Abstract: Polymeric material in the form of fibrids is produced by preparing (1) a homogeneous liquid phase of a first polymeric material and solvent and (2) a second phase of other polymeric material which is incompatible with the first polymeric material and solvent. Phases (1) and (2) are mixed together in such proportions that the quantity by weight of the first polymeric material is greater than that of the second polymeric material in the mixture. The mixture is furnished with sufficient energy to render it flashable and is then subjected to a flash-spinning so that polymeric material in the form of fibrids is produced and those fibrids are thereafter collected.

Abstract: A laminated structure of sheets of fibrous cellulosic and polymeric materials is prepared upon a multiple plane table cardboard manufacturing machine by forming a sheet of cellulosic fibers from a pulp thereof on at least one of the plane tables of the machine, forming a sheet of polyolefinic fibrids from a pulp thereof on a second plane table of the machine, and forming a cellulosic fiber-polyolefinic fibrid sheet from a pulp thereof on a third plane table of the machine, joining those sheets in superposed position so that the sheet of cellulosic fibers is in the middle, drying the superposed sheets, and then calendering the dry superposed sheets at a temperature not lower than that necessary to melt at least partially the polyolefinic fibrids.