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Title: Towards clean technology in the manufacture of high quality sanitary tissue from recycled fibre
Author: Phipps, J. R.
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2002
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The concept of Clean Technology has been applied to the operations of Celtech International Limited (CIL), a small paper company that manufactures high quality tissue products from recycled fibre. A "Clean Technology" is defined as a technology "which, overall uses less resources and causes less environmental damage than alternative means with which it is economically competitive." Applying Clean Technology at the CIL paper mill would, it was hoped, minimise environmental impacts while maintaining product quality and production efficiency. Various approaches to Clean Technology at the CIL mill were reviewed. Among these were computer simulation to gain a better understanding of material flows; selecting and applying more effective fibre retention systems in the papermaking process; introducing better management information systems; and improving the processes for removing contaminants from process waters. The most effective route found was improving the dissolved air flotation processes used to control levels of contaminants in process waters. Clean Technology principles were used to develop a laboratory technique to simulate the dissolved air flotation operations in the paper mill. Applying the precautionary principle ensured that the laboratory tests could be used to predict the impact of process disturbances on performance. Applying the prevention principle facilitated the evaluation of preventative measures for reducing environmental impacts. Applying the integration principle meant that the criteria of simplicity, reliability, compatibility, and cost effectiveness were satisfied. In particular, the technique was found to complement established laboratory methods used in paper manufacturing, in that it is simple enough to be used by mill technical staff. It has also proven useful as a tool for trouble shooting and training. Using the laboratory simulation technique, it was shown that bentonite is important for minimising direct costs and sustaining acceptable clarified water turbidity, especially during deinking operations. The technique facilitated a choice of the most cost-effective chemicals for use in a variety of operating conditions. By helping in developing improved process awareness, use of the technique resulted in several areas for cost savings being identified. This novel approach to improved papermaking chemistry has proved to be a valuable technical tool from which tangible process improvements have been successfully developed. Some limitations in the technique were identified. It is very difficult to simulate process waters sufficiently precisely. The technique was of limited value for analysing the performance of the Stock Approach Clarifier, because the clarifier performance appears to be affected by the stability of the creping process.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available