摘要 |
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. |