Abstract: Nylon 6 chip is obtainable by hydrolytic polymerization of caprolactam in the presence of dicarboxylic acids as chain regulators, subsequent processing of the polymer melt into chip, extraction of the low molecular weight portions from the chip with water and subsequent drying of the chip.

Abstract: A method and device for recovering linear polyesters, such as PET and PBT, from polyester waste of the most varied form, in a continuous manner, in which undried or not dried-through waste is melted, the polymer chains being hydrolytically degraded by adhering moisture, and in which diol, corresponding to the basic constitutional unit of the polymer, is added to the melt resulting in glycolytic degradation, and the melt so treated is further condensed to the desired degree of polymerization.

Abstract: The invention relates to a process for producing polyesters, especially high-molecular polyethylene terephthalate (PET) using titanium-containing catalyst-inhibitor combinations.

Abstract: The invention relates to a device for manufacturing spun-bonded webs with a nozzle arrangement which spins out warps of yarns. The device according to the invention has a longitudinally-extended duct for generating a gas current which transports the yarns in the duct, and a depositing chamber with an air-permeable deposit belt for deposition of the yarns. The deposit chamber (9) surrounds the conveyor belt (2) in the deposition area of the yarns, and is in the form of a gas-tight casing (9), the width of which is greater than the width of the deposit belt. By means of the casing, a greater degree of vacuum may be used to generate the gas current, and thus the yarns are more intensively drawn. Furthermore, undesirable turbulence of the yarns at the edges of the deposit belt is reduced, and an improvement is achieved in the web structure in these areas.

Abstract: The reactor device comprises a horizontally-disposed housing (1), at one end of which there is disposed an inlet (4) for supply of the medium, and at the other end of which there is an outlet (5) for the reaction products. Within the housing (1) of the reactor device a rotor (1) is rotatably mounted. The rotor (8) has a hollow cylinder (9), which is provided with openings (10) and annular members (12, 13) for moving and transporting the medium. The hollow cylinder (9) is partly immersed in the free-flowing medium, the openings (10) in the hollow cylinder (9) ensuring additional admixture of the medium.

Abstract: There are proposed a method and a device for manufacturing polyamides, in which polyamide granulate manufactured by polycondensation in the molten mass is after-condensed in the solid phase, being heated. The polyamide granulate is heated in one step to a first temperature of between 70.degree. C. and 150.degree. C., and held for a predetermined period of time at this temperature, and then, in a second step, is heated to a second higher temperature, however lying beneath the melting point, and is after-condensed at this temperature, until the desired average degree of polycondensation is achieved.

Abstract: A polyurethane and/or polyurethane urea elastomer in the form of a thermostable processable melt, which is immediately processable or which, after cooling and storing, can be remelted and processed. The elastomer is produced by a polyaddition or build-up reaction of longer chain diols with diisocyanate, chain extenders and a polar gelling and/or melting aid for the formation of the thermostable processable melt. A method for manufacturing a polyurethane and/or polyurethane-urea elastomer in the form of a thermally stable processable melt which may be processed immediately or after cooling and storage, being remeltable and reprocessable. The method comprises the steps of: converting n-Mol of a polymeric diol to form a prepolymer with about 1.1 to about 10.0 n-Mol of a diisocyanate at about 50.degree. C. to about 150.degree. C.

Abstract: A process and an apparatus for the continuous crystallization of plastic granules, particularly amorphous plastic granules, in which the granules are introduced into a container and form a granule bed, which is moved downwards by the action of gravity. A hot gas is passed as a primary gas in a countercurrent manner through the granule bed. The granules are kept moving by a stirrer. There is also a gas supply for a secondary gas, which introduces the secondary gas at high speed at several points distributed over the cross-section of the container into the upper area of the granule bed.

Abstract: An apparatus for delivering and depositing groups of continuous threads or filaments, which are conveyed by means of a gas flow and which are introduced substantially parallel into a passage having a corresponding cross-section is proposed, the gas flow accompanying the threads upon entering the upper part of the passage is accelerated to high speed and is then decelerated and the threads are deposited on a moving depositing surface. The gas flow delivering the threads flows at high speed through the passage preferably provided with parallel walls and then is decelerated by the suction of part of the gas in the lower passage area laterally through openings in the passage walls.

Abstract: A reactor for highly viscous media with a horizontally oriented reactor casing having an inlet and an outlet in which a cage-like rotor is mounted in a rotary manner by means of stub shafts. To the cage-like rotor are fixed elements, e.g., rings, which are immersed in and thoroughly mix the media. A stripping rotor is provided coaxially with the cage-like rotor. Both rotors rotate within one another and mix and deliver the media and thereby form free surfaces. In addition, they also clean one another through a scraping action.

Abstract: A process and an apparatus for the production of high molecular weight linear polyester is proposed, in which a pumpable material is produced in particular terephthalic acid and an alkaline diol which is esterified in a two or multi-stage reactor arrangement and is subsequently condensed in vacuo in at least one vacuum reactor. The waste heat of the esterification reactor arrangement is used for producing the vacuum in the vacuum reactors. The water for condensing the steam is also obtained from the process steam.

