Australian Paper Tasmania
I was employed at the Wesley Vale Mill of Australian Paper as a Development Chemist. During this time I attended University in Hobart, Tasmania to complete my Degree. During my tenure I completed a diverse range of projects covering all aspects of pulp and papermaking, including mechanical pulping, bleaching using peroxide and other chemicals, paper machine process control and coated paper techniques.
ISO 3901/9001 Implementation – Australian Paper
Wesley Vale mill implemented a quality policy including the terms of ISO 3902 in early 1988. Combined with this was a need to improve order tracking and production tracking and a mill-wide computer tracking system was to be installed in parallel with ISO 3902. My responsibility was to ensure that all paper testing methods complied with ISO 3902 and that the instrumentation could be calibrated and linked into the new computer system. As this was early in the development of instrument interfaces, many of the testing instruments did not have interfaces for connections. I did research to find retrofit interfaces that could be implemented or replacement instruments, with the economic benefits being carefully assessed. I also researched all of the calibration standards for all of the instruments that could be sufficiently traced to satisfy ISO 3902. This involved significant research and testing, along with the economic assessment as many of the standards were prohibitively expensive. I analysed the interfaces, primarily for the colour instruments, tested and then had software written for the interfaces. The software was written by external consultants as part of the mill-wide system. I was responsible for the information that was given to the software consultants for each of the instruments. I wrote the procedures and methods to suit ISO 3902 for many of the standard tests done in the laboratories specifically for optical and physical properties. The ISO 3902 program was completed in a relatively short timeframe (12 months) and Wesley Vale gained accreditation at its first assessment.
Cell Plant Decommissioning – Australian Paper
The Cell Plant at Wesley Vale Mill was old, beyond capacity and, because of environmental regulations, had to be closed eventually. The plant consisted of flowing mercury cells for the production of chlorine and sodium/mercury amalgam for caustic soda and hypochlorite bleach manufacture. Once the decision was made to de-commission the plant, I was responsible for the chemical decontamination along with detailed calculations for the disposal of both mercury and chlorine/hypochlorite without exceeding any environmental regulations. I completed an assessment, in collaboration with the environmental and safety department and production department, of the residual mercury, caustic soda and other contaminants in the plant. This was achieved by visual inspection, analysis of the remaining tanks and from production knowledge. From this I was able to assess and recommend where the potential problems would be and how to control the discharge. I identified a single point for the discharge and a scheme, using the existing pumps, to collect the contaminated waters in the one tank, thereby limiting the potential of uncontrolled discharge. I designed a matrix of testing and checking the contamination levels by sampling and calculating flow rate so that contaminated water could be released in a controlled manner. I then ensued that no further contamination was present before demolition of the plan was started. To achieve the flow control, I calculated and designed weirs, perforated and blank flanges to be installed at the calculated points. The results of the above were that the plant was decommissioned and demolished without exceeding the limits which were monitored and sampled on an hourly basis.
Steep Bleaching Project – Australian Paper
The Steep Bleaching Project was the culmination of a policy to reduce or eliminate chlorine-based bleaches from the pulping process. The potential investment in infrastructure and development was large and the risks were not insignificant. My role was part of a team investigating process changes in the pulp mill. I was part of a team investigating the retrofitting of injection and mixing equipment into the existing pulp mill. The parameters had been determined by the research department team and were used as a guide for the addition rates. I researched and determined potential addition points for the bleaching chemicals, control points and instrumentation to be used at each point. One of the many problems was the decomposition of Hydrogen Peroxide by many transition metals. I designed the addition points so that the chemicals were added in non-metallic pipes and so that the pulp/bleaching chemical mix had time to react before contacting metal surfaces. It also meant that all of the delivery lines had to be passivated. I then managed the pre commissioning trials where the optimisation of the additions was done. I monitored the process and took samples and data for analysis. I then optimised the additions to best match the parameters required for the pulp.
