Pulping and Retting
Soft tissue paper comes in varying thicknesses and textures but is mainly manufactured for facial tissue, bath tissue, paper towels, napkins and sometimes packing tissue. The first step in the process of making soft tissue paper is creating paper pulp, which can be generated from recycled materials or new ones. Tissue-paper manufacturers create their pulp by stirring together retted (soaked and pulled apart) tree fibres in a large vat. The type of tree fibre and how much water is mixed in depends on the particular product being made.
Once the pulp is ready, it is pressed through two pressure rolls so that a majority of the moisture is squeezed out. Sometimes the pulp might be pressed only between two rolls for thicker paper, and other times it may undergo the pressure of multiple rolls for thinner paper. This leaves the pulp in a manageable consistency for the next step, which will completely dry it out and scrape it down to a thin sheet.
The pulp is processed with a Yankee dryer, a drying cylinder heated by steam. This dryer puts the pulp through a process called creping; hence the term "crepe paper." The hood above the roller dries the pulp with a forceful heat as the roller turns and a fine blade scrapes the tissue down to the soft, desired thickness. The tissue does not get completely scraped away, because the roller is first sprayed with adhesives.
Reeling and Cutting
The long length of paper is reeled and cut with a machine, such as the Advantage SoftReel, into appropriate lengths and sections after it is dried and thinned. Throughout the process of making soft tissue paper, there are times when the fibres are exposed to extreme heat. To keep the fibres from igniting, technology such as Metso's Advantage WetDust is used to keep eliminate air born dust from the area and keep the tissue machines clean.