| 摘要 |
The present invention provides for an apparatus for manufacturing a cuspated sheet having two faces, each face comprising an array of tips of hollow projections wherein the tip of each projection is thicker than the parts of the sheet connecting the tips, and wherein the ratio of height of cusp to maximum diameter of cusp is greater than 2:1 and wherein the cuspated sheet is made from a thermoplastic material, which apparatus comprises an array of cold projections, a second array of cold projections and means of pressing against one face of a hot sheet of thermoplastic material the first array of cold projections, and simultaneously pressing against the second face of the hot sheet of thermoplastic material the second array of cold projections so that the arrays interpenetrate in such a manner that the projections of the second array are spaced from the projections on the first array by a distance greater than the thickness of the sheet and wherein the hot sheet of thermoplastic material is at a temperature sufficient to allow thermoforming and wherein the cold projections are at a temperature insufficient to allow easy thermoforming. The cuspated sheets may be used as cores for laminates. |
