Abstract: A spinnable, gel-free and thermally stable polyester composition includes at least one dicarboxylic acid or monoesters thereof or diesters thereof; at least one diol; at least one carboxylic acid anhydride; at least one sodium or lithium based aromatic co-monomer and at least one hydroxyl terminated polyester polyol. The polyester is produced by esterifying at least one dicarboxylic acid or monoesters thereof or diesters thereof and at least one diol along with at least one acid anhydride at a temperature in the range of 250° C. to 290° C. and pressure in the range of 0 kg/cm2g to 5 kg/cm2g; and polycondensing the esterified mixture along with at least one sodium or lithium based aromatic compound and at least one hydroxyl terminated polyether polyol at a temperature in the range of 250° C. to 290° C. and under vacuum of 0.1 torr to 10 torr.

Abstract: Self-crimping fully drawn high bulk yarns comprising fiber forming bicomponent filaments comprising two polymers having different crystallizability or differential orientation or combination thereof is disclosed herein. Further the present invention discloses a method for producing the self-crimping fully drawn high bulk yarns by single and two-stage process. The invention also discloses the fabric comprising the self-crimping fully drawn high bulk yarns.

Abstract: Improved process for the continuous production of slow crystallizing polyester resin comprising esterification of at least one dicarboxylic acid or mono-esters thereof or di-esters thereof with at least one polyol, melt polymerizing the esterified mixture, preparing uniform crystalline hemispherical prepolymer by particle former process, adding at least one diol having tertiary or quaternary carbon atoms with pendant groups such as neopentyl glycol or 2-methyl-1,3-propanediol or any suitable diol at any stage during esterification or melt polymerization but before the particle former process; and solid state polymerizing the prepolymer to obtain high molecular weight slow crystallizing polyester. Slow crystallizing low molecular weight crystalline hemispherical prepolymer having IV of about 0.1 dl/g to about 0.45 and uniform hemispherical shape, uniform particle size, uniform crystallinity prepared by the above process and is used as precursor to prepare high molecular weight resin.

Abstract: A process for producing ultramicrodenier filaments evenly distributed in a fabric matrix includes producing bicomponent fibers or filaments using two polymer components; converting the bicomponent fibers or filaments into a fabric; and treating the fabric with an alkali to produce ultramicrodenier filaments of the order of 0.05 to 0.13 denier per filament uniformly distributed in the fabric matrix.

Abstract: The present invention discloses an easily alkali soluble polyester comprising at least one dicarboxylic acid or monoesters thereof or diesters thereof; at least one diol; at least one carboxylic acid anhydride; at least one sodium or lithium based aromatic co-monomer and at least one hydroxyl terminated polyester polyol. The polyester is produced by esterifying at least one dicarboxylic acid or monoesters thereof or diesters thereof and at least one diol alongwith at least one acid anhydride at a temperature in the range of 250 to 290° C. and pressure in the range of 0 to 5 kg/cm2g; and polycondensing the esterified mixture along with at least one sodium or lithium based aromatic compound and at least one hydroxyl terminated polyether polyol at temperature in the range of 250 to 290° C. and under vacuum of 0.1 to 10 torr.

Abstract: Method for producing multilobal bicomponent fiber or filaments comprising spinning at least two polymer components by bicomponent spinning system through round capillary to obtain fibers or filaments and treating fibers or filaments with hot alkali to obtain multilobal bicomponent fibers or filaments. Alternatively fabric is produced from the bicomponent fibers or filaments and treated it with hot alkali to obtain fabric comprising multilobal bicomponent fibers or filaments uniformly distributed in the matrix. The wicking property of multilobal bicomponent fibers or filaments or fabric comprising the same improved with respect to standard polyester of equivalent denier.

Abstract: Inherently colored polyester polymers with controlled branching include a chromophoric co-monomer in their backbone. The chromophoric co-monomer may be a carboxyl terminated chromophoric co-monomer. such as metallo-phthalocyanine tetracarboxylic acid. The inherently colored polyester polymer may be melt-spun into a filament or fiber.

Abstract: A filter element comprises a substrate constructed from at least two different materials. A first one of the materials has a first temperature at which the first material activates. A second one of the materials is at least a partially crystalline structure and has a second temperature which is lower than the first temperature at which the second material activates. A porous membrane is supported by the substrate. An attachment is between the substrate and the membrane. The attachment results from the second material of the substrate activated at a temperature less than the first temperature to engage portions of the membrane at spaced apart locations and fix together the membrane and the substrate upon the second material cooled to a temperature less than the second temperature.

Abstract: A filter element is adapted to be located in a gas stream. The filter element comprises a substrate having a structure selected from the group consisting of scrimed needled felt, scrimless needled felt, woven fabric and mesh. The substrate comprises at least two different materials. A first one of the materials has a first melting temperature. A second one of the materials has a second melting temperature lower than the first melting temperature. An expanded polytetrafluoroethylene filtering membrane is adapted to be located upstream relative to the substrate in the gas stream and supported by the substrate. The substrate is attached to the filtering membrane by the second material of the substrate melted to engage the membrane and fix the membrane to the substrate.