Abstract

An investigation of surface heating effects on reinforced plastic tarpaulin covers under various conditions of exposure has been carried out. This investigation is relevant to the use of these types of cover materials in the transportation of green or antiseptic-treated hides or wet-blue hides. A number of samples of tarpaulin cover materials of differing colours and mass per unit area were obtained from a local supplier. These rectangular samples were exposed, horizontally, on a polystyrene board, during the course of a working day on three different days of varying weather conditions (sunny, sunny with cloud, sun with wind) during January. Surface temperatures were monitored using an electronic thermometer with contact probe. Results showed a steady build-up in surface temperatures in each case to a maximum about midday. The largest temperature rises were recorded with black, brown, dark red and dark green materials in the vicinity of 65°C under sunny conditions. Lowest temperature maxima occurred with white tarpaulin material in the region of 45°C at midday. Surface temperatures were also influenced by ambient air temperature, air movement and obscuring cloud. These results indicate that heating effects on tarpaulin covers are considerable under local summer conditions and maxima in some cases were in the vicinity of the denaturation temperature of raw (or antiseptic-treated) hides (65°C). Use of white or light yellow covers is strongly recommended to minimise possible heat denaturation or incubation effects resulting in bacterial or fungal build-up in hides under these conditions. Use of aluminised, reflective cover material was also found effective in minimising heating effects on exposure.