98/02486 Significance of structural and chemical changes in metamorphic coals in the formation of geological discharge hazard : Frolkov, G. D. et al. Bezop. Tr. Prom-sti., 1997, (1), 23–30 (In Russian)

Abstract

The waxed cardboard cartons used to prevent a loss of box strength during high humidity export shipments in intermodal sea containers have been banned in Europe because the boxes cannot be recycled. They have been replaced with laminated water-resistant recyclable paperboard boxes (Solidboard), and with plastic boxes. International Paper’s Climaseries or Interstate Container’s GreencoatTM cardboard boxes are impregnated with wax alternatives that make them recyclable and water resistant or waterproof. They have replaced waxed cardboard boxes in the United States. Any of these box types should prevent the weight loss caused by water condensation in nonwaxed cardboard boxes during hypobaric storage. Vented open-topped waterproof plastic bins are now used to reduce floral water loss when roses and other flower types are stored in Vivafresh hypobaric warehouses. To minimize commodity water loss during LP storage, heat transfer by radiation and convection from the vacuum chamber’s wall to commodity present in storage boxes must be prevented by keeping the plant matter warmer than the wall. Then the only heat available to evaporate commodity water is the small amount of respiratory heat produced at a low pressure. This requirement is readily satisfied in a hypobaric warehouse in which the humidity is brought to supersaturation by a combination of mechanical humidification and commodity transpiration. In a VacuFresh hypobaric intermodal container the venturi pneumatic air horn emits 97% RH low-pressure air around boxes at the door end, and this is not a high enough RH to prevent an excessive commodity water loss. At a 0°C storage temperature a polyethylene liner in the box only needs to warm the commodity in a door-end box by 0.5–1.0°C to increase the RH within the liner by 3.7–7.5%. A temperature rise of this magnitude easily saturates the microclimate around plant matter in door-end boxes and minimizes its water loss.