Glass mat reinforced thermoplastic
Glass mat reinforced thermoplastic ( GMT ) is a plastic in which glass fiber mats are glued together and encased by a thermoplastic material .
Manufacturing
Two glass fiber mats, which are stored on two rolls, are fed onto a double belt. A thermoplastic is injected between these laminate mats with the aid of an extruder . The resulting mat is again enclosed on both sides with a thermoplastic film. The double belt also functions as a press (a so-called double belt press ), at the beginning of which a heating unit is installed (heating laminating zone), which is then followed by a cooling unit. At the end of the belt, the finished sheet material comes out, which can be used as a semi-finished product .
Further processing
In a GMT component production, prefabricated blanks (cold) are heated in a multi-zone / infrared heating oven or, in order to achieve better temperature distribution in the workpiece, in a convection oven . These blanks can then be inserted into a press with a tool (temperature controlled to approx. 40 ° C) by robot or manually. This presses the semi-finished product into the desired shape to form a workpiece.
Advanced GMT
In order to be able to use this technology for components subject to higher loads, there is a GMT in which the glass fibers are replaced by carbon fibers, the so-called Advanced GMT. These can be better placed in the press and thus ideally absorb the forces.