Coated Papers Multiple Coating Upgrade – Australian Paper
Wesley Vale Mill is the only coated paper mill in Australia. The product range was being overtaken in the market by imported papers from Europe and Asia that were multiple coated, rather than the standard of a single pass coating. I was tasked with managing a project investigating a multiple coating process for Australian Paper mills. I first fully investigated all grades of paper currently in the market in Australia. These papers were collected by Marketing personnel under strict sampling conditions and I then designed a full suite of tests that were relevant. I then assessed what advantages the new double coated papers had over Wesley Vale grades. I formulated a detailed set of laboratory tests to analyse and confirm the findings from the competitive papers. I ran this matrix in the laboratory using pilot-scale machinery and standard base papers from production. The coating formulations were also produced in pilot-scale equipment. I then ran the laboratory made papers through the same matrix of tests and compared the results. I was able to confirm that the benefits of multiple coating were real and obtainable from papers made at Wesley Vale. I was then able to identify a small set of coating scenarios that gave the most benefit, and designed a set of laboratory formulations. I made these in the laboratory and subjected them to the same matrix of tests, which confirmed the assumptions and benefits found previously. I then published these findings internally with recommendations for machine trials. I identified a number of possibilities for mill trials, but the most economical scenario was chosen initially. Management of the mill wanted to investigate using the available equipment before considering any new machinery. I arranged the trials in the Burnie Mill for the base paper and then Wesley Vale mill for the finishing coating. I designed the formulations for these trials and prepared them in the laboratory. I then tested them as per the first round. From these I chose a matrix of four to be trialled in the mills. I managed the production of the formulations at Wesley Vale Mill and the transfer to Burnie Mill by tanker for the trials. This involved insulated tankers as the base binder for the trial coatings was natural starch. Burnie paper machines were not set up for coating. I designed and installed a new system, retrofitted to allow for an even and consistent coating application. I engineered and installed the system, consisting of pumps, pipework, spraybars, filters, control loops and return duct and pipework. I ran many trials this way to improve and build on the knowledge gained in each subsequent trial. The outcome was that coating by this method was not feasible due to the limitations of the existing press on No.4 Machine in Burnie. I researched the problems and found that, with normal press configurations, the size (Diameter) of the rolls used in the press were too small. The shear dynamics at the press nip dewatered the coating rather than pressing the coating into the paper sheet, leading to uncontrolled solids build-up at the press nip. I then abandoned the trials, but the potential gains of multiple coating were sufficient to continue with the research. I switched my research effort to worlds best practice for coating and finishing. As a result of this research, a high level team was formed to look at this further. Trial papers were manufactured for machinery manufacturers to evaluate in their laboratories. From this, equipment was chosen, procured and installed to give the highest quality papers available. The investment was in excess of US$ 250 million and resulted in Wesley Vale coated papers business unit increasing profit by 85% in three years.
Control Upgrade of No.11 Machine – Australian Paper
No.11 machine is computer controlled to enable accuracy and production efficiency. The original control strategy was installed 10 to 15 years prior to this investigation and upgrade, when machine speeds were less than half of the current rates. The focus of my area was on the control of colour and optical brightening agent (OBA) addition and the measurement of both. The aim of the project was to improve colour consistency from batch to batch and to reduce the “broke” (off-spec. paper) by as much as possible. I first did research into the current best practice of measuring and quantifying the colour of papers. I studied instrumentation, methods, calibration and standards and how best to implement these on the machine and the testing laboratories. I then recommended the purchase of new instruments for the laboratories along with reference standards, based on this research. I wrote new methods in line with ISO 9002/3902, also based on the research. Once these were in place I then ran matrices of checks to prove that the new methods were reliable and consistent across the whole range of tests. This brought out many problems related to the difference in instruments used on-line and off-line. To overcome these differences, I went back to the original signal data from the on-line instruments and re-wrote the calibrations and addition matrices to ensure that the readings were then calibrated. I then implemented the new colour standards in the mill. Lastly, I ensured that all of the above was correct, calibrated and documented to ISO 3902 standards. Second to my responsibilities was to improve the control strategy and instrumentation for No.11 paper machine. I was part of a small team of engineers and I was to ensure that the on-line measurement conformed to the same standards as the laboratory. The measuring geometry of the instrument on the machine was totally different than the standard instruments. This presented problems with calibration. To overcome this, I analysed the original signal (voltage) data from the instrument and re-wrote the interface matrices to improve the calibration. I then checked these calculations by reading a full suite of papers, covering the whole range. Finally, in collaboration with the Process Control engineers, I agreed the addition points and calculated out the gain matrices to be used for control, closing out the control and measurement strategy. The result of the project was a reduction in off-specification paper (due to colour problems) of 70% to 80%, resulting in a saving of approximately AUD 5,000,000 per annum.