The material is typically delivered to the customer in rectangular, preferably square, sheets which can then be cut and fabricated into a desired configuration. These composite materials are of a given size, e.g., 12×12 inches (4.7×4.7 cm), and are individually molded prior to being sent to the customer. The present invention, which was developed in an attempt to overcome the deficiencies of the prior art, provides a cross-plied material by a continuous, automated method.There would be less waste of material, and thus less expense to the customer, if the composite material could be furnished in continuous roll form, i.e., like a bolt of cloth, rather than in squares or rectangles. 4,403,012, 4,457,985 and 4,916,000, all of which are hereby incorporated by reference. This patent is exemplary of the prior art represented by the SPECTRA SHIELD material discussed above. The present invention provides a method and apparatus for the continuous, automated cross-plying of material, preferably for anti-ballistic end use or in impact resistant structural components, e.g., radomes, sonar domes, helmets.The means for sequentially laying the second plies of material preferably comprises, in combination: a second carrier web on which the discontinuous plies are separately carried; second pull means to pull the second carrier web with the discontinuous plies thereon so that each discontinuous ply and the first ply face each other in the cross-plying zone; and means for guiding each discontinuous ply and the first ply into contact with one another.It is preferred that the discontinuous plies releasably adhere to the second carrier web.The means for advancing the first ply of material into the cross-plying zone preferably comprises, in combination: a first carrier web on which the first ply is carried; first supply means for supplying the first ply of material on the first carrier web; and first pull means to pull the first carrier web from the first supply means under tension into the cross-plying zone.The preferred first supply means comprises a roll on which the first ply of material and the first carrier web are wound together, and the preferred first pull means comprises a pair of driven pinch rolls downstream of the cross-plying zone.It is preferred that each second ply be laid so that it substantially abuts the next adjacent second ply on the first ply.
The preferred means for guiding each discontinuous ply and the first ply into contact with one another comprises a press roll.
AA(College of Environmental Science and Engineering, Ocean University of China), AB(College of Environmental Science and Engineering, Ocean University of China), AC(College of Environmental Science and Engineering, Ocean University of China), AD(College of Environmental Science and Engineering, Ocean University of China)) is the maximum effective stress that a soil has suffered throughout its life.
From a geotechnical point of view, pre-consolidation stress has great importance because it separates elastic and reversible deformations from inelastic and only partially irreversible deformations and marks the starting point of high compressibility.
In yet a third embodiment, apparatus is provided for the automated production of cross-plied material from a first, continuous ply of material and a second, continuous ply of material, each of the plies of material comprising a network of unidirectional fibers substantially coated with a resin matrix.
Each of the plies of material also has a longitudinal axis substantially in the direction of the unidirectional fibers, and both plies exhibit substantial interply adherence when brought into contact with one another.