Abstract: Poly-1,3-dioxepane, poly-1,3-dioxolane, polytetrahydrofurane or mixtures thereof are used in molding materials comprising polyoxymethylene or a copolymer containing a majority of oxymethylene units, for improving the flexural toughness of moldings formed from the molding materials.

Abstract: Poly-1,3-dioxepane, poly-1,3-dioxolane, polytetrahydrofurane or mixtures thereof are used in molding materials comprising polyoxymethylene or a copolymer containing a majority of oxymethylene units, for improving the flexural toughness of moldings formed from the molding materials.

Abstract: The invention relates to a process for the continuous thermal removal of binder from a metallic and/or ceramic shaped body which has been produced by injection molding, extrusion or pressing using a thermoplastic composition and comprises at least one polyoxymethylene homopolymer or copolymer as binder in a binder removal oven, which comprises the steps (a) removal of binder from the shaped body in a binder removal oven at a temperature which is from 5 to 20° C. below, preferably from 10 to 15° C. below, the temperature of a second temperature stage over a period of from 4 to 12 hours in a first temperature stage in an oxygen-comprising atmosphere, (b) removal of binder from the shaped body at a temperature in the range >160 to 200° C. over a period of from 4 to 12 hours in an oxygen-comprising atmosphere in a second temperature stage and (c) removal of binder from the shaped body at a temperature in the range from 200 to 600° C.

Abstract: Process for producing a shaped metallic body from a thermoplastic composition by injection molding or extrusion to form a shaped part, removal of the binder and sintering, wherein a thermoplastic composition composed of a metal powder and a polymer mixture B1) and B2) based on a polyoxymethylene homopolymer or copolymer B1) is used as binder and to remove the binder a) the shaped part is treated with a solvent which extracts the binder component B2) from the shaped part and in which the binder component B1) is insoluble, b) the solvent is then removed from the shaped part by drying and c) the shaped part is treated thermally at from 140 to 200° C. in an oxygen-comprising atmosphere, as a result of which the binder component B1) is removed from the shaped part; and also a shaped metallic body which can be obtained in this way.

Abstract: The invention relates to a process for the continuous thermal removal of binder from a metallic and/or ceramic shaped body which has been produced by injection molding, extrusion or pressing using a thermoplastic composition and comprises at least one polyoxymethylene homopolymer or copolymer as binder in a binder removal oven, which comprises the steps (a) removal of binder from the shaped body in a binder removal oven at a temperature which is from 5 to 20° C. below, preferably from 10 to 15° C. below, the temperature of a second temperature stage over a period of from 4 to 12 hours in a first temperature stage in an oxygen-comprising atmosphere, (b) removal of binder from the shaped body at a temperature in the range >160 to 200° C. over a period of from 4 to 12 hours in an oxygen-comprising atmosphere in a second temperature stage and (c) removal of binder from the shaped body at a temperature in the range from 200 to 600° C.

Abstract: A process for producing a metallic or ceramic shaped body from a thermoplastic material comprising A) 40 to 65% inorganic sinterable powder A B) 35 to 60% binder B1) 50 to 95% polyoxymethylene homo- or copolymers; B2) 5 to 50% of a polymer dissolved or dispersed in B1) with a particle size of less than 1 ?m, and C) 0 to 5% by volume of a dispersing aid, by injection molding or extrusion to give a green body, removing the binder and sintering, which comprises removing the binder by a) treating the molding with a solvent which extracts the binder component B2) from the molding and in which the binder component B1) is insoluble, b) removing the solvent from the molding by drying, and c) treating the molding in an acid-containing atmosphere is described.

Abstract: The invention relates to binders for pulverulent metals, metal alloys or ceramics based on polyacetals, polyethers and polyesters, to thermoplastic compositions comprising these binders for the production of metallic or ceramic moldings, to the use thereof and to processes for production of moldings therefrom.

Abstract: The invention relates to binders for pulverulent metals, metal alloys or ceramics based on polyacetals, polyethers and polyesters, to thermoplastic compositions comprising these binders for the production of metallic or ceramic moldings, to the use thereof and to processes for production of moldings therefrom.

Abstract: Process for producing a shaped metallic body from a thermoplastic composition by injection molding or extrusion to form a shaped part, removal of the binder and sintering, wherein a thermoplastic composition composed of a metal powder and a polymer mixture B1) and B2) based on a polyoxymethylene homopolymer or copolymer B1) is used as binder and to remove the binder a) the shaped part is treated with a solvent which extracts the binder component B2) from the shaped part and in which the binder component B1) is insoluble, b) the solvent is then removed from the shaped part by drying and c) the shaped part is treated thermally at from 140 to 200° C. in an oxygen-comprising atmosphere, as a result of which the binder component B1) is removed from the shaped part; and also a shaped metallic body which can be obtained in this way.

