Abstract:
Hollow metal microspheres are made by forming a liquid film of molten film forming metal composition across a coaxial blowing nozzle and applying a blowing gas at a positive pressure on the inner surface of the metal film to blow the film and form an elongated cylinder shaped liquid film of molten metal. An inert entraining fluid is directed over and around the blowing nozzle at an angle to the axis of the blowing nozzle so that the entraining fluid dynamically induces a pulsating or fluctuating pressure field at the opposite side of the blowing nozzle in the wake of the coaxial blowing nozzle. The continued movement of the entraining fluid produces asymmetric fluid drag forces on the cylinder and closes and detaches the elongated cylinder from the coaxial blowing nozzle. Surface tension forces acting on the detached cylinder form the latter into a spherical shape which is rapidly cooled and solidified by cooling means to form a hard, smooth hollow metal microsphere. A thin metal coating can be deposited on the inner wall surface of the microspheres by using a metal vapor as the blowing gas or by adding to the blowing gas small dispersed metal particles and/or gases of organometallic compounds which are decomposed. The metal microspheres can be used to make insulation materials systems and as filler materials in plastics, plastic foam compositions, rubber and rubber compositions and in metal compositions. Filamented hollow metal microspheres with a thin metal filament connecting adjacent metal microspheres are also disclosed.
Abstract:
Le composant (10) électrique ou électronique est surmoulé dans un bloc (20) de résine souple ou semidure telle qu'une résine silicone ou époxy. Pour permettre la fixation du bloc surmoulé à un support (40), des inserts métalliques (30) sont surmoulés en même temps que le composant. Selon l'invention, chaque insert est lui-même emprisonné dans un bloc (60) en résine dure telle qu'une résine époxy. L'insert métallique est ainsi rigidement solidarisé au bloc de résine souple; les tendances à l'arrachement et à la rotation de l'insert sont considérablement minimisées, ainsi que les conséquences des cycles thermiques que doit pouvoir subir le composant. En outre, la partie inférieure du bloc (20) de résine souple, chargée par des entretoises (70a-70c) reliant les blocs (60) de résine dure, présente un coefficient de dilatation réduit, du même ordre de grandeurque celui du support métallique (40). Application au surmoulage decomposantstels quetrans- formateurs ou condensateurs, notamment pour les matériels aéronautiques.
Abstract:
A spraycasting mould (45) is manufactured of a special material in order to facilitate the loosening of the product from the mould. Carrying boards (34) are coated with a coating layer (5) of synthetic material, preferably in a spraycasting mould (45).
Abstract:
L'invention a pour object un procédé pour obtenir un corps en matière alvéolaire muni d'éléments d'accrochage dans lequel on introduit une barrette (3) en matière alvéolaire portant les éléments d'accrochage J2) dans un élément de moule (4) de même largeur que les dits éléments, ces derniers venant se placer contre le fond de l'élément de moule, et on réalise un surmoulage pour obtenir un corps (1) en matière alvéolaire incorportant la barrette, de façon que les éléments d'accrochage (2) affleurent à la surface du corps. Dans le procédé de l'invention, on utilise une barrette (3) en matière alvéolaire plus large que les éléments d'accrochage (2) et comportant une partie débordante de part et d'autre des dits éléments. Application à la fabrication de sièges sur lesquels on doit poser des housses.
Abstract:
Apparatus for encapsulating portions of objects in plastics comprises upper and lower mold plates (21, 22). The upper plate (21) has an injection opening communicating with feed runners (57, 58). In particular to reduce down time, a cavity plate (20) is removably positionable between the mold plates (21, 22) and has openings (38,39) and holds objects spaced from the upper mold plate (21). The feed runners (58) communicate with the openings (38, 39) directly, or in an alternative by way of gates. In operation, the cavity plate (20) is loaded with objects to be encapsulated, inserted between the mold plates (21, 22) and fluid plastics forced through the injection opening, runners (57, 58) and gates if provided into the openings, (38, 39) to encapsulate the objects.
Abstract:
Articles having polymethyl methacrylate surface regions (32) reinforced by thermoplastics (e.g. polypropylene) members (34) having a surface (33) conforming to the shape of the polymethyl methacrylate surface region (32). Preferably a decorative sheet (36) (e.g. melded cloth) is sandwiched between the surface region (32) and the conforming surface (33). The polymethacrylate surface region may be applied to a preformed conforming surface of the thermoplastics member by using the conforming surface as one part of a mould which defines the shape of the surface; filling the mould with a syrup of methylmethacrylate monomer and polymerizing the syrup in contact with the conforming surface.