement is principal in the specification of a laminate for an application. Cotton fabric (Lamitex grade CE/MFG/LE etc.) is satisfactory for weak acids, weak bases, most alkali solutions and organic solvents. Glass fabric has proven resistant to all chemicals tested, while basalt fabrics are resistant to corrosion and aggressive chemical liquids. The second area of deterioration is in the resin. Each resin used in Lamitex formulations is selected with an application in mind i.e.; wear, dielectric, compressive strengths etc. Each resin also demonstrates different chemical resistance to certain chemicals. For instance; Phenolic (CE/MFG/G3), epoxy (G10/FR4, G11, G12) and silicone (G7) resins are resistant to most chemicals while melamine resin is particularly resistant to alkalis.
Although total chemical inertness may not always be necessary, Lamitex materials are typically designated because they maintain their size, shape and strength when immersed in chemicals. More importantly, our materials are designated because they have a longer life than any other material; taking into consideration labor and materials for the original installation (and cost of replacement). Each chemical application should be considered individually based on past experience. If none exists, laboratory testing should be completed to determine the grade most practical and most economically sound for the application. Some tests may require a great deal of time, but for many applications conclusions can be reached from accelerated tests.
It is most important when organizing such a test to have a complete understanding of the actual chemicals involved along with concentration, time and temperature of immersion. When there is a sequence of operations the entire procedure must be investigated. For example, in some metal plating operations, the racks are exposed to hot concentrated acids which would destroy the laminate if it were exposed to continuous immersion: however, laminates would perform admirably in metal plating lines where racks are immersed in hot acid solutions for short periods of time and then exposed to neutralizing baths and rinsing with water.