seal 7 against the traveling web an elastomeric seal 7 made of for example sponge rubber having a hardness of jis japanese industrial standards 20 25 is in turn held against the wiper on either end of the web to create a small dam to prevent movement of the coating material off either edge of the web on either side of the coater backing roll this prevents loss of coating material as well as undesirable seepage of the coating material around the edges of the web against the roll the elastomeric seal 7 is held in a clip like case member 9 by a plurality of rod like needles 10 protruding from the case thus the seal 7 is mechanically attached to the case 9 in a preferred embodiment case 9 is made of a magnetic material such as magnetized iron or ceramic and has one or more surfaces such as flat back surface 11 on one wall which conforms with the flat surface of blade 4 which is made of a magnetically conductive material such as steel so that the elastomeric end seal member 7 is securely held in position with one end surface 12 assuming the contour shape of the backing roll 1 over the outer surface of wiper 6 in the preferred embodiment there is also a bottom surface 15 on another wall to support the seal thus case 9 has two open sides the magnetic case in which it is mounted is magnetically secured to the blade 4 so that the interface therebetween is sealed.