| 摘要 |
PURPOSE:To form a sheet uniformly, by blowing pressurized air from blowing holes provided in a lower mold against the sheet undersurface thereby at the time when the sheet is being fed or during the mold clamping operation the resin sheet would not sag so that the thickness of the sheet would be prevented from being ununiformed. CONSTITUTION:The heat-softened resin sheet (a) is fed between the lower mold 15 and an upper mold 14 of the forming machine 11 with the edges of the sheet clamped. Against the undersurface of the sheet is blown air under pressure that is supplied to the lower mold via a check valve 37 from a horizontal position supporting blower 36 and is jetted from the pressurized air blowing holes provided in the lower mold, so that the sheet is prevented from sagging and is supported horizontally. The sheet is kept horizontally during the feeding of the heat-softened resin sheet, at the time when the sheet is stopped over the lower mold and during the clamping operation of the upper and lower molds, so that uneven thickness of the sheet due to sagging of the center of the sheet would not occur, and the blowing of the air and stopping of the air are effected by the operation of the valve to make the thickness of the sheet uniform. |
