A foam material with very low thermal conductivity and a process for manufacturing the foam material

摘要

This invention describes a foamed material wherein the foam is characterized by elongated cells, which have an aspect ratio larger than 1.5, and by a density according to ISO 845 of lower than 150 kg/m 3 , preferably lower than 80 kg/m 3 and a process of manufacturing said material with very good thermal insulation properties. The thermal conductivity is decreased from typical 0.035 W/mK down to 0.025 W/mK by combination of cellular orientation and cell size distribution. In order to be able to achieve necessary cellular orientation level, the melt strength of the polyester resin was significantly increased by reactive extrusion and subsequent foaming, and the extrusion tooling and processing conditions were optimized.