Mat material, exhaust gas purification device, and method for producing mat material

A method for producing a mat material, comprising

• an attaching step of attaching an inorganic binder to an inorganic fiber mass, the inorganic fiber mass including inorganic fibers and multiple entanglement points formed by needling at least one of a front surface or a back surface of the inorganic fiber mass, wherein a density ρ of the entanglement points is in a range of 0.5 pcs/cm2≤ρ<18 pcs/cm2, and at least one of a 4 mm×4 mm first region without the entanglement points or a 3 mm×8 mm second region without the entanglement points is arranged in a 25 mm×25 mm region.

A method for producing a mat material, comprising

• an attaching step of attaching both an inorganic binder and an organic binder to an inorganic fiber mass, the inorganic fiber mass including inorganic fibers and multiple entanglement points formed by needling at least one of a front surface or a back surface of the inorganic fiber mass, wherein a density ρ of the entanglement points is in a range of 0.5 pcs/cm2≤ρ<18 pcs/cm2, and at least one of a 4 mm×4 mm first region without the entanglement points or a 3 mm×8 mm second region without the entanglement points is arranged in a 25 mm×25 mm region.