Pulp & Paper

Filtration In The Process of Pulping & Paper Making

The pulp & paper industries are one of the largest industries in the world. The process of paper making includes preparation of raw materials, fiber separation, bleaching process, papermaking process, etc. The best quality of paper can be defined by the best finish, coating, smoothness and thickness of the paper. Raw materials used shall be pure and free from impurities to get paper of higher quality. In this end, impurities must be removed from pulp and paper making water in the paper making process. Hanke provides you with a wide range of pulp & paper filtration solutions including starch slurry filtration solutions, coating filtration solutions and papermaking water filtration solutions.

For details, please refer to:

Pulp & Paper Filtration Solutions

The papermaking workshop is operating for papermaking.

Starch Slurry Filtration
Coating Filtration
Papermaking Water Filtration

Starch Slurry Filtration

Background
Starch slurry filtration is one of the most important processes in the papermaking process. It is very useful in making paper as it can be used as a surface sizing agent to coat the surface of the paper sheet to form a film on the paper surface, so that the fibers on the paper surface are better bonded and free from falling off easily, thus improving the printing performance of the paper. In addition, it is also used in paper coating as one of the binders for the coating formulation, which is a mixture of pigments, binders and thickeners. Coated paper has improved smoothness, hardness, whiteness and gloss, thus improving its printing characteristics.
Problem
Unfiltered starch slurry contains undissolved starch particles, dust and other impurities, which can clog nozzles and cause equipment failure; when applied on the paper surface, impurities in the starch slurry will cause uneven paper surface and poor paper quality.
Solution
Starch slurry needs to be filtered before use to remove unnecessary impurities. Self-cleaning filters are generally adopted for starch slurry filtration as they help manufacturers to obtain high quality starch slurry and eliminate large granular impurities.

Self-cleaning filters for starch slurry filtration

Coating Filtration

Background
Some types of paper require a coating on the body paper during the manufacturing process, such as publishing paper for magazines and books, and printing paper for trademarks, packaging, and catalogs.
Problem
Unfiltered paints may contain impurities such as undissolved solid particles, debris, dust entered during transportation, etc. During the papermaking process, these impurities not only clog the nozzles, but also cause uneven coating, thereby affecting the quality of the final paper products.
Solution
Bag filters are your most economic choice for filtering water-soluble paints or paints with a low viscosity (dynamic viscosity ≤ 1 mPa.s) while scraper self cleaning filters and pneumatic disc filters are recommended for paints with a high viscosity. The latter two filters can effectively remove particulate impurities from paints and improve the purity and color of coatings.

Bag filter for coating filtration

Papermaking Water Filtration

Background
Manufacturers in the paper industry require a large quantity of high quality water available at a low price. For this reason, many manufacturers use rivers or lakes as water sources directly to save costs.
Problem
Water from rivers or lakes contains a large quantity of impurities such as silt, algae and dust. If used directly, these same impurities can clog the nozzles, causing equipment failure and even affecting the quality of the paper.
Solution
Water for pulp & paper mills generally requires a filter rating ranging from 50 μm to 500 μm. elf-cleaning filters are generally adopted for papermaking water filtration. As pulp & paper mills consume a large quantity of water, only self-cleaning filters can clean filter elements and remove impurities from water quickly without interrupting the ongoing filtration process.

Pneumatic disc filters for papermaking water filtration