A pre-expanded particle made of a blend of 10 to 90% by weight of a polypropylene resin having a melt index of 6 to 10 g/10 minutes and 90 to 10% by weight of a polypropylene resin having a melt index of 0.5 to 3 g/10 minutes. The melt index of the blend being within the range of 2 to 5
Resin particles made from a resin mixture of 30 to 70 wt % of a linear low-density polyethylene I having a resin density of 0.930 to 0.935 g/cm.sup.3 and an MI of 1 g/10 minutes or higher and 70 to 30 wt % of a linear low-density polyethylene II having a resin density of 0.915 to 0.9
