into the trough 40 39 in the illustrated embodiment seven hollow rolls 4 are arranged parallel to each other but without making contact with each other rolls 4 are disposed in vertical sliding guides 43 with their journals 44 fixed in the horizontal plane but freely movable in the vertical direction the rolls 4 are of a lightweight design in the form closed hollow bodies and float in the hot water in the trough 40 39 the web of material 1 is guided under the first roll 4 on the left side of fig1 over the following roll 4 under the third roll 4 etc in zig zag fashion the last roll 4 on the right side is located in a cold water compartment divided off by a weir 45 and is used for cooling down the web of material before it leaves the apparatus at the end the web of material 1 is conducted over a deflection roll 46 and then drops into a trough 47 the dropping distance visible on the right hand side from the deflection roll 46 to the trough 47 is sufficient to set the machine in motion i e to pull the web of material 1 through the hot water for thick reels 41 a drive must be provided of course the bearings of the cylinder journals 44 should of course run freely they may be so called carbon bearings which are guided in u profiles open toward the interior of the trough 40 39 and can slide up and down therein in the apparatus 50 of this embodiment the web of material is subjected only to a very.