Abstract: A process for producing a metallic or ceramic shaped body from a thermoplastic material comprising A) 40 to 65% inorganic sinterable powder A B) 35 to 60% binder B1) 50 to 95% polyoxymethylene homo- or copolymers; B2) 5 to 50% of a polymer dissolved or dispersed in B1) with a particle size of less than 1 ?m, and C) 0 to 5% by volume of a dispersing aid, by injection molding or extrusion to give a green body, removing the binder and sintering, which comprises removing the binder by a) treating the molding with a solvent which extracts the binder component B2) from the molding and in which the binder component B1) is insoluble, b) removing the solvent from the molding by drying, and c) treating the molding in an acid-containing atmosphere is described.

Abstract: The apparatus for the continuous catalytic removal of binder from metallic and/or ceramic shaped bodies produced by powder injection molding, which comprises a binder removal furnace through which the shaped bodies pass in a transport direction and are brought to a suitable process temperature, a feed facility for introduction of a process gas which is required for binder removal and comprises a reactant, at least one facility for the introduction of a protective gas into a reaction space of the binder removal furnace and a flare to burn the gaseous reaction products obtained in binder removal, wherein one or more devices which lead to a flow of the process gas directed transversely to the transport direction in the apparatus are present.

Abstract: The invention relates to a process for the continuous thermal removal of binder from a metallic and/or ceramic shaped body which has been produced by injection molding, extrusion or pressing using a thermoplastic composition and comprises at least one polyoxymethylene homopolymer or copolymer as binder in a binder removal oven, which comprises the steps (a) removal of binder from the shaped body in a binder removal oven at a temperature which is from 5 to 20° C. below, preferably from 10 to 15° C. below, the temperature of a second temperature stage over a period of from 4 to 12 hours in a first temperature stage in an oxygen-comprising atmosphere, (b) removal of binder from the shaped body at a temperature in the range>160 to 200° C. over a period of from 4 to 12 hours in an oxygen-comprising atmosphere in a second temperature stage and (c) removal of binder from the shaped body at a temperature in the range from 200 to 600° C.

Abstract: The invention relates to a process for producing a turbine wheel for an exhaust gas turbocharger by metal powder injection molding, which comprises the following steps: (a) provision of a feedstock comprising a metal powder and a binder, (b) provision of a tool which comprises a negative mold of the turbine wheel to be produced for metal powder injection molding of the turbine wheel, (c) introduction of a rotationally symmetrical core comprising a binder into the negative mold of the tool provided in process step (b) and alignment of the core so that it is aligned symmetrically about the axis of rotation of the turbine wheel to be produced, (d) production of a green body by metal powder injection molding of the feedstock provided in process step (a) around the core, (e) carrying out of a binder removal step to remove the binder from the green body in order to obtain a molding in the shape of the turbine wheel, and (f) sintering of the molding.

Abstract: The present invention relates to binders for pulverulent metals or pulverulent metal alloys, thermoplastic compositions comprising these binders for producing shaped metallic bodies, a process for producing them, their use and a process for producing shaped bodies therefrom.

Abstract: A binder B for inorganic powders comprises a mixture of b1 from 80 to 99.5% by weight of a polyoxymethlene homopolymer or copolymer B1 and b2 from 0.5 to 20% by weight of a polymer system B2 which is not miscible with B1 and comprises b21 from 5 to 100% by weight of polytetrahydrofuran B21 and b22 from 0 to 95% by weight of at least one polymer B22 of C2-8-olefins, vinylaromatic monomers, vinyl esters of aliphatic C1-8-carboxylic acids, vinyl C1-8-alkyl ethers or C1-12-alkyl (meth)acrylates.

Abstract: A binder B for inorganic powders comprises a mixture of

Abstract: Thermoplastic compositions useful for producing metallic moldings containA) 40-70% by volume of a sinterable pulverulent metal or of a pulverulent metal alloy or of a mixture thereof,B) 30-60% by volume of a mixture ofB1) 50-100% by weight of a polyoxymethylene homopolymer or copolymer andB2) 0-50% by weight of a polymer which is immiscible with B1) and can be thermally removed without leaving a residue, or a mixture of such polymers,as binder, andC) 0-5% by volume of a dispersant.

Abstract: A process for dewaxing injection molded metal pieces consisting of a metal/binder mixture, wherein a metal oxide is added to the metal/binder mixture.