Patent ID: 8182625
Filing Date: 2012-05-22
Classification: B29C,Y10T

Abstract:
1. Method of manufacturing a sandwich panel that comprises a foamed core layer and two cover layers comprising at least one thermoplastic cover layer by in situ foaming, comprising an assembling step wherein a core web comprising at least one sheet of a thermoplastic material containing an amount of a physical blowing agent is provided, and wherein said core web is positioned between the two cover layers and wherein the assembly of core web and cover layers is arranged between two press plates; a foaming step wherein heat and pressure is supplied to the press plates to cause foaming of the core web and effect bonding thereof to the cover layers, while increasing the distance between the press plates until a predetermined foamed core thickness is obtained; a cooling step wherein the press plates are allowed to cool after a predetermined foamed core thickness is obtained; and a drying step wherein the thus obtained sandwich panel is dried at elevated temperature for a time period sufficient to reduce the level of physical blowing agent wherein the drying step is carried out while the peripheral edges of the foamed core are clamped such that the outflow of physical blowing agent via the peripheral edges of the foamed core layer is at most equal to the flow of physical blowing agent from the foamed core layer through the at least one cover layer, at least during an initial stage of said time period.