subject: Cap Sample And Mould [print this page] A mould for fabricating a moulded product comprising a laminate of a thermoplastic surface material and a structural material. The mould comprises a closed, air impervious first mould surface for shaping the surface material and an air permeable liner which is located in relation to the mould. The liner is adapted such that upon applying a cap mould vacuum pressure to the liner, the surface material contacts the second mould surface and conforms to the shape of the mould.
A method of fabricating a moulded product comprising: a) locating a thermoplastic surface material in relation to a mould, b) heating the surface material to a temperature sufficient to conform the surface material to the mould, c) drawing a cap mould vacuum pressure to conform the surface material to the mould, d) locating a structural material in relation to the surface material in a moulding relationship to bond the structural material with the surface material to form a laminate, and e) processing the laminate to form the moulded product, characterised by the mould comprising a closed, air impervious first mould surface for shaping the surface material, the method further comprising, f) providing the thermoplastic layer with a textured surface in relation to the first mould surface which provides an air extraction path between the first mould surface and the thermoplastic surface material, and g) drawing the in-mould vacuum pressure by applying the vacuum pressure to the extraction path.
n another embodiment, the cap mould vacuum pressure to the air permeable liner is higher (i.e. a lower absolute pressure) than the moulding pressure as applied to the laminate (i.e. higher absolute pressure). This is essential because if the vacuum pressure applied to the liner is lower than the pressure which is applied to the laminate, the surface material is not maintained in contact with the liner. While the structural laminate is curing, the cap mould vacuum pressure must therefore be higher or equal to the moulding vacuum pressure.
