PURPOSE: To manufacture highly stiff and impact-resistant flake filler-reinforced rolled sheets by heating sheets compounded with flake filler, rolling the sheet after melting some of its crystals and recrystallizing the crystals in a state of rolled sheet.
CONSTITUTION: Thermoplastic resin sheets at crystallization degree of more than 10% containing 10W80wt% of flake filler such as mica are heated at melting point of said resin so that some of the crystals may be melted. Then the sheet is rolled isotropically with a press or a roll to orientate the crystal and the molten crystal is recrystallized in a state of rolled sheet. In this way, it is possible to manufacture the sheet having a crystal orientation degree of more than 55%, a thickness change rate of less than 2% at temperature lower than a crystal melting temperature by 20°C, Izod impact strength with notch more than twice as much as an unrolled sheet and a stiffness more than 1.5 times as much as an unrolled sheet. Thus a stiff and impact-resistant sheet free from whitening can be obtained.
FUJII KIYONOBU
UBUKAWA HIROSHI
| JPS5732939A | 1982-02-22 |