METHOD FOR MANUFACTURING THERMALLY EXPANDABLE BASE MATERIAL FOR VEHICLE INTERIOR

The invention provides a method for producing a thermally expandable base material for a vehicle interior and a method for producing a base material for a vehicle interior, used for producing a vehicle interior material that is lightweight, sufficiently sound absorbable and highly rigid. The thermally expandable base material is produced by needling a web (11) containing an inorganic fiber, a thermoplastic resin fiber or thermoplastic resin powder, and a thermally expandable microcapsule to form a fiber mat (1), heating the fiber mat (1) at a temperature at which the thermoplastic resin fiber is melt but which is lower than thermal expansion starting temperature of the thermally expandable microcapsule, hot-pressing, and then cooling. The base material for a vehicle interior is produced by heating the thermally expandable base material at a temperature higher than the thermal expansion starting temperature of the thermally expandable microcapsule to thermally expand.