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Introduction
Published in P. K. Mallick, Processing of Polymer Matrix Composites, 2017
The starting material in a bag molding process is a prepreg, which is a continuous sheet of fibers preimpregnated with a thin layer of a thermosetting polymer. The prepreg may contain either unidirectional continuous fibers or a woven fabric. The polymer in the prepreg is a partially cured (called B-staged) thermosetting resin. The prepreg sheet is typically 0.125–0.25 mm thick. It is made in a separate process prior to bag molding and stored at approximately −18°C. At the time of bag molding, several precut layers of prepregs are stacked on top of a mold surface, covered by a thin bag of a flexible polymer film and then cured in an autoclave or in a press at an elevated temperature. Vacuum is used in addition to pressure to help remove air or volatile matters from the bag and to discharge excess resin flowing out of the prepreg stack. Pressure, in the range of 1–10 bar, is applied to consolidate the layers as the resin is being cured.
Design and validation of a gripper for the automated assembly of film components in flexible electronics manufacturing
Published in International Journal of Computer Integrated Manufacturing, 2023
Marcello Valori, Vito Basile, Gianmauro Fontana, Jose A. Mulet Alberola, Serena Ruggeri, Simone Pio Negri, Irene Fassi
The coverlay base material is coated with a layer of a b-staged acrylic adhesive resin (see Figure 1), to be fully activated during the lamination phase, once the coverlay is applied onto the substrate. The 2D geometry depends on board design and, thus, is characterized by extreme variability; therefore, component dimensions are extremely variable (roughly in the range 1 ÷ 30 cm2). The gripping area requirement was identified as 60 × 60 mm, based on the annual supply data of coverlays’ design provided by an industrial partner.1 Hence, technological solutions should be scalable for the manipulation of larger components.