Extruded foamed polyolefin resin carrier for microorganisms in a fluidized bed

Abstract

A microorganism holding carrier for a fluidized bed is provided that includes an extruded foamed article having continuous cells and independent cells. The article is composed of a polyolefin resin as a main component. The continuous cells include open-cells which are opened to at least two portions of a surface of the article and a semi-open cell which are opened to only one portion of the surface of the article. A ratio of the total volume of the continuous cells to the total volume of the extruded foamed article (a volume ratio of the continuous cells) falls within a range of from 20% to 70%. Further, a ratio of the total volume of the open-cells to the total volume of the continuous cells (a volume ratio of open-cells) is 20% or more. The article may have an apparent density of 0.90 to 1.80 g/cm.sup.3 and an apparent volume from 2.0.times.10.sup.-3 to 5.0 cm.sup.3, and be in the shape of a column, or a tube having an outer diameter of 2 to 20 mm and a thickness of 5 to 30% of the outer diameter. During foam-extruding, a cylinder temperature of 180.degree. C. to 250.degree. C. and a die temperature of 200.degree. C. to 250.degree. C. are preferred. The polyolefin resin may include additives such as an inorganic filler, a foaming agent, and a blowing assistant for controlling foaming temperature of the foaming agent.

Dependencies are inferred from the claim text.