A sheet interleaver is provided for a slicing machine that includes a slicing plane for slicing an elongated food product and a sheet of web material beneath the elongated product. The interleaver includes a supply of web material, a drawing station, and a feed station. A tensioning station is disposed between the supply of web material and the drawing station to maintain the tension of the web material at a pre-determined tension. A web accumulation station is between the drawing station and the feed station to provide a slackened length of web material within an acceptable range of slack between the drawing station and the feed station. The supply of web material is disposed on a spool which rotates about a cylindrical shaft. The cylindrical shaft has a braking mechanism which protrudes from the shaft to generate a frictional force against the spool.