Abstract: The invention comprises a process of producing .epsilon.-caprolactam from extract water of polycaprolactam obtained by hydrolytic polymerization, wherein(i) the extract water is concentrated by distillation of water,(ii) from the concentrated extract water from stage (i) an extract of .epsilon.-caprolactam and oligomers including dimers is obtained by separating an .epsilon.-caprolactam/water vapor mixture,(iii) the extract from stage (ii) is depolymerized in the presence of a catalyst and superheated steam, where a vapor mixture of .epsilon.-caprolactam and water is obtained, and(iv) from the .epsilon.-caprolactam/water vapor mixtures of process stages (ii) and (iii) .epsilon.-caprolactam with a dimer content of .ltoreq.0.2 wt-% is obtained by distillation of water.

Abstract: A process for the improvement of the drawing ability of polyester, pellets of which are thermally post-treated in the solid phase in an inert atmosphere, containing a precise concentration of water vapor. The water vapor concentration is equal to the amount of water, plus 15%/minus 50%, which could theoretically be formed, at the polyester end viscosity, from the --COOH end groups and the excess --OH end groups of the polyester. An equimolar quantity of the vapor of the alkanediol, which serves as the diol reactant for the polyester, may be substituted for all or part of the water vapor.

Abstract: The invention concerns a method of processing polymer blends based on polyester or polyamide with a draw-off speed of .gtoreq.1500 m/min to produce filaments with an elongation at break of .ltoreq.180%, where a second amorphous polymer is added to the polyester or polyamide in the amount of 0.05 to 5 wt % and the polymer is a copolymer composed of at least two of the following monomer units:0 to 90 wt % A, wherein A is a monomer of formula CH.sub.2 .dbd.C(R)--COOR.sup.1, wherein R is --H or --CH.sub.3 and R.sup.1 is straight or branched chain C.sub.1 -C.sub.10 alkyl or cyclohexyl.0 to 40 wt % B, wherein B is a monomer of maleic acid or maleic anhydride, and5 to 85 wt % C, wherein C is a monomer of styrene or methyl substituted styrene such that (wt % A+wt % B+wt % C)=100, and these filaments are processed by a drawing process or a stretch texturing process at high speeds. Preferably R.sup.1 is methyl, ethyl, n-propyl, n-butyl, iso-butyl, 2-ethyl-butyl, 2-ethyl hexyl, n-hexyl, n-heptyl, or cyclohexyl.

Abstract: The invention is a process for spinning solutions of cellulose carbamate by extruding the solution through a spinneret into a precipitation bath, coagulating the cellulose carbamate fibers thus formed and drawing off the fibers by mechanical means, where the fibers are enveloped from the outlet from the spinneret to the outlet from the precipitation bath in a stream of precipitating medium flowing in the same direction, where the velocity of flow of the precipitation medium where the fibers exit the spinneret (plane X1) amounts to 0.1 to 0.8 times the draw-off speed of the fibers, and the velocity of flow of the precipitation medium where the fibers exit the precipitation bath (plane X3) amounts to 0.96 to 1.1 times the draw-off speed of the fibers.

Abstract: The present invention is a pre-oriented, non-stretched polyester fiber spun with spooling speeds of at least 3,000 m/min., wherein the polyester is a copolymer comprised essentially of ethylene terephthalate units and up to 10 weight % of other dicarboxylic acids or other diols, and carboxy phosphonic acid units of the formula: ##STR1## wherein R is selected from C.sub.1-10 -alkylene, C.sub.1-10 -cycloalkylene or C.sub.6-10 -arylene, in a quantity corresponding to 30 to 500 ppm phosphorus, in relation to polyester. The invention also comprises a process for the production of this fiber.

Abstract: A method for the manufacture of cellulose carbamate, whereby cellulose pulp is preliminarily activated by alkaline, hydrothermal and/or enzymatic treatment, then the activated cellulose pulp is mixed with aqueous urea solution, the water in the solution replaced with an organic reaction carrier, and thereafter the cellulose is reacted with urea in the liquid phase to yield cellulose carbamate, which is separated from the liquid medium and washed. The method results in uniform substitution and distribution of carbamate groups and in cellulose chain, which leads to good solubility of the cellulose carbamate in aqueous alkali solution as well as excellent spinnability for producing fibers, films, and other products.

