Using Recycled Fiber - Optimizing Machine Clothing Cleanliness: Perspective from a Consulting Engineer, 1992 Engineering Conference Proceedings

The rapidly increasing interest in using recycled fibers for making paper has added yet another dimension and area for thought for an engineering firm in the design of paper machines and recycled fiber plants. We first recognize the existence of contaminants in all grades of waste paper and their potential influence on machine operating efficiencies.

When we consider the certain problem of deposits on machine components and machine clothing, we first look at the process design in the recycle plant and the basic specification of recycle fiber quality expected. Is the plant designed and specified for maximum yield or maximum fiber quality, including cleanliness? What degree of contamination can we expect in the fiber delivered to the paper machine?

Next we look at how much recycle fiber content is planned and where it will be used, if the sheet is multi-ply. Next we look to equipment to keep the stationary and rotating elements free of deposit buildups which can transfer to machine clothing causing streaks and spots detrimental to good quality and efficiencies. Then we look at including cleaning equipment specifically designed to maintain clothing cleanliness, either intermittently or continuously. These include showers, doctors, and chemical cleaning systems.

Finally we advise our clients, particularly if our scope of work does not cover the entire operation of both the recycle plant and the paper machine. We will suggest items which the client should be considering when using secondary fibers. We will also advise him as to the effects of secondary fiber on operations - in stock preparation, on the paper machine and on product quality.