Abstract:
The invention relates to a method and an apparatus for sound processing, where sound is attenuated by measuring it and by producing with an actuator a sound field of opposite sign in view of the original sound field. A desired value signal (I) is supplied to the actuator which reproduces the signal. To the actuator is attached a sensor, measuring sound pressure, and the difference of the sensor signal (B) and the desired value signal (I) is applied as high gain feedback to the actuator. As a consequence, sound not pertaining to the desired value signal (I) can be attenuated in a simple manner, and sound in accordance with the desired value signal (I) can be produced simultaneously with the same apparatus.
Abstract:
The invention relates to a method for processing extrudable material, especially for the manufacture of a multilayer extrusion product in an extrusion device, wherein the extrudable material is brought in solid form, advantageously as powder or in granular form, and which includes a central extrusion channel (1) and the stator means (2, 3) and the rotor (4) defining it. The invention concerns also such an extrusion device. In the extrusion device according to the invention it is used an optional number of stator and rotor means (2, 3, 4) arranged packlike alternately one within the other, whereby the extrudable material is first melted during its feed into an annular feed defile (5) advantageously in conical or double-conical form between the stator means (2, 3) and the rotor means (4) after the infeed thereof before the central channel, and thereafter compressed to the final extrusion pressure. The feed defile (5) of the extrusion device according to the invention comprises in the flow direction of the extrudable material first an infeed zone (51), then a melting zone (52) and finally a compression zone (53). The invention relates further to a new extrusion product, which is a multilayer product, and at least one layer whereof includes an interlacing orientation field, in which the plastic is helically oriented or directed forming a reinforcing netlike structure into the product.
Abstract:
The present invention concerns a dielectric film for converting the energy of an electric field or of a magnetic field into mechanical work, orfor converting mechanical work into electric energy, and a procedure for manufacturing the film. The film of the invention consists of a homogeneous, e.g. a film layer (A) foamed to a structure (C) of full-cell type and which has been oriented by stretching it in two dimensions and coated at least in part on one side or on both sides with an electrically conductive layer (B). The film is manufactured by extruding the plastic which has been made to be foams able, into tubular shape, performing intermediate cooling of the tube and reheating it, expanding the heated tube in two dimensions, metallizing the outer surfaces and cutting the tube open to become a film.
Abstract:
The invention relates to a method and an apparatus for sound processing, where sound is attenuated by measuring it and by producing with an actuator a sound field of opposite sign in view of the original sound field. A desired value signal (I) is supplied to the actuator which reproduces the signal. To the actuator is attached a sensor, measuring sound pressure, and the difference of the sensor signal (B) and the desired value signal (I) is applied as high gain feedback to the actuator. As a consequence, sound not pertaining to the desired value signal (I) can be attenuated in a simple manner, and sound in accordance with the desired value signal (I) can be produced simultaneously with the same apparatus.
Abstract:
A folded dielectric film element functioning as an energy converter, consisting of a dielectric film (1, 2) bent into folds (L) and provided with electrodes (K). The electrodes (K) are so arranged in the folds (L), different electrodes being placed in successive folds, that the strength of the electric field increases in one fold and decreases in the other. The elements of the invention allow a high acoustic power to be achieved. In noise damping aplications, the elements function in a multi-effect manner and they also have a passive damping effect as the air flows between the folds.
Abstract:
Selon un procédé d'extrusion d'un matériau extrudable, notamment pour la fabrication d'un produit extrudé à couches multiples dans un dispositif d'extrusion, dans lequel on introduit le matériau extrudable à l'état solide, de préférence sous forme d'une poudre ou de granules. Le dispositif d'extrusion décrit comprend un canal central d'extrusion (1) délimité par un stator (2, 3) et par un rotor (4). Le nombre voulu de stators et de rotors (2, 3, 4) sont alternativement emboîtés les uns dans les autres, de sorte que le matériau extrudable est d'abord fondu pendant qu'il est introduit dans un passage annulaire d'alimentation (5), de préférence conique ou à double cône, agencé entre le stator (2, 3) et le rotor (4), entre leur orifice d'alimentation et le canal central, puis comprimé jusqu'à la pression finale d'extrusion. Le passage d'alimentation (5) de ce dispositif d'extrusion comprend d'abord une zone d'alimentation (51), puis une zone de fusion (52) et finalement une zone de compression (53), dans le sens de l'écoulement du matériau extrudable. L'invention concerne également un nouveau produit d'extrusion à couches multiples dont au moins une couche comprend un champ d'orientation entrelacé dans lequel les matières plastiques sont orientées en spirale ou forment dans le produit une structure réticulaire de renforcement.
Abstract:
Des produits d'extrusion, tels que des câbles, des conduites, des films soufflés etc. constitués de plusieurs couches d'un matériau sont généralement fabriqués en utilisant des ajutages à plusieurs couches, dans lesquels les masses du matériau sont divisées en plusieurs composantes d'écoulement, lesquelles sont ensuite à nouveau fondues, afin de produire une structure tubulaire. L'inconvénient de ce procédé est que des saillies inutiles et des rayures risquent d'apparaître à l'endroit de fusion des composantes d'écoulement. Dans le procédé d'extrusion de la présente invention, les masses en écoulement sont homogénisées par des rotors tournant entre des plaques placées les unes sur les autres, les masses de plastique étant introduites dans les espaces des rotors à partir des périphéries des rotors puis acheminées vers les bords internes circulaires des rotors d'où elles se dirigent ensuite en un écoulement tubulaire dans les ajutages. Les matériaux utilisés dans ledit procédé de fabrication, tels que des plastiques, des colorants, des générateurs de mousse, des gaz, des agents de vulcanisation et d'autres substances chimiques, sont appliqués aux périphéries des rotors et mélangés par la rotation des rotors, le résultat étant un mélange homogène et un produit tubulaire de qualité uniforme.
Abstract:
The invention relates to a method and an apparatus for attenuating sound, comprising measuring at least one component (p, ux) of a sound field and producing attenuation sound on the basis of the measurement result by means of at least one actuator (4). The measurement result is adjusted by means of the approximation of the impedance or admittance of the sound field, and the approximation is adjusted on the measured residual sound pressure (pres). This allows the attenuation of sound to be implemented in a reasonably simple and effective way.