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Marietta, GA, United States

Haynes R.D.,Eka Chemicals Inc.
2010 TAPPI PEERS Conference and 9th Research Forum on Recycling | Year: 2010

The introduction of deinked pulp (DIP) into the production of newsprint using thermo-mechanical pulp (TMP) can impact the coefficient of friction (COF). As a particular operation works to increase COF after introduction of DIP or eliminate issues with crepe wrinkles the question of fatty acid carry over from the recycle fiber plant will often arise. To better understand and document this industry question mill data with respect to COF, fatty acid content, and ratio of TMP and DIP have been collected and evaluated. In addition the development of the IPST Total Organic Carbon (TOC) detection method has allowed the inclusion of measurements related to colloidal organics, colloidal pitch, and colloidal micro-stickies with respect to pulp blending impact on colloidal stability and deposition that can impact fiber to fiber bonding. This paper found that TMP can be bringing as much if not more fatty acid to the paper machine than recycle fiber or fatty acid based deinking agent combined. Also observed is that there is a demarcation line at a total fatty acid content of 750 ppm in the final sheet where there is a sharp drop in COF. Also determine was that a drop in COF was seen when more than 150 ppm for palmitic and 100 ppm for stearic fatty acid was detected in the sheet. Oleic and linoleic increased COF when above 100 and 200 ppm respectively and the most sensitive fatty acid was linolenic which saw a drop when above 30 ppm. This observation points to surface fatty acid concentration as being a critical value in the measured COF and a certain quantity of fatty acid needs to be present to see an impact on surface chemistry. Regional differences can be seen in fatty acid content and measured COF. It is possible to understand that the adsorption of dissolved and colloidal organics on to surfaces of fibers and fines due to colloidal instability can lead to lower COF and weakened fiber to fiber bonding leading to crepe wrinkling. The mill scale implications of this discovery is reported and discussed.

Haynes R.D.,Eka Chemicals Inc. | Haynes R.D.,Akzo Nobel
2011 TAPPI PEERS Conference | Year: 2011

For many paper machines producing printing and writing grades the introduction of recycle pulp or increasing the amount of recycle pulp can be a challenge. Most operations will purchase recycle lap pulp and add 10% or more to the furnish mix. The addition of recycle pulp can cause issues and introduces a level of uncertainty with respect to stickies content and impact on runnability. Most operations depend on macrostickies count to determine the stickies content level but the measurement is not always reliable for preventing a stickies outbreak on the paper machine. The unknown possibility of issues for any given bale of recycle lap pulp means many operations will limit or refuse to use recycle fiber. This paper looks at how chemical treatment of the pulp can be used to reduce this fear of the unknown by reducing or eliminating issues caused by colloidal stickies. The potential of colloidal stickies to cause issues can be related to the amount of colloidal stickies, the stability of colloidal stickies, the tackiness of colloidal stickies and tackiness level with respect to colloidal stickies content. The results reported are based on the measurement of colloidal stickies and tackiness of recycle lap pulp collected during mill scale trials. By developing chemistry and test methods that deal with both the invisible (colloidal stickies) and visible world (tackiness) of stickies the recycle lap pulp can be evaluated and the risk reduced or eliminated for paper makers. Mill scale trials have shown treatment can reduce tackiness by 27 to 49%, change colloidal stability by -27% to 113% and shift tackiness from expected levels or below expected levels by 58 to 200%.

The recycle industry has a need to relate some type of stickies measurement to runnability issues. In a survey by Douek, Sitholé and Banerjee [1] deposits were reported to occur throughout the paper machine but most often between the wet end and the dryers However, most operations find no correlation between macrostickies data in the recycle plant and problems on the paper machine. The Douek survey included a list of the industry's top priorities for understanding and controlling stickies and deposit problems. This paper reviews this list of industry needs and evaluates how the measurement of colloidal microstickies can help meet these needs. The evaluation will be broken into two parts; the first part dealing with the first six needs which used off-line testing focusing on the stock coming from the recycle plant; and the second part which deals mainly with issues of pulp blending and issues at the paper machine. 1. Determine mechanism of microstickies formation 2. Reliable tests to measure stickies and predict deposition 3. Efficient removal of contaminants in recycle plant 4. Effect of hardness on deposition 5. Effect of temperature 6. Conversion to neutral deinking-impact of pH 7. Minimizing deposition caused by pulp blending 8. On-line contaminant monitoring 9. Conversion to neutral/alkaline papermaking 10. Deposit control on dryers 11. Devise effective low cost control measures The measurement of colloidal organic solids employed technology developed by IPST at Georgia Tech., and is based on a combination of fractionation with measurement of total organic carbon (TOC). The method has the potential for effective on-line measurement of micro-organic accumulation and has been validated under mill scale conditions for packaging, newsprint, and tissue paper grades. The paper presents examples of how this technology can meet the top priorities of the industry to understand and control stickies.

Gevert B.,Chalmers University of Technology | Eriksson L.,Chalmers University of Technology | Torncrona A.,Chalmers University of Technology | Torncrona A.,Eka Chemicals Inc.
Journal of Porous Materials | Year: 2011

A new method for synthesis of discrete colloidal ZSM-5 particles with SiO 2/Al 2O 3 M ratios as low as 30 and sizes .4-1 micrometer has been developed. The relation between the synthesis parameters and synthesis yield, crystal structure, crystallinity, particle size and morphology was investigated. The synthesis yield increases and the deviation of the SiO 2/Al 2O 3 ratio in the product from that in synthesis mixture decreases with increasing autoclave temperature suggesting that the introduction of aluminium into the zeolite structure is favoured by high autoclave temperature during the synthesis and that temperature determines the lower limit of the SiO 2/Al 2O 3 ratio. The SiO 2/Al 2O 3 ratio in the synthesis mixture decreases with autoclave temperature suggesting that the introduction of aluminium into the zeolite structure is favoured by high autoclave temperature during the synthesis and that the temperature determines the lower limit of SiO 2/Al 2O 3 ratio. Synthesis mixture, aimed to yield a high SiO 2/Al 2O 3 ratio, gives smaller zeolite crystals, higher specific surface areas, higher geometric areas (external surface area of the crystals) and a more oval crystal shape compared with lower ratios, synthesised at the same temperature. Higher autoclave temperature during the synthesis gives larger zeolite crystals and a more hexagonal crystal shape compared with zeolites synthesised at lower temperatures, for the same SiO 2/Al 2O 3 ratios. © 2010 Springer Science+Business Media, LLC.

Haynes R.D.,Eka Chemicals Inc. | Haynes R.D.,Akzo Nobel
Paper Conference and Trade Show 2012, PaperCon 2012: Growing the Future - Co-located with Control Systems 2012 | Year: 2012

Good colloidal stability in the mill process water can be related to good paper machine runnability. While it may be commonly observed that colloidal stability is important the means used to measure colloidal stability and how water management impacts colloidal stability and behavior is not so common. Using results from measurement of colloidal organics over time in the mill process water this review will show how this measurement can be related to runnability issues due to deposits and colloidal stability. Examples from paper machines using virgin and recycle fiber to produce newsprint, tissue and "printing and writing" grades of paper are given to help illustrate why it is important to understand colloidal stability and to show just what it means to have colloidal stability in your mill process water circuits.

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