A method of forming a needled rotary fiberglass glass insulation product is provided. The formation of the needled insulation product may be conducted in a continuous in-line process in which the fibers are rotary formed, a binder is sprayed onto the hot fibers, the fibers are collected onto a conveyor and formed into a fiberglass pack, the fiberglass pack is passed through the oven, and the cured insulation blanket is passed through a needling apparatus. The reduction in thickness and increased density caused by the needling process permits the production of lower thickness and higher density insulation products. In particular, the needled insulation product may have a thickness of less than about 0.75 inches and a density from about 1 pcf to about 10 pcf. The needled insulation product may be utilized in household appliances, water heaters, and HVAC equipment.