Abstract: A disposable garment manufactured from a fusion-slit chassis having a pair of seams. The seams are formed by folding the chassis in the crotch portion so that the longitudinal side regions of the front portion and rear portion are superposed to form seaming areas; each seaming area is treated with ultrasonic energy sufficient to sever the material of the seaming area in a first area while simultaneously bonding the material of the seaming area in a marginal area adjacent the first area to form a flangeless seam which extends from the disposable garment 1/16" or less, preferably 1/32" or less, and in a preferred embodiment will form a splice between the front portion and rear portion of the chassis. The seaming area will consist of layers of polymeric material and in a preferred embodiment will consist of nonwoven webs of 100% polypropylene fibers.