Inorganic Fiber-Formed Article, Mat for Exhaust Gas Cleaning Apparatus, and Exhaust Gas Cleaning Apparatus

An article, comprising:

• inorganic fibers;
• and
• needle marks extending in a thickness direction and each including a vertical bundle comprising inorganic fibers extending in the thickness direction,
• wherein
• (I) an average volume of an effective vertical bundles per needle mark (v/n), determined by dividing a total volume of the effective vertical bundles in the region (v) by the number of the needle marks in the region (n), is 1.0 mm3 or more,
• wherein the effective vertical bundles are vertical bundles having a diameter of 100 μm or more and a protruding length of 2 mm or more among vertical bundles protruding from peeled surfaces in a region measuring 50 mm×50 mm after a peel test is performed, and
• in the peel test, a test specimen having a width of 50 mm and a length of 150 mm is cut out from the article, a cut having a depth of 30 mm is made in a middle of a thickness of an end face of the test specimen, and both ends formed by the cut are held by gripping jigs, mounted on a tensile testing machine, and pulled in opposite thickness directions at a speed of 500 mm/min into two pieces, or
• (II) an average volume per the effective vertical bundle (V/N), determined by dividing the total volume of the effective vertical bundles (V) by the number of the effective vertical bundles (N), is 3.0 mm3 or more.