| 摘要 |
A method is proposed for compacting granular moulding materials, the following compacting procedure being being triggered by means of a pressure-surge: a pressure-surge D1 is caused to act, at a time t1, upon the surface of the mass of moulding material and, at the same time, a pressuresurge D2 is caused to act, at a time t2, upon an area of moulding material which is spaced from the mass of moulding material in the direction of the pattern, so that air fed into the mass of moulding material,by the pressure-surge D2, is removed from the said material before the pressure-surge D1 reaches the pattern-plate. To this end, openings 9 are arranged in the pattern-plate between wall 3 of the moulding box and pattern 2. These openings may be arranged along the entire wall of the moulding box and may vary in size and number as a function of the distance between the said wall and the said pattern, and the shape of the latter. The advantage of this method is that narrow gaps between the wall of the moulding box and the pattern can be well compacted, leading to improved packing of the patern. The economic advantages of the method are therefore obvious. |
