A polyethylene naphthalate fiber of the present invention comprises a naphthalate-based copolyester in which at least 85 mol % or more of the total of recurring units is an ethylene 2,6-naphthalate unit, and it is obtained by copolymerizing an alkylene oxide adduct of a divalent phenol expressed by the following general formula (I) in an amount of 1 to 15 mol % as a part of the diol component. In the formula, A expresses an alkylene group having a carbon number of 2 to 4, m and n are same as or different from each other, and each express an integer of 1 to 5, and Ar expresses a p-phenylene group, an m-phenylene group or a group of the following general formula (II) In the formula, Ph expresses a p-phenylene group, and X expresses a 2,2-propylene group, a sulfone group, a methylene group, an oxygen atom or a sulfur atom. This fiber has high retention ratios of tensile strength and knot strength, and is excellent in durability, and the fiber is suited for applications such as a dryer canvas for papermaking which is used under severe conditions in which especially wet heat treatments and dry heat treatments are repeated.
A core-sheath composite type polyester monofilament for use in a screen gauze in which the sheath ingredient is a polyester formed by adding and copolymerizing, based on the polyester, 2 to 10% by weight of a polyalkylene oxide with a coloration degree (APHA) after heating at 175.degree. C. for one hour of 30 or less and having a number average molecular weight of from 300 to 4000 and having a peak temperature (Tmax) of a dynamic loss tan (tan .delta.), at a measuring frequency of 110 Hz of from 97 to 120.degree. C. which is lower by 10.degree. C. or more than that for the core and the area ratio of core to sheath is within a range from 60:40 to 90:10. The polyester monofilament for use in a screen gauze is a monofilament for use in the high mesh screen gauze capable of completely preventing formation of scams during weaving, satisfactory in the gauze tension and excellent in the dimensional stability of gauze and in the adhesion to the photosensitive resin.
Methods for cleaning air intake for a gas turbine system include utilizing filter arrangements that include a barrier media, usually pleated, treated with a deposit of fine fibers. The media is particularly advantageous in high operating temperature (140 to 350.degree. F.) and/or high humidity (greater than 50 to 90% RH) environments.
The filter structures commonly known as a bag house or a filter bag or an air filter with a bag construction can be made by preparing the bag assembly, either in a tubular or a bi-fold construction by placing a layer of fine fiber on the upstream surface of the filter media structure. The filter assembly includes a filter cabinet with an interior component. The filter component is suspended within the filter cabinet interior. The filter component includes a frame or support for the filter media. The frame or support holds the filter bags such that the filter bags are suspended from the frame in the cabinet interior. The intake air enters the cabinet, passes through the filter assembly and exits the cabinet. The air must pass first into the fine fiber layer, the filter media and then the exterior of the cabinet.
Filter arrangements include a barrier media in the form of fluted media treated with a deposit of fine fibers. The media is particularly advantageous in high temperature (greater than 140 to 240.degree. F.) systems. Such systems may include engine systems, gas turbine systems, and fuel cell systems. Filter arrangements may take the form of media packs having a circular cross-section or a racetrack shaped cross-section, or media packs formed in a panel configuration.
Filter arrangements include a barrier media in the form of fluted media treated with a deposit of fine fibers. The media is particularly advantageous in high temperature (greater than 140 to 240.degree. F.) systems. Such systems may include engine systems, gas turbine systems, and fuel cell systems. Filter arrangements may take the form of media packs having a circular cross-section or a racetrack shaped cross-section, or media packs formed in a panel configuration.
