Engineering improvements in the quality production of boiled sweets

  • M.P. Corcoran

Student thesis: Doctoral ThesisDoctor of Philosophy


This thesis describes the procedures developed to control
the quality of centred boiled sweet production at the TREBOR
factory at Chesterfield.

The current Quality Control theory and documentation of existing sweet process lines is examined and used as a basis to assess the problems and possibilities of implementing techniques in this application.

Initial statistical analyses of the range of centres produced and common defects are shown. From these analyses came a confirmation that the Quality Control organisation was essentially limited by the low level of process knowledge and technology and the high level of skill required to operate the current process.

Based on this analysis of the problem areas the major necessary improvements were then investigated and corrections implemented. These were the design of the rope sizing equipment, and the establishing of control and monitoring functions within the process.
A mechanism for rope sizing was then built, a larger and improved centre pipe was designed and installed, and these together with a photodiode camera system to monitor rope size and reject waste has resolved the problems not resolved by the original quality control system.
The results have been, a greater understanding of the way in which
Quality Control organisations work in practice, and ways in which a high speed continuous and multivariable process can be altered to facilitate more effective control to enhance the product.
TREBOR have gained a manufacturing process line which is improved because of a clear increase in the understanding of the old process, and the modifications necessary to include features for the maintenance of better quality during production. Some of the operators' high skill requirement has been replaced with better designed equipment and in-process monitoring.
Date of Award1982
Original languageEnglish


  • engineering improvements
  • quality production
  • boiled sweets

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