摘要 |
<p>A method of producing a mould by forming around a pattern (20, 21) of an article to be produced comprises, (a) pressing a mould matrix (50) material around said pattern (20, 21) in a chamber bounded by solid retaining means (40, 80); (b) causing said mould matrix (50) material to harden to produce a flexible mould (50) having the following physical properties: flexural strength in the range 20-175 Mpa; flexural modulus in the range 700-5,000 Mpa; tensile strength in the range 10-120 Mpa; tensile modulus in the range 850-4,000 Mpa; compressive strength in the range 30-200 Mpa; compressive modulus in the range 400-5,000 Mpa; hardness in the range 5-20 Vickers; relative density in the range 0.5 to 3.0 g/cm3, and (c) removing the pattern (20, 21) to leave a mould (50), conforming to the pattern; wherein said mould matrix material (50) contains from 10 to 90 % by volume of fibres, said fibres having a length in the range from 10 to 1000 νm and a thickness in the range from 0.1 to 30 νm.</p> |