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Optimal sizing performance in all process conditions

Internal sizing

Hydrophobation is crucial for all types of paper and board as well as molded fiber, to control the absorption of liquids such as ink and water and to improve other physical properties of the fiber-based materials, such as strength, dimensional stability, and coating and converting properties. Kemira has the most comprehensive portfolio of internal sizing agents to create efficient, fast, and even sizing for various paper and board grades, such as liquid packaging board, containerboards, fine paper, and printing paper and molded fiber products. Our FennoSize™ products include ASA sizing, AKD sizing, and Rosin size agents for optimal performance in all process conditions and with both virgin fibers and recycled pulps.

FennoSize AS is a performance-driven internal sizing program that consists of 100% active liquid ASA sizing products (alkenyl succinic anhydride). The synthetic sizing agents are highly reactive and together with Kemira’s efficient on-site ASA emulsification techniques, they allow over 90% immediate sizing development.

  • Applied for hydrophobation of e.g. fine paper, liner, sack paper, packaging board, containerboard, and gypsum board.
  • Used typically for neutral and alkaline sizing (pH 7–8), but works over a wide pH range 5–9
  • No curing time needed
  • Advanced production ensures high ASA sizing purity and quality

Kemira’s latest innovation in sizing chemistry is the biobased, ASA-like internal sizing agent. Made from maleated high oleic sunflower oil (MSOHO) instead of the fossil-based olefins that are used in traditional ASA sizing, the “sunflower ASA” helps improve the environmental footprint of the paper and board. Product performance, application, and cost-efficiency are similar to standard ASA sizing. Our current FennoSize MO product is a mixture of MSOHO and standard ASA sizing.

  • Applicable to various paper and board grades
  • Manufactured from renewable, locally available sunflower oil
  • Applicable for a wide pH range
  • Highly reactive as synthetic ASA sizing
  • Fulfills BfR and FDA regulations and is compliant to be used in food contact

Read more: FAQ Renewable sizing chemistry

Frequently asked questions

Renewable sizing chemistry

Here are the most frequently asked questions about our novel renewable sizing chemistry, the sunflower ASA, and answers to them.

FennoSize KD portfolio consists of easy-to-use anionic or cationic alkyl ketene dimer (AKD) products for various grades, e.g. fine paper, printing paper and packaging boards, and molded fiber products. AKD sizing agents are used when a hard sizing is needed.

  • Applicable to various paper and board grades and molded fiber
  • Efficient, fast, and even sizing
  • Provides unique resistance to lactic acid
  • Applicable to moderately acidic, neutral or very alkaline processes (up to pH 10)
  • Improved paper machine and process runnability

Our portfolio of rosin sizes includes a wide variety of cationic and anionic rosin dispersions and liquid rosin soap. Starch-stabilized FennoSize RS and polymer-stabilized FennoSize RN portfolios include gum and tall oil rosin, ensuring high performance for different paper and board grades and various temperature, pH, and other wet end conditions.

Internal sizing agents Chemical composition Best suited pH range Most suitable grades
FennoSize AS ASA sizing From acidic to alkaline Fine paper, liner, sack paper, packaging board, gypsum board
FennoSize MO MSOHO From acidic to alkaline Fine paper, liner, sack paper, packaging board, gypsum board
FennoSize KD AKD Moderately acidic, neutral or very alkaline Packaging boards, high-quality fine paper, printing paper, specialty papers like label paper
FennoSize G AKD and rosin size Acidic and neutral Liquid packaging board, liner, fine paper, specialty papers, newsprint
FennoSize RN Rosin size Alkaline Liquid packaging board
FennoSize RS Rosin size Acidic and neutral Packaging boards, liner, sack and bag paper

Material safety data sheet


Technical data sheet


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