Setting and evaluating paper machine trials

Russell Allan, Director
Aurelia Consulting

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Keywords: paper, trial machine data, measurement

An important activity around the paper machine is the running of machine trials to validate new processes, machinery, measurement, or additives. Often these trials are left to technical and support staff to run and subsequently persuasively convince production and operational staff of the benefit (or not) of the new activity proposed. Because there is a natural inertia to change in production positioning it is important that trials are designed and undertaken in a way that clearly show an outcome. Usually, the aim is to minimise losses during the trial by avoiding out-of-specification product, maintaining cost and production, and undertaking the trial with a minimum disruption and over the smallest possible time. Sometimes, this is not possible and to obtain a clear and profitable result going forward some losses must be accepted, and the possibility needs to be spelt out at the design stage and communicated and acknowledged by all the stakeholders on the paper machine.

This paper describes aspects of machine trials that are often overlooked or falsely accepted without question and shows the limitations of trials that have not been thought through in enough detail. The most egregious result for a machine trial is not to show a definitive result.

To illustrate potential issues with evaluation of data from machine trials, two scenarios are compared based on our work running machine trials around the world. We compare trials undertaken using top of reel and process data with those run, using our PSM-Q on-line measurement system to illustrate issues around trial length, data rates, confidence in the test result, machine capability and measurement and paper variability. Typical methods we use to validate trials are described.

Russell Allan is the Managing Director of Aurelia Group Consulting, a business that specialises in optimising paper machines for cost and product performance. He is the holder of several patents innovative measurement in the paper and packaging industry, most notably related to on-line, continuous non-destructive stiffness measurement on the paper machine. Russell is the current editor of Appita magazine (Australian Pulp and Paper Industry Technical Association), the 2014 winner of the L R Benjamin medal and was most recently awarded the Jasper Mardon Memorial Prize in 2015 for a “significant contribution to the science and technology of paper making”. Russell has delivered a number of papers related to paper measurement, quality and paper and paper packaging performance at Appita and around the world.