Stiffening material is applied to the end of an elongate battery electrode sheath by spreading the material onto a disc in the form of an apertured circle. The circle is continually rotated in a horizontal plane. The battery sheaths are oriented vertically and are displaced so that the lower end of each sheath is passed into the material at one location thereof such that the material approaches one side of the sheath. The sheath is then passed into the material at another location thereof spaced from the first location so that material approaches another side of the sheath.