Pulp and Paper

Pulp

Pulping wood is about separating the lignin and cellulose in the most efficient way possible. Kraft pulp is the most common method, in which wood chips are added to a digester with sodium hydroxide and sodium sulfide to be cooked and dissolve lignin from the wood chips, leaving cellulose. The pulp is then sent to a series of washers where the cellulose is washed of all residual lignin and contaminants and is then sent to be processed into paper. Kraft pulp produces very active surfactants and they cause several issues with the washing efficiency during the pulp process. A quality defoamer will improve washing efficiency, improve total dissolved solids, reduce water consumption, and increase drainage. SIXIN’s range of defoamers is suitable for hardwood and softwood species and comes in a variety of concentrations and base chemistry.

Paper Machine

The paper machine is where the washed cellulose pulp is formed into a sheet of paper. Several chemical additives are put into the process to improve wet strength, dry strength, texture, color, and surface properties. Often times, foam is generated in the wire pit, headbox, and recycle streams because of the chemical additives and high speed of the machine. Defoamers in this process are essential for the high demands of a paper machines production standards and SIXIN has created several lines of products which are suitable at different temperature ranges, concentrations, price points, and paper types.

Paper Coatings

In special grades of paper, a coating can be applied to the sheet to add color, adhesive, or impart unique properties such as gloss or reduced ink absorbency. The coating is applied at the end of the paper making process and dried before being sent to the customer. Defoamer is added to the coating to prevent unwanted bubbles in the coating which would compromise surface quality. SIXIN has created multiple products for every type of paper coating and process to ensure your performance, environmental, and cost concerns are addressed.

Water Treatment

Most paper mills are closed loop systems with a water treatment facility on site. Residual surfactant from the pulp and paper making processes can create foam in the water treatment basins which will affect the pumps, cause overflow, and create downstream foam problems at the paper machine. SIXIN has water dispersible and environmentally friendly products which can be easily dosed to control all foam associated with the water treatment site.