Felt mat

Hot Pressing of Felted Mats. An experiment intended to identify which of thetwo mechanisms is operative was designed and executed. The approach taken was based on the argument that each mechanism requires certain cell wall components be present and that removal of all or most of the component will be detrimental to wet-strength development. The phenol-furfural condensation mechanism requires hemicellulose as a source of furfural. The thermoplasticity of lignin mechanism requires lignin. Consequently, three pulps were prepared containing ... 

CN)2C=C(CN)2 this addition also improves the electrode kinetics. Current collection is improved by adding -> graphite felt mats into the electrode volume. 

Below pH ca. 4.0, the lake becomes a suitable habitat for white moss, which prefers an acidic environment. This plant forms a felt mat , which may grow to 0.5 m or more thick, on the lake bottom. The mat prevents the exchange of nutrients between the water and the bottom sediments and also prevents the sediments from exerting any buffering action. The resultant lake waters are crystal clear, but this water supports very few forms of aquatic living organisms. 

In 1971, one of the first pipes was installed in the UK in London in the form of 1.17 X 0.61 m egg shaped profiles. A polyester felt mat tube impregnated with an isophthalic polyester resin was installed and cured in place. After 20 years, a section of the pipe was taken out of service and the strength properties were measured. The cured-in-place pipe retained its properties and still had a flexural strength that was 30% over the initial installation requirements. The parts showed no sign of wear or deformation. Several other pipe sections have been checked after years of service and found to be virtually unchanged. 

Oxide fibers are manufactured by thermal or chemical processes into a loose wool mat, which can then be fabricated into a flexible blanket combined with binders and formed into boards, felts, and rigid shapes or fabricated into ropes, textiles and papers. The excellent thermal properties of these products make them invaluable for high temperature industrial appHcations. 

Built-Up Roofing. Built-up roofing (BUR) is a continuous-membrane covering manufactured on-site from alternate layers of bitumen, bitumen-saturated or coated felts, or asphalt-impregnated glass mats and surfacings. These membranes are generally appHed with hot bitumens or cold apphed bituminous adhesives (qv). 

The deck may be nailable, eg, wood or light weight concrete, or not, eg, steel or stmctural concrete. The felts or mats may be organic (cellulose), or fiber glass. The roof slope ranges from dead level (0—2.1 cm/m), to flat (2.1—12.5 cm/m), to steep (12.5—25 cm, /m). 

The components must be anchored as protection against wind uplift, shppage, and membrane movement. Apphcation rates for BUR membranes ate given in Table 2. Membrane strength is related to felt or glass-mat strengths and the number of phes. Continuous bonding is inadvisable if the elastic... 

Property Organic felt, asphalt-saturated Fiber glass mat, asphalt-impregnated ... 

Fire and Wind Hazards. Weather resistance of roof covetings is not necessarily correlated to fire and wiad resistance. Underwriters Laboratory and the Factory Mutual System test and rate fire and wiad hazard resistance, and some durabiUty tests. Organic felt or fiber glass mat base shingles are commonly manufactured to meet minimum UL requirements, which, ia addition to minimum mass, require wiad and fire resistance properties. 

Goal Tar. In roofing, coal tar is used as mopping bitumen in between 15 and 20% of the BUR roofs installed. Coal-tar pitch and asphalt are considered incompatible and should not be mixed. If mixed, an oily exudate is formed that plasticizes the bitumen, and the mixture remains soft and does not weather well. For this reason, if coal tar is used in BUR systems the felts must be coal-tar saturated. There has been some success using asphalt-coated fiber-glass mat felts with coal-tar pitch. However, this has only been done for a limited number of years so the actual compatibiHty is not fully known. 

Pressed Felts and Cotton Batting These materials are used to filter gelatinous particles from paints, spinning solutions, and other viscous liquids. Filtration occurs by deposition of the particles in and on the fibers throughout the mat. 

The filter medium can be fibrous, such as cloth granular, such as sand a rigid solid, such as a screen or a mat, such as a felt pad. It can be in the shape of a tube, sheet, bed, fluidized bed, or any other desired form. The material can be natural or man-made fibers, granules, cloth, felt, paper, metal, ceramic, glass, or plastic. It is not surprising that filters are manufactured in an infinite variety of types, sizes, shapes, and materials. 

The filters used for gas cleaning separate the solid particles by a combination of impingement and filtration the pore sizes in the filter media used are too large simply to filter out the particles. The separating action relies on the precoating of the filter medium by the first particles separated which are separated by impingement on the filter medium fibres. Woven or felted cloths of cotton and various synthetic fibres are commonly used as the filter media. Glass-fibre mats and paper filter elements are also used. 

In addition to the particulate adsorbents listed in Table 16-5, some adsorbents are available in structured form for specific applications. Monoliths, papers, and paint formulations have been developed for zeolites, with these driven by the development of wheels (Fig. 16-60), adsorptive refrigeration, etc. Carbon monoliths are also available as are activated carbon fibers, created from polymeric materials, and sold in the forms of fabrics, mats, felts, and papers for use in various applications including in pleated form in filters. Zeolitic and carbon membranes are also available, with the latter developed for separation by selective surface flow [Rao and Sircar, J. Membrane Sci., 85, 253 (1993)]. 

Continuous filament mats sheet of continuous filament felt with a binder. 

Mats chopped fibres (50 mm) are held together with a binder to form a sheet. Continuous filament mats sheets of felt of continuous filaments with a binder. Stratipregs or prepregs rovings impregnated with a resin. 

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