Abstract: The invention relates to a process for producing a strengthened fiber assembly containing cellulosic fibers with the cellulose being present in the crystalline structure of cellulose II, by contacting the fiber assembly with an aqueous solution of N-methylmorpholine-N-oxide (NMMO) at elevated temperature and subsequently washing the fiber assembly, characterized in that contacting is effected in a manner that from the relation-947+0.30.times.log.sub.(10) t+0.046.times.T-3.53.times.C +645.times.log.sub.(10) Cwherein t indicates the time in minutes during which the fiber assembly is contacted with the aqueous NMMO solution, T indicates the temperature of the aqueous NMMO solution in .degree.C. and C is the concentration of NMMO in % by mass, based on the aqueous NMMO solution, a number in the range of 0.30 to 1.70 results with the proviso that the temperature T is smaller than 130.degree. C. and the concentration C ranges between 70 and 84 % by mass.

Abstract: The invention is concerned with a cellulose sponge which may be produced by mixing a solution of cellulose in an aqueous tertiary amine-oxide with a pore forming agent and a sponging agent and subsequently exposing it to conditions which cause a decomposition of the sponging agent and a foaming of the cellulose solution, whereafter the foamed cellulose is contacted with water to precipitate the cellulose.

Abstract: Spinning apparatus for carrying out a dry/wet-spinning process includes a spinneret for extruding filaments, a blowing device whereby the extruded filaments may be cooled immediately after being delivered from the spinning holes, a container containing spinning bath liquid, and means for bundling the extruded filaments provided in the spinning bath liquid. Preferably, the same means serves both for bundling and diverting the extruded filaments and is non-rotatable.

Abstract: The invention is an amine-oxide process for the production of a cellulose moulded body, wherein a suspension of cellulose in an aqueous tertiary amine-oxide is converted into a cellulose solution which is moulded and passed through an aqueous precipitation bath. A moulded body is obtained which, optionally after washing, is treated with a crosslinking agent. The cellulose solution contains a substance whereby the crosslinking agent may be activated. The process according to the invention allows the production of fibres having effectively controllable fibrillation properties.

Abstract: The invention is concerned with a process for the production of a solution of N-methylmorpholine-N-oxide in water, characterized by the following steps:(a) providing an aqueous solution containing N-methylmorpholine and morpholine and exhibiting a pH value of from 6.0 to 9.0, thereafter(b) treating said aqueous solution with a peroxidic oxidant to oxidize N-methylmorpholine to N-methylmorpholine-N-oxide.

Abstract: The invention is concerned with a process for the production of an aqueous amine-oxide solution used in the amine-oxide process for the production of a mouldable cellulose solution, wherein aqueous, amine-oxide containing solutions produced in said amine-oxide process particularly as precipitation baths are purified and concentrated, characterized in that a microbiocide agent is added to said aqueous, amine-oxide containing solutions before, during or after purification.

Abstract: Process for the production of cellulose fibres having a reduced tendency to fibrillation, in which a solution of cellulose in a tertiary amine-oxide is spun into fibres and the freshly spun fibres are contacted with a textile agent comprising at least two reactive groups, and are heat-treated, characterized in that the heat treatment is carried out by means of irradiation with electromagnetic waves.

Abstract: This invention relates to a process for the production of a cellulose molded body according to the amine-oxide process, which results in a molded body having reduced and effectively controllable fibrillation properties.

Abstract: The invention is concerned with a process for transporting a solution of cellulose in an aqueous tertiary amine-oxide through a component wherein said cellulose solution has different flow rates in said component, characterized in that an outlet wherethrough part of said cellulose solution is discharged from said component is provided at a point within said component whereat said flow rate is relatively low. (FIG.

Abstract: The invention is concerned with a process for the production of cellulose moulded bodies wherein a suspension of cellulose in an aqueous solution of a tertiary amine-oxide is transformed into a mouldable solution, said solution being extruded by means of a forming tool and conducted into a precipitation bath. The process is characterized in that at least part of the materials in devices and pipes for the transportation and processing of the solution, which material is in contact with the mouldable solution contains at a minimum of 90% up to a depth of at least 0,5 .mu.m, preferably more than 1 .mu.m, at least one element of the group consisting of titanium, zirconium, chromium and nickel in elementary form and/or in the form of compounds provided that the remaining of the material does not contain any of the elements of the group consisting of copper, molybdenum, tungsten or cobalt.

Abstract: Moulding material and spinning material respectively containing cellulose, an aqueous tertiary amine-oxide, a non-solvent and a stabiliser, characterised in that, one or more stabilisers are provided which altogether have a basic and antioxidant action with the proviso that the basic stabiliser is not phosphate. The moulding material and spinning material respectively according to the invention are thermally stabilised against a runaway of the decomposition reaction. The degradation of the cellulose and of the amine-oxide is also largely prevented.

