The principle of the processchain is shown in fig. 1 (7.2.3 Buch 3). From the endless or precut flat sheet the different cut pieces are stacked together (by weight). The complete stack is heated in an oven and, after reaching its melting phase, is shaped in a press and cooled down to a rigid structure by the cooled steel mould. In principle a similar procedure and processtechnology can be used as with SMC, only regarding that GMT does not require curing of the matrix system in the mould.
The advantages of GMT are - related to SMC - short cycle time (only limited by the cooling rate), better joining (welding instead of bonding) better impact characteristics and improved recycling behaviour. Nevertheless the mechanical properties are lower (in comparison to SMC) due to the low E-modulus of the PP-matrixsystem (especially under compression).