Abstract: The invention comprises a method for synthesizing polyethylene terephthalate from waste polyethylene terephthalate by cleavage with ethylene glycol and separation of bis(hydroxyethylene) terephthalate from the cleavage mixture with a specific temperature program, recrystallization from water, and esterification and polycondensation with the addition of terephthalic acid.The invention further comprises a method for synthesis of polyethylene naphthalate from waste polyethylene naphthalate in a similar manner.

Abstract: The present invention comprises a process for the production of flame-resistant polyesters with at least 50 mol-% ethylene carboxylate units through esterification or ester interchange and co-polycondensation of at least one diol and a dicarboxylic acid or its dialkyl ester with a carboxyphosphinic acid, whereby the carboxyphosphinic acid, before being added to the co-polycondensation mixture, is dissolved in ethylene glycol of not more than 90.degree. C., and the acid number of this solution is standardized to 50 to 350 mg KOH/g of carboxyphosphinic acid by adding at least one basic alkali metal compound in the absence of oxygen, and said solution is added to the co-polycondensation mixture during the second half of the esterification or ester interchange reaction.

Abstract: The invention comprises a process for producing cellulose carbamate with improved solubility properties comprising converting cellulose with urea in an inert, liquid, organic reaction carrier, at reaction temperature in the range of 80.degree. to 180.degree. C. where the reaction temperature is increased as the reaction time increases.

Abstract: The present invention provides a method of synthesizing polypropylene terephthalate with no more than 5 ppm acrolein and no more than 3 ppm allyl alcohol. The method comprises direct esterification of terephthalic acid with 1,3-propanediol in the presence of 30 to 200 ppm titanium in the form of an inorganic esterification catalyst containing at least 50 mol % TiO.sub.2 precipitate, blocking the esterification catalyst after esterification by adding 10 to 100 ppm phosphorus in the form of a phosphorus-oxygen compound, and then performing precondensation and polycondensation in the presence of 100 to 300 ppm antimony in the form of a conventional antimony polycondensation catalyst and optional conventional coloring agent.

Abstract: A spinning pack with a sand filter for the melt spinning of thermoplastics, whereby at least one perforated plate with evenly distributed D-shaped holes with slanting openings that taper conically in the direction of flow is placed in the direction of flow in front of and/or behind the sand filter. Spinning packs according to the invention surprisingly give highly uniform distribution and flow of thermoplastic melt through the sand filter.

Abstract: The present invention is a pre-oriented, undrawn polyester fiber spun with spooling speeds of at least 3,000 m/min., wherein the polyester is a copolymer comprised essentially of ethylene terephthalate units and up to 10 weight % of other dicarboxylic acids or other diols, and carboxy phosphonic acid units of the formula: ##STR1## wherein R is selected from C.sub.1-10 -alkylene, C.sub.1-10 -cycloalkylene or C.sub.6-10 -arylene, in a quantity corresponding to 30 to 500 ppm phosphorus, in relation to polyester. The invention also comprises a process for the production of this fiber.

Abstract: Process for purification of essentially oxygen-free process gases by catalytic oxidation of the oxidizable, mainly organic impurities with the addition of a oxygen-containing gas, where oxygen-containing gas is added to the process gas in an amount responsive to the carbon monoxide content of the process gas measured after oxidation. The carbon monoxide set point is in the range of 10 to 1000 vpm.

Abstract: A zeolite polycondensation catalyst comprising an alkali- or alkaline earth metal aluminum silicate zeolite having an original water content of 12 to 30 weight % and a solubility, measured at 260.degree. C., in an esterification mixture consisting essentially of bis(hydroxy ethylene)terephthalate, of over 8.0 weight %, and an average particle size of less than 1.0.mu.. The present invention is also a process for the production of polyester using this catalyst.

