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  1. Ask the Expert

Improving Work Conditions While Producing Defect-Free Castings

Oct. 1, 2021
Choosing the right sand additive may address EPA’s HAP standards and reduce atmospheric dust and smoke in the workplace.
Q: How can we reduce smoke and emissions in our foundry and at the same time produce defect-free castings?

A: The Environmental Protection Agency sets emission standards for hazardous air pollutants (HAPs) at foundries – many of which are traced to the emissions that result from chemical binders used in mold and coremaking. Some organic HAP emissions include benzene, toluene, and xylene (BTX) as well as naphthalene.

VEINO ULTRATM NB-LOSMK is a sand additive developed by ASK Chemicals to reduce these emissions by as much as 30% in no-bake molding applications.  (See Figure 1.)
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Figure 1. Mix 1 - no sand additive; Mix 2 - 3% iron oxide 1; Mix 3 - 3% VEINO ULTRA™ 350; Mix 4 - 3% competitive sample 2; Mix 5 - 3% competitive sample 3; Mix 6 - VEINO ULTRA™ NB-LOSMK.
Figure 1. Mix 1 - no sand additive; Mix 2 - 3% iron oxide 1; Mix 3 - 3% VEINO ULTRA™ 350; Mix 4 - 3% competitive sample 2; Mix 5 - 3% competitive sample 3; Mix 6 - VEINO ULTRA™ NB-LOSMK.

In addition to reducing emissions, VEINO ULTRA NB-LOSMK also reduces smoke, which contributes to an improved working environment for foundry personnel. By removing the smoke from the air, workers’ line of sight is improved substantially.

When working with most sand additives, it’s necessary to increase the amount of the binder being used in order to compensate for a decrease in tensile strength that results due to the addition of high-surface area, finer particles. VEINO ULTRA NB-LOSMK’s size distribution has been optimized in order to minimize the negative effects on tensile strength.  (See Figure 2.)
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Figure 2. Tensile comparison for different types of catalysts.
Figure 2. Tensile comparison for different types of catalysts.
The speed of the reaction, including the work time and strip time, may be adjusted with slower or faster catalysts, depending upon the needs of a particular foundry.  (See Figure 3.)
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Figure 3. The speed of the reaction, including the work time and strip time, may be adjusted with slower or faster catalysts,
Figure 3. The speed of the reaction, including the work time and strip time, may be adjusted with slower or faster catalysts,

As with standard sand additives, VEINO ULTRA NB-LOSMK will combat veining, penetration, and surface finish defects in addition to lowering emissions and smoke. Furthermore, it has the ability to scavenge for various mold gases.

For those foundries that reclaim sand, either mechanically or thermally, sand additive build up in the reclamation system may be a concern as tensile levels for the sand will diminish over time. These worries are negated by VEINO ULTRA NB-LOSMK, as the particles will be drawn off in the foundry’s dust-collection system.

VEINO ULTRA NB-LOSMK provides a solution to smoke and emissions in the foundry, and will working conditions for operators.

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