Troubleshooting Wrinkles and Ridges of forming fabrics, five easy solutions:

1. Carefully check the machine alignment

   Misalignment of rolls or dewatering elements is the most common cause of waviness. Every machine part touching the fabric and which is not perfectly aligned will try to guide the fabric sideways. If on both tender and drive side forces are working towards the machining center, waves and ridges can appear. Read more about cross machine direction forces in the downloadable whitepaper Solving Guiding Problems on Forming Fabrics.

2. Roll speed differences

1. Just imagine that the couch roll is running a little bit faster than the main drive roll. The fabric will be more-or-less pushed into the pick-up zone. This creates a certain ‘surplus’ of fabric in that area, which results in waviness.
   There are many possible causes for any driven roll to run faster or slower than expected; it can be an input error of the roll diameter into the Drive Control System (DCS), slip of the drive roll, a drive overload, etc. The first step however is to check if speed differences are the root cause for the waviness, so use the Rking TrueSpeed Sensor to accurately measure the actual surface speed of both fabric and rolls.

2. High-Pressure showers

   High pressure showers clean by moving dirt particles through the fabric by force. When a nozzle wears, the amount of water hitting the fabric sharply increases, just as the forces on the fabric. This effect alone can create waviness in the forming fabric.
   Additionally, little air bubbles in the high-pressure shower water have a devastating effect on the forming fabric. The HP shower will work like a machine gun on the yarns, which will break and the fabric will quickly lose its stability. Use a RKing PocketStrobe for a high-pressure shower inspection during a machine shutdown.

3. Narrowing of the forming fabric

4. Creases during installation

   Forming fabrics are delicate and it is quite easy to damage them during installation. When the fabric has to be pulled over the rolls towards the drive side, the crew needs a good grip. To avoid creases near the drive side edge of the fabric, use a number of Rking Capto pullers. By the way: they’re also great for installing felts and dryer fabrics!