| 摘要 |
A method of filling a mould with heat expandable beads of polystyrene arranged in a plurality of layers of different density, so that when the mould is heated to fuse the beads, the parts having the greatest density are stronger than the remainder of the article. The mould is provided internally with a vertical baffle plate mounted on the bottom of the mould directly below the filler opening and arranged so that beads fed through the filler opening are divided by the baffle plate into two streams which are deflected by the baffle plate in different directions towards different parts of the mould. The beads are drawn from two hoppers, one containing beads of high density and the other containing beads of low density, and the beads for a layer at an intermediate density are drawn simultaneously from both hoppers and mixed together before being fed into the mould. During the filling operation, the proportion of beads from the two hoppers is progressively varied to vary the average density of the beads entering the mould and form the desired density pattern within the mould. The baffle plate is withdrawn through a slot in the bottom of the mould before the mould is heated. |
