MARE as a partner to approach Halogenated Organic Compounds Management in tissue making

Dear TissueMAG Reader, MARE is back on TissueMAG pages to introduce its capabilities in the field of Halogenated Organic Compounds (HOC) assessment and management. Halogenated Organic Compounds have become a matter of concern in the latest years for many industrial fields, papermaking being one of those, as they have been indicated as possible precursors of mutagenics. The chemical categories in which they fall are today well known, namely AOX (Adsorbable Organically bound Halogens), that is HOC which can be absorbed on activated carbon, EOX (Extractable Organically Bound Halides), that is HOC which can be extracted with a non-polar solvent and POX (Purgeable Organically Bound Halogens), HOC which can be purged in the gas phase under defined conditions with an auxiliary gas.

AOX is by far the most common category in many industrial fields as it is in Papermaking and Tissuemaking. Inside AOX, the substances of highest interest for Tissue are the well-known 1.3-dichloro-2-propanol (1.3-DCP) and 3-monochloropropane-1.2-diol (3-MCPD), generally referred to as DCP and MCPD. Recommendation BFR XXXVI for the production of paper for food contact defines the maximum residual quantities of these substances to be found in paper and tissue. As DCP and MCPD are typical byproducts of wet strength resin productions, a lot of effort has been put by the producers of Wet Strength Resins to reduce their quantity in the product mix.

From Paper and Board to manufacturing as a whole

Nowadays we can supply our customers with Wet Strength Resins allowing the production of tissue fulfilling BFR indications. Anyway, we have been observing, lately, that some of our customers would anyway report a significant residual of Halogenated Organic Compounds in their finished products. Investigating more deeply the situation, we came together with them to some surprising (although not so much) conclusions. In collaboration with a group producing Premium Tissue grades on the market, an extensive survey was done collecting various process parameters and correlating them with AOX values obtained in relevant paper samples. This was made possible by the full assembly of equipment (Picture 1 and Picture 2) to measure HOC available in MARE laboratory and the expertise accumulated in the latest years by our personnel, allowing the assessment of the said data with high reproducibility.

Results are shown in Picture 3. As you can see, while the correlation between the AOX residue and the dosage of WSR is poor, a much more fitting correlation can be done found with the dosage of other process aids. In particular, we observed that, in this case study, AOX residual on paper was linked to two different aids, one in the wet end and one in the dry. Based on this, the substitution of the specific additive with other ones not containing AOX was suggested. In other case studies, a correlation between AOX residuals and different process aids was done, leading to different suggestions to the customer, while, in some additional case study, a correlation between the use of specific raw materials in the furnish was and AOX was highlighted. During the completion of the aforementioned case histories, the results of MARE laboratory were compared repeatedly with the ones released by accredited independent European laboratories. It was definitely shown that the “numbers” were overlapping, showing to our customer the reliability of MARE measurements.

MARE product portfolio is well integrated with all the products needed to achieve a minimization of the AOX residuals in tissue. Actually, a part of these additives has already been made available and used in years by our customers both in the wet and dry end of the machine, but only lately their importance has been re-discovered as a toll to control AOX in tissue paper, due to the growing interest in this topic.

Dear TissueMAG Reader, in case we have caught your attention with this paper, please contact your local MARE sales rep in order to discover more. Thanks for your attention,
MARE GROUP.