Abstract: A semi-active noise control system includes a layer configured to be part of an interior panel of an aircraft The layer includes conductive tracks, a driver arrangement, tuned mass dampers, and sensors. Each tuned mass damper has an eigenfrequency that depends on a control signal applied to the tuned mass damper and is connected to the driver arrangement via a conductive track and configured to receive control signals from the driver arrangement. Each sensor is connected to the driver arrangement via a conductive track and is configured to sense vibrations and/or acoustic sounds and send measurement signals to the driver arrangement. The driver arrangement is configured to analyze the measurement signals and to generate and send control signals to the tuned mass dampers such that the eigenfrequency of the tuned mass dampers is matched with the frequency of the vibrations and/or acoustic sounds sensed by the sensors.

Abstract: A description is given of a sandwich structure which comprises a core and outer layers arranged on both sides of the core, in which the core has core clearances which are dimensioned such that the acoustic behavior of the sandwich structure in the region of the core clearances corresponds to the acoustic behavior of a double wall, and at the same time the global acoustic behavior of the sandwich structure is retained.

Abstract: A description is given of a sandwich structure which comprises a core and outer layers arranged on both sides of the core, in which the core has core clearances which are dimensioned such that the acoustic behavior of the sandwich structure in the region of the core clearances corresponds to the acoustic behavior of a double wall, and at the same time the global acoustic behavior of the sandwich structure is retained.

Abstract: This invention relates to decomposable polyamide masses for packaging materials containing 5 to 25% by weight of an addition of linear, oligomeric aliphatic polyesters or polycarbonates with molecular weights from 800 to 4000. These additives preferably consist of polyesters of aliphatic diols and dicarboxylic acids having up to 10 carbon atoms or aliphatic carbonates having up to 10 carbon atoms.The use of such mixtures for easily degradable, decomposable polyamide packages is also claimed, in particular in the form of films or thin walled injection moulded parts for (food) packaging.

Abstract: Polyamide moulding materials which have been impact-modified with diene and/or acrylic rubbers and can be processed by thermoplastic means and contain special diphenols.

Abstract: Highly heat distortion resistant moulding compositions are disclosed comprising an aromatic polycarbonate having molecular weights Mw (weight average) of a least 10,000, containing bifunctional carbonate structural units corresponding to formula (Ia) ##STR1## wherein R.sup.1 and R.sup.2 denote, independently of one another, hydrogen, halogen, C.sub.1 -C.sub.8 -alkyl, C.sub.5 -C.sub.6 -cycloalkyl, C.sub.6 -C.sub.10 -aryl or C.sub.7 -C.sub.12 -aralkyl,m stands for an integer from 4 to 7,R.sup.3 and R.sup.4, which are selected individually for each X, denote, independently of one another, hydrogen or C.sub.1 -C.sub.6 -alkyl, andX denotes carbonunder the condition that R.sup.3 and R.sup.4 are both alkyl on at least one X atom andas the only thermo stabilizer, from 0.001 to 1% by weight of a siloxane corresponding to formula (II) ##STR2## wherein R and R' denote, independently of one another, C.sub.1 -C.sub.4 -alkyl or -aryl andx and y stand for the numbers 1,2 or 3 and x+y always add up to 4.

Abstract: A thermoplastic molding composition comprising a polycarbonate resin and ABS is rendered improved levels of resistance to gasoline environment and thermal stability upon the incorporation therewith of a particular vinyl copolymer.

Abstract: The invention relates to new, free-flowing polyamide molding compounds and blends, characterized in that they are prepared by mixing of polyamides known per se in the melt with low molecular weight, liquid-crystalline esters and/or ester amides corresponding to formula (I) and/or liquid-crystalline, oligomeric esters and/or ester amides corresponding to formula (II) and, optionally, other additives, at least one polymeric blending component being used as a further additive in the case of polyamide blends, and to the use of these liquid-crystalline (LC) additives I and/or II as flow promoters in polyamide molding compounds and blends and to a process for the production of the new polyamide molding compounds and blends. The invention also relates to the new oligomeric esters and/or ester amides corresponding to formula (II).

Abstract: The subject of the invention is flameproofed, non-dripping polyamide moulding compounds which contain specific amounts of the following:A) Phosphinic acid esters of polyphenols based on phenolaldehyde/ketone condensates,B) Anti-dripping agents (such as polyfluoroethylene polymers or aramides),C) Zinc borate,D) Thermoplastics with a predominantly aromatic main chain and a high thermal deflection temperature (Vicat B.gtoreq.180.degree. C.),and, if applicable, reinforcing agents and other additives for flameproofing and processing.

Abstract: The invention relates to flameproofed, non-dripping polyamide moulding compositions which contain certain amounts ofA) phosphinic acid esters of polyphenols based on phenol-aldehyde/ketone condensates,B) antidripping agents (such as polyfluoroethylene polymers or aramides) andC) zinc borateand if appropriate reinforcing agents and other additives for flameproofing and for processing etc.

Abstract: This invention relates to the process of applying heat curable reaction resin mixtures of polyisocyanates (a), polyepoxides (b), reaction inhibitors (c), heat activated reaction catalysts (d) and optionally auxiliary agents and additives (e) for the production of multilayered moulded products based on polyamides with a cured duromer layer by applying the mixture and heat curing of the reaction resin mixtures are preferably applied to the polyamide moulded products produced by the anionic lactam polymerization process by rotation, extrusion or centrifugal casting while the said polyamide products are still hot from the heat of polymerization, e.g. to form internal coatings on rotation cast polyamide pipes. The invention further relates to duromer coated multilayered moulded products produced by the above process.

Abstract: This invention relates to thermoplastically deformable branched aliphatic polyamides prepared by the hydrolytic polycondensation of lactams in the presence of small quantities of .alpha.-amino-.epsilon.-caprolactam (ACL) and approximately equivalent quantities of polycarboxylic acids (preferably dicarboxylic acids) and to a process for their preparation which is distinguished by considerably reduced polycondensation times without giving rise to cross-linked products. The process optionally in addition employs a solid phase after-condensation in which rapid further condensation takes place to the products with increased melt viscosity which are branched but are still soluble in m-cresol.

Abstract: The invention relates to fibre or filament mixtures consisting of high shrinkage side-by-side bifilar (mod)acrylic fibres or filaments separately containing TiO.sub.2 and carbon black and of normal fibres or filaments of polyamide, polyester, polyalkylene, poly(mod)acrylic, wool or cotton.