A disposable undergarment such as a disposable diaper includes a front waist region, a rear waist region and a crotch region extending therebetween, the undergarment has afterward bonded edges extending along a longitudinal center line of the rear waist region and a concavity depressed toward a surface...http://www.google.es/patents/US6497693?utm_source=gb-gplus-sharePatente US6497693 - Disposable undergarment