Abstract: Process for the production of cellulose fibres having a reduced tendency to fibrillation, in which a solution of cellulose in a tertiary amine-oxide is spun into fibres and the freshly spun fibres are contacted with a textile agent comprising at least two reactive groups, and are heat-treated, characterized in that the heat treatment is carried out by means of irradiation with electromagnetic waves.

Abstract: The invention is concerned with a process for the production of cellulose moulded bodies, particularly films and fibres, by extruding a solution of cellulose in a tertiary amine-oxide through a shaping device, for example a spinneret, and conducting the extruded moulded body while drawing it into an aqueous precipitation bath, in which it coagulates, whereafter the coagulated moulded body is washed with an aqueous washing liquid, characterized in that the precipitation bath employed for coagulation and/or the washing liquid employed for washing contain(s) a surfactant in dissolved form.

Abstract: The invention is concerned with a process for the production of cellulose moulded bodies. In this process, cellulose is first dissolved in an aqueous solution of a tertiary amine-oxide, in particular N-methylmorpholine-N-oxide (NMMO), to produce a mouldable cellulose solution. Second, the cellulose solution is molded and conducted into an aqueous precipitation bath, wherein the cellulose is precipitated, which produces a moulded body and a spent precipitation bath. Next, the spent precipitation bath is regenerated. This regenerated aqueous amine-oxide solution is re-used to dissolve cellulose, thereby repeating the process. In the above process, the repeated aqueous amine-oxide solution has a pH within certain defined limits.

Abstract: The invention is concerned with a process for the production of cellulose molded bodies. This process has the following steps:(A) dissolving cellulose in an aqueous solution of a tertiary amine-oxide to produce a moldable cellulose solution,(B) molding said cellulose solution and conducting said molded cellulose solution into an aqueous precipitation bath, wherein the cellulose is precipitated, thus producing a molded body and a spent precipitation bath, and(C) purifying said spent precipitation bath by contacting said precipitation bath with an ion exchanger, thus producing a purified aqueous amine-oxide solution which, optionally after concentration, is re-used again in step (A) as a cellulose solvent. In this process, the ion exchanger comprises a cellulose carrier which has attached groups which are capable of exchanging ions.

Abstract: A process for the production of a cellulose moulded body, particularly cellulose fibres, characterized by the combination of the measures offeeding a cellulose-containing material into an aqueous solution of a tertiary amine-oxide in order to suspend said cellulose-containing material,removing water from the suspension while intensively mixing it and providing elevated temperature and reduced pressure, until a solution of cellulose is produced andmoulding said solution by means of a moulding device, particularly a spinneret, and introducing it into a precipitation bath in order to precipitate the dissolved cellulose,provided that as said cellulose-containing material, basically shredded waste paper, shredded cellulose-containing fibre assemblies and/or shredded, mechanically and/or chemically broken up annual plants are used.

Abstract: Moulding material and spinning material respectively containing cellulose, an aqueous tertiary amine-oxide, a non-solvent and a stabiliser, characterised in that, one or more stabilisers are provided which altogether have a basic and antioxidant action with the proviso that the basic stabiliser is not phosphate. The moulding material and spinning material respectively according to the invention are thermally stabilised against a runaway of the decomposition reaction. The degradation of the cellulose and of the amine-oxide is also largely prevented.

Abstract: A process for the purification of aqueous solutions of amine-oxides, characterized in that said solutions are contacted with an aqueous purification solution of an alkali hydroxide and/or ion pair reagent by means of an anion active membrane. By means of the process according to the invention, an efficient separation, particularly of anions of lower carboxylic acids and inorganic acids, can be achieved.

Abstract: There is disclosed a process for preparing solutions of cellulose in aqueous tertiary amine oxides from a suspension of cellulose in an aqueous solution of the tertiary amine oxide by supplying heat at a reduced pressure. The suspension is transported over a heating surface, spread in layers or coats, until a homogenous solution of the cellulose has formed, which has a viscosity of between 50 and 15,000 Pas.s. Feeding of the suspension and drawing-off of the homogenous solution are carried out continuously. The solutions are prepared in an indirectly heated evacuatable vessel provided with a stirring device. The vessel is designed as a cylindrical container including a centrically mounted stirring shaft having agitators joined thereto, the radial distance of the agitators from the internal wall of the container being 20 mm at the most. There are provided an intake for the cellulose suspension in the upper part of the container and an outlet for the homogenous cellulose solution in its lower end.

Abstract: A cellulosic solution in a amine oxide and water is forced through an elongated orifice passage having a minimum length of 1000 /.mu.m and a minimum diameter along the length which is up to 150 /.mu.m so that fiber characteristics are imparted to the emerging strand which passes through an air gap of at the most 35 mm in length into the coagulating solution.