Methods for producing multi-layer foamed sheets

摘要

The invention provides, as a method for producing a multi-layer foamed sheet whose scale-like appearance has been improved by means of a multi-layer circular die coextrusion method, a method for producing a multi-layer foamed sheet having foam layers and non-foam layers by a multi-layer circular die coextrusion method which is a method for producing a multi-layer foamed sheet wherein the shear stress at the interface of each layer is 5000 Pa or higher and not higher than 50000 Pa, a method for producing a multi-layer foamed sheet wherein the resin of said non-foam layer is a linear propylenic resin having a melt flow rate of 5 to 30 g/10 minutes, and a method for producing a multi-layer foamed sheet wherein the resin of said foam layer is a propylenic resin whose melt tension (MT) at 190° C. and melt flow rate (MFR) at 230° C. satisfy the following equation A: