Abstract: A process for using low-molecular weight compounds that are water-extracted from (co)polyamides in the production of polyamide is disclosed. The process entails reacting these compounds with 10 to 15 wt. % water for a period of 3.5 to 6 hours at a temperature of 220° C. to 270° C., and polymerizing the resulting product along with caprolactam.

Abstract: A process for removing low molecular weight constituents from polyamide 6 or from copolyamides based on caprolactam (herein (co)polyamide) is disclosed. The process comprise subjecting the (co)polyamide to liquid-extraction at a temperature which is above the boiling point of the liquid at atmospheric pressure said liquid containing water in an amount of at least 80 percent relative to its weight.

Abstract: The invention relates to a process and a device for alignment of sheet material (1) which is conveyed in one conveyor plane (9). The sheet material is conveyed on bodies (35) of revolution and aligned by means of triggerable alignment elements (25) in the conveyor direction (22) and perpendicular to the conveyor direction (22). The alignment elements (25) are assigned to an alignment unit (8). The alignment motion necessary for alignment of the sheet material in the conveyor direction (2) and perpendicular thereto takes placed by separate alignment elements (25) which can be triggered independently of one another during conveyance of the sheet material (1) with the process speed.

Abstract: A process for removing low molecular weight constituents from polyamide 6 or from copolyamides based on caprolactam (herein (co)polyamide) is disclosed. The process comprise subjecting the (co)polyamide to liquid-extraction at a temperature which is above the boiling point of the liquid at atmospheric pressure said liquid containing water in an amount of at least 80 percent relative to its weight .

Abstract: A process for using low-molecular weight compounds that are water-extracted from (co)polyamides in the production of polyamide is disclosed. The process entails reacting these compounds with 10 to 15 wt. % water for a period of 3.5 to 6 hours at a temperature of 220° C. to 270° C., and polymerizing the resulting product along with caprolactam.

Abstract: The invention relates to a method for the alignment of sheet-like material (1). Its alignment occurs via rotation elements (25), wherein the sheet-like material (1) is rotated around its central axis in order to print on the front and backsides. During the rotation of the sheet-like material (1) around its central axis, the material's leading edge (23) remains in its aligned position. Into the conveyor surface (9) is incorporated a sensor pair (30), preferably in the form of CCD line sensors, with which the sheet-like material (1) is aligned on the same lateral edge (24) following the rotation, as is the case during the alignment procedure of the sheet-like material (1) before it is rotated around its center axis.

Abstract: The invention relates to a process and a device for alignment of sheet material (1) which is conveyed in one conveyor plane (9). The sheet material is conveyed on bodies (35) of revolution and aligned by means of triggerable alignment elements (25) in the conveyor direction (22) and perpendicular to the conveyor direction (22). The alignment elements (25) are assigned to an alignment unit (8). The alignment motion necessary for alignment of the sheet material in the conveyor direction (2) and perpendicular thereto takes placed by separate alignment elements (25) which can be triggered independently of one another during conveyance of the sheet material (1) with the process speed.

Abstract: The invention relates to a process for compensation of dimension changes on sheet material (1) which is first provided with a printed image (36) on the front (35) and which is then provided with a printed image (40) on its back (39). The dimensions (41, 42) of the sheet material (1) are determined before an image is printed on the front (35) and before an image is printed on the back (39), and before an image is printed on the back (39) of the sheet material (1) the latter is centered to its position when the image was printed on the front (35).

Abstract: The invention relates to a method for recycling (reprocessing) aqueous extract solutions obtained in the production of polyamides. The method for reprocessing the aqueous extract solutions obtained consists in that the aqueous extract solution is concentrated and polymerised, adding small amounts of dicarboxylic acid or polycarboxylic acid to the extract solution.

Abstract: This invention relates to high-impact mixtures of polyamides and polymers based on polyacrylates or polybutadienes having improved processing behaviour and improved technological properties and to the production of these polymers by a multistage process.

Abstract: Unfilled, unreinforced polyamide moulding compounds are disclosed which have high rigidity and notched impact strength and are highly fluid in the molten state, containing aliphatic polycarbonate polyurethanes which are substantially unbranched in the carbon chain, prepared from polyhexamethylene carbonate diols and/or mixtures thereof with oligo- or polyalkylene glycols having 4-100 carbon atoms and 1,6-diisocyanatohexane.

Abstract: Thermoplastic moulding materials, with improved toughness at low temperatures, of polyamide and cross-linked graft rubbers from the diene rubber and acrylate rubber series, obtained by heating blends of the two components below the melting point of the polyamide.

Abstract: Weather-resistant polyamides stabilized by a combination of special cyclic phosphorous acid esters and certain indole derivatives.

Abstract: This invention relates to flame-proved polyamide moulding compositions containing a combination of from 10 to 18%, by weight melamine and from 1 to 7% by weight of a thermoplastic polyacetal, in each case based on the moulding composition.

Abstract: Stabilized polyamides containing from 0.02 to 5%, by weight of a diphenylamine compound corresponding to the following general formula: ##STR1## wherein R.sup.1 and R.sup.3, which may be the same or different, represent hydrogen, a CH.sub.3 --, C.sub.2 H.sub.5 -- or isopropyl group and R.sup.3 is in the o-, m- or p-position to the N-atom substitution;R.sup.2 represents hydrogen, a C.sub.4 -C.sub.12 alkyl, C.sub.7 -C.sub.12 aralkyl or C.sub.5 -C.sub.12 cycloalkyl group and is in the o-, or p-position to the N-atom substitution;n represents an integer of from 1 to 29; andY is a divalent, non-mono-olefinically unsaturated radical having the same meaning as R.sup.2 and, in addition, may represent (in a proportion of up to 50 mole percent) --S--, --CH.sub.2 --S--CH.sub.2 --, --CH.sub.2 --O--CH-- or >CH--R.sup.4, wherein R.sup.4 represents H, C.sub.1 -C.sub.6 alkyl or C.sub.5 or C.sub.6 cycloalkyl, and may be in the o- or p-position to the N-atom substitution.

Abstract: Extruded films having reduced proneness to stress-cracking, good resistance to casting resins of unsaturated polyesters and no blocking effect and produced from branched aromatic polycarbonates which are the reaction products of aromatic dihydroxy compounds and branching agents having more than three phenolic hydroxyl groups, with polycarbonate precursors. The films are useful as insulating films in the electrical industry.