Gaskets are materials used to seal one compartment of a device ...

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Reinforced cellulose based gaskets have increased in popularity in the past few years. These gaskets can duplicate all asbestos performance parameters, except high temperature resistance. Although they can be used at a maximum continuous operating temperature of 350°F, their life is substantially shortened in temperatures over 95°F. Despite this, manufacturers indicate that the service life of these asbestos free gaskets is the same as for asbestos gaskets (Carborundum 1986). Cellulose fiber formulations in combination with clay and mineral thickeners are estimated to capture 15 percent of the sheet gasketing market in the event of an asbestos ban. Prices would be expected to rise 20 percent to $6.83 per square yard due to increased material and production costs (ICF 1986a). 5. PTFE PTFE fibers offer chemical resistance to all but the most powerful oxidizing agents, acids, and alkalies in temperatures ranging from -450°Fto 500°F(Chem Eng. News 1986). This material has good dielectric strength and impact resistance. PTFE can be used in specialized applications because it has been approved by the FDA for contact with food and in medical equipment. In addition, it does not stain the fluid with which it has contact (Krusell and Cogley 1982). PTFE, and PTFE and graphite mixtures can be formulated into gasketing material easily, reducing the price of the gasketing that would otherwise be quite high (PTFE is twenty times as expensive as asbestos). The final product, however, is only 3.5 times as expensive as the asbestos product. PTFE gasketing is, therefore, $19.91 per square yard. Industry officials indicated that PTFE gaskets will capture 10 percent of the total asbestos - market in the case of an asbestos ban (Palmetto Packing 1986, ICF l986a). - 12 -
6. Ceramic Fiber Mixtures Ceramic fibers, composed of alumina-silica blends are used in the manufacture of gasketing material to replace compressed asbestos sheet, although their performance has not been outstanding (Union Carbide 1987). These fibers impart high temperature resistance to gaskets made from them, but little information is available on the performance characteristics of these materials. Costs are expected to be the same as for other ceramic based products that can replace asbestos products (two times as expensive), but it is unlikely that ceramic products will occupy more than five percent of the market in the event of an asbestos ban (ICF estimate). E. Summary It appears that substitutes for asbestos containing sheet gaskets currently exist. However, these products cost more to produce and may not perform as well. Substitute fiber formulations include aramid, glass, graphite, cellulose, PTFE, and ceramic fibers. The substitute materials are a combination of fibers and fillers designed on an application-by-application basis. The substitute materials are classified by the fiber with the highest content. The estimation of market shares and prices of the substitute formulations in the event of an asbestos ban and the data inputs for the Asbestos Regulatory Cost Model are presented in Table 5. - 13 -
Page 1 and 2: XXVII. SHEET GASKETS A. Product Des
Page 3 and 4: Table 1. Fluid and Pressure Ranges
Page 5 and 6: $20.5 million in 1985, based on an
Page 7 and 8: Table 3. Substitutes for Asbestos S
Page 9 and 10: Aramid gaskets are usually composed
Page 11: esistance. A wire insert is often a
Page 15 and 16: REFERENCES Carborundum. 1986. Produ
Page 17 and 18: Bulk Square braád Rolled (over cor
Page 19 and 20: Table 1. Standards of Asbestos Yarn
Page 21 and 22: A. ‘I’ A. ‘-I PRESSURE ~ Movi
Page 23 and 24: Table 2. Operating Conditions and U
Page 25 and 26: Table 3. Production of Asbestos Pac
Page 27 and 28: een forced to replace the asbestos
Page 29 and 30: Table 4. Estimated Market Share for
Page 31 and 32: useful temperature limit of approxi
Page 33 and 34: 6. Other Substitute Fibers Other fi
Page 35 and 36: Table 6. Data Inputs for Asbestos R
Page 37 and 38: TSCA Section 8(a) submission. 1982.
Page 39 and 40: a viscosity control for waterproofi
Page 41 and 42: Table 1. Production of Asbestos Roo
Page 43 and 44: or talc. The additives ease grindin
Page 45 and 46: Table 2. Manufacturers of Cellulose
Page 47 and 48: Cellulose bodied roof coatings and
Page 49 and 50: equivalent basis, they are favored
Page 51 and 52: compounds. These formulations have,
Page 53 and 54: . Other Roof Coatings and Cements O
Page 55 and 56: Table 4. Data Inputs for Asbestos R
Page 57 and 58: ATTACHMENT B PROJECTED PRICES ANALY
Page 59: ICF Incorporated. 1986 (July-Decemb

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