Control Parameters in the Batchwise Production of Synthetic Resins

Abstract

The work reported in this thesis was performed as part of a Teaching Company Scheme organised between BIP Chemicals Ltd and the University of Aston. Within the overall aim of the Scheme, which was to "maximise the efficiency and economics of batch processes used for synthetic resin manufacture", this investigation forms an important part relating to the control parameters used in the batchwise production of synthetic resins. The specific reactions involved in the preparation of butylated-amino-formaldehyde resins (otherwise known as coating resins) are discussed along with their commercial manufacturing method. The important process stages and control requirements are identified by laboratory experimentation. Potential new control parameters of refractive index, density, gas-liquid chromatography, aqueous distillate weight (a process by-product), viscosity and acoustic emission monitoring were investigated firstly on the laboratory scale for initial evaluation, then, on pilot-scale equipment for more extensive tests and finally, where appropriate, transferred to the full scale production plant. Product density was identified as an excellent control parameter to monitor resin solids content and the density to solids content calibration limits are quoted for the range of butylated amino resins made by BIP Chemicals Ltd. Viscosity is identified as being an important parameter in the resin production process and a specific in-vessel instrument was procured and evaluated. Aqueous distillate weight, when accurately monitored, is shown to be the significant control parameter required to monitor reaction stage progression through to completion. It is shown that the implementation of the control strategy proposed will lead to more consistent operation of the process and therefore result in a higher product quality.