Method and apparatus for relofting a nonwoven substrate

A method for relofting a substrate, the method comprising:

• advancing a substrate in a machine direction MD around a traversing idler having an axis, the substrate comprising a first surface and an opposing second surface and defining a width in a cross direction;
• providing a first infrared radiation source;
• directing a first length of the substrate to advance in a first direction;
• and
• moving the axis from a first position to a second position to place the first surface of the first length of the substrate in a facing relationship with the first infrared radiation source;
• irradiating the first surface of the first length of the substrate with infrared radiation from the first infrared radiation source, wherein the substrate comprises a first caliper upstream of the first infrared radiation source and wherein the substrate comprises a second caliper downstream of the first infrared radiation source, wherein the second caliper is at least 1.2 times the first caliper;
• redirecting a second length of the substrate around the axis to advance the second length of the substrate from the first direction to a second direction that is opposite the first direction, wherein the second surface of the first length of the substrate is in a facing relationship with the second surface of the second length of the substrate;
• providing a second infrared radiation source in a facing relationship with the first surface of the second length of the substrate;
• and
• irradiating the first surface of the second length of the substrate with infrared radiation from the second infrared radiation source.