摘要 |
The invention provides a process for forming a sheet of thermoplastic material into a three-dimensional shape comprising at least one vertex, the process comprising the steps of (i) forming the sheet by means of a former having a profile such as to produce a first formed shape in the sheet, followed by (ii) positioning a male former within the first formed shape, the male former having a profile within the first formed shape comprising at least one vertex and (iii) raising the temperature of the first formed shape above that of forming in step (i), thereby causing the first formed shape to shrink back towards its original sheet form and thereby adopting the profile of the male former. |