Patent EP-3037237-A1 (EP)
Inventor: VOLPATO MARCO
IPC: B29C35/02
Filed: 2015-12-17
Abstract: A method for foaming objects (2) is disclosed, the objects (2) having two dimensions prevailing on a third dimension and each provided with two coating elements (3, 3') of the shell or shaped panel type or of the flat or curved or thermoformed plate or sheet type, between said two coating elements (3, 3') there being interposed an intermediate layer (6) in expanded polyurethane or phenol material. The method comprises the steps of: 
i). providing one or more moulding units (4) each comprising a first half mould (5A) and a second half mould (5B) suitable for receiving respective coating elements (3, 3') of said objects (2) to be foamed, and intended for being conveyed along a closed advancement path (P) in which a foaming cycle occurs; 
ii). arranging in succession, one next to the other, according to a desired spatial sequence, a desired number of operative modules (M, M1,...M11,.., Mn) that are mutually distinct and separate, provided with driving devices that are independent of one another and mutually synchronized, comprising first rolling means (7) and second rolling means (8) for clamping and conveying said moulding units (4), said operative modules (M, M1,...M11,..,Mn) being reciprocally combinable so as to make up a modular structure of a desired length and shape defining said advancement path (P), wherein the number and mutual arrangement of said operative modules (M, M1,...M11,..,Mn) are chosen and optimised for adapting to specific process parameters, to characteristics of said polyurethane or phenol material and to characteristics of said objects (2) to be foamed, 
iii). setting said first rolling means (7) and second rolling means (8) at a reciprocal operating distance (D) so as to define, along said advancement path (P), an advancement and clamping gap (I) for said moulding units (4); 
iv). inserting into said first half mould (5A) and into said second half mould (5B) respectively conjugate coating elements (3, 3') of one or more respective objects (2), 
i). dispensing on the coating element/s (3) contained in a half mould (5A) a quantity of polyurethane or phenol mixture, 
ii). taking said first half mould (5A) and said second half mould (5B) to a mutually opposite position so as to define a respective closed moulding unit (4) in which the coating element/s (3; 3') contained in a half mould (5A; 5B) faces/face and matches/match the respective conjugate coating element/s (3'; 3) contained in the other half mould (5B; 5A); 
iii). inserting said moulding unit (4) closed in said advancement and clamping gap (I) and 
iv). applying to opposite sides of said closed moulding unit (4) opposite pressure actions (PI; P2) by said first rolling means (7) and said second rolling means (8) respectively so as to maintain reciprocally closed and clamped said first (5A) and second (5B) half moulds and so as to contrast the thrusts exerted by the expanding foam; 
v). driving said first rolling means (7) and said second rolling means (8) to advance, maintaining in a closed and clamped configuration, said moulding unit (4) inside said advancement and clamping gap (I) and along said advancement path (P) to complete the respective foaming cycle, wherein along at least part of said advancement path (P) there is provided heating of said moulding units (4).