| Résumé : |
Pre-cured sealants are produced by extruding elastomeric sealant material and allowing it to cure to a rubbery, flexible product in a controlled manufacturing environment. Pre-cured sealants are packaged in cured form (often in rolls) instead of typical liquid packaging (e.g., tubes, pails, etc.), and are attached to the substrate being sealed by using a thin layer of adhesive on each side. The material is then pressed into the adhesive to ensure adequate contact between the pre-cured sealant and the adhesive, as well as between the adhesive and the substrate. With the outer edges adhered to the substrate, the middle of the pre-cured sealant material, which is not bonded to the substrate, acts as the area for expansion and contraction.
Pre-cured sealants are most commonly produced as flat extrusions with a thickness of approximately 2 mm and sizes (widths) that vary from 0.5 in. to 14 in. wide. Pre-cured sealants are readily available in many standard sizes and colors. Manufacturers also offer custom color and custom design pre-cured sealants to fit different application requirements. Custom pre-cured sealants are available with a variety of surface textures designed to match the appearance of exterior insulation and finish systems (EIFS), stucco, and other surfaces. Pre-cured sealants can also be produced with one or more notches in the extrusion. These notches allow the pre-cured sealant to bend uniformly in specific locations and seal complex configurations in applications such as inside and outside corners, parapet caps, window mullions, and others.
Because of its excellent aging characteristics, resistance to ultraviolet light and weathering, and long effective lifespan, silicone is almost always chosen for pre-cured sealants in construction-related applications. In addition, the movement capability for silicone pre-cured sealants is commonly +200%, significantly higher than other types of sealing products. The combination of high movement capability and thin material allows silicone pre-cured sealants to easily handle multi-directional movement. Additional advantages of silicone over other materials include a wide operational temperature range and better resistance to color fading. |
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Pre-cured construction in ADHESIVES & SEALANTS INDUSTRY (ASI), Vol. 19, N° 3 (03/2012)
