How tissue and paper products are made

Have you ever wondered how Kruger Products’ tissue and paper products are made? If so, you’ll find the answer here, using the process for making SpongeTowels® paper towels as an example.

When we make SpongeTowels paper towels at our mills, there are two principal stages in the manufacturing process: papermaking, where large parent rolls are produced on a paper machine, and converting, where the parent rolls are transformed into finished product and packaged for shipment to customers.

Throughout the process, we conduct testing at the mill to ensure the quality of the finished product meets established standards for wet and dry strength, thickness, basis weight (the weight of 3,000 square feet of paper), stretch, rate of water absorbency, total water-holding capacity, brightness, softness and dimensions (e.g. sheet size, roll diameter and pack width).
Sponge Towels Enviro Image




Stage 1 – Papermaking

The tissue that Kruger Products manufactures is produced on paper machines that have special features specifically designed to make tissue (versus, for example, heavier stocks of paper like newsprint).

The main raw material used in paper production is pulp, which consists of very fine cellulose fibres. There are a number of different kinds of pulp, including Chemical or Kraft, CTMP (chemi-thermo mechanical pulp), Groundwood and Recycled Fibre.

We either produce our own pulp (for example, Recycled Fibre at our Hull and Crabtree, Quebec mills and Groundwood at our New Westminster, British Columbia mill) or purchase it from pulp mills.

The papermaking process begins in the stock preparation room. Here, depending on the final product (each grade of paper has its own recipe, called "furnish"), different pulps and necessary chemicals are mixed in a pulper to form a pulp slurry. Reclaimed paper and trim returned from the paper machine and converting operations are also added back to the slurry.

From the stock preparation room, the pulp slurry (made up of approximately 99.7% water and 0.3% fibre) is pumped through refiners (designed to develop softness and strength in the fibres) to paper machine storage tanks and, ultimately, to the headbox of the paper machine.

From the headbox, the slurry is forced through a controlled opening onto an endless wire screen. As the water is drained through the screen, a fibre mat is formed. This sequence is the heart of the papermaking process since paper is basically a "felt" of these fibres formed on a fine screen from a water suspension.

From the wire screen, the paper sheet is transferred to the felt, which carries the sheet through large rubber press rolls and "wrings" most of the water out of the paper sheet.

Once the pressing is complete, the wet sheet is transferred to the surface of a massive, polished, heated steel cylinder called a Yankee. Heat from the cylinder fully dries the paper, which is then deflected by a creping blade onto rubber-covered steel rolls, where it is wound onto a large “parent” roll. Parent rolls for SpongeTowels are approximately 2.3 metres (7.5 feet) wide and 1.5 metres (5 feet) in diameter. The parent roll is then transferred to a rewinder, where it is slit and rewound to the size required for converting to finished product, and is then stored in the parent-roll storage area to await converting.





Stage 2 – Converting

From the storage area, parent rolls are transported to the converting (or finishing) area, mounted on a towel winder and embossed in order to develop a cloth-like feel and provide greater water absorbency. Absorbent capacity can be varied by the amount of fibre in the towel and the embossing pattern used.

Two separate sheets (or plies) of paper are then pressed together and perforated to provide the ability to tear-off individual sheets. These sheets are then wound onto heavy paper tubes (the core found on the inside of each roll of paper towel) and the resulting 90-inch "log" is cut into rolls 11 inches wide. The size and number of sheets per roll are established by market requirements and the capabilities of the converting equipment.

The individual rolls are then conveyed to a wrapper, where they are wrapped in polyethylene film and packed in corrugated cardboard cases before being transported to our warehouse and, later, to the marketplace.