Specification sealant

Sealant Specifications Compendium, The Adhesive and Sealant Council, Washington, D.C., 1988. 

ASTM C920 sealant specification, 22 46 ASTM classification, of pig tin, 24 790,... 

ISO 9000 standards, 15 757 ISO 11600 sealant specification, 22 46. See also International Standards Organization (ISO)... 

An adhesive or sealant specification, like all material specifications, is a document that specifies values for all the important properties, together with limits of variability and methods for determining these values. There are many adhesives and sealant specifications, of which the most prominent are the industrial and government specifications. These describe and establish the technical and physical characteristics or performance requirements of adhesive materials. The most common sources of standards and specifications for the adhesives and sealants industry are the following ... 

Standard Test Method for Determining Compatibility of Liquid Applied Sealants with Accessories Used in Structural Glazing Systems Determining Tensile Adhesion Properties of Structural Sealants Specification for Structural Silicone Sealants... 

Test Method for Tack Free Time of Caulking Compounds and Sealants Specification for Nonbituminous Inserts for Contraction Joints in Portland Cement Concrete Airfield Pavements, Sawable Type Specification for Joint Sealant, Hot Poured, Elastomeric Type, for Portland Cement Concrete Pavements... 

The various dental polymers discussed in this article include impression materials, dentures and denture liners, artificial teeth, crown and bridge materials, mouth protectors, maxillofacial materials, restoratives (consisting of glass polyalkenoates or glass-ionomers and composites), adhesives, and sealants. Specifications and standards for dental materials are also briefly mentioned in the text. 

Our results are qualitative in that we report positive reactions by audible detection, evidence of burning, or by a visible flash at impact. Our LOX sealant specification (for static applications) requires no positive reactions in 20 tests when tested at the 20 ft-lb level. Materials proposed for use in critical dynamic applications must not detonate during 20 trials at 70 ft-lb. Materials falling in between these levels are selected on the basis of the hazardous potential expected for their intended uses and are evaluated thoroughly under simulated service conditions. 

Standard practice for use of solvent-release type sealants Specification for latex sealing compounds... 

Toporcer, L.H., 1986, " Sealant Specifications", Caulks and Sealants Short Course, Adhesive and Sealant Council, Washington, DC, Dec., pp 1-10. 

Typical specifications for the polysulfide polymers are summarized in Table 1. Specifications for the sealants vary widely depending on the specific apphcation and the needs of the appHcators. Standards for sealant testing vary in different countries. Ultimately, the tests should simulate the environment the sealants will be exposed to and measure their performance under these conditions. 

Wea.ther lbillty. One of the more destmctive elements is exposure to sunlight specifically, ultraviolet (uv) light. AH sealants are affected by weathering, but there is much difference in the effect of weathering on different sealants. Most sHicones are stable with respect to uv exposure. Urethanes and polysulfides show effects of uv exposure, but can be formulated with uv absorbers to provide reasonable lifetimes in most appHcations. However, there are exceptions in aH classes of sealants and specifiers must be carehil to look for test data that has proven a specific sealant s durabHity. The source of the test data is also important data from an independent testing laboratory is generaHy apt to be more reHable. 

Talc is sold for use in a wide variety of appHcations, including paper (qv), ceramics (qv), roofing, paint (qv), plastics, mbber (qv), cosmetics (qv), pharmaceuticals (qv), adhesives (qv), sealants (qv), and animal feedstuffs (see Feeds and feed additives). In all of these appHcations it is a functional ingredient with specific beneficial properties. Talc is rarely used as a filler because it is much more expensive than alternative minerals such as limestone and clay. 

The specification must recognize this very important auxiliary part of the compressor. API 614 is a very complete specification and should be used when applicable. When direct use is not applicable, it makes an excellent guide. The seal system in many cases is combined with the lube system. When separate, many of the seal system components are fundamentally the same, with some specifics, such as operating pressure and control, being unique. For those applications where the sealant is other than lubricating oil, the particular fluid will need discussion. The system basic components, on the other hand, will probably be quite similar. General items that must be considered include ... 

Previous reviews on silicones in relation to adhesion have dealt with specific technologies such as adhesives, sealants, and coupling agents [12-17]. This review attempts to address the fundamental properties of silicones and to relate them to various aspects of adhesion technologies. The perspective taken in this review is from the point of view of a newcomer in the field of adhesion and silicones. 

This chapter first reviews the general structures and properties of silicone polymers. It goes on to describe the crosslinking chemistry and the properties of the crosslinked networks. The promotion of both adhesive and cohesive strength is then discussed. The build up of adhesion and the loss of adhesive strength are explained in the light of the fundamental theories of adhesion. The final section of the chapter illustrates the use of silicones in various adhesion applications and leads to the design of specific adhesive and sealant products. 

A chemical property of silicones is the possibility of building reactivity on the polymer [1,32,33]. This allows the building of cured silicone networks of controlled molecular architectures with specific adhesion properties while maintaining the inherent physical properties of the PDMS chains. The combination of the unique bulk characteristics of the silicone networks, the surface properties of the PDMS segments, and the specificity and controllability of the reactive groups, produces unique materials useful as adhesives, protective encapsulants, coatings and sealants. 

The role played by the various ingredients in the composition of sealant, and in particular on the durability of adhesion has been discussed recently [77]. Inert plasticizers, such as trimethylsilyl-endblocked-PDMS, are typically added to silicone sealant compositions in order to adjust the rheology of the uncured sealant. They result in a reduction of the modulus and hardness of the cured sealant. Differences in the durability of silicone sealants are found to be due to differences in their cure chemistry, and more specifically to the nature and... 

The surface energy of silicones, the liquid nature of the silicone polymers, the mechanical properties of the filled networks, the relative insensitivity to temperature variations from well below zero to very high, and the inherent or added reactivity towards specific substrates, are among the properties that have contributed to the success of silicone materials as adhesives, sealants, coatings, encapsulants, etc. 

In 1998, the FDA approved fibrin sealant for three specific indications. These include hemostasis at the time of cardiac surgical operations [8] (Fig. 2) as well as at the time of operative procedures to treat splenic trauma. The application of the fibrin sealant which consists of normal biologic components in the body s clotting cascade creates a localized clot which further enhances inherent clotting ability. Although approved for these specific hemostatic indications only, fibrin sealant is useful as a hemostat in a wide variety of off-label clinical situations as well [9,10]. These include such applications as hemostasis for liver trauma or resection [11], vascular anastomoses [12], tonsillectomy [13], peripheral joint replacement [14], dental extractions [15], and bum debridement [16]. 

Sealants. Gaskets, and Beads. All gaskets or beads are required to be at least 3/8 inch wide with a Shore "A" durometer hardness of 50 and conform to ASTM Specification C509-84 (Cellular Elastomeric Preformed Gasket and Sealing Material). 

The next two chapters discuss two supporting components of the fuel cell stack —specifically, interconnects and sealants. The interconnect conducts the electrical current between the two electrodes through the external circuit and is thus simultaneously exposed to both high oxygen partial pressure (air) and low oxygen partial pressure (fuel), which places stringent requirements on the materials stability. Ceramic interconnects have been used, but metallic interconnects offer promise... 

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