Thesis Details

Thesis Title: A study of fluoborate catalyst systems in resin finishing of cotton fabrics with particular attention to energy requirements during curing
Thesis Author: John Rawls
Abstract: This thesis research comprised the development of a strongly active catalyst system based on magnesium fluoborate to replace the conventional magnesium chloride and zinc salt catalysts used in resin finishing. Textile finishers have questioned the use of chloride-containing catalysts, which may form carcinogens in the presence of methylolamide crosslinking agents. Discharges into the waste disposal system of heavy metal compounds, such as zinc salts, have been banned or severely restricted in several states. Increasing fuel costs necessitate the investigation of catalysts which can permit curing of fabrics with substantial reduction in the curing temperature, thereby saving energy. The purpose of this investigation was to study the effects of a magnesium fluoborate catalyst on the properties of cotton printcloth cross-linked with two popular resins: a DMDHEU permanent-press resin, which requires a high curing temperature; and a DMEU wash-wear resin, which cures at lower temperatures. Variables in the experiments were catalyst concentration and cure temperature. A magnesium chloride catalyst was also evaluated so that the properties of the fabrics resin-treated with the two catalyst systems could be compared. The experimental work performed on laboratory scale equipment was divided into two parts: a) preliminary trials, and b) final trials. Preliminary trials were undertaken for each of the four resin-catalyst systems to establish the cure temperature ranges in which the resin and catalyst concentration recommended by the manufacturers for commercial use would produce conditions of undercuring, curing, and overcuring. From the final runs, results from a comparison of the fabric properties produced with each catalyst system would determine: a) whether the magnesium fluoborate catalyst could be substituted for magnesium chloride, and b) whether low temperature curing with the fluoborate catalyst could be achieved. Results from the final runs indicated that magnesium fluoborate can be an alternative chloride-free, heavy metal-free catalyst for cross-linking cotton fabrics with a DMEU resin. Fabrics finished with a DMEU resin and both the magnesium fluoborate and magnesium chloride catalyst exhibited a comparable relationship in crease recovery angle/breaking strength loss. Calculations of energy requirements for a curing oven demonstrated that a thirty percent reduction in energy consumption in curing can be achieved from lowering the cure temperature by 300 C. From the results of the final runs, it was concluded that the magnesium fluoborate can be substituted for a magnesium chloride catalyst, provided strict control of catalyst concentration is maintained. No energy savings would be realized by using a magnesium fluoborate catalyst with a DMDHEU resin because the higher catalyst concentration required for curing at low temperatures produced unacceptable strength losses.