There are numerous processes in a paper mill. One of the early processes is reducing a tree into chips. The chips must be of a similar size in order to accurately know how long the pulping process will take. If the chips are too large, the paper will come out chunky (not good if it’s being made into tissue) and if the chips are too small, it affects consistency.
They way paper mills assure the proper size chips is with a machine called a shaker, manufactured by Rotex, which manufactures industrial separation and sifting equipment. It consists of two screens, one of coarse mesh on top and fine mesh on the bottom, with space in between. Material that can’t fit through the top mesh goes back to be chipped again and material that falls through the fine mesh is used for fuel. The chips that fall between the mesh are the perfect size for pulping.
The screens inside of the shaker are a continuous maintenance issue for paper mills. During prolonged rainy periods the screens tend to clog up and often holes are broken through the screen causing costly downtime if not replaced or repaired quickly.
Hydradyne provides the service to repair and maintain these screens for its pulp and paper customers. The screens and any rotten wood is replaced and then stapled back into place. Overhanging material is trimmed, so the screens fit back in place. The completed product, which typically consists of 3 screens, is then delivered to the mill and any used screens are picked up for repair and drop off at a later date.
The repairs Hydradyne does on these shaker screens helps support the paper mill’s chip production process and keeps them working. This is not a typical Hydradyne project, but our customers appreciate the extra work we do to take care of their needs, which is typical for Hydradyne.