Abstract: A process for the production of a polyamide stabilizer concentrate in which the concentrate consists of at least two interactive stabilizer components with defined particle sizes and, optionally, micro-dispersed silicic acid, as well as a wax bonding agent with a solidification temperature t.sub.A between 65.degree. and 120.degree. C., in which a homogeneous mixture of these ingredients is compacted into tablets when subjected to a compression force p that is sufficient to heat the mixture to a temperature of at least 40.degree. C. and equal to t.sub.A minus 10.degree. to 50.degree. C.

Abstract: The present invention comprises a new catalyst for the production of polyesters consisting essentially of a finely dispersed, large surface area titanium compound selected from hydrated TiO.sub.2 obtained by hydrolysis and having the composition yTiO.sub.2.zH.sub.2 O and from titanates having the composition (Me.sub.n O).sub.x.(TiO.sub.2).sub.y.(H.sub.2 O).sub.z, wherein Me is an alkaline earth metal or alkali metal. In addition, the present method comprises a process for the production of polyesters using this catalyst as an esterification or transesterification catalyst and as a polycondensation catalyst, whereby a phosphorous-oxygen-compound is added immediately before, during, or after the polycondensation.

Abstract: Process for direct production of shaped packaging material made of thermoplastic polyesters with no effect on the taste of foods packaged in them, where the diol component of the polyester consists of at least 70 wt % ethylene glycol, and the polyester is produced in the presence of the usual catalysts plus additional cobalt or cobalt and manganese compounds and phosphorus compounds. An inert gas is introduced into the polyester melt and distributed uniformly in the melt immediately after its discharge from the polycondensation reactor, 0.05 to 1.0 wt % of an amide compound with a low volatility is added to the polyester melt directly next to the gas inlet. Finally, the polyester melt is subjected to a vacuum degassing immediately before the shaping apparatus and the melt is sent directly to the shaping apparatus within a maximum of 30 minutes after its discharge from the reactor at a maximum temperature of 35.degree. C. above the crystallite melting point of the polyester.

Abstract: Process for synthesis of spinnable polyamide from .alpha., .omega.-alkyldinitriles and .alpha., .omega.-alkyldiamines and excess water, where a) the aqueous solution of the dinitrile is mixed with a catalytic amount of at least one oxygen-containing acid of phosphorus and/or a water-soluble salt of calcium, zinc, cadmium or manganese in the absence of the diamine, and the pH of this solution is adjusted to an initial value in the range of 2.0 to 4.0 before hydrolysis by adding a saturated aliphatic or aromatic dicarboxylic acid and the dinitrile is and the amide-containing precursors derived therefrom are hydrolyzed to dicarboxylic acid at an elevated temperature under autogenous pressure, whereby the hydrolysis is controlled by conductometric determination of the hydrolysate, and b) at least an equimolar amount of diamine is added to the solution from step a) and the mixture is subjected to polycondensation to form polyamide [nylon].

Abstract: Spinning head for spinning polymer melts, having a filter cartridge made of a seamless metal cloth cylinder having an end cap and a connector, said cartridge being disposed within a melt passage having a conical taper toward the bottom. The connector is inserted into the melt channel and has a matching conical shape to seal against the channel wall. A die plate having a maximum area of 90 cm.sup.2 connects to the connector. An opening through the connector permits filtered polymer melt to flow from the filter cartridge through the connector to the die plate. A single filter cartridge is provided for each die plate, whereby the ratio of filter area to die plate area is at least 0.5:1.

Abstract: Process for separating preshredded carpet materials into as many as three main components of different densities which comprises finely comminuting the carpet materials in the liquid phase. The density of the liquid phase is adjusted to a level between two adjacent densities of the components. Separation of one component from the other components and from the liquid phase in the suspension is effected in a double-cone full-jacketed screw centrifuge. The process is repeated if there are two materials of different densities in the other components fraction. The process is useful for recovering nylon, polyester, or polypropylene from carpet scraps which nylon or polyester can be depolymerized to reusable monomers and which polypropylene can be reprocessed into pellets, non-wovens or fibers.