Abstract: Avivage deposits on and between the dents of a reed, especially in an air weaving loom, are removed by heating at least a portion of the reed dents in the vicinity of the weft insertion channel to a temperature sufficient to melt the avivage which can then be discharged from the reed dents and the spaces between the reed dents by dripping downwardly, for example, into a collecting trough.

Abstract: The balloon closure device of the present invention includes an integrally formed flat seal portion and removable tab portion (made of biodegradable material) and a loop of string or other type of line. The loop of string may be wrapped neatly around the tab portion, which eases handling of the device before it is used to seal a balloon. Once the device is used to seal a balloon, the loop of string may be used to secure the sealed balloon to the user's wrist without requiring the user to tie a knot.

Abstract: Apparatus for carrying out a method for the catalytic conversion of waste gases such as those which accumulate in the synthesis of vinyl chloride is presented in which the waste gases are successively treated at an elevated temperature with a catalyst for oxidative cracking and with a catalyst for oxidative afterburning.

Abstract: Polyoxyalkylene glycols are prepared by a process in which tetrahydrofuran is polymerized with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals in the absence of water and in the presence of a monohydric alcohol or of a monocarboxylic acid with the aid of an anhydrous heteropoly acid catalyst, and the polyoxyalkylene glycol is liberated from the resulting polyoxyalkylene glycol monoethers or polyoxyalkylene glycol monoesters by cleavage of the monoether or monoester bond.

Abstract: Polyoxyalkylene glycol monoethers of monohydric alcohols are prepared by a process in which tetrahydrofuran or a mixture of tetrahydrofuran with a total of not more than 95 mol %, based on the amount of tetrahydrofuran used, of one or more comonomers from the group consisting of the cyclic ethers and acetals is polymerised in the absence of water and in the presence of a monohydric alcohol and of an anhydrous heteropoly acid catalyst.

Abstract: When a faulty weft thread must be removed after it has been bound into the fabric and beat-up, it is necessary to perform a so-called reverse weaving operation following the stopping of the normal weaving operation in response to a stop signal signifying that a faulty weft thread has been detected. For this purpose the loom main shaft and the heald drive shaft are rotated for a number of rotational degrees in the same direction in which these shafts are rotated just prior to the stopping of a weaving operation in response to the above mentioned signal. Next, the drive between the main shaft and the heald shaft is interrupted. Next, the main shaft and thus also the reed shaft and with it the reed, are rotated back within a predetermined angular range between two successive reed beat-up motions. During this time the heald shaft is rotated back, preferably to the so-called detection point with a higher r.p.m., or rather with a higher angular speed than the main shaft.

Abstract: The average molecular weight of polyoxyalkylene glycols and polyoxyalkylene glycol derivatives is adjusted in the heteropolyacid-catalyzed polymerization of cyclic ethers and/or acetals with ring cleavage in the presence of proton donors by a process in which the amount of the relevant proton donor present in the reaction system is regulated in the course of the reaction by the measurement of the electrical conductivity.

Abstract: A process for preparing copolymers of ethylene with acrylic esters by copolymerizing 100 parts by weight of ethylene with from 0.1 to 25.0 parts by weight of acrylic ester in a continuous tubular polymerization system at from 500 to 4000 bar and from 100.degree. to 400.degree. C. in the presence of free radical polymerization initiators, comprises controlling the temperature for the reaction mixture, comprising ethylene, the acrylic ester, the polymerization initiator and optionally a regulator, after entry into the reaction zone in such a way that the ratio dT/dt (temperature increase per unit time) is kept constant at a value within the range from 1.5.degree. to 2.5.degree. C. per second.

Abstract: A process for the reactivation of spent montmorillonite catalysts by thermal treatment, in which the spent catalysts are heated at a temperature of from 650.degree. to 850.degree. over a period of from 0.2 to 3 hours, and the montmorillonite catalysts thus obtained.

