| abstract |
An expansion-molded article of a polyolefin resin, which is high in fusion-bonding strength and excellent in water permeability and compressive strength and has open voids, and a production process thereof are disclosed. The expansion-molded article is made of tubular foamed particles with a through-hole, whose dMIN is at least 1.5 mm and whose dMIN/DMIN value is 0.25-0.85 wherein dMIN is a minimum diameter of the hole in sections perpendicular to the direction of the hole and DMIN is a minimum outer diameter of the foamed particle in a section that dMIN has been provided. The production process includes filling the tubular foamed particles with a through-hole, whose dMIN and dMIN/DMIN are at least 1.5 mm and 0.25-0.85, respectively, into a mold and then molding the foamed particles under heat, whereby the foamed particles are fusion-bonded to one another. |