| 摘要 |
A method of forming a shaped thermoplastic sheet is described. The method includes providing a mold apparatus ( 1 ) that includes, a first mold portion ( 11 ) having an interior mold surface ( 14 ) having a plurality of perforations ( 26 ) and a perimeter edge ( 17 ). The mold apparatus ( 11 ) further includes at least one sheet retainer ( 35 ) having an upper surface ( 38 ) having a plurality of perforations ( 41 ) and a longitudinal axis ( 44 ) that is oriented along at least a portion of the perimeter edge ( 17 ) of the first mold portion ( 11 ). Each sheet retainer ( 35 ) is reversibly and controllably: (i) positionable along an x-, y- and/or z-axis relative to the perimeter edge ( 17 ); and (ii) rotatable around its longitudinal axis ( 44 ), toward and/or away from the perimeter edge ( 17 ). A heated thermoplastic sheet ( 95 ) is formed and contacted (while at a thermoformable temperature) with the interior surface ( 14 ) of the first mold portion ( 11 ) and the exterior surfaces ( 38 ) of the tubular sheet retainers ( 35 ). Reduced pressure is drawn through the perforations ( 41 ) of the sheet retainers ( 35 ) thereby retaining a portion of the heated thermoplastic sheet ( 95 ) thereon. The sheet retainers ( 35 ) are moved along the x-, y- and/or z-axes, and optionally rotated, with the sheet retained thereon, relative to the perimeter edge ( 17 ). Reduced pressure is drawn through the perforations ( 26 ) of the interior mold surface ( 14 ), thereby drawing the heated thermoplastic sheet ( 95 ) into intimate contour matching contact there-with. The heated thermoplastic sheet ( 95 ) is allowed to cool, and a shaped thermoplastic sheet retaining the contour of interior mold surface ( 14 ) is formed. A sheet molding apparatus ( 1 ) is also described.
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