Abstract: The invention relates to thermoplastic polyurethane elastomers obtainable by reaction ofa) unmodified and/or modified organic polyisocyanates, preferably 4,4'-diisocyanatodiphenylmethane, withb) polyoxybutylene glycols and/or polyoxybutylene/polyoxyalkylene glycols with a molecular weight of from 150 to 1800 and a content of crown ethers, preferably those of the formula (--CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O--).sub.m, where m is from 3 to 6, not exceeding 0.06% of the total weight andc) chain extenders with a molecular weight of from 60 to 400, preferably 1,4-butanediol,to a process for the preparation thereof and to the use thereof for producing molded articles and sheets for use in the medical or hygiene sector and in the foodstuffs sector.

Abstract: Polyoxybutylene polyoxyalkylene glycol dicarboxylates are prepared by a process in which tetrahydrofuran is copolymerized with a molar excess of a 1,2-alkylene oxide in the presence of a carboxylic anhydride using, as a catalyst, a bleaching earth containing less than 3% by weight of water.

Abstract: A process is described for the preparation of high purity polymers or copolymers obtained by cationic polymerization of tetrahydrofuran and, if desired, alkylene oxide, in which hydrogen having a bubble diameter of less than 50 .mu.m is passed into the polymers in the presence of a hydrogenation catalyst.

Abstract: Apparatus for the catalytic conversion of waste gases such as those which accumulate in the synthesis of vinyl chloride is presented in which the waste gases are successively treated at an elevated temperature with a catalyst for oxidative cracking and with a catalyst for oxidative afterburning.

Abstract: A process for the preparation of polyether glycols by polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with oxiranes in the presence of from 20 to 500% w/w of a hydrocarbon, based on the weight of tetrahydrofuran used.

Abstract: A process is described for the purification of crude polyalkylene ether glycols contaminated by heteropolyacids or salts thereof, by treatment with solvents, which comprises mixing the crude polyalkylene ether glycols with a liquid hydrocarbon and water, allowing the phases to separate, and isolating the purified polyalkylene ether glycols from the upper phase.

Abstract: A method for the catalytic conversion of waste gases such as those which accumulate in the synthesis of vinyl chloride is presented in which the waste gases are successively treated at an elevated temperature with a catalyst for oxidative cracking and with a catalyst for oxidative afterburning. Apparatus for carrying out the method is also shown.

Abstract: 1,2,4-Butanetriol is prepared by catalytic hydrogenation of malic esters over a copper-containing catalyst by passing the esters over the fixed-bed catalyst at from 130.degree. to 190.degree. C. under hydrogen partial pressures of from 100 to 300 bar while substantially avoiding the formation of a gas phase.

Abstract: Aminomono- or di-[(poly-n-butoxy)-n-butylamino]-(poly-n-butoxy)-n-butylamines of the general formula IH.sub.2 N--[(CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --(CH.sub.2).sub.4 --NH].sub.y --(CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --(CH.sub.2).sub.4 --NH.sub.2 (I)where x is from 1 to 150 and y is 1 or 2, are prepared by a process in which a hydroxy-(poly-n-butoxy)-butanol of the formula IIHO--(CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --(CH.sub.2).sub.4 --OH (II)where x is from 1 to 150, is reacted with from 1.01 to 300 mole equivalents of ammonia per hydroxyl group in the presence of a hydrogenation/dehydrogenation catalyst and hydrogen at from 150.degree. to 300.degree. C. and under from 20 to 400 bar.

Abstract: A process for the purification of the polyetherdiols obtained by copolymerization of tetrahydrofuran and 1-alkene oxides by catalytic hydrogenation at temperatures up to 250.degree. C.

Abstract: The molecular weight distribution of polytetrahydrofuran and of copolymers of tetrahydrofuran and alkylene oxides are narrowed by a process in which low molecular weight fractions are distilled off from the polymers under pressures of less than 0.3 mbar and at from 200.degree. to 260.degree. C., the distillation residue is mixed with a solvent mixture consisting of (a) an alkanol, (b) a hydrocarbon and (c) water, the content of the individual components a, b and c in the mixture being from 4 to 60% by weight, the phases formed are then separated from one another and the polymer having a narrower molecular weight distribution is isolated from the phase.