Abstract: The surface of a shaped article produced in a first step, for example by means of rapid prototyping, is subsequently decorated by a method for the production of a surface-decorated shaped article in which a) a shaped article is provided, and b) at least a portion of the surface of the shaped article is welded to a decorating film with incidence of electromagnetic radiation.

Abstract: Two shaped articles A and B which are not directly weldable to one another can be welded to one another with the aid of a film C if the material of the first surface of this film is compatible with the material of the shaped article A and the material of the second surface of this film is compatible with the material of the shaped article B and if either the film C or a surface region in contact therewith absorbs electromagnetic radiation. The welding is carried out by brining the first surface of the film C into contact with the shaped article A and the second surface of the film C into contact with the shaped article B and inputting electromagnetic radiation.

Abstract: The present invention relates to a process for the bonding of material for the production of three-dimensional objects by means of selective heating via a laser of wavelength from 100 to 3000 nm. The beam spot here may be a focused or unfocused beam spot, or may indeed be spread, as is the case with the diode laser, where the bars may have a stacked arrangement. The selectivity of the melting process is achieved via the application of an absorber to certain subregions of a layer composed of a pulverulent substrate, and then heating of the absorber by means of laser radiation of wavelength from 100 to 3000 nm. The heated absorber transfers the energy present therein to its surrounding pulverulent substrate, which is melted thereby and, after cooling, has firm cohesive bonding. The process is markedly more flexible, less expensive, and faster than conventional laser sintering.

Abstract: A coolant line which comprises the following layers: I. an outer layer comprising a polyamide molding composition and II. an inner layer comprising polypropylene and at least 0.02% by weight of a heat stabilizer, has a high thermal aging resistance and bursting strength.

Abstract: Multilayer composites are obtained from a molding composition which contains the following components: a) 100 parts by weight of polyamide and b) from 0.005 to 10 parts by weight of a compound having at least two carbonate units by coextruding with a molding composition based on a high-melting-point polymer whose crystallite melting point Tm is at least 255° C. and/or whose glass transition temperature Tg is at least 180° C.

Abstract: A process for producing moldings with condensing-up of a polyamide molding composition by means of a compound having at least two carbonate units, wherein a) a polyamide molding composition is made available, b) a mixture of the polyamide molding composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, and the molding is a hollow body or hollow profile having an external diameter of at least 30 mm and a wall thickness of at least 1 mm, effects a significant increase in the melt stiffness combined with moderate processing presssures, which considerably simplifies the production of these moldings.

Abstract: A process for producing moldings with condensing-up of a polyamide molding composition whose polyamide component contains, as a result of the method of preparation, at least 5 ppm of phosphorus in the form of an acidic compound by means of a compound having at least two carbonate units, wherein a) from 0.001 to 10% by weight, based on the polyamide, of a salt of a weak acid is added to the polyamide molding composition prior to compounding or during compounding, b) a mixture of the finished composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, effects a significant increase in the melt stiffness combined with moderate processing presssures, which considerably simplifies, in particular, the production of hollow bodies and hollow profiles having large diameters.

Abstract: A process for condensing polyamides to increase their molecular weight, using a compound having at least two carbonate units comprises using a polyamide which, as a result of its preparation, comprises from 5 to 500 ppm of phosphorus in the form of an acidic compound, and adding, to the polyamide, from 0.001 to 10% by weight of a salt of a weak acid, thus eliminating the inhibiting action of the phosphorus compound.