Sealing and sealants

Bearings, bushings, gears, nonstick surfaces, low friction surfaces, pipes and pipe coatings, fittings, valves and valve parts, seals and sealants, foams, conveyor belts for manufacture of ceramic tiles, outdoor signs... 

Fiorillo, A.R. (1994) Case-histories of successfully sealed expansion joints with polysulfide sealants, in Proceedings of Third Symposium on Science and Technology of Building Seals and Sealants, FL, USA, ASTM special technical publication 1254, part 3, American Society of Testing and Materials, Philadelphia, PA. 

Panek, J. "Building Seals and Sealants" ASTM Spec Tech Bull 606, Philadelphia, PA 1976. 

Shephard, N.E. and Wightman, J.P., An Analysis of the 180° Peel Test for Measuring Sealant Adhesion. In Lacasse, Michael, A. (Ed.), Science and Technology of Budding Seals and Sealants Fifth Volume, ASTM STP 1271. American Society for Testing and Materials, Philadelphia, PA, 1995. 

ASTM C 1589 [406] Standard Practice for Outdoor Weathering of Construction Seals and Sealants... 

Standard Terminology of Building Seals and Sealants, ASTM C717-OOa. 

Table 24 lists important U.S. specifications for sealants and caulks Table 25 lists ASTM test methods for building seals and sealants and Table 26 is a reference guide for sources of sealant and caulk specifications. 

Table 25. ASTM Building Seals and Sealants Test Methods.

The 1986 Annual Book of ASTM Standard on Building Seals and Sealants in Volume 04.07... 

There are a multitude of tests which have been estabUshed by various organizations to describe the properties and performance of adhesives and sealants. For construction sealants, these include Federal Specification (TT), Military Specifications (MIL), and American Society of Testing and Materials (ASTM). Major work has been carried out by the ASTM D-14 Committee on Adhesives and ASTM C-24 Committee on Building Seals and Sealants. 

The seal must also resist the vibrations from the explosions of internal combustion in the engine, chassis and wheel vibrations, and even potholes in the road. This seal must resist strong chemicals (anti freeze, anti-rust agents, radiator stop-leak and sealant chemicals, gasoline and lubricant residuals), and also solid particles (rust, iron slag, minerals, asbestos fibers, and silica from the engine casting mold). In spite of all this, the mechanical seal on the water pump of your car can run 7, 10, even 15 years without problems. 

Like the 1-RTV systems, the two-part room temperature vulcanization systems (2-RTV) cure to produce flexible elastomers that resist humidity and other harsh environments. Interestingly, they display primerless adhesion property to many substrates, and are used in silicone adhesives, sealants, seals, and gaskets, to name a few. 

When metal inserts require hermetic sealing, consider coating them with a flexible elastomer such as an RTV rubber, polyurethane, or epoxy system. A second method is to design an annular space or reservoir at one end of the insert from which to dispense the flexible elastomers to effectively create a hermetic seal. Flexible sealants are also used to compensate for differences in the thermal coefficient of expansion between metal and plastic. 

The bead and sealant are required to form a weatherproof seal. 

In addition to the YSZ electrolyte and metallic interconnect, SOFC stack also includes component materials such as seals and manifolds. Sealant materials based on glass or... 

PMMA is prone to stress cracking and contact with plasticized PVC, rubber seals and silicone sealants must be avoided or carefully studied. 

Hose, belting, and cable, 28% 0-rings and seals, 20% latex, 15% molded and extruded products, 15% adhesives and sealants, 10% sponge, 5% footwear, 2% miscellaneous, 5%... 

Because PIB is fully saturated, it is cured as a thermoset elastomer through inclusion of about l%-2% isoprene that supplies the needed double bonds used in the curing process. Other materials including brominated paramethyl styrene are replacing isoprene for this use. PIB is also used in sealing applications and medical closures and sealants. 

Adhesives and Sealants. Dominated by copolymers, adhesives and sealants remain somewhat of a specialty market. These polymers usually contain high copolymer content and low viscosity, and often require blending with oilier compounds prior to final application. Their uses are numerous, e.g., as seals for bottled drinks, as tie layers between incompatible polymers, or as automotive adhesives... 

Medium-molecular-weight PMTFPS with vinyl or hydroxyl end blocks are used for adhesives and sealants. They are cured either at ambient temperature (RTV-room temperature vulcanization) or at elevated temperature. One-part moisture-activated RTV sealants have been available commercially for many years. Because of then-very high resistance to jet engine fuels, excellent flexibility at very low temperatures, and high thermal stability, they have been used in both military and civilian aerospace applications.78 Two-part, heat-cured fluorosilicone sealants have been used in military aircraft applications and for sealing automotive fuel systems.79 Special class of fluorosilicone sealants are channel sealants or groove injection sealants, sticky, puttylike compounds, which do not cure. They are used to seal fuel tanks of military aircraft and missiles.75... 

Petrie, E. M., Chapter 16 Bonding and Sealing Specific Substrates, in Handbook of Adhesives and Sealants, McGraw-Hill, New York, 2000. 

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