| 摘要 |
<p>A foamed polyester resin article is made by a method comprising forming a molten mixture containing poly (ethylene terephthalate) having an intrinsic viscosity greater than 0.7 and a moisture content of not greater than 0.03 %, a melt viscosity modifier and a heat activatable foaming agent having a decomposition temperature greater than 150 °C, heating the mixture in the barrel of an extruder and extruding the mixture through the die of the extruder. The method can be used to produce extruded poly (ethylene terephthalate) sheet having a foamed structure suitable for subsequent thermoforming into packaging articles and food containers such as those used as dualovenable food trays used for reheating foods in microwave or conventional ovens. The articles produced by the method have a density which may be 35 - 40 % less than that of similar articles made from conventional, non-foamed poly (ethylene therephthalate).</p> |
