Polyethylene Resin Extruded Foamed Sheets and Their Manufacturing Method

Abstract

The present invention addresses the issue of providing a method for manufacturing polyethylene-based resin extruded foam sheets that exhibit low apparent density when containing linear low-density polyethylene, thereby readily yielding good extruded foam sheets, and the polyethylene-based resin extruded foam sheets obtained by this method. The solution involves a method for manufacturing polyethylene-based resin extruded foam sheets 1 that includes an extrusion foaming step, wherein a foaming resin melt, formed by melt-blending a polyethylene-based resin (as a base resin) with a physical foaming agent, is extruded and foamed. The polyethylene-based resin contains linear low-density polyethylene. The difference between the crystallization initiation temperature Tcs (in °C) and the crystallization temperature Tc (in °C), Tcs-Tc, of the linear low-density polyethylene is 8 °C or less. The tensile viscosity λ of the linear low-density polyethylene, measured according to the Cogswell method at a measurement temperature of 150 °C and a shear rate of 375 s⁻¹, is 50,000 Pa·s or more.

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