Abstract: Process for producing formed cellulosic articles, such as fibers, filaments, sheetings, membranes or tubes, comprising a) extruding a solution of cellulose in an aqueous amine oxide, particularly N-methylmorpholine N-oxide, through an extrusion die via an air gap and coagulating the formed article in an aqueous precipitation bath containing amine oxide, and b) passing the formed article through at least one washing stage for removing residual amine oxide from the article, characterized in that the liquor of the precipitation bath in the precipitation stage and/or the washing liquor of the washing stage(s) is treated with ultra-violet radiation. In this manner the formation and growth of coatings, films and slime deposits caused by microorganisms is avoided on parts of the plant which come into contact with said liquors containing the amine oxide.

Abstract: HMLS filaments consisting of a polyester, from 0.1 to 2.5% by weight of an incompatible, thermoplastic, amorphous, polymeric additive having a glass transition temperature of from 90 to 170° C. and a ratio of its melt viscosity to that of the polyester component of from 1:1 to 7:1, and from 0 to 5.0% by weight of conventional additives, where the polymeric additive is present in the filaments in the form of fibrils having a mean diameter of ≦80 nm. Process for the production of these HMLS filaments by static mixing with shearing of the polyester and of the polymeric additive and, optionally, of the additives, spinning of the mixture at a spinning take-off speed of from 2500 to 4000 m/min to give spun filaments which are stretched, heat-set and wound up, where the concentration of the polymeric additive is determined as a function of the pre-specified spinning take-off speed and the desired birefringence of the spun filaments.

Abstract: The present invention relates to a method for the manufacture of synthetic fibers from a melt mixture of fiber forming matrix polymers, wherein at least one second amorphous additive polymer, which is immiscible with the fiber forming matrix polymer, is added to the fiber forming matrix polymers in a quantity of 0.05-5 wt % (with reference to the total weight of fiber forming matrix polymer and the additive copolymer). The additive polymer is obtained by multiple initiation. Furthermore, the present invention also relates to the synthetic fibers produced by the method.

Abstract: High strength polyester fibers comprising from 0.1 to 2.0 by weight of an incompatible, thermoplastic amorphous, polymeric additive.

Abstract: PTT staple fibers which are characterised by a novel combination of properties. In combination with novel stress-strain properties and modulus parameters, staple fibers or textiles or home textiles having extremely desirable aesthetics and service quality are obtained. Economical two-stage process for the production of PTT staple fibers. The melt spinning is carried out at a high polymer throughput and a spinning take-off speed of at least 600 m/min. In a separate fiber drawing frame, the stretching, heat-setting, crimping and drying are carried out.

Abstract: The invention pertains to an apparatus for premixing additives and feeding them into a polymer melt stream. The apparatus has a conducting element 2, first and a second intermediate element 4a and 4b, and a pump assembly 6, wherein the polymer melt stream is guided through channels 8 and 10 of the conducting element. The second intermediate element 4a has a feed element 12 that extends into the first channel 8 to form a ring channel. The feed element 12 is surrounded by openings 14, through which a portion of the polymer melt is drawn off, so that it can be mixed with an additive inside the pump assembly 6. This mixture is then returned via the feed element 12 to the polymer melt stream. The apparatus according to the invention makes it possible to decrease the residence times of the polymer and requires very little in the way of apparatus.

Abstract: Polyester staple fibres consisting of a polyester, from 0.1 to 2.0% by weight of an incompatible, thermoplastic, amorphous, polymeric additive having a glass transition temperature of from 90 to 170° C. and a ratio of its melt viscosity to that of the polyester component of from 1:1 to 10:1, and from 0 to 5.0% by weight of conventional additives, where the polymeric additive is present in the staple fibres in the form of fibrils having a mean diameter of ≦80 nm. Process for the production of these staple fibres by mixing with shearing of the polyester and of the polymeric additive and, optionally, of the conventional additives, spinning at a spinning take-off speed of <2500 m/min to give spun filaments, which are combined to form tows and stretched in a separate fibre stretching stage, crimped, dried and chopped to give staple fibres.

Abstract: Process for producing cellulosic moldings such as fibers, foils, casings and beads from cellulose, wherein (a) the initial cellulose is hydrothermally treated with water in a water/cellulose ratio on a weight basis of at least 1 at a temperature in the range from about 100.degree. to about 200.degree. C. and under a pressure in the range from 0.1 to about 1.5 MPa; (b) the treated cellulose is dissolved in an aqueous solution of alkali hydroxide at a temperature of at least 0.degree. C. to form a homogenous cellulose solution containing from about 5% to about 10% by weight cellulose and at maximum 10% by weight alkali hydroxide, and (c) the alkaline cellulose solution is formed and coagulated by contacting it with an aqueous solution containing 1 to about 30% by weight of an acid. This fully ecological process avoids handling of toxic products or by-products and uses aqueous solvents instead of expensive organic solvents. The cellulose solution is stable for at least 48 hours.

Abstract: A process for the acceleration of the polycondensation of polyester made by the esterification of at least one dicarboxylic acid with at least one diol, precondensation, melt phase polycondensation, granulation, crystallization and solid phase polycondensation comprising the addition, prior to the precondensation reaction, of from about 30 to about 900 ppm phosphorus in relation to the polyester in the form of carboxy phosphonic acid of the formula: ##STR1## wherein, R is selected from the group consisting of C.sub.1-10 -alkylene, C.sub.1-10 -cycloalkylene, and C.sub.6-10 -arylene and R.sup.1, R.sup.2, and R.sup.3 are selected from the group consisting of hydrogen, C.sub.1-10 -alkyl, C.sub.1-10 -cycloalkyl, and C.sub.6-10 -aryl, provided that at least two of R.sup.1, R.sup.2, and R.sup.3 are hydrogen.

Abstract: Filaments emerging from the nozzle plate of a spinneret are cooled by being passed through a cooling channel. The motion of the filaments through the cooling channel serves to suck-in air through an air inlet arrangement of the cooling channel. The air inlet arrangement includes an upper air inlet which sucks-in air at the underside of the nozzle plate, so that the filaments are contacted by the cooling air immediately upon emerging from the nozzle plate. Contact of the cooling air with the filaments (which are drawn off at a speed of at least 2400 m/min) takes place throughout the length of the cooling channel.