the temperature at which the polymer changes from a glass to a rubbery state.
glass mat thermoplastic, a thermoplastic prepreg, offering better mechanical properties than injection-moulded reinforced thermoplastics, thanks to the higher residual length of the glass strands. GMT is widely used in automotive applications such as under-body shields, seat structures and front ends. GMT is obtained by consolidating a glass strand mat with a sheet of polypropylene. The glass mat is obtained by chopping assembled rovings and then needling the strands together. The intermediate product is delivered in the form of rigid sheets and subsequently moulded by the end user.