It is in the nature of needle felt manufacturing that the surface of the product will have a slightly hairy appearance. In some applications this creates problems as dust accretions can build up on the fibers which are very difficult to dislodge during the cleaning process.

This problem can be all but eliminated by suitably singeing the surface of the felt. This involves rapidly moving the felt through a gas flame which then either burns off these protruding fibers or causes them to shrivel up into tight balls of polymer.

Lydall Industrial Filtration has taken this technique a stage further and advocates the "Superglaze" treatment which reduces the abrasive feel of conventional singeing. Both sides of a needle felt can be treated though it is most common to singe one. The treatment is applicable to all but PTFE needle felts.