“Developments in the Latest Cold Box Technologies”

Thursday, 21 December 2017

Branch President Richard Heath, Prof MICME, welcomed members and guests to the branch December technical meeting and introduced Ian Shergold, Prof MICME, and his paper Developments in the Latest Cold Box Technologies.

Ian stated that ASK Chemicals had ambitions to be at the forefront of developments to make products environmentally friendly and less harmful to employees. The paper he was presenting would concentrate on the latest cold box system, Ecocure Blue, and real foundry experiences with the product. Two foundries, one in the Netherlands and the other in Germany have given approval and it is their experiences, verified by external bodies, which would be presented.

Ian explained that in the standard cold box process the part 1 component, the phenolic resin, will contain some free phenol and formaldehyde due to incomplete reaction of the component parts. Also present will be solvents and additives which help control the viscosity and flowability. Some of the solvent will be material considered to be a low hazardous substance but other solvents and additives are classified as having a low occupational exposure limit and therefore must be declared in safety data and in labelling on the product itself.

In developing Ecocure Blue resin new production procedures and controls were developed to bring free phenols and formaldehydes down to levels of less than 1% for free phenol and less than 0.1% for free formaldehyde. The only solvents then used then used were those classified as low hazard with the resultant materiel now free of need of a hazardous substance label. The part 2 isocyanate material must still be declared and labelled.

Volatile organic compounds will be emitted by evaporation during various stages of core production and storage whereas the “nasties” of benzene, toluene, xylene and nitrous oxides are generated through decomposition during casting, cooling and knockout. In the Dutch and German foundries who undertook to change to the Ecocure Blue system all these emissions were measured before and after the change. Also measured were strengths, storage and other production criterea.

Both foundries stated their desire to improve the safety and environment for employees and the locality. The products also had to have no adverse impact on product quality or production rates and be usable on the existing equipment. All these demands were met.

The Dutch foundry is producing cold box cores for its greensand moulding line. Core strengths, core production and casting finish were as good with the Ecocure Blue system as with the previous one. Phenols were reduced by 60% with the added benefit that phenol in the greensand was reduced over time and as a result the cost of sending waste sand to land fill fell. No VOC’s and little smell outside the factory resulted in much improved relationships with the neighbours.

The German foundry was able to reduce binder and amine addition and maintain core strengths and achieved a 66% reduction in benzene emissions into the atmosphere on casting. A 30% reduction in benzene emission from the greensand was also achieved.

Developments continue on a range of binders to achieve products that will be better for the environment, the employees and keep the foundry industry viable whilst becoming ever greener.

In Q&A the problem of the higher price of the Ecocure Blue system was raised but Ian commented that there were financial benefits such as lower land fill costs and that overall cost in use principles should be applied. However pressure for improved workplace environments will force industry to move in this direction and it is essential that foundries do not leave such consideration too late. Price is expected to come down as demand increases.

The foundries found that it was a straight swap from original product to new with the only change being a reduction in bench life of the mixed sand. The amount of reduction would depend on types of sand used. However it was generally agreed that leaving sand for such a long time was not good practice.

Steve Smith gave the vote of thanks for a well prepared and presented lecture. The members and guests then enjoyed an excellent buffet sponsored by ASK Chemicals.