Abstract: This invention relates to a process for carrying out continuous demonomerization and postpolymerization of Polyamide 6 melts and a reactor for carrying out this process. The reactor of this invention has a cylinder with a horizontal axis around which an interior rotor shaped like a cage rotates. The reactor can be partially filled with polymer melt. There is a multitude of elements along the periphery of the rotor which partly dip into the melt and serve to convey the melt through the reactor, generate new surfaces and mix and homogenize the melt as the polymer melt undergoes demonomerization and postpolymerization under vacuum.

Abstract: Simple cleaning, exact dosing and a high degree of operating safety are assured with a dosing device for dispensing a liquid through a liquid dispensing nozzle from a container holding the liquid under pressure in the interior thereof, which comprises a liquid dosing piston displaceable along the axis thereof and housed in a bushing having a screw thread for attachment to the container. The piston has a valve body at an end thereof adjacent the interior of the container and a section of reduced cross section adjoining the valve body, the valve body having a cylindrical surface coaxial with the piston.

Abstract: Described are a process and an apparatus for the aftercondensation of polycondensates, wherein moist and amorphous polymer in a granular or powderous form is continuously introduced from above into a single reactor. The granulate flows downward under gravity, with a hot gas being caused to flow in counter-current relation thereto. The reactor is formed as a continuous shaft or column which has positioned in the upper portion thereof an agitating element acting to prevent agglutination of the granulate. The granulate is crystallized and pre-dried in the upper portion of the shaft or column. In a further (subsequent) portion of the shaft or column, drying and aftercondensation take place without separation from the remainder of the shaft or column.

Abstract: This invention relates to a process for carrying out continuous demonomerization and postpolymerization of Polyamide 6 melts and a reactor for carrying out this process. The reactor of this invention has a cylinder with a horizontal axis around which an interior rotor shaped like a cage rotates. The reactor can be partially filled with polymer melt. There is a multitude of elements along the periphery of the rotor which partly dip into the melt and serve to convey the melt through the reactor, generate new surfaces and mix and homogenize the melt as the polymer melt undergoes demonomerization and postpolymerization under vacuum.

Abstract: A conventional electric hotplate with a sheet metal supporting ring surrounding the same is fitted into a glass or ceramic built-in plate, while using an intermediate ring, whose outer rim rests on the built-in plate, while the support ring is supported thereon. The intermediate ring has a flat S-shaped configuration and is much wider than it is high. Thus, the built-in opening can be made larger than the hotplate. A packing, which is held and shielded by an insert ring, surrounds the inner rim of the built-in opening. The packing is located on a substructure, which has centering projections for the insert ring or the hotplate.

Abstract: A hotplate is fitted by means of a relatively wide and shallow mounting ring, whose outer edge rests on a mounting plate made from glass, ceramic or other materials. At its edge, the mounting ring is adhered to mounting plate using a thermally stable adhesive, which simultaneously forms a seal against cooked articles running through. The sheet metal insert ring covers the inner circumference of mounting a opening in the mounting plate and has an upper outwardly directed flange engaging over the seal. Simultaneously the seal, in conjunction with the insert ring, centers the hotplate in the mounting opening. A release ring can be inserted for releasing the hotplate.

Abstract: A two-circuit automatic hotplate has a switch, which can be controlled both by a bimetallic strip of a power control device and by an expansion member of a hydraulic temperature sensor. The control heating system of the bimetallic strip is in series with a cooking heating system of the hotplate.The electric power levels of the cooking heating systems are preferably selected in such a way that, wherever possible, a current of the same level flows through the control heating system for the bimetallic strip, so that the same bimetallic strip can always be used.

Abstract: An electric hotplate with a cast hotplate member has a downwardly-directed border on its outer periphery. The edge of a covering sheet centrally fixed to the hot plate by a hollow screw rests on the lower edge of the border. A covering sheet step is centered within the border. A moisture-proof closure is obtained through an interposed seal and insulation is provided by crinkled aluminum foil. The hot plate connecting leads are passed via an insulating member through the covering sheet which, peripherally displaced by 180.degree., faces a depression in the covering sheet, so that hot plates according to the invention can be stacked in a space-saving manner. The connecting leads are flexible and their ends are brought together in a common connecting member.

Abstract: An electric heating apparatus for heating foods and liquids in a cooking vessel, comprising: a metal upper part, having an upper cooking surface and a lower surface; a metal lower part covering the bottom of the heating apparatus, a sealable space being formed between the upper part and the lower part; and, at least one tubular heating device with a metal covering arranged in the space and having a large flat contact surface for thermally conductively engaging the lower surface of the upper metal part, the space having at least a partial vacuum formed therein, the at least partial vacuum reducing convective heat loss and imparting a concave distortion to the upper metal part which counteracts a convex distortion of the upper metal part due to expansion upon heating, thereby holding the upper metal part substantially flat during heating and maximizing surface contact between the cooking surface and a cooking vessel resting thereon, whereby heat is transferred from the cooking surface to the cooking vessel with