When fibers are manufactured they invariably have a residual tendency to shrink in length when heated substantially. After these raw materials are converted to filter felts, they need to be heat stabilized to ensure that any shrinkage in the final application is minimized.

There are a number of ways of achieving this, but in essence, all require that the product is exposed to a temperature comfortably above the expected operating temperature. The material has then has to be held at that temperature to ensure that the in-built stresses are relaxed out.

The result is a stabilized fabric which will exhibit minimal shrinkage at the anticipated operating temperature.