Optimizing the benefit of retention chemicals

Pre-flocculation of filler has been tested as a concept for improving the retention of filler and the strength properties of the sheet. The impact of the size of the filler floes on the mechanical retentionin a fibre network was investigated using a modified laboratory hand sheet former. The mechanical retention was found to increase linearly with both particle size and grammage of the fibre web. These results were confirmed in a full scale production trial on the FEX pilot paper machine at Innventia. Here different filler floe sizes were created through different chemical pre-flocculation strategies. The particle size in the flow to the headbox was measured with FBRM, and a linear relation between particle size and filler retention was found. Corresponding linear relation was seen in a pilot trial when adding filler and retention aid conventionally. This implies that mechanical retention constitute an important part of the filler retention not only upon pre-flocculation but also with conventional addition of filler and retention aid. Thus, the particle size before the headbox can be a good indicator of the retention level. For the conventional application of a two component retention aid system, the increased filler retention correlated to impaired formation and decreased sheet strength. On the contrary, pre-flocculation led to an increase in both sheet strength and filler retention, demonstrating the advantage of pre-flocculating filler.

By the author/editor: Athley, Karin; Granlöf, Lars; Söderberg, Danie ...; Ström, Göran

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Chemical Science ...; and Organic Chemistr ...

ENGINEERING AND TECHNOLOGY: ENGINEERING AND ...; and Materials Engine ...; and Paper Pulp and F ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.