Fabrication of perforated hollow metal, ceramic or polymer spheres for use in soundproofing applications, notably for aeronautical and space reactors and engines

• Main Authors: DELVERDIER OSMIN, VIE PHILIPPE
• Format: Patent
• Language: English; French
• Published: 27.05.2005
• Edition: 7
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

The fabrication of hollow spheres comprises: coating some mandrels in a pug mill with a polymer binder; preparing a first pulverulent material, in the form of an organic or metal or mineral powder or fibres, and a second pulverulent material that can be decomposed by heat and/or soluble in a solvent; mixing the two pulverulent materials and adding this mixture to the pug mill; drying the coated mandrels; firing the coated mandrels in order to provoke the destruction of the mandrels and the second pulverulent material, and reticulating the binder, to obtain some hollow spheres with porous and perforated walls; possibly plunging the spheres in a solvent; and realising a mechanical piercing of the hollow spheres. Independent claims are also included for: (a) the hollow spheres obtained; and (b) an absorption device using these hollow spheres. Procédé de fabrication de sphères creuses :- on recouvre des mandrins dans un malaxeur par un liant polymérique ;- on prépare un premier matériau pulvérulent, sous forme de poudre organique ou de poudre métallique ou minérale ou de fibres, et un second matériau pulvérulent décomposable par la chaleur et/ou soluble dans un solvant- on mélange lesdits matériaux pulvérulents et on les ajoute dans le malaxeur;- on sèche les mandrins revêtus ainsi obtenus ;- on réalise une cuisson des mandrins revêtus pour provoquer la destruction des mandrins et du second matériau pulvérulent, et la réticulation du liant, pour obtenir des sphères creuses à parois poreuses et perforées ;- éventuellement on plonge les sphères dans un solvant ;- et on réalise un perçage mécanique desdites sphères creuses.Sphères creuses, et dispositif d'absorption des sons les utilisant.